Drugs that bind to but do not activate DOPAMINE RECEPTORS, thereby blocking the actions of dopamine or exogenous agonists. Many drugs used in the treatment of psychotic disorders (ANTIPSYCHOTIC AGENTS) are dopamine antagonists, although their therapeutic effects may be due to long-term adjustments of the brain rather than to the acute effects of blocking dopamine receptors. Dopamine antagonists have been used for several other clinical purposes including as ANTIEMETICS, in the treatment of Tourette syndrome, and for hiccup. Dopamine receptor blockade is associated with NEUROLEPTIC MALIGNANT SYNDROME.
One of the catecholamine NEUROTRANSMITTERS in the brain. It is derived from TYROSINE and is the precursor to NOREPINEPHRINE and EPINEPHRINE. Dopamine is a major transmitter in the extrapyramidal system of the brain, and important in regulating movement. A family of receptors (RECEPTORS, DOPAMINE) mediate its action.
A specific blocker of dopamine receptors. It speeds gastrointestinal peristalsis, causes prolactin release, and is used as antiemetic and tool in the study of dopaminergic mechanisms.
A dopamine D2 antagonist that is used as an antiemetic.
A subfamily of G-PROTEIN-COUPLED RECEPTORS that bind the neurotransmitter DOPAMINE and modulate its effects. D2-class receptor genes contain INTRONS, and the receptors inhibit ADENYLYL CYCLASES.
A phenyl-piperidinyl-butyrophenone that is used primarily to treat SCHIZOPHRENIA and other PSYCHOSES. It is also used in schizoaffective disorder, DELUSIONAL DISORDERS, ballism, and TOURETTE SYNDROME (a drug of choice) and occasionally as adjunctive therapy in INTELLECTUAL DISABILITY and the chorea of HUNTINGTON DISEASE. It is a potent antiemetic and is used in the treatment of intractable HICCUPS. (From AMA Drug Evaluations Annual, 1994, p279)
A thioxanthene neuroleptic that, unlike CHLORPROMAZINE, is claimed to have CNS-activating properties. It is used in the treatment of psychoses although not in excited or manic patients. (From Martindale, The Extra Pharmacopoeia, 30th ed, p595)
A spiro butyrophenone analog similar to HALOPERIDOL and other related compounds. It has been recommended in the treatment of SCHIZOPHRENIA.
Cell-surface proteins that bind dopamine with high affinity and trigger intracellular changes influencing the behavior of cells.
Drugs that bind to and activate dopamine receptors.
A diphenylbutylpiperidine that is effective as an antipsychotic agent and as an alternative to HALOPERIDOL for the suppression of vocal and motor tics in patients with Tourette syndrome. Although the precise mechanism of action is unknown, blockade of postsynaptic dopamine receptors has been postulated. (From AMA Drug Evaluations Annual, 1994, p403)
A subfamily of G-PROTEIN-COUPLED RECEPTORS that bind the neurotransmitter DOPAMINE and modulate its effects. D1-class receptor genes lack INTRONS, and the receptors stimulate ADENYLYL CYCLASES.
A butyrophenone with general properties similar to those of HALOPERIDOL. It is used in the treatment of PSYCHOSES including MANIA and SCHIZOPHRENIA. (From Martindale, The Extra Pharmacopoeia, 30th ed, p621)
A dopamine D2-receptor antagonist. It has been used therapeutically as an antidepressant, antipsychotic, and as a digestive aid. (From Merck Index, 11th ed)
Compounds with BENZENE fused to AZEPINES.
A benzocycloheptapyridoisoquinolinol that has been used as an antipsychotic, especially in schizophrenia.
A phenothiazine used in the treatment of PSYCHOSES. Its properties and uses are generally similar to those of CHLORPROMAZINE.
Compounds containing phenyl-1-butanone.
Poisoning caused by ingesting ergotized grain or by the misdirected or excessive use of ergot as a medicine.
A phenylethylamine derivative that acts as a calcium antagonist showing hemodynamic effects in patients with acute myocardial infarction.
A semisynthetic ergotamine alkaloid that is a dopamine D2 agonist. It suppresses prolactin secretion.
A subtype of dopamine D2 receptors that are highly expressed in the LIMBIC SYSTEM of the brain.
A series of structurally-related alkaloids that contain the ergoline backbone structure.
A mitosporic fungal genus with many reported ascomycetous teleomorphs. Cephalosporin antibiotics are derived from this genus.
Sodium chloride-dependent neurotransmitter symporters located primarily on the PLASMA MEMBRANE of dopaminergic neurons. They remove DOPAMINE from the EXTRACELLULAR SPACE by high affinity reuptake into PRESYNAPTIC TERMINALS and are the target of DOPAMINE UPTAKE INHIBITORS.
A lactogenic hormone secreted by the adenohypophysis (PITUITARY GLAND, ANTERIOR). It is a polypeptide of approximately 23 kD. Besides its major action on lactation, in some species prolactin exerts effects on reproduction, maternal behavior, fat metabolism, immunomodulation and osmoregulation. Prolactin receptors are present in the mammary gland, hypothalamus, liver, ovary, testis, and prostate.
Any drugs that are used for their effects on dopamine receptors, on the life cycle of dopamine, or on the survival of dopaminergic neurons.
Agents that control agitated psychotic behavior, alleviate acute psychotic states, reduce psychotic symptoms, and exert a quieting effect. They are used in SCHIZOPHRENIA; senile dementia; transient psychosis following surgery; or MYOCARDIAL INFARCTION; etc. These drugs are often referred to as neuroleptics alluding to the tendency to produce neurological side effects, but not all antipsychotics are likely to produce such effects. Many of these drugs may also be effective against nausea, emesis, and pruritus.
A strain of albino rat used widely for experimental purposes because of its calmness and ease of handling. It was developed by the Sprague-Dawley Animal Company.
The relationship between the dose of an administered drug and the response of the organism to the drug.
A subtype of dopamine D1 receptors that has higher affinity for DOPAMINE and differentially couples to GTP-BINDING PROTEINS.
The observable response an animal makes to any situation.
Drugs that block the transport of DOPAMINE into axon terminals or into storage vesicles within terminals. Most of the ADRENERGIC UPTAKE INHIBITORS also inhibit dopamine uptake.
Dopamine beta-Hydroxylase is an enzyme that catalyzes the conversion of dopamine to norepinephrine, a crucial step in the synthesis of catecholamines within the adrenal glands and central nervous system.
Striped GRAY MATTER and WHITE MATTER consisting of the NEOSTRIATUM and paleostriatum (GLOBUS PALLIDUS). It is located in front of and lateral to the THALAMUS in each cerebral hemisphere. The gray substance is made up of the CAUDATE NUCLEUS and the lentiform nucleus (the latter consisting of the GLOBUS PALLIDUS and PUTAMEN). The WHITE MATTER is the INTERNAL CAPSULE.
Genetically identical individuals developed from brother and sister matings which have been carried out for twenty or more generations or by parent x offspring matings carried out with certain restrictions. This also includes animals with a long history of closed colony breeding.
A dopamine D2/D3 receptor agonist.
Chemical substances which inhibit the function of the endocrine glands, the biosynthesis of their secreted hormones, or the action of hormones upon their specific sites.
A substituted benzamide that has antipsychotic properties. It is a dopamine D2 receptor (see RECEPTORS, DOPAMINE D2) antagonist.
Collection of pleomorphic cells in the caudal part of the anterior horn of the LATERAL VENTRICLE, in the region of the OLFACTORY TUBERCLE, lying between the head of the CAUDATE NUCLEUS and the ANTERIOR PERFORATED SUBSTANCE. It is part of the so-called VENTRAL STRIATUM, a composite structure considered part of the BASAL GANGLIA.
Drugs that bind to but do not activate excitatory amino acid receptors, thereby blocking the actions of agonists.
Amides of salicylic acid.
Agents inhibiting the effect of narcotics on the central nervous system.
A derivative of morphine that is a dopamine D2 agonist. It is a powerful emetic and has been used for that effect in acute poisoning. It has also been used in the diagnosis and treatment of parkinsonism, but its adverse effects limit its use.
An alkaloid ester extracted from the leaves of plants including coca. It is a local anesthetic and vasoconstrictor and is clinically used for that purpose, particularly in the eye, ear, nose, and throat. It also has powerful central nervous system effects similar to the amphetamines and is a drug of abuse. Cocaine, like amphetamines, acts by multiple mechanisms on brain catecholaminergic neurons; the mechanism of its reinforcing effects is thought to involve inhibition of dopamine uptake.
Compounds that inhibit or block the activity of NEUROKININ-1 RECEPTORS.
The phylogenetically newer part of the CORPUS STRIATUM consisting of the CAUDATE NUCLEUS and PUTAMEN. It is often called simply the striatum.
Drugs that selectively bind to but do not activate histamine H2 receptors, thereby blocking the actions of histamine. Their clinically most important action is the inhibition of acid secretion in the treatment of gastrointestinal ulcers. Smooth muscle may also be affected. Some drugs in this class have strong effects in the central nervous system, but these actions are not well understood.
The naturally occurring form of DIHYDROXYPHENYLALANINE and the immediate precursor of DOPAMINE. Unlike dopamine itself, it can be taken orally and crosses the blood-brain barrier. It is rapidly taken up by dopaminergic neurons and converted to DOPAMINE. It is used for the treatment of PARKINSONIAN DISORDERS and is usually given with agents that inhibit its conversion to dopamine outside of the central nervous system.
Drugs that bind to but do not activate MUSCARINIC RECEPTORS, thereby blocking the actions of endogenous ACETYLCHOLINE or exogenous agonists. Muscarinic antagonists have widespread effects including actions on the iris and ciliary muscle of the eye, the heart and blood vessels, secretions of the respiratory tract, GI system, and salivary glands, GI motility, urinary bladder tone, and the central nervous system.
A technique for measuring extracellular concentrations of substances in tissues, usually in vivo, by means of a small probe equipped with a semipermeable membrane. Substances may also be introduced into the extracellular space through the membrane.
A powerful central nervous system stimulant and sympathomimetic. Amphetamine has multiple mechanisms of action including blocking uptake of adrenergics and dopamine, stimulation of release of monamines, and inhibiting monoamine oxidase. Amphetamine is also a drug of abuse and a psychotomimetic. The l- and the d,l-forms are included here. The l-form has less central nervous system activity but stronger cardiovascular effects. The d-form is DEXTROAMPHETAMINE.
A family of hexahydropyridines.
A ligand that binds to but fails to activate the INTERLEUKIN 1 RECEPTOR. It plays an inhibitory role in the regulation of INFLAMMATION and FEVER. Several isoforms of the protein exist due to multiple ALTERNATIVE SPLICING of its mRNA.
Drugs that bind to but do not activate GABA RECEPTORS, thereby blocking the actions of endogenous GAMMA-AMINOBUTYRIC ACID and GABA RECEPTOR AGONISTS.
The basic cellular units of nervous tissue. Each neuron consists of a body, an axon, and dendrites. Their purpose is to receive, conduct, and transmit impulses in the NERVOUS SYSTEM.
An enzyme that catalyzes the conversion of L-tyrosine, tetrahydrobiopterin, and oxygen to 3,4-dihydroxy-L-phenylalanine, dihydrobiopterin, and water. EC 1.14.16.2.
Homovanillic acid (HVA) is a major metabolite of dopamine, formed in the body through the catabolic breakdown of this neurotransmitter by the enzyme catechol-O-methyltransferase and then further metabolized in the liver before excretion in urine.
Neurons whose primary neurotransmitter is DOPAMINE.
Drugs that bind to nicotinic cholinergic receptors (RECEPTORS, NICOTINIC) and block the actions of acetylcholine or cholinergic agonists. Nicotinic antagonists block synaptic transmission at autonomic ganglia, the skeletal neuromuscular junction, and at central nervous system nicotinic synapses.
A strain of albino rat developed at the Wistar Institute that has spread widely at other institutions. This has markedly diluted the original strain.
A region in the MESENCEPHALON which is dorsomedial to the SUBSTANTIA NIGRA and ventral to the RED NUCLEUS. The mesocortical and mesolimbic dopaminergic systems originate here, including an important projection to the NUCLEUS ACCUMBENS. Overactivity of the cells in this area has been suspected to contribute to the positive symptoms of SCHIZOPHRENIA.
The black substance in the ventral midbrain or the nucleus of cells containing the black substance. These cells produce DOPAMINE, an important neurotransmitter in regulation of the sensorimotor system and mood. The dark colored MELANIN is a by-product of dopamine synthesis.
A phosphoprotein that was initially identified as a major target of DOPAMINE activated ADENYLYL CYCLASE in the CORPUS STRIATUM. It regulates the activities of PROTEIN PHOSPHATASE-1 and PROTEIN KINASE A, and it is a key mediator of the biochemical, electrophysiological, transcriptional, and behavioral effects of DOPAMINE.
Compounds that bind to and block the stimulation of PURINERGIC P1 RECEPTORS.
Drugs that selectively bind to but do not activate histamine H1 receptors, thereby blocking the actions of endogenous histamine. Included here are the classical antihistaminics that antagonize or prevent the action of histamine mainly in immediate hypersensitivity. They act in the bronchi, capillaries, and some other smooth muscles, and are used to prevent or allay motion sickness, seasonal rhinitis, and allergic dermatitis and to induce somnolence. The effects of blocking central nervous system H1 receptors are not as well understood.
A biochemical messenger and regulator, synthesized from the essential amino acid L-TRYPTOPHAN. In humans it is found primarily in the central nervous system, gastrointestinal tract, and blood platelets. Serotonin mediates several important physiological functions including neurotransmission, gastrointestinal motility, hemostasis, and cardiovascular integrity. Multiple receptor families (RECEPTORS, SEROTONIN) explain the broad physiological actions and distribution of this biochemical mediator.
Compounds that selectively bind to and block the activation of ADENOSINE A2 RECEPTORS.
A neurotransmitter analogue that depletes noradrenergic stores in nerve endings and induces a reduction of dopamine levels in the brain. Its mechanism of action is related to the production of cytolytic free-radicals.
The physical activity of a human or an animal as a behavioral phenomenon.
Drugs that bind to but do not activate histamine receptors, thereby blocking the actions of histamine or histamine agonists. Classical antihistaminics block the histamine H1 receptors only.
The middle of the three primitive cerebral vesicles of the embryonic brain. Without further subdivision, midbrain develops into a short, constricted portion connecting the PONS and the DIENCEPHALON. Midbrain contains two major parts, the dorsal TECTUM MESENCEPHALI and the ventral TEGMENTUM MESENCEPHALI, housing components of auditory, visual, and other sensorimoter systems.
Quantitative determination of receptor (binding) proteins in body fluids or tissue using radioactively labeled binding reagents (e.g., antibodies, intracellular receptors, plasma binders).
Drugs that bind to and block the activation of ADRENERGIC ALPHA-1 RECEPTORS.
Drugs that bind to but do not activate SEROTONIN 5-HT2 RECEPTORS, thereby blocking the actions of SEROTONIN or SEROTONIN 5-HT2 RECEPTOR AGONISTS. Included under this heading are antagonists for one or more specific 5-HT2 receptor subtypes.
The part of CENTRAL NERVOUS SYSTEM that is contained within the skull (CRANIUM). Arising from the NEURAL TUBE, the embryonic brain is comprised of three major parts including PROSENCEPHALON (the forebrain); MESENCEPHALON (the midbrain); and RHOMBENCEPHALON (the hindbrain). The developed brain consists of CEREBRUM; CEREBELLUM; and other structures in the BRAIN STEM.
N-methyl-8-azabicyclo[3.2.1]octanes best known for the ones found in PLANTS.
Precursor of epinephrine that is secreted by the adrenal medulla and is a widespread central and autonomic neurotransmitter. Norepinephrine is the principal transmitter of most postganglionic sympathetic fibers and of the diffuse projection system in the brain arising from the locus ceruleus. It is also found in plants and is used pharmacologically as a sympathomimetic.
Compounds that bind to and block the stimulation of PURINERGIC P2 RECEPTORS.
Elongated gray mass of the neostriatum located adjacent to the lateral ventricle of the brain.
The action of a drug that may affect the activity, metabolism, or toxicity of another drug.
An inhibitor of the enzyme TYROSINE 3-MONOOXYGENASE, and consequently of the synthesis of catecholamines. It is used to control the symptoms of excessive sympathetic stimulation in patients with PHEOCHROMOCYTOMA. (Martindale, The Extra Pharmacopoeia, 30th ed)
Drugs that bind to but do not activate SEROTONIN 5-HT3 RECEPTORS, thereby blocking the actions of SEROTONIN or SEROTONIN 5-HT3 RECEPTOR AGONISTS.
Pyrrolidines are saturated, heterocyclic organic compounds containing a five-membered ring with four carbon atoms and one nitrogen atom (NRCH2CH2), commonly found as structural components in various alkaloids and used in the synthesis of pharmaceuticals and other organic materials.
Piperazines are a class of heterocyclic organic compounds containing a seven-membered ring with two nitrogen atoms at positions 1 and 4, often used in pharmaceuticals as smooth muscle relaxants, antipsychotics, antidepressants, and antihistamines, but can also be found as recreational drugs with stimulant and entactogen properties.
Drugs that bind to but do not activate alpha-adrenergic receptors thereby blocking the actions of endogenous or exogenous adrenergic agonists. Adrenergic alpha-antagonists are used in the treatment of hypertension, vasospasm, peripheral vascular disease, shock, and pheochromocytoma.
Drugs that bind to and block the activation of ADRENERGIC ALPHA-2 RECEPTORS.
An isoquinoline derivative that prevents dopamine reuptake into synaptosomes. The maleate was formerly used in the treatment of depression. It was withdrawn worldwide in 1986 due to the risk of acute hemolytic anemia with intravascular hemolysis resulting from its use. In some cases, renal failure also developed. (From Martindale, The Extra Pharmacopoeia, 30th ed, p266)
An object or a situation that can serve to reinforce a response, to satisfy a motive, or to afford pleasure.
Compounds that bind to and block the stimulation of ADENOSINE A1 RECEPTORS.
Cell-surface proteins that bind SEROTONIN and trigger intracellular changes which influence the behavior of cells. Several types of serotonin receptors have been recognized which differ in their pharmacology, molecular biology, and mode of action.
A class of ionotropic glutamate receptors characterized by affinity for N-methyl-D-aspartate. NMDA receptors have an allosteric binding site for glycine which must be occupied for the channel to open efficiently and a site within the channel itself to which magnesium ions bind in a voltage-dependent manner. The positive voltage dependence of channel conductance and the high permeability of the conducting channel to calcium ions (as well as to monovalent cations) are important in excitotoxicity and neuronal plasticity.
The interaction of two or more substrates or ligands with the same binding site. The displacement of one by the other is used in quantitative and selective affinity measurements.
A beta-hydroxylated derivative of phenylalanine. The D-form of dihydroxyphenylalanine has less physiologic activity than the L-form and is commonly used experimentally to determine whether the pharmacological effects of LEVODOPA are stereospecific.
The communication from a NEURON to a target (neuron, muscle, or secretory cell) across a SYNAPSE. In chemical synaptic transmission, the presynaptic neuron releases a NEUROTRANSMITTER that diffuses across the synaptic cleft and binds to specific synaptic receptors, activating them. The activated receptors modulate specific ion channels and/or second-messenger systems in the postsynaptic cell. In electrical synaptic transmission, electrical signals are communicated as an ionic current flow across ELECTRICAL SYNAPSES.
Use of electric potential or currents to elicit biological responses.
Elements of limited time intervals, contributing to particular results or situations.
Drugs that bind to but do not activate ADRENERGIC RECEPTORS. Adrenergic antagonists block the actions of the endogenous adrenergic transmitters EPINEPHRINE and NOREPINEPHRINE.
A central nervous system stimulant and sympathomimetic with actions and uses similar to DEXTROAMPHETAMINE. The smokable form is a drug of abuse and is referred to as crank, crystal, crystal meth, ice, and speed.
Drugs that bind to but do not activate GABA-A RECEPTORS thereby blocking the actions of endogenous or exogenous GABA-A RECEPTOR AGONISTS.
A class of drugs designed to prevent leukotriene synthesis or activity by blocking binding at the receptor level.
Agents that antagonize ANGIOTENSIN RECEPTORS. Many drugs in this class specifically target the ANGIOTENSIN TYPE 1 RECEPTOR.
A family of vesicular amine transporter proteins that catalyze the transport and storage of CATECHOLAMINES and indolamines into SECRETORY VESICLES.
Biogenic amines having only one amine moiety. Included in this group are all natural monoamines formed by the enzymatic decarboxylation of natural amino acids.
The largest and most lateral of the BASAL GANGLIA lying between the lateral medullary lamina of the GLOBUS PALLIDUS and the EXTERNAL CAPSULE. It is part of the neostriatum and forms part of the LENTIFORM NUCLEUS along with the GLOBUS PALLIDUS.
A potent noncompetitive antagonist of the NMDA receptor (RECEPTORS, N-METHYL-D-ASPARTATE) used mainly as a research tool. The drug has been considered for the wide variety of neurodegenerative conditions or disorders in which NMDA receptors may play an important role. Its use has been primarily limited to animal and tissue experiments because of its psychotropic effects.
A statistical technique that isolates and assesses the contributions of categorical independent variables to variation in the mean of a continuous dependent variable.
Partially saturated 1,2,3,4-tetrahydronaphthalene compounds.
The rostral part of the frontal lobe, bounded by the inferior precentral fissure in humans, which receives projection fibers from the MEDIODORSAL NUCLEUS OF THE THALAMUS. The prefrontal cortex receives afferent fibers from numerous structures of the DIENCEPHALON; MESENCEPHALON; and LIMBIC SYSTEM as well as cortical afferents of visual, auditory, and somatic origin.
Cells propagated in vitro in special media conducive to their growth. Cultured cells are used to study developmental, morphologic, metabolic, physiologic, and genetic processes, among others.
Drugs that selectively bind to but do not activate HISTAMINE H3 RECEPTORS. They have been used to correct SLEEP WAKE DISORDERS and MEMORY DISORDERS.
Administration of a drug or chemical by the individual under the direction of a physician. It includes administration clinically or experimentally, by human or animal.
A non-essential amino acid naturally occurring in the L-form. Glutamic acid is the most common excitatory neurotransmitter in the CENTRAL NERVOUS SYSTEM.
A general class of ortho-dihydroxyphenylalkylamines derived from tyrosine.
Endogenous compounds and drugs that bind to and activate SEROTONIN RECEPTORS. Many serotonin receptor agonists are used as ANTIDEPRESSANTS; ANXIOLYTICS; and in the treatment of MIGRAINE DISORDERS.
A loosely defined group of drugs that tend to increase behavioral alertness, agitation, or excitation. They work by a variety of mechanisms, but usually not by direct excitation of neurons. The many drugs that have such actions as side effects to their main therapeutic use are not included here.
The intracellular transfer of information (biological activation/inhibition) through a signal pathway. In each signal transduction system, an activation/inhibition signal from a biologically active molecule (hormone, neurotransmitter) is mediated via the coupling of a receptor/enzyme to a second messenger system or to an ion channel. Signal transduction plays an important role in activating cellular functions, cell differentiation, and cell proliferation. Examples of signal transduction systems are the GAMMA-AMINOBUTYRIC ACID-postsynaptic receptor-calcium ion channel system, the receptor-mediated T-cell activation pathway, and the receptor-mediated activation of phospholipases. Those coupled to membrane depolarization or intracellular release of calcium include the receptor-mediated activation of cytotoxic functions in granulocytes and the synaptic potentiation of protein kinase activation. Some signal transduction pathways may be part of larger signal transduction pathways; for example, protein kinase activation is part of the platelet activation signal pathway.
Compounds with a six membered aromatic ring containing NITROGEN. The saturated version is PIPERIDINES.
A condition characterized by inactivity, decreased responsiveness to stimuli, and a tendency to maintain an immobile posture. The limbs tend to remain in whatever position they are placed (waxy flexibility). Catalepsy may be associated with PSYCHOTIC DISORDERS (e.g., SCHIZOPHRENIA, CATATONIC), nervous system drug toxicity, and other conditions.
Learning situations in which the sequence responses of the subject are instrumental in producing reinforcement. When the correct response occurs, which involves the selection from among a repertoire of responses, the subject is immediately reinforced.
Inbred C57BL mice are a strain of laboratory mice that have been produced by many generations of brother-sister matings, resulting in a high degree of genetic uniformity and homozygosity, making them widely used for biomedical research, including studies on genetics, immunology, cancer, and neuroscience.
A common name used for the genus Cavia. The most common species is Cavia porcellus which is the domesticated guinea pig used for pets and biomedical research.
Naturally occurring or experimentally induced animal diseases with pathological processes sufficiently similar to those of human diseases. They are used as study models for human diseases.
A class of drugs that act by selective inhibition of calcium influx through cellular membranes.
Drugs that bind to but do not activate SEROTONIN 5-HT1 RECEPTORS, thereby blocking the actions of SEROTONIN 5-HT1 RECEPTOR AGONISTS. Included under this heading are antagonists for one or more of the specific 5-HT1 receptor subtypes.
An alkaloid found in the roots of Rauwolfia serpentina and R. vomitoria. Reserpine inhibits the uptake of norepinephrine into storage vesicles resulting in depletion of catecholamines and serotonin from central and peripheral axon terminals. It has been used as an antihypertensive and an antipsychotic as well as a research tool, but its adverse effects limit its clinical use.
Relatively invariant mode of behavior elicited or determined by a particular situation; may be verbal, postural, or expressive.
A specific opiate antagonist that has no agonist activity. It is a competitive antagonist at mu, delta, and kappa opioid receptors.
Benzopyrroles with the nitrogen at the number one carbon adjacent to the benzyl portion, in contrast to ISOINDOLES which have the nitrogen away from the six-membered ring.
Derivative of noroxymorphone that is the N-cyclopropylmethyl congener of NALOXONE. It is a narcotic antagonist that is effective orally, longer lasting and more potent than naloxone, and has been proposed for the treatment of heroin addiction. The FDA has approved naltrexone for the treatment of alcohol dependence.
A group of disorders which feature impaired motor control characterized by bradykinesia, MUSCLE RIGIDITY; TREMOR; and postural instability. Parkinsonian diseases are generally divided into primary parkinsonism (see PARKINSON DISEASE), secondary parkinsonism (see PARKINSON DISEASE, SECONDARY) and inherited forms. These conditions are associated with dysfunction of dopaminergic or closely related motor integration neuronal pathways in the BASAL GANGLIA.
Changes in the amounts of various chemicals (neurotransmitters, receptors, enzymes, and other metabolites) specific to the area of the central nervous system contained within the head. These are monitored over time, during sensory stimulation, or under different disease states.
A tricylic dibenzodiazepine, classified as an atypical antipsychotic agent. It binds several types of central nervous system receptors, and displays a unique pharmacological profile. Clozapine is a serotonin antagonist, with strong binding to 5-HT 2A/2C receptor subtype. It also displays strong affinity to several dopaminergic receptors, but shows only weak antagonism at the dopamine D2 receptor, a receptor commonly thought to modulate neuroleptic activity. Agranulocytosis is a major adverse effect associated with administration of this agent.
Agents used in the treatment of Parkinson's disease. The most commonly used drugs act on the dopaminergic system in the striatum and basal ganglia or are centrally acting muscarinic antagonists.
A basic element found in nearly all organized tissues. It is a member of the alkaline earth family of metals with the atomic symbol Ca, atomic number 20, and atomic weight 40. Calcium is the most abundant mineral in the body and combines with phosphorus to form calcium phosphate in the bones and teeth. It is essential for the normal functioning of nerves and muscles and plays a role in blood coagulation (as factor IV) and in many enzymatic processes.
Pinched-off nerve endings and their contents of vesicles and cytoplasm together with the attached subsynaptic area of the membrane of the post-synaptic cell. They are largely artificial structures produced by fractionation after selective centrifugation of nervous tissue homogenates.
Substances used for their pharmacological actions on any aspect of neurotransmitter systems. Neurotransmitter agents include agonists, antagonists, degradation inhibitors, uptake inhibitors, depleters, precursors, and modulators of receptor function.
'Nerve tissue proteins' are specialized proteins found within the nervous system's biological tissue, including neurofilaments, neuronal cytoskeletal proteins, and neural cell adhesion molecules, which facilitate structural support, intracellular communication, and synaptic connectivity essential for proper neurological function.
The most common inhibitory neurotransmitter in the central nervous system.
Cell surface proteins that bind ENDOTHELINS with high affinity and trigger intracellular changes which influence the behavior of cells.
An adenine nucleotide containing one phosphate group which is esterified to both the 3'- and 5'-positions of the sugar moiety. It is a second messenger and a key intracellular regulator, functioning as a mediator of activity for a number of hormones, including epinephrine, glucagon, and ACTH.
Drugs that bind to and block the activation of ADRENERGIC BETA-2 RECEPTORS.
Large subcortical nuclear masses derived from the telencephalon and located in the basal regions of the cerebral hemispheres.

Plasticity of first-order sensory synapses: interactions between homosynaptic long-term potentiation and heterosynaptically evoked dopaminergic potentiation. (1/1654)

Persistent potentiations of the chemical and electrotonic components of the eighth nerve (NVIII) EPSP recorded in vivo in the goldfish reticulospinal neuron, the Mauthner cell, can be evoked by afferent tetanization or local dendritic application of an endogenous transmitter, dopamine (3-hydroxytyramine). These modifications are attributable to the activation of distinct intracellular kinase cascades. Although dopamine-evoked potentiation (DEP) is mediated by the cAMP-dependent protein kinase (PKA), tetanization most likely activates a Ca2+-dependent protein kinase via an increased intracellular Ca2+ concentration. We present evidence that the eighth nerve tetanus that induces LTP does not act by triggering dopamine release, because it is evoked in the presence of a broad spectrum of dopamine antagonists. To test for interactions between these pathways, we applied the potentiating paradigms sequentially. When dopamine was applied first, tetanization produced additional potentiation of the mixed synaptic response, but when the sequence was reversed, DEP was occluded, indicating that the synapses potentiated by the two procedures belong to the same or overlapping populations. Experiments were conducted to determine interactions between the underlying regulatory mechanisms and the level of their convergence. Inhibiting PKA does not impede tetanus-induced LTP, and chelating postsynaptic Ca2+ with BAPTA does not block DEP, indicating that the initial steps of the induction processes are independent. Pharmacological and voltage-clamp analyses indicate that the two pathways converge on functional AMPA/kainate receptors for the chemically mediated EPSP and gap junctions for the electrotonic component or at intermediaries common to both pathways. A cellular model incorporating these interactions is proposed on the basis of differential modulation of synaptic responses via receptor-protein phosphorylation.  (+info)

Measurement of striatal D2 dopamine receptor density and affinity with [11C]-raclopride in vivo: a test-retest analysis. (2/1654)

Subacute and long-term stability of measurements of D2 dopamine receptor density (Bmax), affinity (Kd) was studied with positron emission tomography in eight healthy male volunteers. [11C]-Raclopride and the transient equilibrium method were used to measure D2 receptor characteristics. The interval between measurements (scan pairs) was 3 to 7 weeks (subacute) for four subjects and 6 to 11 months (long-term) for four subjects. A test-retest analysis of quantitative measurements of D2 receptor Bmax and Kd was compared with that done on binding potential (BP, Bmax/Kd) measures. In addition, the effect of error in defining the transient equilibrium time (tmax) in the parameter estimation procedure was explored with simulations. The subacute test-retest indicates good reproducibility of D2 receptor density, affinity, and BP ratio measurements with intraclass correlation coefficients of 0.90, 0.96, and 0.86, respectively. The variability of the measurements after 6 to 11 months was slightly higher than that seen in a subacute testing for Kd and more clearly so for binding potential and Bmax. The absolute variability in Bmax (14.5%) measurements was consistently higher than that of Kd (8.4%) or BP (7.9%) both in subacute and long-term measurements. Simulations indicated that the Bmax and Kd estimation procedure is more sensitive to error in the tmax than that for the BP. The results indicate a good overall stability of the equilibrium method with [11C]raclopride for measuring dopamine D2 receptor binding characteristics in the striatum. The BP approach is more stable than Kd and especially Bmax measurements. Error in defining the tmax in particular in the low specific radioactivity scan may be one source of greater variability in Bmax versus BP. However, a higher intraindividual variability in measurements of the D2 receptor Bmax also may include a component of continuous regulation of this parameter over time. These methodologic aspects should be considered in the design and interpretation of longitudinal studies on D2 dopamine receptor characteristics with [11C]-raclopride.  (+info)

Behavioral, toxic, and neurochemical effects of sydnocarb, a novel psychomotor stimulant: comparisons with methamphetamine. (3/1654)

Sydnocarb (3-(beta-phenylisopropyl)-N-phenylcarbamoylsydnonimine) is a psychostimulant in clinical practice in Russia as a primary and adjunct therapy for a host of psychiatric disorders, including schizophrenia and depression. It has been described as a stimulant with an addiction liability and toxicity less than that of amphetamines. The present study undertook to evaluate the psychomotor stimulant effects of sydnocarb in comparison to those of methamphetamine. Sydnocarb increased locomotor activity of mice with reduced potency (approximately 10-fold) and efficacy compared with methamphetamine. Sydnocarb blocked the locomotor depressant effects of haloperidol at doses that were inactive when given alone. The locomotor stimulant effects of both methamphetamine and sydnocarb were dose-dependently blocked by the dopamine D1 and D2 antagonists SCH 39166 and spiperone, respectively; blockade generally occurred at doses of the antagonists that did not depress locomotor activity when given alone. In mice trained to discriminate methamphetamine from saline, sydnocarb fully substituted for methamphetamine with a 9-fold lower potency. When substituted for methamphetamine under self-administration experiments in rats, 10-fold higher concentrations of sydnocarb maintained responding by its i.v. presentation. Sydnocarb engendered stereotypy in high doses with approximately a 2-fold lower potency than methamphetamine. However, sydnocarb was much less efficacious than methamphetamine in inducing stereotyped behavior. Both sydnocarb and methamphetamine increased dialysate levels of dopamine in mouse striatum; however, the potency and efficacy of sydnocarb was less than methamphetamine. The convulsive effects of cocaine were significantly enhanced by the coadministration of nontoxic doses of methamphetamine but not of sydnocarb. Taken together, the present findings indicate that sydnocarb has psychomotor stimulant effects that are shared by methamphetamine while demonstrating a reduced behavioral toxicity.  (+info)

Depression of peripheral chemosensitivity by a dopaminergic mechanism in patients with obstructive sleep apnoea syndrome. (4/1654)

In the present study, respiratory drives to chemical stimuli and peripheral chemosensitivity were evaluated in patients with obstructive sleep apnoea (OSAS). The effects of oral administration of domperidone, a selective dopamine D2-receptor antagonist, were also examined, to study the respiratory effects of endogenous dopamine on peripheral chemoreceptors. Sixteen patients with OSAS and nine normal control subjects were studied. Respiratory responses to hypercapnia and hypoxia were measured using the rebreathing method and isocapnic progressive hypoxia method, respectively. The hypoxic withdrawal test, which measures the decrease in ventilation caused by two breaths of 100% O2 under mild hypercapnic hypoxic conditions (end-tidal oxygen and carbon dioxide tensions approximately 8.0 kPa and 5.3-6.7 kPa, respectively), was used to evaluate peripheral chemosensitivity. In the patients with OSAS, ventilatory responses to hypercapnia and hypoxia were significantly decreased compared with those of control subjects. Hypoxic withdrawal tests showed that peripheral chemosensitivity was significantly lower in patients with OSAS than in normal subjects. Hypercapnic ventilatory response and peripheral chemosensitivity were enhanced by administration of domperidone in the patients with OSAS, although no changes in either of these were observed in the control subjects. The hypoxic ventilatory response and peripheral chemosensitivity in the patients with OSAS were each significantly correlated with severity of hypoxia during sleep. These findings suggest that peripheral chemosensitivity in patients with obstructive sleep apnoea syndrome may be decreased as a result of abnormality in dopaminergic mechanisms and that the reduced chemosensitivity observed in patients with obstructive sleep apnoea syndrome may affect the severity of hypoxia during sleep.  (+info)

(-)-Stepholidine enhances K+ depolarization-induced activation of synaptosomal tyrosine 3-monooxygenase from rat striatum. (5/1654)

AIM: To study the mechanism of K+ depolarization-induced activation of synaptosomal tyrosine 3-monooxygenase (TM) in rat striatum and the effect of (-)-stepholidine (SPD) on this activation. METHODS: The TM was assayed for DOPA by HPLC-ECD; the activities of Ca2+/calmodulin (CaM)-dependent protein kinase (PK II) and Ca2+/phosphoinositide-dependent protein kinase (PKC) were assayed using histidine as substrate. RESULTS: The incubation of striatal synaptosomes in K(+)-riched (60 mmol.L-1) medium resulted in a marked activation of TM. PKC inhibitor polymyxin B (PMB) completely blocked the activation of K+ 60 mmol.L-1 on TM. Selective D2 receptor agonist quinpirole (QP), Ca2+ removal from incubation medium and CaM antagonist W7 failed to affect the activation. However, SPD enhanced the activation of K+ 60 mmol.L-1 on TM. Meanwhile, the incubation in K+ 60 mmol.L-1 also activated PKC. Neither QP nor SPD affected K+ depolarization-induced activation of PKC. CONCLUSION: The activation of K+ depolarization on synaptosomal TM is enhanced by SPD and this activation is mediated by PKC rather than by PK II.  (+info)

Preproopiomelanocortin and preprodynorphin mRNA expressions in rat brain after electroacupuncture + droperidol. (6/1654)

AIM: To study the expression of preproopiomelanocortin (POMC) and preprodynorphin (PPD) mRNA following the combination of electroacupuncture (EA) with droperidol (Dro), a dopamine receptor antagonist. METHODS: The brains and spinal cords of Sprague-Dawley rats were sectioned after combination of EA with Dro, and the gene expression was investigated using nonradioactive in situ hybridization histochemistry (ISHH). RESULTS: Ten hours after EA, the POMC mRNA expression was enhanced; the expression was further enhanced when EA was combined with Dro. The expression of PPD mRNA showed regional difference in central nervous system (CNS): in spinal cord, EA enhanced the PPD mRNA expression and the combination of EA with Dro further promoted the expression; in the brain, the PPD mRNA expression after EA or combination of EA with Dro showed no obvious change in most regions (caudate-putamen, accumbens, arcuate nucleus of hypothalamus) or was decreased in supraoptic nucleus. CONCLUSION: Dro combined with EA promoted the expression of POMC mRNA in CNS and PPD mRNA in spinal cord, but reduced or had no effect on PPD mRNA expression in the brain.  (+info)

Chimeric dopamine D2/angiotensin AT1 receptors: role of the length of third intracellular loop of D2 receptors in conferring specificity of receptor binding and G-protein coupling. (7/1654)

AIM: To define roles of the third intracellular loop (IL3) length of G-protein coupled receptors in conferring the specificity for receptor binding and G-protein coupling. METHODS: By polymerase chain reaction (PCR), the IL3 of D2 receptor was replaced with the counter part of AT1 receptor which has the shortest loop among all G-protein coupled receptors. D2/AT1 receptor cDNA was then stably transfected into Chinese hamster ovary cells and a clone with high level expression was obtained for receptor binding and agonist-induced phosphatidylinositols (PI) turnover experiments. RESULTS: Comparing to the D2 receptor, D2/AT1 chimeric receptor had lower affinities for all D2 receptor antagonists tested (spiperone, haloperidol, (+)-butaclamol, chlopromazine, clozapine, trifluoperdazine) and different affinity profiles to agonists (apomorphine, dopamine, quinpirole, bromocriptine). But the chimeric receptor failed to couple to G-protein and subsequent stimulation of PI turnover. CONCLUSION: The length of IL3 of D2 receptor participates defining recpetor binding sites conformation, and structure beyond IL3 may affect receptor G-protein coupling.  (+info)

Characteristics of tetrahydroprotoberberines on dopamine D1 and D2 receptors in calf striatum. (8/1654)

AIM: To study the characteristics of tetrahydroprotoberberines (THPB) on dopamine D1 and D2 receptors and elucidate their structure-activity relationship. METHODS: Radioligand assay in vitro with a two-site model program analysis. RESULTS: Four THPB with two hydorxyl groups on C2 and C9 or C2 and C10 exhibited RH and RL two binding sites to D1 receptors and guanosine triphosphate regulated the RH binding site of SPD and THPB-132A in competition assay, while eleven THPB including nonhydroxy-THPB, monohydroxy-THPB, and THPB with two hydroxyl groups attaching to C3 and C10 showed one binding site to D1 receptors under the same conditions. However, the tested eleven THPB all manifested one binding site to D2 receptors in competition assay, and the 2-hydroxy-THPB had the most potent affinity for D2 receptors. CONCLUSION: Dihydroxy-THPB with two hydroxyl groups attaching to C2 and C9 or C2 and C10 possess the intrinsic activity of agonist to D1 receptors, while the other THPB do not. The tested eleven THPB all are the antagonists of D2 receptors.  (+info)

Dopamine antagonists are a class of drugs that block the action of dopamine, a neurotransmitter in the brain associated with various functions including movement, motivation, and emotion. These drugs work by binding to dopamine receptors and preventing dopamine from attaching to them, which can help to reduce the symptoms of certain medical conditions such as schizophrenia, bipolar disorder, and gastroesophageal reflux disease (GERD).

There are several types of dopamine antagonists, including:

1. Typical antipsychotics: These drugs are primarily used to treat psychosis, including schizophrenia and delusional disorders. Examples include haloperidol, chlorpromazine, and fluphenazine.
2. Atypical antipsychotics: These drugs are also used to treat psychosis but have fewer side effects than typical antipsychotics. They may also be used to treat bipolar disorder and depression. Examples include risperidone, olanzapine, and quetiapine.
3. Antiemetics: These drugs are used to treat nausea and vomiting. Examples include metoclopramide and prochlorperazine.
4. Dopamine agonists: While not technically dopamine antagonists, these drugs work by stimulating dopamine receptors and can be used to treat conditions such as Parkinson's disease. However, they can also have the opposite effect and block dopamine receptors in high doses, making them functionally similar to dopamine antagonists.

Common side effects of dopamine antagonists include sedation, weight gain, and movement disorders such as tardive dyskinesia. It's important to use these drugs under the close supervision of a healthcare provider to monitor for side effects and adjust the dosage as needed.

Dopamine is a type of neurotransmitter, which is a chemical messenger that transmits signals in the brain and nervous system. It plays several important roles in the body, including:

* Regulation of movement and coordination
* Modulation of mood and motivation
* Control of the reward and pleasure centers of the brain
* Regulation of muscle tone
* Involvement in memory and attention

Dopamine is produced in several areas of the brain, including the substantia nigra and the ventral tegmental area. It is released by neurons (nerve cells) and binds to specific receptors on other neurons, where it can either excite or inhibit their activity.

Abnormalities in dopamine signaling have been implicated in several neurological and psychiatric conditions, including Parkinson's disease, schizophrenia, and addiction.

Domperidone is a medication that belongs to the class of dopamine antagonists. It works by blocking the action of dopamine, a chemical in the brain that can cause nausea and vomiting. Domperidone is primarily used to treat symptoms of gastroesophageal reflux disease (GERD) and gastric motility disorders, including bloating, fullness, and regurgitation. It works by increasing the contractions of the stomach muscles, which helps to move food and digestive juices through the stomach more quickly.

Domperidone is available in various forms, such as tablets, suspension, and injection. The medication is generally well-tolerated, but it can cause side effects such as dry mouth, diarrhea, headache, and dizziness. In rare cases, domperidone may cause more serious side effects, including irregular heart rhythms, tremors, or muscle stiffness.

It is important to note that domperidone has a risk of causing cardiac arrhythmias, particularly at higher doses and in patients with pre-existing heart conditions. Therefore, it should be used with caution and only under the supervision of a healthcare professional.

Metoclopramide is a medication that is primarily used to manage gastrointestinal disorders. It is classified as a dopamine antagonist and a prokinetic agent, which means it works by blocking the action of dopamine, a chemical in the brain that can slow down stomach and intestine function.

The medical definition of Metoclopramide is:
A synthetic congener of procainamide, used as an antiemetic and to increase gastrointestinal motility. It has a antidopaminergic action, binding to D2 receptors in the chemoreceptor trigger zone and stomach, and it may also block 5HT3 receptors at intrapyloric and central levels. Its actions on the gut smooth muscle are mediated via cholinergic muscarinic receptors. (Source: Dorland's Medical Dictionary)

Metoclopramide is commonly used to treat conditions such as gastroesophageal reflux disease (GERD), gastritis, and gastroparesis, which is a condition that affects the normal movement of food through the digestive tract. It can also be used to prevent nausea and vomiting caused by chemotherapy or radiation therapy.

Like any medication, Metoclopramide can have side effects, including drowsiness, restlessness, and muscle spasms. In some cases, it may cause more serious side effects such as tardive dyskinesia, a condition characterized by involuntary movements of the face, tongue, or limbs. It is important to use Metoclopramide only under the supervision of a healthcare provider and to follow their instructions carefully.

Dopamine D2 receptor is a type of metabotropic G protein-coupled receptor that binds to the neurotransmitter dopamine. It is one of five subtypes of dopamine receptors (D1-D5) and is encoded by the gene DRD2. The activation of D2 receptors leads to a decrease in the activity of adenylyl cyclase, which results in reduced levels of cAMP and modulation of ion channels.

D2 receptors are widely distributed throughout the central nervous system (CNS) and play important roles in various physiological functions, including motor control, reward processing, emotion regulation, and cognition. They are also involved in several neurological and psychiatric disorders, such as Parkinson's disease, schizophrenia, drug addiction, and Tourette syndrome.

D2 receptors have two main subtypes: D2 short (D2S) and D2 long (D2L). The D2S subtype is primarily located in the presynaptic terminals and functions as an autoreceptor that regulates dopamine release, while the D2L subtype is mainly found in the postsynaptic neurons and modulates intracellular signaling pathways.

Antipsychotic drugs, which are used to treat schizophrenia and other psychiatric disorders, work by blocking D2 receptors. However, excessive blockade of these receptors can lead to side effects such as extrapyramidal symptoms (EPS), tardive dyskinesia, and hyperprolactinemia. Therefore, the development of drugs that selectively target specific subtypes of dopamine receptors is an active area of research in the field of neuropsychopharmacology.

Haloperidol is an antipsychotic medication, which is primarily used to treat schizophrenia and symptoms of psychosis, such as delusions, hallucinations, paranoia, or disordered thought. It may also be used to manage Tourette's disorder, tics, agitation, aggression, and hyperactivity in children with developmental disorders.

Haloperidol works by blocking the action of dopamine, a neurotransmitter in the brain, which helps to regulate mood and behavior. It is available in various forms, including tablets, liquid, and injectable solutions. The medication can cause side effects such as drowsiness, restlessness, muscle stiffness, and uncontrolled movements. In rare cases, it may also lead to more serious neurological side effects.

As with any medication, haloperidol should be taken under the supervision of a healthcare provider, who will consider the individual's medical history, current medications, and other factors before prescribing it.

Flupenthixol is an antipsychotic medication that belongs to the chemical class of diphenylbutylpiperidines. It has potent dopamine D2 receptor blocking activity and moderate serotonin 5-HT2A receptor blocking activity, which makes it effective in managing various psychiatric disorders.

Flupenthixol is primarily used for the treatment of chronic schizophrenia and other related psychotic disorders. It can help alleviate symptoms such as hallucinations, delusions, thought disorders, and hostility. Additionally, flupenthixol may also be used off-label to manage depression, anxiety, and aggression in individuals with developmental disabilities or dementia.

The medication is available in two forms: immediate-release tablets (Flupenthixol decanoate) for short-term use and a long-acting depot injection (Flupenthixol dihydrochloride) that can be administered every 2-4 weeks, providing sustained therapeutic levels of the drug.

As with any medication, flupenthixol should be used under the close supervision of a healthcare professional due to potential side effects and interactions with other drugs. Common side effects include extrapyramidal symptoms (involuntary muscle movements), sedation, weight gain, and sexual dysfunction. Rare but serious adverse reactions may include neuroleptic malignant syndrome, tardive dyskinesia, and metabolic disorders.

Spiperone is an antipsychotic drug that belongs to the chemical class of diphenylbutylpiperidines. It has potent dopamine D2 receptor blocking activity and moderate serotonin 5-HT2A receptor affinity. Spiperone is used primarily in research settings for its ability to bind to and block dopamine receptors, which helps scientists study the role of dopamine in various physiological processes.

In clinical practice, spiperone has been used off-label to treat chronic schizophrenia, but its use is limited due to its significant side effects, including extrapyramidal symptoms (involuntary muscle movements), tardive dyskinesia (irregular, jerky movements), and neuroleptic malignant syndrome (a rare but potentially fatal complication characterized by fever, muscle rigidity, and autonomic instability).

It's important to note that spiperone is not approved by the US Food and Drug Administration (FDA) for use in the United States. Its use is more common in research settings or in countries where it may be approved for specific indications.

Dopamine receptors are a type of G protein-coupled receptor that bind to and respond to the neurotransmitter dopamine. There are five subtypes of dopamine receptors (D1-D5), which are classified into two families based on their structure and function: D1-like (D1 and D5) and D2-like (D2, D3, and D4).

Dopamine receptors play a crucial role in various physiological processes, including movement, motivation, reward, cognition, emotion, and neuroendocrine regulation. They are widely distributed throughout the central nervous system, with high concentrations found in the basal ganglia, limbic system, and cortex.

Dysfunction of dopamine receptors has been implicated in several neurological and psychiatric disorders, such as Parkinson's disease, schizophrenia, attention deficit hyperactivity disorder (ADHD), drug addiction, and depression. Therefore, drugs targeting dopamine receptors have been developed for the treatment of these conditions.

Dopamine agonists are a class of medications that mimic the action of dopamine, a neurotransmitter in the brain that regulates movement, emotion, motivation, and reinforcement of rewarding behaviors. These medications bind to dopamine receptors in the brain and activate them, leading to an increase in dopaminergic activity.

Dopamine agonists are used primarily to treat Parkinson's disease, a neurological disorder characterized by motor symptoms such as tremors, rigidity, bradykinesia (slowness of movement), and postural instability. By increasing dopaminergic activity in the brain, dopamine agonists can help alleviate some of these symptoms.

Examples of dopamine agonists include:

1. Pramipexole (Mirapex)
2. Ropinirole (Requip)
3. Rotigotine (Neupro)
4. Apomorphine (Apokyn)

Dopamine agonists may also be used off-label to treat other conditions, such as restless legs syndrome or certain types of dopamine-responsive dystonia. However, these medications can have significant side effects, including nausea, dizziness, orthostatic hypotension, compulsive behaviors (such as gambling, shopping, or sexual addiction), and hallucinations. Therefore, they should be used with caution and under the close supervision of a healthcare provider.

Pimozide is an antipsychotic medication that is primarily used to treat chronic tics and Tourette's disorder. It works by blocking the action of dopamine, a neurotransmitter in the brain that is involved in regulating movement and mood. By blocking dopamine receptors, pimozide helps to reduce the severity and frequency of tics and other symptoms associated with these conditions.

Pimozide may also be used off-label for the treatment of other conditions, such as severe behavioral problems in children with developmental disabilities. It is important to note that pimozide can have serious side effects, including cardiac arrhythmias and neurological symptoms, and should only be prescribed by a healthcare professional who is experienced in managing its use.

As with all medications, it's essential to follow the dosage instructions carefully and to report any unusual or concerning symptoms to your healthcare provider promptly.

Dopamine D1 receptors are a type of G protein-coupled receptor that bind to the neurotransmitter dopamine. They are classified as D1-like receptors, along with D5 receptors, and are activated by dopamine through a stimulatory G protein (Gs).

D1 receptors are widely expressed in the central nervous system, including the striatum, prefrontal cortex, hippocampus, and amygdala. They play important roles in various physiological functions, such as movement control, motivation, reward processing, working memory, and cognition.

Activation of D1 receptors leads to increased levels of intracellular cyclic adenosine monophosphate (cAMP) and activation of protein kinase A (PKA), which in turn modulate the activity of various downstream signaling pathways. Dysregulation of dopamine D1 receptor function has been implicated in several neurological and psychiatric disorders, including Parkinson's disease, schizophrenia, attention deficit hyperactivity disorder (ADHD), and drug addiction.

Trifluperidol is a potent, long-acting typical antipsychotic drug that is primarily used in the management of chronic schizophrenia. It belongs to the chemical class of diphenylbutylpiperidines and has strong antagonist activity at dopamine D2 receptors.

The medical definition of Trifluperidol can be stated as follows:

Trifluperidol (INN, BAN), also known as Etrafon, Stelazine, or Trilafon, is a potent antipsychotic medication used to treat chronic schizophrenia and related psychotic disorders. It has a high affinity for dopamine D2 receptors and exhibits strong antagonist activity, which contributes to its therapeutic effects in managing positive symptoms of schizophrenia such as hallucinations, delusions, and disorganized thinking.

Trifluperidol is available in oral and injectable forms, with the latter being used for more rapid symptom control or when oral administration is not feasible. Its long-acting properties make it suitable for once-daily dosing, although its use has declined in recent years due to the availability of newer atypical antipsychotic medications with fewer side effects.

Like other typical antipsychotics, Trifluperidol can cause extrapyramidal symptoms (EPS), including akathisia, dystonia, parkinsonism, and tardive dyskinesia, as well as other adverse effects such as sedation, orthostatic hypotension, and weight gain. Its use should be monitored closely to minimize these risks and optimize therapeutic outcomes.

Sulpiride is an antipsychotic drug that belongs to the chemical class of benzamides. It primarily acts as a selective dopamine D2 and D3 receptor antagonist. Sulpiride is used in the treatment of various psychiatric disorders such as schizophrenia, psychosis, anxiety, and depression. In addition, it has been found to be effective in managing gastrointestinal disorders like gastroparesis due to its prokinetic effects on the gastrointestinal tract.

The medical definition of Sulpiride is as follows:

Sulpiride (INN, BAN), also known as Sultopride (USAN) or SP, is a selective dopamine D2 and D3 receptor antagonist used in the treatment of various psychiatric disorders such as schizophrenia, psychosis, anxiety, and depression. It has been found to be effective in managing gastrointestinal disorders like gastroparesis due to its prokinetic effects on the gastrointestinal tract. Sulpiride is available under various brand names worldwide, including Dogmatil, Sulpitac, and Espirid."

Please note that this definition includes information about the drug's therapeutic uses, which are essential aspects of understanding a medication in its entirety.

Benzazepines are a class of heterocyclic compounds that contain a benzene fused to a diazepine ring. In the context of pharmaceuticals, benzazepines refer to a group of drugs with various therapeutic uses, such as antipsychotics and antidepressants. Some examples of benzazepine-derived drugs include clozapine, olanzapine, and loxoprofen. These drugs have complex mechanisms of action, often involving multiple receptor systems in the brain.

Butaclamol is a type of antipsychotic drug that is used primarily in research settings. It is not commonly used in clinical practice due to its significant side effects.

Chemically, butaclamol is a derivative of haloperidol, another antipsychotic medication. It works as an antagonist at dopamine receptors in the brain, particularly at the D1 and D2 receptor subtypes. This can help to reduce the symptoms of psychosis, such as delusions and hallucinations, although other antipsychotics are typically preferred due to their more favorable side effect profiles.

In addition to its use in research, butaclamol has been investigated for its potential therapeutic benefits in a range of conditions, including substance abuse disorders, Tourette's syndrome, and chronic pain. However, further research is needed to establish its safety and efficacy in these contexts.

It is important to note that butaclamol should only be used under the close supervision of a healthcare provider, and its use is typically reserved for cases where other treatments have been ineffective or are not well-tolerated.

Fluphenazine is an antipsychotic medication that belongs to the class of phenothiazines. It works by blocking the action of dopamine, a neurotransmitter in the brain, which helps to reduce the symptoms of psychosis such as delusions, hallucinations, and disordered thought.

Fluphenazine is available in several forms, including oral tablets, orally disintegrating tablets, and injectable solutions. It may be used for the treatment of schizophrenia, psychotic disorders, and other conditions associated with elevated levels of dopamine in the brain.

Like all antipsychotic medications, fluphenazine can cause side effects, including extrapyramidal symptoms (EPS), such as stiffness, tremors, and spasms of the face and neck muscles, as well as other systemic side effects like weight gain, sedation, and orthostatic hypotension. It is essential to use fluphenazine under the close supervision of a healthcare provider who can monitor for side effects and adjust the dosage accordingly.

Butyrophenones are a group of synthetic antipsychotic drugs that are primarily used to treat symptoms of schizophrenia and other psychotic disorders. They act as dopamine receptor antagonists, which means they block the action of dopamine, a neurotransmitter in the brain associated with mood, motivation, and pleasure.

Some examples of butyrophenones include haloperidol, droperidol, and benperidol. These drugs are known for their potent antipsychotic effects and can also be used to manage agitation, aggression, and other behavioral disturbances in patients with various psychiatric and neurological disorders.

In addition to their antipsychotic properties, butyrophenones have been used off-label for their sedative and analgesic effects. However, they are associated with a range of side effects, including extrapyramidal symptoms (EPS), such as involuntary muscle spasms and tremors, as well as other neurological and cardiovascular adverse reactions. Therefore, their use is typically reserved for cases where other treatments have been ineffective or contraindicated.

Ergotism is a condition that results from the consumption of ergot alkaloids, which are found in ergot fungus that infects grains such as rye. There are two types of ergotism: convulsive and gangrenous. Convulsive ergotism can cause seizures, muscle spasms, vomiting, and mental disturbances. Gangrenous ergotism, on the other hand, can lead to constriction of blood vessels, resulting in dry gangrene of the extremities, which can ultimately require amputation. Ergotism has been known since ancient times and was once a significant public health problem before modern agricultural practices were implemented.

Tiapamil Hydrochloride is a calcium channel blocker, which is a type of medication that is used to treat various cardiovascular conditions. It works by blocking the influx of calcium ions into the muscle cells of the heart and blood vessels, leading to relaxation of the blood vessels and decreased workload on the heart.

Tiapamil Hydrochloride is primarily used in the management of chronic stable angina (chest pain due to reduced blood flow to the heart) and certain types of arrhythmias (irregular heart rhythms). It may also be used to lower blood pressure in some patients.

Like other calcium channel blockers, Tiapamil Hydrochloride can have side effects such as dizziness, headache, constipation, and peripheral edema (swelling of the legs and ankles). It is important for patients taking this medication to follow their doctor's instructions carefully and report any bothersome or persistent side effects promptly.

Bromocriptine is a dopamine receptor agonist drug, which means it works by binding to and activating dopamine receptors in the brain. It has several therapeutic uses, including:

* Treatment of Parkinson's disease: Bromocriptine can be used alone or in combination with levodopa to help manage the symptoms of Parkinson's disease, such as stiffness, tremors, spasms, and poor muscle control.
* Suppression of lactation: Bromocriptine can be used to suppress milk production in women who are not breastfeeding or who have stopped breastfeeding but still have high levels of prolactin, a hormone that stimulates milk production.
* Treatment of pituitary tumors: Bromocriptine can be used to shrink certain types of pituitary tumors, such as prolactinomas, which are tumors that secrete excessive amounts of prolactin.
* Management of acromegaly: Bromocriptine can be used to manage the symptoms of acromegaly, a rare hormonal disorder characterized by abnormal growth and enlargement of body tissues, by reducing the production of growth hormone.

Bromocriptine is available in immediate-release and long-acting formulations, and it is usually taken orally. Common side effects of bromocriptine include nausea, dizziness, lightheadedness, and drowsiness. Serious side effects are rare but can include hallucinations, confusion, and priapism (prolonged erection).

Dopamine D3 receptors are a type of G protein-coupled receptor that bind to the neurotransmitter dopamine. They are classified as part of the D2-like family of dopamine receptors, which also includes the D2 and D4 receptors. The D3 receptor is primarily expressed in the limbic areas of the brain, including the hippocampus and the nucleus accumbens, where it plays a role in regulating motivation, reward, and cognition.

D3 receptors have been found to be involved in several neurological and psychiatric disorders, such as Parkinson's disease, schizophrenia, and drug addiction. In Parkinson's disease, the loss of dopamine-producing neurons in the substantia nigra results in a decrease in dopamine levels and an increase in D3 receptor expression. This increase in D3 receptor expression has been linked to the development of motor symptoms such as bradykinesia and rigidity.

In schizophrenia, antipsychotic medications that block D2-like receptors, including D3 receptors, are used to treat positive symptoms such as hallucinations and delusions. However, selective D3 receptor antagonists have also been shown to have potential therapeutic effects in treating negative symptoms of schizophrenia, such as apathy and anhedonia.

In drug addiction, D3 receptors have been found to play a role in the rewarding effects of drugs of abuse, such as cocaine and amphetamines. Selective D3 receptor antagonists have shown promise in reducing drug-seeking behavior and preventing relapse in animal models of addiction.

Overall, dopamine D3 receptors play an important role in several neurological and psychiatric disorders, and further research is needed to fully understand their functions and potential therapeutic uses.

Ergolines are a group of ergot alkaloids that have been widely used in the development of various pharmaceutical drugs. These compounds are known for their ability to bind to and stimulate specific receptors in the brain, particularly dopamine receptors. As a result, they have been explored for their potential therapeutic benefits in the treatment of various neurological and psychiatric conditions, such as Parkinson's disease, migraine, and depression.

However, ergolines can also have significant side effects, including hallucinations, nausea, and changes in blood pressure. In addition, some ergot alkaloids have been associated with a rare but serious condition called ergotism, which is characterized by symptoms such as muscle spasms, vomiting, and gangrene. Therefore, the use of ergolines must be carefully monitored and managed to ensure their safety and effectiveness.

Some specific examples of drugs that contain ergolines include:

* Dihydroergotamine (DHE): used for the treatment of migraine headaches
* Pergolide: used for the treatment of Parkinson's disease
* Cabergoline: used for the treatment of Parkinson's disease and certain types of hormonal disorders

It is important to note that while ergolines have shown promise in some therapeutic areas, they are not without their risks. As with any medication, it is essential to consult with a healthcare provider before using any drug containing ergolines to ensure that it is safe and appropriate for an individual's specific needs.

"Acremonium" is a genus of filamentous fungi that are commonly found in soil, decaying vegetation, and water. Some species of Acremonium can cause infections in humans, particularly in individuals with weakened immune systems. These infections can affect various organs and tissues, including the skin, nails, lungs, and eyes.

The medical definition of "Acremonium" is therefore a type of fungus that can cause a variety of infectious diseases, particularly in immunocompromised individuals. It's important to note that Acremonium infections are relatively rare, but they can be serious and require prompt medical treatment.

Dopamine plasma membrane transport proteins, also known as dopamine transporters (DAT), are a type of protein found in the cell membrane that play a crucial role in the regulation of dopamine neurotransmission. They are responsible for the reuptake of dopamine from the synaptic cleft back into the presynaptic neuron, thereby terminating the signal transduction of dopamine and regulating the amount of dopamine available for further release.

Dopamine transporters belong to the family of sodium-dependent neurotransmitter transporters and are encoded by the SLC6A3 gene in humans. Abnormalities in dopamine transporter function have been implicated in several neurological and psychiatric disorders, including Parkinson's disease, attention deficit hyperactivity disorder (ADHD), and substance use disorders.

In summary, dopamine plasma membrane transport proteins are essential for the regulation of dopamine neurotransmission by mediating the reuptake of dopamine from the synaptic cleft back into the presynaptic neuron.

Prolactin is a hormone produced by the pituitary gland, a small gland located at the base of the brain. Its primary function is to stimulate milk production in women after childbirth, a process known as lactation. However, prolactin also plays other roles in the body, including regulating immune responses, metabolism, and behavior. In men, prolactin helps maintain the sexual glands and contributes to paternal behaviors.

Prolactin levels are usually low in both men and non-pregnant women but increase significantly during pregnancy and after childbirth. Various factors can affect prolactin levels, including stress, sleep, exercise, and certain medications. High prolactin levels can lead to medical conditions such as amenorrhea (absence of menstruation), galactorrhea (spontaneous milk production not related to childbirth), infertility, and reduced sexual desire in both men and women.

Dopamine agents are medications that act on dopamine receptors in the brain. Dopamine is a neurotransmitter, a chemical messenger that transmits signals in the brain and other areas of the body. It plays important roles in many functions, including movement, motivation, emotion, and cognition.

Dopamine agents can be classified into several categories based on their mechanism of action:

1. Dopamine agonists: These medications bind to dopamine receptors and mimic the effects of dopamine. They are used to treat conditions such as Parkinson's disease, restless legs syndrome, and certain types of dopamine-responsive dystonia. Examples include pramipexole, ropinirole, and rotigotine.
2. Dopamine precursors: These medications provide the building blocks for the body to produce dopamine. Levodopa is a commonly used dopamine precursor that is converted to dopamine in the brain. It is often used in combination with carbidopa, which helps to prevent levodopa from being broken down before it reaches the brain.
3. Dopamine antagonists: These medications block the action of dopamine at its receptors. They are used to treat conditions such as schizophrenia and certain types of nausea and vomiting. Examples include haloperidol, risperidone, and metoclopramide.
4. Dopamine reuptake inhibitors: These medications increase the amount of dopamine available in the synapse (the space between two neurons) by preventing its reuptake into the presynaptic neuron. They are used to treat conditions such as attention deficit hyperactivity disorder (ADHD) and depression. Examples include bupropion and nomifensine.
5. Dopamine release inhibitors: These medications prevent the release of dopamine from presynaptic neurons. They are used to treat conditions such as Tourette's syndrome and certain types of chronic pain. Examples include tetrabenazine and deutetrabenazine.

It is important to note that dopamine agents can have significant side effects, including addiction, movement disorders, and psychiatric symptoms. Therefore, they should be used under the close supervision of a healthcare provider.

Antipsychotic agents are a class of medications used to manage and treat psychosis, which includes symptoms such as delusions, hallucinations, paranoia, disordered thought processes, and agitated behavior. These drugs work by blocking the action of dopamine, a neurotransmitter in the brain that is believed to play a role in the development of psychotic symptoms. Antipsychotics can be broadly divided into two categories: first-generation antipsychotics (also known as typical antipsychotics) and second-generation antipsychotics (also known as atypical antipsychotics).

First-generation antipsychotics, such as chlorpromazine, haloperidol, and fluphenazine, were developed in the 1950s and have been widely used for several decades. They are generally effective in reducing positive symptoms of psychosis (such as hallucinations and delusions) but can cause significant side effects, including extrapyramidal symptoms (EPS), such as rigidity, tremors, and involuntary movements, as well as weight gain, sedation, and orthostatic hypotension.

Second-generation antipsychotics, such as clozapine, risperidone, olanzapine, quetiapine, and aripiprazole, were developed more recently and are considered to have a more favorable side effect profile than first-generation antipsychotics. They are generally effective in reducing both positive and negative symptoms of psychosis (such as apathy, anhedonia, and social withdrawal) and cause fewer EPS. However, they can still cause significant weight gain, metabolic disturbances, and sedation.

Antipsychotic agents are used to treat various psychiatric disorders, including schizophrenia, bipolar disorder, major depressive disorder with psychotic features, delusional disorder, and other conditions that involve psychosis or agitation. They can be administered orally, intramuscularly, or via long-acting injectable formulations. The choice of antipsychotic agent depends on the individual patient's needs, preferences, and response to treatment, as well as the potential for side effects. Regular monitoring of patients taking antipsychotics is essential to ensure their safety and effectiveness.

Sprague-Dawley rats are a strain of albino laboratory rats that are widely used in scientific research. They were first developed by researchers H.H. Sprague and R.C. Dawley in the early 20th century, and have since become one of the most commonly used rat strains in biomedical research due to their relatively large size, ease of handling, and consistent genetic background.

Sprague-Dawley rats are outbred, which means that they are genetically diverse and do not suffer from the same limitations as inbred strains, which can have reduced fertility and increased susceptibility to certain diseases. They are also characterized by their docile nature and low levels of aggression, making them easier to handle and study than some other rat strains.

These rats are used in a wide variety of research areas, including toxicology, pharmacology, nutrition, cancer, and behavioral studies. Because they are genetically diverse, Sprague-Dawley rats can be used to model a range of human diseases and conditions, making them an important tool in the development of new drugs and therapies.

A dose-response relationship in the context of drugs refers to the changes in the effects or symptoms that occur as the dose of a drug is increased or decreased. Generally, as the dose of a drug is increased, the severity or intensity of its effects also increases. Conversely, as the dose is decreased, the effects of the drug become less severe or may disappear altogether.

The dose-response relationship is an important concept in pharmacology and toxicology because it helps to establish the safe and effective dosage range for a drug. By understanding how changes in the dose of a drug affect its therapeutic and adverse effects, healthcare providers can optimize treatment plans for their patients while minimizing the risk of harm.

The dose-response relationship is typically depicted as a curve that shows the relationship between the dose of a drug and its effect. The shape of the curve may vary depending on the drug and the specific effect being measured. Some drugs may have a steep dose-response curve, meaning that small changes in the dose can result in large differences in the effect. Other drugs may have a more gradual dose-response curve, where larger changes in the dose are needed to produce significant effects.

In addition to helping establish safe and effective dosages, the dose-response relationship is also used to evaluate the potential therapeutic benefits and risks of new drugs during clinical trials. By systematically testing different doses of a drug in controlled studies, researchers can identify the optimal dosage range for the drug and assess its safety and efficacy.

Dopamine D5 receptor is a type of dopamine receptor that belongs to the family of G protein-coupled receptors. It is also known as D5R or DRD5. These receptors are found in various parts of the brain, including the cortex and the hippocampus.

The activation of Dopamine D5 receptors leads to the stimulation of several intracellular signaling pathways, including the cAMP-dependent pathway, which results in the modulation of neuronal excitability, neurotransmitter release, and other cellular functions.

Dopamine D5 receptors have been implicated in various physiological processes, such as cognition, emotion, motor control, and reward processing. They have also been associated with several neurological and psychiatric disorders, including schizophrenia, Parkinson's disease, attention deficit hyperactivity disorder (ADHD), and drug addiction.

The medical definition of "Receptors, Dopamine D5" can be summarized as follows:

Dopamine D5 receptor is a type of G protein-coupled receptor that binds dopamine and activates several intracellular signaling pathways, leading to the modulation of various physiological processes. These receptors have been implicated in several neurological and psychiatric disorders and are a target for drug development.

'Animal behavior' refers to the actions or responses of animals to various stimuli, including their interactions with the environment and other individuals. It is the study of the actions of animals, whether they are instinctual, learned, or a combination of both. Animal behavior includes communication, mating, foraging, predator avoidance, and social organization, among other things. The scientific study of animal behavior is called ethology. This field seeks to understand the evolutionary basis for behaviors as well as their physiological and psychological mechanisms.

Dopamine uptake inhibitors are a class of medications that work by blocking the reuptake of dopamine, a neurotransmitter, into the presynaptic neuron. This results in an increased concentration of dopamine in the synapse, leading to enhanced dopaminergic transmission and activity.

These drugs are used in various medical conditions where dopamine is implicated, such as depression, attention deficit hyperactivity disorder (ADHD), and neurological disorders like Parkinson's disease. They can also be used to treat substance abuse disorders, such as cocaine addiction, by blocking the reuptake of dopamine and reducing the rewarding effects of the drug.

Examples of dopamine uptake inhibitors include:

* Bupropion (Wellbutrin), which is used to treat depression and ADHD
* Methylphenidate (Ritalin, Concerta), which is used to treat ADHD
* Amantadine (Symmetrel), which is used to treat Parkinson's disease and also has antiviral properties.

It's important to note that dopamine uptake inhibitors can have side effects, including increased heart rate, blood pressure, and anxiety. They may also have the potential for abuse and dependence, particularly in individuals with a history of substance abuse. Therefore, these medications should be used under the close supervision of a healthcare provider.

Dopamine beta-hydroxylase (DBH) is an enzyme that plays a crucial role in the synthesis of catecholamines, which are important neurotransmitters and hormones in the human body. Specifically, DBH converts dopamine into norepinephrine, another essential catecholamine.

DBH is primarily located in the adrenal glands and nerve endings of the sympathetic nervous system. It requires molecular oxygen, copper ions, and vitamin C (ascorbic acid) as cofactors to perform its enzymatic function. Deficiency or dysfunction of DBH can lead to various medical conditions, such as orthostatic hypotension and neuropsychiatric disorders.

The corpus striatum is a part of the brain that plays a crucial role in movement, learning, and cognition. It consists of two structures called the caudate nucleus and the putamen, which are surrounded by the external and internal segments of the globus pallidus. Together, these structures form the basal ganglia, a group of interconnected neurons that help regulate voluntary movement.

The corpus striatum receives input from various parts of the brain, including the cerebral cortex, thalamus, and other brainstem nuclei. It processes this information and sends output to the globus pallidus and substantia nigra, which then project to the thalamus and back to the cerebral cortex. This feedback loop helps coordinate and fine-tune movements, allowing for smooth and coordinated actions.

Damage to the corpus striatum can result in movement disorders such as Parkinson's disease, Huntington's disease, and dystonia. These conditions are characterized by abnormal involuntary movements, muscle stiffness, and difficulty initiating or controlling voluntary movements.

"Inbred strains of rats" are genetically identical rodents that have been produced through many generations of brother-sister mating. This results in a high degree of homozygosity, where the genes at any particular locus in the genome are identical in all members of the strain.

Inbred strains of rats are widely used in biomedical research because they provide a consistent and reproducible genetic background for studying various biological phenomena, including the effects of drugs, environmental factors, and genetic mutations on health and disease. Additionally, inbred strains can be used to create genetically modified models of human diseases by introducing specific mutations into their genomes.

Some commonly used inbred strains of rats include the Wistar Kyoto (WKY), Sprague-Dawley (SD), and Fischer 344 (F344) rat strains. Each strain has its own unique genetic characteristics, making them suitable for different types of research.

Quinpirole is not a medical condition or disease, but rather a synthetic compound used in research and medicine. It's a selective agonist for the D2 and D3 dopamine receptors, which means it binds to and activates these receptors, mimicking the effects of dopamine, a neurotransmitter involved in various physiological processes such as movement, motivation, reward, and cognition.

Quinpirole is used primarily in preclinical research to study the role of dopamine receptors in different neurological conditions, including Parkinson's disease, schizophrenia, drug addiction, and others. It helps researchers understand how dopamine systems work and contributes to the development of new therapeutic strategies for these disorders.

It is important to note that quinpirole is not used as a medication in humans or animals but rather as a research tool in laboratory settings.

Hormone antagonists are substances or drugs that block the action of hormones by binding to their receptors without activating them, thereby preventing the hormones from exerting their effects. They can be classified into two types: receptor antagonists and enzyme inhibitors. Receptor antagonists bind directly to hormone receptors and prevent the hormone from binding, while enzyme inhibitors block the production or breakdown of hormones by inhibiting specific enzymes involved in their metabolism. Hormone antagonists are used in the treatment of various medical conditions, such as cancer, hormonal disorders, and cardiovascular diseases.

Raclopride is not a medical condition but a drug that belongs to the class of dopamine receptor antagonists. It's primarily used in research and diagnostic settings as a radioligand in positron emission tomography (PET) scans to visualize and measure the distribution and availability of dopamine D2 and D3 receptors in the brain.

In simpler terms, Raclopride is a compound that can be labeled with a radioactive isotope and then introduced into the body to track the interaction between the radioligand and specific receptors (in this case, dopamine D2 and D3 receptors) in the brain. This information can help researchers and clinicians better understand neurochemical processes and disorders related to dopamine dysfunction, such as Parkinson's disease, schizophrenia, and drug addiction.

It is important to note that Raclopride is not used as a therapeutic agent in clinical practice due to its short half-life and the potential for side effects associated with dopamine receptor blockade.

The nucleus accumbens is a part of the brain that is located in the ventral striatum, which is a key region of the reward circuitry. It is made up of two subregions: the shell and the core. The nucleus accumbens receives inputs from various sources, including the prefrontal cortex, amygdala, and hippocampus, and sends outputs to the ventral pallidum and other areas.

The nucleus accumbens is involved in reward processing, motivation, reinforcement learning, and addiction. It plays a crucial role in the release of the neurotransmitter dopamine, which is associated with pleasure and reinforcement. Dysfunction in the nucleus accumbens has been implicated in various neurological and psychiatric conditions, including substance use disorders, depression, and obsessive-compulsive disorder.

Excitatory amino acid antagonists are a class of drugs that block the action of excitatory neurotransmitters, particularly glutamate and aspartate, in the brain. These drugs work by binding to and blocking the receptors for these neurotransmitters, thereby reducing their ability to stimulate neurons and produce an excitatory response.

Excitatory amino acid antagonists have been studied for their potential therapeutic benefits in a variety of neurological conditions, including stroke, epilepsy, traumatic brain injury, and neurodegenerative disorders such as Alzheimer's disease and Parkinson's disease. However, their use is limited by the fact that blocking excitatory neurotransmission can also have negative effects on cognitive function and memory.

There are several types of excitatory amino acid receptors, including N-methyl-D-aspartate (NMDA), alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA), and kainite receptors. Different excitatory amino acid antagonists may target one or more of these receptor subtypes, depending on their specific mechanism of action.

Examples of excitatory amino acid antagonists include ketamine, memantine, and dextromethorphan. These drugs have been used in clinical practice for various indications, such as anesthesia, sedation, and treatment of neurological disorders. However, their use must be carefully monitored due to potential side effects and risks associated with blocking excitatory neurotransmission.

Salicylamides are organic compounds that consist of a salicylic acid molecule (a type of phenolic acid) linked to an amide group. They are derivatives of salicylic acid and are known for their analgesic, anti-inflammatory, and antipyretic properties. Salicylamides have been used in various pharmaceutical and therapeutic applications, including the treatment of pain, fever, and inflammation. However, they have largely been replaced by other compounds such as acetylsalicylic acid (aspirin) due to their lower potency and potential side effects.

Narcotic antagonists are a class of medications that block the effects of opioids, a type of narcotic pain reliever, by binding to opioid receptors in the brain and blocking the activation of these receptors by opioids. This results in the prevention or reversal of opioid-induced effects such as respiratory depression, sedation, and euphoria. Narcotic antagonists are used for a variety of medical purposes, including the treatment of opioid overdose, the management of opioid dependence, and the prevention of opioid-induced side effects in certain clinical situations. Examples of narcotic antagonists include naloxone, naltrexone, and methylnaltrexone.

Apomorphine is a non-selective dopamine receptor agonist, which means that it activates dopamine receptors in the brain. It has a high affinity for D1 and D2 dopamine receptors and is used medically to treat Parkinson's disease, particularly in cases of severe or intractable motor fluctuations.

Apomorphine can be administered subcutaneously (under the skin) as a solution or as a sublingual (under the tongue) film. It works by stimulating dopamine receptors in the brain, which helps to reduce the symptoms of Parkinson's disease such as stiffness, tremors, and difficulty with movement.

In addition to its use in Parkinson's disease, apomorphine has also been investigated for its potential therapeutic benefits in other neurological disorders, including alcohol use disorder and drug addiction. However, more research is needed to establish its safety and efficacy in these conditions.

Cocaine is a highly addictive stimulant drug derived from the leaves of the coca plant (Erythroxylon coca). It is a powerful central nervous system stimulant that affects the brain and body in many ways. When used recreationally, cocaine can produce feelings of euphoria, increased energy, and mental alertness; however, it can also cause serious negative consequences, including addiction, cardiovascular problems, seizures, and death.

Cocaine works by increasing the levels of dopamine in the brain, a neurotransmitter associated with pleasure and reward. This leads to the pleasurable effects that users seek when they take the drug. However, cocaine also interferes with the normal functioning of the brain's reward system, making it difficult for users to experience pleasure from natural rewards like food or social interactions.

Cocaine can be taken in several forms, including powdered form (which is usually snorted), freebase (a purer form that is often smoked), and crack cocaine (a solid form that is typically heated and smoked). Each form of cocaine has different risks and potential harms associated with its use.

Long-term use of cocaine can lead to a number of negative health consequences, including addiction, heart problems, malnutrition, respiratory issues, and mental health disorders like depression or anxiety. It is important to seek help if you or someone you know is struggling with cocaine use or addiction.

Neurokinin-1 (NK-1) receptor antagonists are a class of drugs that block the action of substance P, a neuropeptide involved in pain transmission and inflammation. These drugs work by binding to NK-1 receptors found on nerve cells, preventing substance P from activating them and transmitting pain signals. NK-1 receptor antagonists have been studied for their potential use in treating various conditions associated with pain and inflammation, such as migraine headaches, depression, and irritable bowel syndrome. Some examples of NK-1 receptor antagonists include aprepitant, fosaprepitant, and rolapitant.

The neostriatum is a component of the basal ganglia, a group of subcortical nuclei in the brain that are involved in motor control, procedural learning, and other cognitive functions. It is composed primarily of two types of neurons: medium spiny neurons and aspiny interneurons. The neostriatum receives input from various regions of the cerebral cortex and projects to other parts of the basal ganglia, forming an important part of the cortico-basal ganglia-thalamo-cortical loop.

In medical terminology, the neostriatum is often used interchangeably with the term "striatum," although some sources reserve the term "neostriatum" for the caudate nucleus and putamen specifically, while using "striatum" to refer to the entire structure including the ventral striatum (also known as the nucleus accumbens).

Damage to the neostriatum has been implicated in various neurological conditions, such as Huntington's disease and Parkinson's disease.

Histamine H2 antagonists, also known as H2 blockers, are a class of medications that work by blocking the action of histamine on the H2 receptors in the stomach. Histamine is a chemical that is released by the body during an allergic reaction and can also be released by certain cells in the stomach in response to food or other stimuli. When histamine binds to the H2 receptors in the stomach, it triggers the release of acid. By blocking the action of histamine on these receptors, H2 antagonists reduce the amount of acid produced by the stomach, which can help to relieve symptoms such as heartburn, indigestion, and stomach ulcers. Examples of H2 antagonists include ranitidine (Zantac), famotidine (Pepcid), and cimetidine (Tagamet).

Levodopa, also known as L-dopa, is a medication used primarily in the treatment of Parkinson's disease. It is a direct precursor to the neurotransmitter dopamine and works by being converted into dopamine in the brain, helping to restore the balance between dopamine and other neurotransmitters. This helps alleviate symptoms such as stiffness, tremors, spasms, and poor muscle control. Levodopa is often combined with carbidopa (a peripheral decarboxylase inhibitor) to prevent the conversion of levodopa to dopamine outside of the brain, reducing side effects like nausea and vomiting.

Muscarinic antagonists, also known as muscarinic receptor antagonists or parasympatholytics, are a class of drugs that block the action of acetylcholine at muscarinic receptors. Acetylcholine is a neurotransmitter that plays an important role in the parasympathetic nervous system, which helps to regulate various bodily functions such as heart rate, digestion, and respiration.

Muscarinic antagonists work by binding to muscarinic receptors, which are found in various organs throughout the body, including the eyes, lungs, heart, and gastrointestinal tract. By blocking the action of acetylcholine at these receptors, muscarinic antagonists can produce a range of effects depending on the specific receptor subtype that is affected.

For example, muscarinic antagonists may be used to treat conditions such as chronic obstructive pulmonary disease (COPD) and asthma by relaxing the smooth muscle in the airways and reducing bronchoconstriction. They may also be used to treat conditions such as urinary incontinence or overactive bladder by reducing bladder contractions.

Some common muscarinic antagonists include atropine, scopolamine, ipratropium, and tiotropium. It's important to note that these drugs can have significant side effects, including dry mouth, blurred vision, constipation, and confusion, especially when used in high doses or for prolonged periods of time.

Microdialysis is a minimally invasive technique used in clinical and research settings to continuously monitor the concentration of various chemicals, such as neurotransmitters, drugs, or metabolites, in biological fluids (e.g., extracellular fluid of tissues, blood, or cerebrospinal fluid). This method involves inserting a small, flexible catheter with a semipermeable membrane into the region of interest. A physiological solution is continuously perfused through the catheter, allowing molecules to diffuse across the membrane based on their concentration gradient. The dialysate that exits the catheter is then collected and analyzed for target compounds using various analytical techniques (e.g., high-performance liquid chromatography, mass spectrometry).

In summary, microdialysis is a valuable tool for monitoring real-time changes in chemical concentrations within biological systems, enabling better understanding of physiological processes or pharmacokinetic properties of drugs.

Amphetamine is a central nervous system stimulant drug that works by increasing the levels of certain neurotransmitters (chemical messengers) in the brain, such as dopamine and norepinephrine. It is used medically to treat conditions such as attention deficit hyperactivity disorder (ADHD), narcolepsy, and obesity, due to its appetite-suppressing effects.

Amphetamines can be prescribed in various forms, including tablets, capsules, or liquids, and are available under several brand names, such as Adderall, Dexedrine, and Vyvanse. They are also known by their street names, such as speed, uppers, or wake-ups, and can be abused for their euphoric effects and ability to increase alertness, energy, and concentration.

Long-term use of amphetamines can lead to dependence, tolerance, and addiction, as well as serious health consequences, such as cardiovascular problems, mental health disorders, and malnutrition. It is essential to use amphetamines only under the supervision of a healthcare provider and follow their instructions carefully.

Piperidines are not a medical term per se, but they are a class of organic compounds that have important applications in the pharmaceutical industry. Medically relevant piperidines include various drugs such as some antihistamines, antidepressants, and muscle relaxants.

A piperidine is a heterocyclic amine with a six-membered ring containing five carbon atoms and one nitrogen atom. The structure can be described as a cyclic secondary amine. Piperidines are found in some natural alkaloids, such as those derived from the pepper plant (Piper nigrum), which gives piperidines their name.

In a medical context, it is more common to encounter specific drugs that belong to the class of piperidines rather than the term itself.

Interleukin-1 Receptor Antagonist Protein (IL-1Ra) is a naturally occurring protein that acts as a competitive inhibitor of the interleukin-1 (IL-1) receptor. IL-1 is a pro-inflammatory cytokine involved in various physiological processes, including the immune response and inflammation. The binding of IL-1 to its receptor triggers a signaling cascade that leads to the activation of inflammatory genes and cellular responses.

IL-1Ra shares structural similarities with IL-1 but does not initiate the downstream signaling pathway. Instead, it binds to the same receptor site as IL-1, preventing IL-1 from interacting with its receptor and thus inhibiting the inflammatory response.

Increased levels of IL-1Ra have been found in various inflammatory conditions, such as rheumatoid arthritis, inflammatory bowel disease, and sepsis, where it acts to counterbalance the pro-inflammatory effects of IL-1. Recombinant IL-1Ra (Anakinra) is used clinically as a therapeutic agent for the treatment of rheumatoid arthritis and other inflammatory diseases.

GABA (gamma-aminobutyric acid) antagonists are substances that block the action of GABA, which is the primary inhibitory neurotransmitter in the central nervous system. GABA plays a crucial role in regulating neuronal excitability and reducing the transmission of nerve impulses.

GABA antagonists work by binding to the GABA receptors without activating them, thereby preventing the normal function of GABA and increasing neuronal activity. These agents can cause excitation of the nervous system, leading to various effects depending on the specific type of GABA receptor they target.

GABA antagonists are used in medical treatments for certain conditions, such as sleep disorders, depression, and cognitive enhancement. However, they can also have adverse effects, including anxiety, agitation, seizures, and even neurotoxicity at high doses. Examples of GABA antagonists include picrotoxin, bicuculline, and flumazenil.

Neurons, also known as nerve cells or neurocytes, are specialized cells that constitute the basic unit of the nervous system. They are responsible for receiving, processing, and transmitting information and signals within the body. Neurons have three main parts: the dendrites, the cell body (soma), and the axon. The dendrites receive signals from other neurons or sensory receptors, while the axon transmits these signals to other neurons, muscles, or glands. The junction between two neurons is called a synapse, where neurotransmitters are released to transmit the signal across the gap (synaptic cleft) to the next neuron. Neurons vary in size, shape, and structure depending on their function and location within the nervous system.

Tyrosine 3-Monooxygenase (also known as Tyrosinase or Tyrosine hydroxylase) is an enzyme that plays a crucial role in the synthesis of catecholamines, which are neurotransmitters and hormones in the body. This enzyme catalyzes the conversion of the amino acid L-tyrosine to 3,4-dihydroxyphenylalanine (L-DOPA) by adding a hydroxyl group to the 3rd carbon atom of the tyrosine molecule.

The reaction is as follows:

L-Tyrosine + O2 + pterin (co-factor) -> L-DOPA + pterin (oxidized) + H2O

This enzyme requires molecular oxygen and a co-factor such as tetrahydrobiopterin to carry out the reaction. Tyrosine 3-Monooxygenase is found in various tissues, including the brain and adrenal glands, where it helps regulate the production of catecholamines like dopamine, norepinephrine, and epinephrine. Dysregulation of this enzyme has been implicated in several neurological disorders, such as Parkinson's disease.

Homovanillic acid (HVA) is a major metabolite of dopamine, a neurotransmitter in the human body. It is formed in the body when an enzyme called catechol-O-methyltransferase (COMT) breaks down dopamine. HVA can be measured in body fluids such as urine, cerebrospinal fluid, and plasma to assess the activity of dopamine and the integrity of the dopaminergic system. Increased levels of HVA are associated with certain neurological disorders, including Parkinson's disease, while decreased levels may indicate dopamine deficiency or other conditions affecting the nervous system.

Dopaminergic neurons are a type of specialized brain cells that produce, synthesize, and release the neurotransmitter dopamine. These neurons play crucial roles in various brain functions, including motivation, reward processing, motor control, and cognition. They are primarily located in several regions of the midbrain, such as the substantia nigra pars compacta (SNc) and the ventral tegmental area (VTA).

Dopaminergic neurons have a unique physiology characterized by their ability to generate slow, irregular electrical signals called pacemaker activity. This distinctive firing pattern allows dopamine to be released in a controlled manner, which is essential for proper brain function.

The degeneration and loss of dopaminergic neurons in the SNc are associated with Parkinson's disease, a neurodegenerative disorder characterized by motor impairments such as tremors, rigidity, and bradykinesia (slowness of movement). The reduction in dopamine levels caused by this degeneration leads to an imbalance in the brain's neural circuitry, resulting in the characteristic symptoms of Parkinson's disease.

Nicotinic antagonists are a class of drugs that block the action of nicotine at nicotinic acetylcholine receptors (nAChRs). These receptors are found in the nervous system and are activated by the neurotransmitter acetylcholine, as well as by nicotine. When nicotine binds to these receptors, it can cause the release of various neurotransmitters, including dopamine, which can lead to rewarding effects and addiction.

Nicotinic antagonists work by binding to nAChRs and preventing nicotine from activating them. This can help to reduce the rewarding effects of nicotine and may be useful in treating nicotine addiction. Examples of nicotinic antagonists include mecamylamine, varenicline, and cytisine.

It's important to note that while nicotinic antagonists can help with nicotine addiction, they can also have side effects, such as nausea, vomiting, and abnormal dreams. Additionally, some people may experience more serious side effects, such as seizures or cardiovascular problems, so it's important to use these medications under the close supervision of a healthcare provider.

"Wistar rats" are a strain of albino rats that are widely used in laboratory research. They were developed at the Wistar Institute in Philadelphia, USA, and were first introduced in 1906. Wistar rats are outbred, which means that they are genetically diverse and do not have a fixed set of genetic characteristics like inbred strains.

Wistar rats are commonly used as animal models in biomedical research because of their size, ease of handling, and relatively low cost. They are used in a wide range of research areas, including toxicology, pharmacology, nutrition, cancer, cardiovascular disease, and behavioral studies. Wistar rats are also used in safety testing of drugs, medical devices, and other products.

Wistar rats are typically larger than many other rat strains, with males weighing between 500-700 grams and females weighing between 250-350 grams. They have a lifespan of approximately 2-3 years. Wistar rats are also known for their docile and friendly nature, making them easy to handle and work with in the laboratory setting.

The Ventral Tegmental Area (VTA) is a collection of neurons located in the midbrain that is part of the dopamine system. It is specifically known as the A10 group and is the largest source of dopaminergic neurons in the brain. These neurons project to various regions, including the prefrontal cortex, amygdala, hippocampus, and nucleus accumbens, and are involved in reward, motivation, addiction, and various cognitive functions. The VTA also contains GABAergic and glutamatergic neurons that modulate dopamine release and have various other functions.

The Substantia Nigra is a region in the midbrain that plays a crucial role in movement control and reward processing. It is composed of two parts: the pars compacta and the pars reticulata. The pars compacta contains dopamine-producing neurons, whose loss or degeneration is associated with Parkinson's disease, leading to motor symptoms such as tremors, rigidity, and bradykinesia.

In summary, Substantia Nigra is a brain structure that contains dopamine-producing cells and is involved in movement control and reward processing. Its dysfunction or degeneration can lead to neurological disorders like Parkinson's disease.

Dopamine and cAMP-regulated phosphoprotein 32 (DARPP-32) is a protein that plays a crucial role in the regulation of signal transduction pathways in the brain. It is primarily expressed in neurons of the striatum, a region involved in movement control, motivation, and reward processing.

DARPP-32 acts as a molecular switch in response to various neurotransmitters, including dopamine and glutamate. When phosphorylated by protein kinase A (PKA), DARPP-32 inhibits protein phosphatase-1 (PP-1), thereby enhancing the effects of PKA and promoting long-term changes in synaptic plasticity. Conversely, when phosphorylated by other kinases such as cyclin-dependent kinase 5 (Cdk5) or protein kinase C (PKC), DARPP-32 inhibits PKA, counteracting its effects.

Dysregulation of DARPP-32 has been implicated in several neurological and psychiatric disorders, including drug addiction, Parkinson's disease, and schizophrenia. Therefore, understanding the molecular mechanisms underlying DARPP-32 function is essential for developing novel therapeutic strategies to treat these conditions.

Purinergic P1 receptor antagonists are a class of pharmaceutical drugs that block the activity of purinergic P1 receptors, which are a type of G-protein coupled receptor found in many tissues throughout the body. These receptors are activated by extracellular nucleotides such as adenosine and ATP, and play important roles in regulating a variety of physiological processes, including cardiovascular function, neurotransmission, and immune response.

Purinergic P1 receptor antagonists work by binding to these receptors and preventing them from being activated by nucleotides. This can have various therapeutic effects, depending on the specific receptor subtype that is targeted. For example, A1 receptor antagonists have been shown to improve cardiac function in heart failure, while A2A receptor antagonists have potential as anti-inflammatory and neuroprotective agents.

However, it's important to note that the use of purinergic P1 receptor antagonists is still an area of active research, and more studies are needed to fully understand their mechanisms of action and therapeutic potential.

Histamine H1 antagonists, also known as H1 blockers or antihistamines, are a class of medications that work by blocking the action of histamine at the H1 receptor. Histamine is a chemical mediator released by mast cells and basophils in response to an allergic reaction or injury. It causes various symptoms such as itching, sneezing, runny nose, and wheal and flare reactions (hives).

H1 antagonists prevent the binding of histamine to its receptor, thereby alleviating these symptoms. They are commonly used to treat allergic conditions such as hay fever, hives, and eczema, as well as motion sickness and insomnia. Examples of H1 antagonists include diphenhydramine (Benadryl), loratadine (Claritin), cetirizine (Zyrtec), and doxylamine (Unisom).

Serotonin, also known as 5-hydroxytryptamine (5-HT), is a monoamine neurotransmitter that is found primarily in the gastrointestinal (GI) tract, blood platelets, and the central nervous system (CNS) of humans and other animals. It is produced by the conversion of the amino acid tryptophan to 5-hydroxytryptophan (5-HTP), and then to serotonin.

In the CNS, serotonin plays a role in regulating mood, appetite, sleep, memory, learning, and behavior, among other functions. It also acts as a vasoconstrictor, helping to regulate blood flow and blood pressure. In the GI tract, it is involved in peristalsis, the contraction and relaxation of muscles that moves food through the digestive system.

Serotonin is synthesized and stored in serotonergic neurons, which are nerve cells that use serotonin as their primary neurotransmitter. These neurons are found throughout the brain and spinal cord, and they communicate with other neurons by releasing serotonin into the synapse, the small gap between two neurons.

Abnormal levels of serotonin have been linked to a variety of disorders, including depression, anxiety, schizophrenia, and migraines. Medications that affect serotonin levels, such as selective serotonin reuptake inhibitors (SSRIs), are commonly used to treat these conditions.

Adenosine A2 receptor antagonists are a class of pharmaceutical compounds that block the action of adenosine at A2 receptors. Adenosine is a naturally occurring molecule in the body that acts as a neurotransmitter and has various physiological effects, including vasodilation and inhibition of heart rate.

Adenosine A2 receptor antagonists work by binding to A2 receptors and preventing adenosine from activating them. This results in the opposite effect of adenosine, leading to vasoconstriction and increased heart rate. These drugs are used for a variety of medical conditions, including asthma, chronic obstructive pulmonary disease (COPD), and heart failure.

Examples of Adenosine A2 receptor antagonists include theophylline, caffeine, and some newer drugs such asistradefylline and tozadenant. These drugs have different pharmacological properties and are used for specific medical conditions. It is important to note that adenosine A2 receptor antagonists can have side effects, including restlessness, insomnia, and gastrointestinal symptoms, and should be used under the guidance of a healthcare professional.

Oxidopamine is not a recognized medical term or a medication commonly used in clinical practice. However, it is a chemical compound that is often used in scientific research, particularly in the field of neuroscience.

Oxidopamine is a synthetic catecholamine that can be selectively taken up by dopaminergic neurons and subsequently undergo oxidation, leading to the production of reactive oxygen species. This property makes it a useful tool for studying the effects of oxidative stress on dopaminergic neurons in models of Parkinson's disease and other neurological disorders.

In summary, while not a medical definition per se, oxidopamine is a chemical compound used in research to study the effects of oxidative stress on dopaminergic neurons.

"Motor activity" is a general term used in the field of medicine and neuroscience to refer to any kind of physical movement or action that is generated by the body's motor system. The motor system includes the brain, spinal cord, nerves, and muscles that work together to produce movements such as walking, talking, reaching for an object, or even subtle actions like moving your eyes.

Motor activity can be voluntary, meaning it is initiated intentionally by the individual, or involuntary, meaning it is triggered automatically by the nervous system without conscious control. Examples of voluntary motor activity include deliberately lifting your arm or kicking a ball, while examples of involuntary motor activity include heartbeat, digestion, and reflex actions like jerking your hand away from a hot stove.

Abnormalities in motor activity can be a sign of neurological or muscular disorders, such as Parkinson's disease, cerebral palsy, or multiple sclerosis. Assessment of motor activity is often used in the diagnosis and treatment of these conditions.

Histamine antagonists, also known as histamine blockers or H1-blockers, are a class of medications that work by blocking the action of histamine, a substance in the body that is released during an allergic reaction. Histamine causes many of the symptoms of an allergic response, such as itching, sneezing, runny nose, and hives. By blocking the effects of histamine, these medications can help to relieve or prevent allergy symptoms.

Histamine antagonists are often used to treat conditions such as hay fever, hives, and other allergic reactions. They may also be used to treat stomach ulcers caused by excessive production of stomach acid. Some examples of histamine antagonists include diphenhydramine (Benadryl), loratadine (Claritin), and famotidine (Pepcid).

It's important to note that while histamine antagonists can be effective at relieving allergy symptoms, they do not cure allergies or prevent the release of histamine. They simply block its effects. It's also worth noting that these medications can have side effects, such as drowsiness, dry mouth, and dizziness, so it's important to follow your healthcare provider's instructions carefully when taking them.

The mesencephalon, also known as the midbrain, is the middle portion of the brainstem that connects the hindbrain (rhombencephalon) and the forebrain (prosencephalon). It plays a crucial role in several important functions including motor control, vision, hearing, and the regulation of consciousness and sleep-wake cycles. The mesencephalon contains several important structures such as the cerebral aqueduct, tectum, tegmentum, cerebral peduncles, and several cranial nerve nuclei (III and IV).

A radioligand assay is a type of in vitro binding assay used in molecular biology and pharmacology to measure the affinity and quantity of a ligand (such as a drug or hormone) to its specific receptor. In this technique, a small amount of a radioactively labeled ligand, also known as a radioligand, is introduced to a sample containing the receptor of interest. The radioligand binds competitively with other unlabeled ligands present in the sample for the same binding site on the receptor. After allowing sufficient time for binding, the reaction is stopped, and the amount of bound radioligand is measured using a technique such as scintillation counting. The data obtained from this assay can be used to determine the dissociation constant (Kd) and maximum binding capacity (Bmax) of the receptor-ligand interaction, which are important parameters in understanding the pharmacological properties of drugs and other ligands.

Adrenergic alpha-1 receptor antagonists, also known as alpha-blockers, are a class of medications that block the effects of the neurotransmitter norepinephrine at alpha-1 receptors. These receptors are found in various tissues throughout the body, including the smooth muscle of blood vessels, the bladder, and the eye.

When norepinephrine binds to alpha-1 receptors, it causes smooth muscle to contract, leading to vasoconstriction (constriction of blood vessels), increased blood pressure, and other effects. By blocking these receptors, alpha-blockers can cause relaxation of smooth muscle, leading to vasodilation (expansion of blood vessels), decreased blood pressure, and other effects.

Alpha-blockers are used in the treatment of various medical conditions, including hypertension (high blood pressure), benign prostatic hyperplasia (enlarged prostate), and pheochromocytoma (a rare tumor of the adrenal gland). Examples of alpha-blockers include doxazosin, prazosin, and terazosin.

It's important to note that while alpha-blockers can be effective in treating certain medical conditions, they can also have side effects, such as dizziness, lightheadedness, and orthostatic hypotension (a sudden drop in blood pressure when standing up). As with any medication, it's important to use alpha-blockers under the guidance of a healthcare provider.

Serotonin 5-HT2 receptor antagonists are a class of drugs that block the action of serotonin, a neurotransmitter, at 5-HT2 receptors. These receptors are found in the central and peripheral nervous systems and are involved in various physiological functions such as mood regulation, cognition, appetite control, and vasoconstriction.

By blocking the action of serotonin at these receptors, serotonin 5-HT2 receptor antagonists can produce a range of effects depending on the specific receptor subtype that they target. For example, some serotonin 5-HT2 receptor antagonists are used to treat psychiatric disorders such as schizophrenia and depression, while others are used to treat migraines or prevent nausea and vomiting associated with chemotherapy.

Some common examples of serotonin 5-HT2 receptor antagonists include risperidone, olanzapine, and paliperidone (used for the treatment of schizophrenia), mirtazapine (used for the treatment of depression), sumatriptan (used for the treatment of migraines), and ondansetron (used to prevent nausea and vomiting).

The brain is the central organ of the nervous system, responsible for receiving and processing sensory information, regulating vital functions, and controlling behavior, movement, and cognition. It is divided into several distinct regions, each with specific functions:

1. Cerebrum: The largest part of the brain, responsible for higher cognitive functions such as thinking, learning, memory, language, and perception. It is divided into two hemispheres, each controlling the opposite side of the body.
2. Cerebellum: Located at the back of the brain, it is responsible for coordinating muscle movements, maintaining balance, and fine-tuning motor skills.
3. Brainstem: Connects the cerebrum and cerebellum to the spinal cord, controlling vital functions such as breathing, heart rate, and blood pressure. It also serves as a relay center for sensory information and motor commands between the brain and the rest of the body.
4. Diencephalon: A region that includes the thalamus (a major sensory relay station) and hypothalamus (regulates hormones, temperature, hunger, thirst, and sleep).
5. Limbic system: A group of structures involved in emotional processing, memory formation, and motivation, including the hippocampus, amygdala, and cingulate gyrus.

The brain is composed of billions of interconnected neurons that communicate through electrical and chemical signals. It is protected by the skull and surrounded by three layers of membranes called meninges, as well as cerebrospinal fluid that provides cushioning and nutrients.

Tropane alkaloids are a class of naturally occurring compounds that contain a tropane ring in their chemical structure. This ring is composed of a seven-membered ring with two nitrogen atoms, one of which is part of a piperidine ring. Tropane alkaloids are found in various plants, particularly those in the Solanaceae family, which includes nightshade, belladonna, and datura. Some well-known tropane alkaloids include atropine, scopolamine, and cocaine. These compounds have diverse pharmacological activities, such as anticholinergic, local anesthetic, and central nervous system stimulant effects.

Norepinephrine, also known as noradrenaline, is a neurotransmitter and a hormone that is primarily produced in the adrenal glands and is released into the bloodstream in response to stress or physical activity. It plays a crucial role in the "fight-or-flight" response by preparing the body for action through increasing heart rate, blood pressure, respiratory rate, and glucose availability.

As a neurotransmitter, norepinephrine is involved in regulating various functions of the nervous system, including attention, perception, motivation, and arousal. It also plays a role in modulating pain perception and responding to stressful or emotional situations.

In medical settings, norepinephrine is used as a vasopressor medication to treat hypotension (low blood pressure) that can occur during septic shock, anesthesia, or other critical illnesses. It works by constricting blood vessels and increasing heart rate, which helps to improve blood pressure and perfusion of vital organs.

Purinergic P2 receptor antagonists are pharmaceutical agents that block the activity of P2 receptors, which are a type of cell surface receptor that binds extracellular nucleotides such as ATP and ADP. These receptors play important roles in various physiological processes, including neurotransmission, inflammation, and platelet aggregation.

P2 receptors are divided into two main subfamilies: P2X and P2Y. The P2X receptors are ligand-gated ion channels that allow the flow of ions across the cell membrane upon activation, while the P2Y receptors are G protein-coupled receptors that activate intracellular signaling pathways.

Purinergic P2 receptor antagonists are used in clinical medicine to treat various conditions, such as chronic pain, urinary incontinence, and cardiovascular diseases. For example, the P2X3 receptor antagonist gefapixant is being investigated for the treatment of refractory chronic cough, while the P2Y12 receptor antagonists clopidogrel and ticagrelor are used to prevent thrombosis in patients with acute coronary syndrome.

Overall, purinergic P2 receptor antagonists offer a promising therapeutic approach for various diseases by targeting specific receptors involved in pathological processes.

The caudate nucleus is a part of the brain located within the basal ganglia, a group of structures that are important for movement control and cognition. It has a distinctive C-shaped appearance and plays a role in various functions such as learning, memory, emotion, and motivation. The caudate nucleus receives inputs from several areas of the cerebral cortex and sends outputs to other basal ganglia structures, contributing to the regulation of motor behavior and higher cognitive processes.

A drug interaction is the effect of combining two or more drugs, or a drug and another substance (such as food or alcohol), which can alter the effectiveness or side effects of one or both of the substances. These interactions can be categorized as follows:

1. Pharmacodynamic interactions: These occur when two or more drugs act on the same target organ or receptor, leading to an additive, synergistic, or antagonistic effect. For example, taking a sedative and an antihistamine together can result in increased drowsiness due to their combined depressant effects on the central nervous system.
2. Pharmacokinetic interactions: These occur when one drug affects the absorption, distribution, metabolism, or excretion of another drug. For example, taking certain antibiotics with grapefruit juice can increase the concentration of the antibiotic in the bloodstream, leading to potential toxicity.
3. Food-drug interactions: Some drugs may interact with specific foods, affecting their absorption, metabolism, or excretion. An example is the interaction between warfarin (a blood thinner) and green leafy vegetables, which can increase the risk of bleeding due to enhanced vitamin K absorption from the vegetables.
4. Drug-herb interactions: Some herbal supplements may interact with medications, leading to altered drug levels or increased side effects. For instance, St. John's Wort can decrease the effectiveness of certain antidepressants and oral contraceptives by inducing their metabolism.
5. Drug-alcohol interactions: Alcohol can interact with various medications, causing additive sedative effects, impaired judgment, or increased risk of liver damage. For example, combining alcohol with benzodiazepines or opioids can lead to dangerous levels of sedation and respiratory depression.

It is essential for healthcare providers and patients to be aware of potential drug interactions to minimize adverse effects and optimize treatment outcomes.

Alpha-Methyltyrosine (α-MT) is a synthetic amino acid that acts as an inhibitor of the enzyme tyrosine hydroxylase. This enzyme is a rate-limiting step in the biosynthesis of catecholamines, including neurotransmitters such as dopamine and norepinephrine. By inhibiting tyrosine hydroxylase, α-MT reduces the synthesis of these catecholamines, which can lead to various effects on the nervous system.

In medical contexts, α-MT has been used in research settings to study the functions of catecholamines and their role in various physiological processes. It has also been investigated as a potential treatment for certain conditions, such as hypertension and anxiety disorders, although its clinical use is not widespread due to its side effects and limited efficacy.

It's important to note that α-MT should only be used under the supervision of a medical professional, as it can have significant effects on the nervous system and may interact with other medications or health conditions.

Serotonin 5-HT3 receptor antagonists are a class of medications that work by blocking the serotonin 5-HT3 receptors, which are found in the gastrointestinal tract and the brain. These receptors play a role in regulating nausea and vomiting, among other functions.

When serotonin binds to these receptors, it can trigger a series of events that lead to nausea and vomiting, particularly in response to chemotherapy or surgery. By blocking the 5-HT3 receptors, serotonin cannot bind to them and therefore cannot trigger these events, which helps to reduce nausea and vomiting.

Examples of 5-HT3 receptor antagonists include ondansetron (Zofran), granisetron (Kytril), palonosetron (Aloxi), and dolasetron (Anzemet). These medications are commonly used to prevent and treat nausea and vomiting associated with chemotherapy, radiation therapy, and surgery.

Pyrrolidines are not a medical term per se, but they are a chemical compound that can be encountered in the field of medicine and pharmacology. Pyrrolidine is an organic compound with the molecular formula (CH2)4NH. It is a cyclic secondary amine, which means it contains a nitrogen atom surrounded by four carbon atoms in a ring structure.

Pyrrolidines can be found in certain natural substances and are also synthesized for use in pharmaceuticals and research. They have been used as building blocks in the synthesis of various drugs, including some muscle relaxants, antipsychotics, and antihistamines. Additionally, pyrrolidine derivatives can be found in certain plants and fungi, where they may contribute to biological activity or toxicity.

It is important to note that while pyrrolidines themselves are not a medical condition or diagnosis, understanding their chemical properties and uses can be relevant to the study and development of medications.

Piperazines are a class of heterocyclic organic compounds that contain a seven-membered ring with two nitrogen atoms at positions 1 and 4. They have the molecular formula N-NRR' where R and R' can be alkyl or aryl groups. Piperazines have a wide range of uses in pharmaceuticals, agrochemicals, and as building blocks in organic synthesis.

In a medical context, piperazines are used in the manufacture of various drugs, including some antipsychotics, antidepressants, antihistamines, and anti-worm medications. For example, the antipsychotic drug trifluoperazine and the antidepressant drug nefazodone both contain a piperazine ring in their chemical structure.

However, it's important to note that some piperazines are also used as recreational drugs due to their stimulant and euphoric effects. These include compounds such as BZP (benzylpiperazine) and TFMPP (trifluoromethylphenylpiperazine), which have been linked to serious health risks, including addiction, seizures, and death. Therefore, the use of these substances should be avoided.

Adrenergic alpha-antagonists, also known as alpha-blockers, are a class of medications that block the effects of adrenaline and noradrenaline at alpha-adrenergic receptors. These receptors are found in various tissues throughout the body, including the smooth muscle of blood vessels, the heart, the genitourinary system, and the eyes.

When alpha-blockers bind to these receptors, they prevent the activation of the sympathetic nervous system, which is responsible for the "fight or flight" response. This results in a relaxation of the smooth muscle, leading to vasodilation (widening of blood vessels), decreased blood pressure, and increased blood flow.

Alpha-blockers are used to treat various medical conditions, such as hypertension (high blood pressure), benign prostatic hyperplasia (enlarged prostate), pheochromocytoma (a rare tumor of the adrenal gland), and certain types of glaucoma.

Examples of alpha-blockers include doxazosin, prazosin, terazosin, and tamsulosin. Side effects of alpha-blockers may include dizziness, lightheadedness, headache, weakness, and orthostatic hypotension (a sudden drop in blood pressure upon standing).

Adrenergic alpha-2 receptor antagonists are a class of medications that block the action of norepinephrine, a neurotransmitter and hormone, at adrenergic alpha-2 receptors. These receptors are found in the central and peripheral nervous system and play a role in regulating various physiological functions such as blood pressure, heart rate, and insulin secretion.

By blocking the action of norepinephrine at these receptors, adrenergic alpha-2 receptor antagonists can increase sympathetic nervous system activity, leading to vasodilation, increased heart rate, and increased insulin secretion. These effects make them useful in the treatment of conditions such as hypotension (low blood pressure), opioid-induced sedation and respiratory depression, and diagnostic procedures that require vasodilation.

Examples of adrenergic alpha-2 receptor antagonists include yohimbine, idazoxan, and atipamezole. It's important to note that these medications can have significant side effects, including hypertension, tachycardia, and agitation, and should be used under the close supervision of a healthcare provider.

Nomifensine is a medication that was previously used in the treatment of depression, but it is no longer available in many countries due to safety concerns. It is a non-tricyclic antidepressant that works by inhibiting the reuptake of dopamine and noradrenaline, which helps to increase the levels of these neurotransmitters in the brain and improve mood.

The medical definition of Nomifensine is:

"Nomifensine is a non-tricyclic antidepressant that is a potent inhibitor of dopamine and noradrenaline reuptake, with minimal effects on serotonin reuptake. It was used in the treatment of depression but has been withdrawn from the market due to safety concerns."

It's important to note that Nomifensine should only be taken under the supervision of a medical professional, and it is not available in many countries due to its potential for causing serious side effects such as liver toxicity and the risk of developing a rare but potentially fatal condition called hemolytic anemia.

In the context of medicine, particularly in behavioral neuroscience and psychology, "reward" is not typically used as a definitive medical term. However, it generally refers to a positive outcome or incentive that reinforces certain behaviors, making them more likely to be repeated in the future. This can involve various stimuli such as food, water, sexual activity, social interaction, or drug use, among others.

In the brain, rewards are associated with the activation of the reward system, primarily the mesolimbic dopamine pathway, which includes the ventral tegmental area (VTA) and the nucleus accumbens (NAcc). The release of dopamine in these areas is thought to reinforce and motivate behavior linked to rewards.

It's important to note that while "reward" has a specific meaning in this context, it is not a formal medical diagnosis or condition. Instead, it is a concept used to understand the neural and psychological mechanisms underlying motivation, learning, and addiction.

Adenosine A1 receptor antagonists are a class of pharmaceutical compounds that block the action of adenosine at A1 receptors. Adenosine is a naturally occurring purine nucleoside that acts as a neurotransmitter and modulator of various physiological processes, including cardiovascular function, neuronal excitability, and immune response.

Adenosine exerts its effects by binding to specific receptors on the surface of cells, including A1, A2A, A2B, and A3 receptors. The activation of A1 receptors leads to a variety of physiological responses, such as vasodilation, negative chronotropy (slowing of heart rate), and negative inotropy (reduced contractility) of the heart, as well as inhibition of neurotransmitter release in the brain.

Adenosine A1 receptor antagonists work by binding to and blocking the action of adenosine at A1 receptors, thereby preventing or reducing its effects on these physiological processes. These drugs have been investigated for their potential therapeutic uses in various conditions, such as heart failure, cardiac arrest, and neurological disorders.

Examples of adenosine A1 receptor antagonists include:

* Dipyridamole: a vasodilator used to treat peripheral arterial disease and to prevent blood clots.
* Caffeine: a natural stimulant found in coffee, tea, and chocolate, which acts as a weak A1 receptor antagonist.
* Rolofylline: an experimental drug that has been investigated for its potential use in treating acute ischemic stroke and traumatic brain injury.
* KW-3902: another experimental drug that has been studied for its potential therapeutic effects in heart failure, cardiac arrest, and neurodegenerative disorders.

It's important to note that adenosine A1 receptor antagonists may have side effects and potential risks, and their use should be monitored and managed by healthcare professionals.

Serotonin receptors are a type of cell surface receptor that bind to the neurotransmitter serotonin (5-hydroxytryptamine, 5-HT). They are widely distributed throughout the body, including the central and peripheral nervous systems, where they play important roles in regulating various physiological processes such as mood, appetite, sleep, memory, learning, and cognition.

There are seven different classes of serotonin receptors (5-HT1 to 5-HT7), each with multiple subtypes, that exhibit distinct pharmacological properties and signaling mechanisms. These receptors are G protein-coupled receptors (GPCRs) or ligand-gated ion channels, which activate intracellular signaling pathways upon serotonin binding.

Serotonin receptors have been implicated in various neurological and psychiatric disorders, including depression, anxiety, schizophrenia, and migraine. Therefore, selective serotonin receptor agonists or antagonists are used as therapeutic agents for the treatment of these conditions.

N-Methyl-D-Aspartate (NMDA) receptors are a type of ionotropic glutamate receptor, which are found in the membranes of excitatory neurons in the central nervous system. They play a crucial role in synaptic plasticity, learning, and memory processes. NMDA receptors are ligand-gated channels that are permeable to calcium ions (Ca2+) and other cations.

NMDA receptors are composed of four subunits, which can be a combination of NR1, NR2A-D, and NR3A-B subunits. The binding of the neurotransmitter glutamate to the NR2 subunit and glycine to the NR1 subunit leads to the opening of the ion channel and the influx of Ca2+ ions.

NMDA receptors have a unique property in that they require both agonist binding and membrane depolarization for full activation, making them sensitive to changes in the electrical activity of the neuron. This property allows NMDA receptors to act as coincidence detectors, playing a critical role in synaptic plasticity and learning.

Abnormal functioning of NMDA receptors has been implicated in various neurological disorders, including Alzheimer's disease, Parkinson's disease, epilepsy, and chronic pain. Therefore, NMDA receptors are a common target for drug development in the treatment of these conditions.

"Competitive binding" is a term used in pharmacology and biochemistry to describe the behavior of two or more molecules (ligands) competing for the same binding site on a target protein or receptor. In this context, "binding" refers to the physical interaction between a ligand and its target.

When a ligand binds to a receptor, it can alter the receptor's function, either activating or inhibiting it. If multiple ligands compete for the same binding site, they will compete to bind to the receptor. The ability of each ligand to bind to the receptor is influenced by its affinity for the receptor, which is a measure of how strongly and specifically the ligand binds to the receptor.

In competitive binding, if one ligand is present in high concentrations, it can prevent other ligands with lower affinity from binding to the receptor. This is because the higher-affinity ligand will have a greater probability of occupying the binding site and blocking access to the other ligands. The competition between ligands can be described mathematically using equations such as the Langmuir isotherm, which describes the relationship between the concentration of ligand and the fraction of receptors that are occupied by the ligand.

Competitive binding is an important concept in drug development, as it can be used to predict how different drugs will interact with their targets and how they may affect each other's activity. By understanding the competitive binding properties of a drug, researchers can optimize its dosage and delivery to maximize its therapeutic effect while minimizing unwanted side effects.

Dihydroxyphenylalanine is not a medical term per se, but it is a chemical compound that is often referred to in the context of biochemistry and neuroscience. It is also known as levodopa or L-DOPA for short.

L-DOPA is a precursor to dopamine, a neurotransmitter that plays a critical role in regulating movement, emotion, and cognition. In the brain, L-DOPA is converted into dopamine through the action of an enzyme called tyrosine hydroxylase.

L-DOPA is used medically to treat Parkinson's disease, a neurological disorder characterized by motor symptoms such as tremors, rigidity, and bradykinesia (slowness of movement). In Parkinson's disease, the dopamine-producing neurons in the brain gradually degenerate, leading to a deficiency of dopamine. By providing L-DOPA as a replacement therapy, doctors can help alleviate some of the symptoms of the disease.

It is important to note that L-DOPA has potential side effects and risks, including nausea, dizziness, and behavioral changes. Long-term use of L-DOPA can also lead to motor complications such as dyskinesias (involuntary movements) and fluctuations in response to the medication. Therefore, it is typically used in combination with other medications and under the close supervision of a healthcare provider.

Synaptic transmission is the process by which a neuron communicates with another cell, such as another neuron or a muscle cell, across a junction called a synapse. It involves the release of neurotransmitters from the presynaptic terminal of the neuron, which then cross the synaptic cleft and bind to receptors on the postsynaptic cell, leading to changes in the electrical or chemical properties of the target cell. This process is critical for the transmission of signals within the nervous system and for controlling various physiological functions in the body.

Electric stimulation, also known as electrical nerve stimulation or neuromuscular electrical stimulation, is a therapeutic treatment that uses low-voltage electrical currents to stimulate nerves and muscles. It is often used to help manage pain, promote healing, and improve muscle strength and mobility. The electrical impulses can be delivered through electrodes placed on the skin or directly implanted into the body.

In a medical context, electric stimulation may be used for various purposes such as:

1. Pain management: Electric stimulation can help to block pain signals from reaching the brain and promote the release of endorphins, which are natural painkillers produced by the body.
2. Muscle rehabilitation: Electric stimulation can help to strengthen muscles that have become weak due to injury, illness, or surgery. It can also help to prevent muscle atrophy and improve range of motion.
3. Wound healing: Electric stimulation can promote tissue growth and help to speed up the healing process in wounds, ulcers, and other types of injuries.
4. Urinary incontinence: Electric stimulation can be used to strengthen the muscles that control urination and reduce symptoms of urinary incontinence.
5. Migraine prevention: Electric stimulation can be used as a preventive treatment for migraines by applying electrical impulses to specific nerves in the head and neck.

It is important to note that electric stimulation should only be administered under the guidance of a qualified healthcare professional, as improper use can cause harm or discomfort.

In the field of medicine, "time factors" refer to the duration of symptoms or time elapsed since the onset of a medical condition, which can have significant implications for diagnosis and treatment. Understanding time factors is crucial in determining the progression of a disease, evaluating the effectiveness of treatments, and making critical decisions regarding patient care.

For example, in stroke management, "time is brain," meaning that rapid intervention within a specific time frame (usually within 4.5 hours) is essential to administering tissue plasminogen activator (tPA), a clot-busting drug that can minimize brain damage and improve patient outcomes. Similarly, in trauma care, the "golden hour" concept emphasizes the importance of providing definitive care within the first 60 minutes after injury to increase survival rates and reduce morbidity.

Time factors also play a role in monitoring the progression of chronic conditions like diabetes or heart disease, where regular follow-ups and assessments help determine appropriate treatment adjustments and prevent complications. In infectious diseases, time factors are crucial for initiating antibiotic therapy and identifying potential outbreaks to control their spread.

Overall, "time factors" encompass the significance of recognizing and acting promptly in various medical scenarios to optimize patient outcomes and provide effective care.

Adrenergic antagonists, also known as beta blockers or sympatholytic drugs, are a class of medications that block the effects of adrenaline and noradrenaline (also known as epinephrine and norepinephrine) on the body. These neurotransmitters are part of the sympathetic nervous system and play a role in the "fight or flight" response, increasing heart rate, blood pressure, and respiratory rate.

Adrenergic antagonists work by binding to beta-adrenergic receptors in the body, preventing the neurotransmitters from activating them. This results in a decrease in heart rate, blood pressure, and respiratory rate. These medications are used to treat various conditions such as hypertension, angina, heart failure, arrhythmias, glaucoma, and anxiety disorders.

There are two types of adrenergic antagonists: beta blockers and alpha blockers. Beta blockers selectively bind to beta-adrenergic receptors, while alpha blockers bind to alpha-adrenergic receptors. Some medications, such as labetalol, have both beta and alpha blocking properties.

It is important to note that adrenergic antagonists can interact with other medications and may cause side effects, so it is essential to use them under the guidance of a healthcare professional.

Methamphetamine is a powerful, highly addictive central nervous system stimulant that affects brain chemistry, leading to mental and physical dependence. Its chemical formula is N-methylamphetamine, and it is structurally similar to amphetamine but has additional methyl group, which makes it more potent and longer-lasting.

Methamphetamine exists in various forms, including crystalline powder (commonly called "meth" or "crystal meth") and a rocklike form called "glass." It can be taken orally, snorted, smoked, or injected after being dissolved in water or alcohol.

Methamphetamine use leads to increased levels of dopamine, a neurotransmitter responsible for reward, motivation, and reinforcement, resulting in euphoria, alertness, and energy. Prolonged use can cause severe psychological and physiological harm, including addiction, psychosis, cardiovascular issues, dental problems (meth mouth), and cognitive impairments.

GABA-A receptor antagonists are pharmacological agents that block the action of gamma-aminobutyric acid (GABA) at GABA-A receptors. GABA is the primary inhibitory neurotransmitter in the central nervous system, and it exerts its effects by binding to GABA-A receptors, which are ligand-gated chloride channels. When GABA binds to these receptors, it opens the chloride channel, leading to an influx of chloride ions into the neuron and hyperpolarization of the membrane, making it less likely to fire.

GABA-A receptor antagonists work by binding to the GABA-A receptor and preventing GABA from binding, thereby blocking the inhibitory effects of GABA. This can lead to increased neuronal excitability and can result in a variety of effects depending on the specific antagonist and the location of the receptors involved.

GABA-A receptor antagonists have been used in research to study the role of GABA in various physiological processes, and some have been investigated as potential therapeutic agents for conditions such as anxiety, depression, and insomnia. However, their use is limited by their potential to cause seizures and other adverse effects due to excessive neuronal excitation. Examples of GABA-A receptor antagonists include picrotoxin, bicuculline, and flumazenil.

Leukotriene antagonists are a class of medications that work by blocking the action of leukotrienes, which are chemicals released by the immune system in response to an allergen or irritant. Leukotrienes cause airway muscles to tighten and inflammation in the airways, leading to symptoms such as wheezing, shortness of breath, and coughing. By blocking the action of leukotrienes, leukotriene antagonists can help relieve these symptoms and improve lung function. These medications are often used to treat asthma and allergic rhinitis (hay fever). Examples of leukotriene antagonists include montelukast, zafirlukast, and pranlukast.

Angiotensin receptor antagonists (ARAs), also known as angiotensin II receptor blockers (ARBs), are a class of medications used to treat hypertension, heart failure, and protect against kidney damage in patients with diabetes. They work by blocking the action of angiotensin II, a potent vasoconstrictor and hormone that increases blood pressure and promotes tissue fibrosis. By blocking the binding of angiotensin II to its receptors, ARAs cause relaxation of blood vessels, decreased sodium and water retention, and reduced cardiac remodeling, ultimately leading to improved cardiovascular function and reduced risk of organ damage. Examples of ARAs include losartan, valsartan, irbesartan, and candesartan.

Vesicular Monoamine Transporter Proteins (VMATs) are a type of transmembrane protein that play a crucial role in the packaging and transport of monoamines, such as serotonin, dopamine, and norepinephrine, into synaptic vesicles within neurons. There are two main isoforms of VMATs, VMAT1 and VMAT2, which differ in their distribution and function.

VMAT1 (also known as SLC18A1) is primarily found in neuroendocrine cells and is responsible for transporting monoamines into large dense-core vesicles. VMAT2 (also known as SLC18A2), on the other hand, is mainly expressed in presynaptic neurons and is involved in the transport of monoamines into small synaptic vesicles.

Both VMAT1 and VMAT2 are integral membrane proteins that utilize a proton gradient to drive the uptake of monoamines against their concentration gradient, allowing for their storage and subsequent release during neurotransmission. Dysregulation of VMAT function has been implicated in several neurological and psychiatric disorders, including Parkinson's disease and depression.

Biogenic monoamines are a type of neurotransmitter, which are chemical messengers that transmit signals in the brain and other parts of the nervous system. They are called "biogenic" because they are derived from biological substances, and "monoamines" because they contain one amine group (-NH2) and are derived from the aromatic amino acids: tryptophan, tyrosine, and phenylalanine.

Examples of biogenic monoamines include:

1. Serotonin (5-hydroxytryptamine or 5-HT): synthesized from the amino acid tryptophan and plays a crucial role in regulating mood, appetite, sleep, memory, and learning.
2. Dopamine: formed from tyrosine and is involved in reward, motivation, motor control, and reinforcement of behavior.
3. Norepinephrine (noradrenaline): also derived from tyrosine and functions as a neurotransmitter and hormone that modulates attention, arousal, and stress responses.
4. Epinephrine (adrenaline): synthesized from norepinephrine and serves as a crucial hormone and neurotransmitter in the body's fight-or-flight response to stress or danger.
5. Histamine: produced from the amino acid histidine, it acts as a neurotransmitter and mediates allergic reactions, immune responses, and regulates wakefulness and appetite.

Imbalances in biogenic monoamines have been linked to various neurological and psychiatric disorders, such as depression, anxiety, Parkinson's disease, and schizophrenia. Therefore, medications that target these neurotransmitters, like selective serotonin reuptake inhibitors (SSRIs) for depression or levodopa for Parkinson's disease, are often used in the treatment of these conditions.

The putamen is a round, egg-shaped structure that is a part of the basal ganglia, located in the forebrain. It is situated laterally to the globus pallidus and medially to the internal capsule. The putamen plays a crucial role in regulating movement and is involved in various functions such as learning, motivation, and habit formation.

It receives input from the cerebral cortex via the corticostriatal pathway and sends output to the globus pallidus and substantia nigra pars reticulata, which are also part of the basal ganglia circuitry. The putamen is heavily innervated by dopaminergic neurons from the substantia nigra pars compacta, and degeneration of these neurons in Parkinson's disease leads to a significant reduction in dopamine levels in the putamen, resulting in motor dysfunction.

Dizocilpine maleate is a chemical compound that is commonly known as an N-methyl-D-aspartate (NMDA) receptor antagonist. It is primarily used in research settings to study the role of NMDA receptors in various physiological processes, including learning and memory.

The chemical formula for dizocilpine maleate is C16H24Cl2N2O4·C4H4O4. The compound is a white crystalline powder that is soluble in water and alcohol. It has potent psychoactive effects and has been investigated as a potential treatment for various neurological and psychiatric disorders, although it has not been approved for clinical use.

Dizocilpine maleate works by blocking the action of glutamate, a neurotransmitter that plays a key role in learning and memory, at NMDA receptors in the brain. By doing so, it can alter various cognitive processes and has been shown to have anticonvulsant, analgesic, and neuroprotective effects in animal studies. However, its use is associated with significant side effects, including hallucinations, delusions, and memory impairment, which have limited its development as a therapeutic agent.

Analysis of Variance (ANOVA) is a statistical technique used to compare the means of two or more groups and determine whether there are any significant differences between them. It is a way to analyze the variance in a dataset to determine whether the variability between groups is greater than the variability within groups, which can indicate that the groups are significantly different from one another.

ANOVA is based on the concept of partitioning the total variance in a dataset into two components: variance due to differences between group means (also known as "between-group variance") and variance due to differences within each group (also known as "within-group variance"). By comparing these two sources of variance, ANOVA can help researchers determine whether any observed differences between groups are statistically significant, or whether they could have occurred by chance.

ANOVA is a widely used technique in many areas of research, including biology, psychology, engineering, and business. It is often used to compare the means of two or more experimental groups, such as a treatment group and a control group, to determine whether the treatment had a significant effect. ANOVA can also be used to compare the means of different populations or subgroups within a population, to identify any differences that may exist between them.

Tetrahydronaphthalenes are organic compounds that consist of a naphthalene ring with two hydrogens replaced by saturated carbon chains. It is a polycyclic aromatic hydrocarbon (PAH) with a chemical formula C10H12. Tetrahydronaphthalenes can be found in various natural sources, including coal tar and some essential oils. They also have potential applications in the synthesis of pharmaceuticals and other organic compounds.

The prefrontal cortex is the anterior (frontal) part of the frontal lobe in the brain, involved in higher-order cognitive processes such as planning complex cognitive behavior, personality expression, decision making, and moderating social behavior. It also plays a significant role in working memory and executive functions. The prefrontal cortex is divided into several subregions, each associated with specific cognitive and emotional functions. Damage to the prefrontal cortex can result in various impairments, including difficulties with planning, decision making, and social behavior regulation.

"Cells, cultured" is a medical term that refers to cells that have been removed from an organism and grown in controlled laboratory conditions outside of the body. This process is called cell culture and it allows scientists to study cells in a more controlled and accessible environment than they would have inside the body. Cultured cells can be derived from a variety of sources, including tissues, organs, or fluids from humans, animals, or cell lines that have been previously established in the laboratory.

Cell culture involves several steps, including isolation of the cells from the tissue, purification and characterization of the cells, and maintenance of the cells in appropriate growth conditions. The cells are typically grown in specialized media that contain nutrients, growth factors, and other components necessary for their survival and proliferation. Cultured cells can be used for a variety of purposes, including basic research, drug development and testing, and production of biological products such as vaccines and gene therapies.

It is important to note that cultured cells may behave differently than they do in the body, and results obtained from cell culture studies may not always translate directly to human physiology or disease. Therefore, it is essential to validate findings from cell culture experiments using additional models and ultimately in clinical trials involving human subjects.

Histamine H3 antagonists, also known as inverse agonists, are a class of drugs that block the activity of histamine at the H3 receptor. Histamine is a naturally occurring neurotransmitter and autacoid involved in various physiological functions, including the modulation of wakefulness and arousal, regulation of food intake, and control of blood pressure and fluid balance.

The H3 receptor is primarily located in the central nervous system (CNS) and acts as an auto-receptor on histamine-containing neurons to regulate the release of histamine. By blocking the activity of these receptors, histamine H3 antagonists increase the release of histamine in the CNS, which can lead to increased wakefulness and arousal.

Histamine H3 antagonists have been studied for their potential therapeutic use in various neurological and psychiatric disorders, including narcolepsy, attention deficit hyperactivity disorder (ADHD), and Alzheimer's disease. However, further research is needed to fully understand the clinical benefits and safety of these drugs.

Self-administration, in the context of medicine and healthcare, refers to the act of an individual administering medication or treatment to themselves. This can include various forms of delivery such as oral medications, injections, or topical treatments. It is important that individuals who self-administer are properly trained and understand the correct dosage, timing, and technique to ensure safety and effectiveness. Self-administration promotes independence, allows for timely treatment, and can improve overall health outcomes.

Glutamic acid is an alpha-amino acid, which is one of the 20 standard amino acids in the genetic code. The systematic name for this amino acid is (2S)-2-Aminopentanedioic acid. Its chemical formula is HO2CCH(NH2)CH2CH2CO2H.

Glutamic acid is a crucial excitatory neurotransmitter in the human brain, and it plays an essential role in learning and memory. It's also involved in the metabolism of sugars and amino acids, the synthesis of proteins, and the removal of waste nitrogen from the body.

Glutamic acid can be found in various foods such as meat, fish, beans, eggs, dairy products, and vegetables. In the human body, glutamic acid can be converted into gamma-aminobutyric acid (GABA), another important neurotransmitter that has a calming effect on the nervous system.

Catecholamines are a group of hormones and neurotransmitters that are derived from the amino acid tyrosine. The most well-known catecholamines are dopamine, norepinephrine (also known as noradrenaline), and epinephrine (also known as adrenaline). These hormones are produced by the adrenal glands and are released into the bloodstream in response to stress. They play important roles in the "fight or flight" response, increasing heart rate, blood pressure, and alertness. In addition to their role as hormones, catecholamines also function as neurotransmitters, transmitting signals in the nervous system. Disorders of catecholamine regulation can lead to a variety of medical conditions, including hypertension, mood disorders, and neurological disorders.

Serotonin receptor agonists are a class of medications that bind to and activate serotonin receptors in the body, mimicking the effects of the neurotransmitter serotonin. These drugs can have various effects depending on which specific serotonin receptors they act upon. Some serotonin receptor agonists are used to treat conditions such as migraines, cluster headaches, and Parkinson's disease, while others may be used to stimulate appetite or reduce anxiety. It is important to note that some serotonin receptor agonists can have serious side effects, particularly when taken in combination with other medications that affect serotonin levels, such as selective serotonin reuptake inhibitors (SSRIs) or monoamine oxidase inhibitors (MAOIs). This can lead to a condition called serotonin syndrome, which is characterized by symptoms such as agitation, confusion, rapid heart rate, high blood pressure, and muscle stiffness.

Central nervous system (CNS) stimulants are a class of drugs that increase alertness, attention, energy, and/or mood by directly acting on the brain. They can be prescribed to treat medical conditions such as narcolepsy, attention deficit hyperactivity disorder (ADHD), and depression that has not responded to other treatments.

Examples of CNS stimulants include amphetamine (Adderall), methylphenidate (Ritalin, Concerta), and modafinil (Provigil). These medications work by increasing the levels of certain neurotransmitters, such as dopamine and norepinephrine, in the brain.

In addition to their therapeutic uses, CNS stimulants are also sometimes misused for non-medical reasons, such as to enhance cognitive performance or to get high. However, it's important to note that misusing these drugs can lead to serious health consequences, including addiction, cardiovascular problems, and mental health issues.

Signal transduction is the process by which a cell converts an extracellular signal, such as a hormone or neurotransmitter, into an intracellular response. This involves a series of molecular events that transmit the signal from the cell surface to the interior of the cell, ultimately resulting in changes in gene expression, protein activity, or metabolism.

The process typically begins with the binding of the extracellular signal to a receptor located on the cell membrane. This binding event activates the receptor, which then triggers a cascade of intracellular signaling molecules, such as second messengers, protein kinases, and ion channels. These molecules amplify and propagate the signal, ultimately leading to the activation or inhibition of specific cellular responses.

Signal transduction pathways are highly regulated and can be modulated by various factors, including other signaling molecules, post-translational modifications, and feedback mechanisms. Dysregulation of these pathways has been implicated in a variety of diseases, including cancer, diabetes, and neurological disorders.

I'm sorry for any confusion, but "Pyridines" is not a medical term. It is a chemical term that refers to a class of organic compounds with the chemical structure of a six-membered ring containing one nitrogen atom and five carbon atoms (heterocyclic aromatic compound).

In a biological or medical context, pyridine derivatives can be found in various natural and synthetic substances. For example, some medications contain pyridine rings as part of their chemical structure. However, "Pyridines" itself is not a medical term or condition.

Catalepsy is a medical condition characterized by a trance-like state, with reduced sensitivity to pain and external stimuli, muscular rigidity, and fixed postures. In this state, the person's body may maintain any position in which it is placed for a long time, and there is often a decreased responsiveness to social cues or communication attempts.

Catalepsy can be a symptom of various medical conditions, including neurological disorders such as epilepsy, Parkinson's disease, or brain injuries. It can also occur in the context of mental health disorders, such as severe depression, catatonic schizophrenia, or dissociative identity disorder.

In some cases, catalepsy may be induced intentionally through hypnosis or other forms of altered consciousness practices. However, when it occurs spontaneously or as a symptom of an underlying medical condition, it can be a serious concern and requires medical evaluation and treatment.

Operant conditioning is a type of learning in which behavior is modified by its consequences, either reinforcing or punishing the behavior. It was first described by B.F. Skinner and involves an association between a response (behavior) and a consequence (either reward or punishment). There are two types of operant conditioning: positive reinforcement, in which a desirable consequence follows a desired behavior, increasing the likelihood that the behavior will occur again; and negative reinforcement, in which a undesirable consequence is removed following a desired behavior, also increasing the likelihood that the behavior will occur again.

For example, if a child cleans their room (response) and their parent gives them praise or a treat (positive reinforcement), the child is more likely to clean their room again in the future. If a child is buckling their seatbelt in the car (response) and the annoying buzzer stops (negative reinforcement), the child is more likely to buckle their seatbelt in the future.

It's important to note that operant conditioning is a form of learning, not motivation. The behavior is modified by its consequences, regardless of the individual's internal state or intentions.

C57BL/6 (C57 Black 6) is an inbred strain of laboratory mouse that is widely used in biomedical research. The term "inbred" refers to a strain of animals where matings have been carried out between siblings or other closely related individuals for many generations, resulting in a population that is highly homozygous at most genetic loci.

The C57BL/6 strain was established in 1920 by crossing a female mouse from the dilute brown (DBA) strain with a male mouse from the black strain. The resulting offspring were then interbred for many generations to create the inbred C57BL/6 strain.

C57BL/6 mice are known for their robust health, longevity, and ease of handling, making them a popular choice for researchers. They have been used in a wide range of biomedical research areas, including studies of cancer, immunology, neuroscience, cardiovascular disease, and metabolism.

One of the most notable features of the C57BL/6 strain is its sensitivity to certain genetic modifications, such as the introduction of mutations that lead to obesity or impaired glucose tolerance. This has made it a valuable tool for studying the genetic basis of complex diseases and traits.

Overall, the C57BL/6 inbred mouse strain is an important model organism in biomedical research, providing a valuable resource for understanding the genetic and molecular mechanisms underlying human health and disease.

I must clarify that the term "Guinea Pigs" is not typically used in medical definitions. However, in colloquial or informal language, it may refer to people who are used as the first to try out a new medical treatment or drug. This is known as being a "test subject" or "in a clinical trial."

In the field of scientific research, particularly in studies involving animals, guinea pigs are small rodents that are often used as experimental subjects due to their size, cost-effectiveness, and ease of handling. They are not actually pigs from Guinea, despite their name's origins being unclear. However, they do not exactly fit the description of being used in human medical experiments.

Animal disease models are specialized animals, typically rodents such as mice or rats, that have been genetically engineered or exposed to certain conditions to develop symptoms and physiological changes similar to those seen in human diseases. These models are used in medical research to study the pathophysiology of diseases, identify potential therapeutic targets, test drug efficacy and safety, and understand disease mechanisms.

The genetic modifications can include knockout or knock-in mutations, transgenic expression of specific genes, or RNA interference techniques. The animals may also be exposed to environmental factors such as chemicals, radiation, or infectious agents to induce the disease state.

Examples of animal disease models include:

1. Mouse models of cancer: Genetically engineered mice that develop various types of tumors, allowing researchers to study cancer initiation, progression, and metastasis.
2. Alzheimer's disease models: Transgenic mice expressing mutant human genes associated with Alzheimer's disease, which exhibit amyloid plaque formation and cognitive decline.
3. Diabetes models: Obese and diabetic mouse strains like the NOD (non-obese diabetic) or db/db mice, used to study the development of type 1 and type 2 diabetes, respectively.
4. Cardiovascular disease models: Atherosclerosis-prone mice, such as ApoE-deficient or LDLR-deficient mice, that develop plaque buildup in their arteries when fed a high-fat diet.
5. Inflammatory bowel disease models: Mice with genetic mutations affecting intestinal barrier function and immune response, such as IL-10 knockout or SAMP1/YitFc mice, which develop colitis.

Animal disease models are essential tools in preclinical research, but it is important to recognize their limitations. Differences between species can affect the translatability of results from animal studies to human patients. Therefore, researchers must carefully consider the choice of model and interpret findings cautiously when applying them to human diseases.

Calcium channel blockers (CCBs) are a class of medications that work by inhibiting the influx of calcium ions into cardiac and smooth muscle cells. This action leads to relaxation of the muscles, particularly in the blood vessels, resulting in decreased peripheral resistance and reduced blood pressure. Calcium channel blockers also have anti-arrhythmic effects and are used in the management of various cardiovascular conditions such as hypertension, angina, and certain types of arrhythmias.

Calcium channel blockers can be further classified into two main categories based on their chemical structure: dihydropyridines (e.g., nifedipine, amlodipine) and non-dihydropyridines (e.g., verapamil, diltiazem). Dihydropyridines are more selective for vascular smooth muscle and have a greater effect on blood pressure than heart rate or conduction. Non-dihydropyridines have a more significant impact on cardiac conduction and contractility, in addition to their vasodilatory effects.

It is important to note that calcium channel blockers may interact with other medications and should be used under the guidance of a healthcare professional. Potential side effects include dizziness, headache, constipation, and peripheral edema.

Serotonin 5-HT1 receptor antagonists are a class of pharmaceutical drugs that block the activation of serotonin 5-HT1 receptors. Serotonin, also known as 5-hydroxytryptamine (5-HT), is a neurotransmitter that plays a role in various physiological functions, including mood regulation, appetite control, and sensory perception. The 5-HT1 receptor family includes several subtypes (5-HT1A, 5-HT1B, 5-HT1D, 5-HT1E, and 5-HT1F) that are widely distributed throughout the central and peripheral nervous systems.

When serotonin binds to these receptors, it triggers a series of intracellular signaling events that can have excitatory or inhibitory effects on neuronal activity. By blocking the interaction between serotonin and 5-HT1 receptors, antagonists modulate the downstream consequences of receptor activation.

Serotonin 5-HT1 receptor antagonists are used in various clinical contexts to treat or manage a range of conditions:

1. Migraine prevention: Some 5-HT1B/1D receptor antagonists, such as sumatriptan and rizatriptan, are highly effective in aborting migraine attacks by constricting dilated cranial blood vessels and reducing the release of pro-inflammatory neuropeptides.
2. Nausea and vomiting: Certain 5-HT3 receptor antagonists, like ondansetron and granisetron, are used to prevent chemotherapy-induced nausea and vomiting by blocking the activation of emetic circuits in the brainstem.
3. Psychiatric disorders: Although not widely used, some 5-HT1A receptor antagonists have shown promise in treating depression and anxiety disorders due to their ability to modulate serotonergic neurotransmission.
4. Neuroprotection: Preclinical studies suggest that 5-HT1A receptor agonists may have neuroprotective effects in various neurological conditions, such as Parkinson's disease and stroke. However, further research is needed to establish their clinical utility.

In summary, serotonin 5-HT1 receptor antagonists are a diverse group of medications with applications in migraine prevention, nausea and vomiting management, psychiatric disorders, and potential neuroprotection. Their unique pharmacological profiles enable them to target specific pathophysiological mechanisms underlying various conditions, making them valuable tools in modern therapeutics.

Reserpine is an alkaloid derived from the Rauwolfia serpentina plant, which has been used in traditional medicine for its sedative and hypotensive effects. In modern medicine, reserpine is primarily used to treat hypertension (high blood pressure) due to its ability to lower both systolic and diastolic blood pressure.

Reserpine works by depleting catecholamines, including norepinephrine, epinephrine, and dopamine, from nerve terminals in the sympathetic nervous system. This leads to a decrease in peripheral vascular resistance and heart rate, ultimately resulting in reduced blood pressure.

Reserpine is available in various forms, such as tablets or capsules, and is typically administered orally. Common side effects include nasal congestion, dizziness, sedation, and gastrointestinal disturbances like diarrhea and nausea. Long-term use of reserpine may also lead to depression in some individuals. Due to its potential for causing depression, other antihypertensive medications are often preferred over reserpine when possible.

Stereotyped behavior, in the context of medicine and psychology, refers to repetitive, rigid, and invariant patterns of behavior or movements that are purposeless and often non-functional. These behaviors are not goal-directed or spontaneous and typically do not change in response to environmental changes or social interactions.

Stereotypies can include a wide range of motor behaviors such as hand flapping, rocking, head banging, body spinning, self-biting, or complex sequences of movements. They are often seen in individuals with developmental disabilities, intellectual disabilities, autism spectrum disorder, and some mental health conditions.

Stereotyped behaviors can also be a result of substance abuse, neurological disorders, or brain injuries. In some cases, these behaviors may serve as a self-soothing mechanism or a way to cope with stress, anxiety, or boredom. However, they can also interfere with daily functioning and social interactions, and in severe cases, may cause physical harm to the individual.

Naloxone is a medication used to reverse the effects of opioids, both illicit and prescription. It works by blocking the action of opioids on the brain and restoring breathing in cases where opioids have caused depressed respirations. Common brand names for naloxone include Narcan and Evzio.

Naloxone is an opioid antagonist, meaning that it binds to opioid receptors in the body without activating them, effectively blocking the effects of opioids already present at these sites. It has no effect in people who have not taken opioids and does not reverse the effects of other sedatives or substances.

Naloxone can be administered via intranasal, intramuscular, intravenous, or subcutaneous routes. The onset of action varies depending on the route of administration but generally ranges from 1 to 5 minutes when given intravenously and up to 10-15 minutes with other methods.

The duration of naloxone's effects is usually shorter than that of most opioids, so multiple doses or a continuous infusion may be necessary in severe cases to maintain reversal of opioid toxicity. Naloxone has been used successfully in emergency situations to treat opioid overdoses and has saved many lives.

It is important to note that naloxone does not reverse the effects of other substances or address the underlying causes of addiction, so it should be used as part of a comprehensive treatment plan for individuals struggling with opioid use disorders.

Indole is not strictly a medical term, but it is a chemical compound that can be found in the human body and has relevance to medical and biological research. Indoles are organic compounds that contain a bicyclic structure consisting of a six-membered benzene ring fused to a five-membered pyrrole ring.

In the context of medicine, indoles are particularly relevant due to their presence in certain hormones and other biologically active molecules. For example, the neurotransmitter serotonin contains an indole ring, as does the hormone melatonin. Indoles can also be found in various plant-based foods, such as cruciferous vegetables (e.g., broccoli, kale), and have been studied for their potential health benefits.

Some indoles, like indole-3-carbinol and diindolylmethane, are found in these vegetables and can have anti-cancer properties by modulating estrogen metabolism, reducing inflammation, and promoting cell death (apoptosis) in cancer cells. However, it is essential to note that further research is needed to fully understand the potential health benefits and risks associated with indoles.

Naltrexone is a medication that is primarily used to manage alcohol dependence and opioid dependence. It works by blocking the effects of opioids and alcohol on the brain, reducing the euphoric feelings and cravings associated with their use. Naltrexone comes in the form of a tablet that is taken orally, and it has no potential for abuse or dependence.

Medically, naltrexone is classified as an opioid antagonist, which means that it binds to opioid receptors in the brain without activating them, thereby blocking the effects of opioids such as heroin, morphine, and oxycodone. It also reduces the rewarding effects of alcohol by blocking the release of endorphins, which are natural chemicals in the brain that produce feelings of pleasure.

Naltrexone is often used as part of a comprehensive treatment program for addiction, along with counseling, behavioral therapy, and support groups. It can help individuals maintain abstinence from opioids or alcohol by reducing cravings and preventing relapse. Naltrexone is generally safe and well-tolerated, but it may cause side effects such as nausea, headache, dizziness, and fatigue in some people.

It's important to note that naltrexone should only be used under the supervision of a healthcare provider, and it is not recommended for individuals who are currently taking opioids or who have recently stopped using them, as it can cause withdrawal symptoms. Additionally, naltrexone may interact with other medications, so it's important to inform your healthcare provider of all medications you are taking before starting naltrexone therapy.

Parkinsonian disorders are a group of neurological conditions characterized by motor symptoms such as bradykinesia (slowness of movement), rigidity, resting tremor, and postural instability. These symptoms are caused by the degeneration of dopamine-producing neurons in the brain, particularly in the substantia nigra pars compacta.

The most common Parkinsonian disorder is Parkinson's disease (PD), which is a progressive neurodegenerative disorder. However, there are also several other secondary Parkinsonian disorders, including:

1. Drug-induced parkinsonism: This is caused by the use of certain medications, such as antipsychotics and metoclopramide.
2. Vascular parkinsonism: This is caused by small vessel disease in the brain, which can lead to similar symptoms as PD.
3. Dementia with Lewy bodies (DLB): This is a type of dementia that shares some features with PD, such as the presence of alpha-synuclein protein clumps called Lewy bodies.
4. Progressive supranuclear palsy (PSP): This is a rare brain disorder that affects movement, gait, and eye movements.
5. Multiple system atrophy (MSA): This is a progressive neurodegenerative disorder that affects multiple systems in the body, including the autonomic nervous system, motor system, and cerebellum.
6. Corticobasal degeneration (CBD): This is a rare neurological disorder that affects both movement and cognition.

It's important to note that while these disorders share some symptoms with PD, they have different underlying causes and may require different treatments.

Brain chemistry refers to the chemical processes that occur within the brain, particularly those involving neurotransmitters, neuromodulators, and neuropeptides. These chemicals are responsible for transmitting signals between neurons (nerve cells) in the brain, allowing for various cognitive, emotional, and physical functions.

Neurotransmitters are chemical messengers that transmit signals across the synapse (the tiny gap between two neurons). Examples of neurotransmitters include dopamine, serotonin, norepinephrine, GABA (gamma-aminobutyric acid), and glutamate. Each neurotransmitter has a specific role in brain function, such as regulating mood, motivation, attention, memory, and movement.

Neuromodulators are chemicals that modify the effects of neurotransmitters on neurons. They can enhance or inhibit the transmission of signals between neurons, thereby modulating brain activity. Examples of neuromodulators include acetylcholine, histamine, and substance P.

Neuropeptides are small protein-like molecules that act as neurotransmitters or neuromodulators. They play a role in various physiological functions, such as pain perception, stress response, and reward processing. Examples of neuropeptides include endorphins, enkephalins, and oxytocin.

Abnormalities in brain chemistry can lead to various neurological and psychiatric conditions, such as depression, anxiety disorders, schizophrenia, Parkinson's disease, and Alzheimer's disease. Understanding brain chemistry is crucial for developing effective treatments for these conditions.

Clozapine is an atypical antipsychotic medication that is primarily used to treat schizophrenia in patients who have not responded to other antipsychotic treatments. It is also used off-label for the treatment of severe aggression, suicidal ideation, and self-injurious behavior in individuals with developmental disorders.

Clozapine works by blocking dopamine receptors in the brain, particularly the D4 receptor, which is thought to be involved in the development of schizophrenia. It also has a strong affinity for serotonin receptors, which contributes to its unique therapeutic profile.

Clozapine is considered a medication of last resort due to its potential side effects, which can include agranulocytosis (a severe decrease in white blood cell count), myocarditis (inflammation of the heart muscle), seizures, orthostatic hypotension (low blood pressure upon standing), and weight gain. Because of these risks, patients taking clozapine must undergo regular monitoring of their blood counts and other vital signs.

Despite its potential side effects, clozapine is often effective in treating treatment-resistant schizophrenia and has been shown to reduce the risk of suicide in some patients. It is available in tablet and orally disintegrating tablet formulations.

Antiparkinson agents are a class of medications used to treat the symptoms of Parkinson's disease and related disorders. These agents work by increasing the levels or activity of dopamine, a neurotransmitter in the brain that is responsible for regulating movement and coordination.

There are several types of antiparkinson agents, including:

1. Levodopa: This is the most effective treatment for Parkinson's disease. It is converted to dopamine in the brain and helps to replace the missing dopamine in people with Parkinson's.
2. Dopamine agonists: These medications mimic the effects of dopamine in the brain and can be used alone or in combination with levodopa. Examples include pramipexole, ropinirole, and rotigotine.
3. Monoamine oxidase B (MAO-B) inhibitors: These medications block the breakdown of dopamine in the brain and can help to increase its levels. Examples include selegiline and rasagiline.
4. Catechol-O-methyltransferase (COMT) inhibitors: These medications block the breakdown of levodopa in the body, allowing it to reach the brain in higher concentrations. Examples include entacapone and tolcapone.
5. Anticholinergic agents: These medications block the action of acetylcholine, another neurotransmitter that can contribute to tremors and muscle stiffness in Parkinson's disease. Examples include trihexyphenidyl and benztropine.

It is important to note that antiparkinson agents can have side effects, and their use should be carefully monitored by a healthcare professional. The choice of medication will depend on the individual patient's symptoms, age, overall health, and other factors.

Calcium is an essential mineral that is vital for various physiological processes in the human body. The medical definition of calcium is as follows:

Calcium (Ca2+) is a crucial cation and the most abundant mineral in the human body, with approximately 99% of it found in bones and teeth. It plays a vital role in maintaining structural integrity, nerve impulse transmission, muscle contraction, hormonal secretion, blood coagulation, and enzyme activation.

Calcium homeostasis is tightly regulated through the interplay of several hormones, including parathyroid hormone (PTH), calcitonin, and vitamin D. Dietary calcium intake, absorption, and excretion are also critical factors in maintaining optimal calcium levels in the body.

Hypocalcemia refers to low serum calcium levels, while hypercalcemia indicates high serum calcium levels. Both conditions can have detrimental effects on various organ systems and require medical intervention to correct.

Synaptosomes are subcellular structures that can be isolated from the brain tissue. They are formed during the fractionation process of brain homogenates and consist of intact presynaptic terminals, including the synaptic vesicles, mitochondria, and cytoskeletal elements. Synaptosomes are often used in neuroscience research to study the biochemical properties and functions of neuronal synapses, such as neurotransmitter release, uptake, and metabolism.

Neurotransmitter agents are substances that affect the synthesis, storage, release, uptake, degradation, or reuptake of neurotransmitters, which are chemical messengers that transmit signals across a chemical synapse from one neuron to another. These agents can be either agonists, which mimic the action of a neurotransmitter and bind to its receptor, or antagonists, which block the action of a neurotransmitter by binding to its receptor without activating it. They are used in medicine to treat various neurological and psychiatric disorders, such as depression, anxiety, and Parkinson's disease.

Nerve tissue proteins are specialized proteins found in the nervous system that provide structural and functional support to nerve cells, also known as neurons. These proteins include:

1. Neurofilaments: These are type IV intermediate filaments that provide structural support to neurons and help maintain their shape and size. They are composed of three subunits - NFL (light), NFM (medium), and NFH (heavy).

2. Neuronal Cytoskeletal Proteins: These include tubulins, actins, and spectrins that provide structural support to the neuronal cytoskeleton and help maintain its integrity.

3. Neurotransmitter Receptors: These are specialized proteins located on the postsynaptic membrane of neurons that bind neurotransmitters released by presynaptic neurons, triggering a response in the target cell.

4. Ion Channels: These are transmembrane proteins that regulate the flow of ions across the neuronal membrane and play a crucial role in generating and transmitting electrical signals in neurons.

5. Signaling Proteins: These include enzymes, receptors, and adaptor proteins that mediate intracellular signaling pathways involved in neuronal development, differentiation, survival, and death.

6. Adhesion Proteins: These are cell surface proteins that mediate cell-cell and cell-matrix interactions, playing a crucial role in the formation and maintenance of neural circuits.

7. Extracellular Matrix Proteins: These include proteoglycans, laminins, and collagens that provide structural support to nerve tissue and regulate neuronal migration, differentiation, and survival.

Gamma-Aminobutyric Acid (GABA) is a major inhibitory neurotransmitter in the mammalian central nervous system. It plays a crucial role in regulating neuronal excitability and preventing excessive neuronal firing, which helps to maintain neural homeostasis and reduce the risk of seizures. GABA functions by binding to specific receptors (GABA-A, GABA-B, and GABA-C) on the postsynaptic membrane, leading to hyperpolarization of the neuronal membrane and reduced neurotransmitter release from presynaptic terminals.

In addition to its role in the central nervous system, GABA has also been identified as a neurotransmitter in the peripheral nervous system, where it is involved in regulating various physiological processes such as muscle relaxation, hormone secretion, and immune function.

GABA can be synthesized in neurons from glutamate, an excitatory neurotransmitter, through the action of the enzyme glutamic acid decarboxylase (GAD). Once synthesized, GABA is stored in synaptic vesicles and released into the synapse upon neuronal activation. After release, GABA can be taken up by surrounding glial cells or degraded by the enzyme GABA transaminase (GABA-T) into succinic semialdehyde, which is further metabolized to form succinate and enter the Krebs cycle for energy production.

Dysregulation of GABAergic neurotransmission has been implicated in various neurological and psychiatric disorders, including epilepsy, anxiety, depression, and sleep disturbances. Therefore, modulating GABAergic signaling through pharmacological interventions or other therapeutic approaches may offer potential benefits for the treatment of these conditions.

Endothelin receptors are a type of G protein-coupled receptor that bind to endothelin, a potent vasoconstrictor peptide. There are two main types of endothelin receptors: ETA and ETB. ETA receptors are found in vascular smooth muscle cells and activate phospholipase C, leading to an increase in intracellular calcium and subsequent contraction of the smooth muscle. ETB receptors are found in both endothelial cells and vascular smooth muscle cells. In endothelial cells, ETB receptor activation leads to the release of nitric oxide and prostacyclin, which cause vasodilation. In vascular smooth muscle cells, ETB receptor activation causes vasoconstriction through a mechanism that is not fully understood.

Endothelin receptors play important roles in regulating blood flow, vascular remodeling, and the development of cardiovascular diseases such as hypertension and heart failure. They are also involved in the regulation of cell growth, differentiation, and apoptosis in various tissues.

Cyclic adenosine monophosphate (cAMP) is a key secondary messenger in many biological processes, including the regulation of metabolism, gene expression, and cellular excitability. It is synthesized from adenosine triphosphate (ATP) by the enzyme adenylyl cyclase and is degraded by the enzyme phosphodiesterase.

In the body, cAMP plays a crucial role in mediating the effects of hormones and neurotransmitters on target cells. For example, when a hormone binds to its receptor on the surface of a cell, it can activate a G protein, which in turn activates adenylyl cyclase to produce cAMP. The increased levels of cAMP then activate various effector proteins, such as protein kinases, which go on to regulate various cellular processes.

Overall, the regulation of cAMP levels is critical for maintaining proper cellular function and homeostasis, and abnormalities in cAMP signaling have been implicated in a variety of diseases, including cancer, diabetes, and neurological disorders.

Adrenergic beta-2 receptor antagonists, also known as beta-2 adrenergic blockers or beta-2 antagonists, are a class of medications that block the action of epinephrine (adrenaline) and other catecholamines at beta-2 adrenergic receptors. These receptors are found in various tissues throughout the body, including the lungs, blood vessels, and skeletal muscles.

Beta-2 adrenergic receptor antagonists are primarily used to treat respiratory conditions such as asthma and chronic obstructive pulmonary disease (COPD). They work by relaxing the smooth muscle in the airways, which helps to reduce bronchoconstriction and improve breathing.

Some examples of beta-2 adrenergic receptor antagonists include:

* Butoxamine
* ICI 118,551
* Salbutamol (also a partial agonist)
* Terbutaline (also a partial agonist)

It's important to note that while these medications are called "antagonists," some of them can also act as partial agonists at beta-2 receptors, meaning they can both block the action of catecholamines and stimulate the receptor to some degree. This property can make them useful in certain clinical situations, such as during an asthma attack or preterm labor.

The basal ganglia are a group of interconnected nuclei, or clusters of neurons, located in the base of the brain. They play a crucial role in regulating motor function, cognition, and emotion. The main components of the basal ganglia include the striatum (made up of the caudate nucleus, putamen, and ventral striatum), globus pallidus (divided into external and internal segments), subthalamic nucleus, and substantia nigra (with its pars compacta and pars reticulata).

The basal ganglia receive input from various regions of the cerebral cortex and other brain areas. They process this information and send output back to the thalamus and cortex, helping to modulate and coordinate movement. The basal ganglia also contribute to higher cognitive functions such as learning, decision-making, and habit formation. Dysfunction in the basal ganglia can lead to neurological disorders like Parkinson's disease, Huntington's disease, and dystonia.

A dopamine antagonist, also known as an anti-dopaminergic and a dopamine receptor antagonist (DRA), is a type of drug which ... Several other dopamine antagonists are antiemetics used in the treatment of nausea and vomiting. Dopamine receptors are all G ... Dopamine+antagonists at the U.S. National Library of Medicine Medical Subject Headings (MeSH) (CS1: long volume value, Articles ... Most antipsychotics are dopamine antagonists, and as such they have found use in treating schizophrenia, bipolar disorder, and ...
"Dopamine receptor antagonists". Ann Palliat Med. 1 (2): 137-42. doi:10.3978/j.issn.2224-5820.2012.07.09. PMID 25841474. Waknine ... Trimethobenzamide is an antagonist of the D2 receptor. It is believed to affect the chemoreceptor trigger zone (CTZ) of the ...
... dopamine antagonists). Treat depression efficaciously when both DDM and depression are present. Increase motivation through use ... As a result of more and more evidence showing that the mesolimbic and the mesocortical dopamine system are key to motivation ... of stimulants, dopamine agonists, or other agents such as cholinesterase inhibitors. A case of abulia after a transient ... and responsiveness to reward, abulia may be a dopamine-related dysfunction. Abulia may also result from a variety of brain ...
September 2007). "Dopamine D1 receptor agonist and D2 receptor antagonist effects of the natural product (-)-stepholidine: ... "Dopamine receptor antagonists - Pharmacorama". www.pharmacorama.com. Retrieved 2016-12-15. Kaufmann, Horacio; Saadia, Daniela; ... Dopamine beta (β)-hydroxylase deficiency is a condition involving inadequate dopamine beta-hydroxylase. It is characterized by ... Prolactin is frequently suppressed by excessive dopamine found in the patient's central nervous system. Excess dopamine can ...
SB-277,011A is a drug which acts as a potent and selective dopamine D3 receptor antagonist, which is around 80-100x selective ... Malik P, Andersen MB, Peacock L (August 2004). "The effects of dopamine D3 agonists and antagonists in a nonhuman primate model ... Ross JT, Corrigall WA, Heidbreder CA, LeSage MG (March 2007). "Effects of the selective dopamine D3 receptor antagonist SB- ... September 2000). "Pharmacological actions of a novel, high-affinity, and selective human dopamine D(3) receptor antagonist, SB- ...
Dopamine antagonists reduce the effect of piribedil. Dopamine receptor agonist, selective for subtypes D2 and D3. Dopamine ... Agonist and antagonist properties at subtypes of dopamine D(2)-like receptor and alpha(1)/alpha(2)-adrenoceptor". The Journal ... Arnsten AF, Murphy B, Merchant K (October 2000). "The selective dopamine D4 receptor antagonist, PNU-101387G, prevents stress- ... Adrenergic receptor antagonist, subtypes α2A and α2C: could be the reason why piribedil seems to cause less drowsiness than ...
In contrast, dopamine antagonists can sometimes cause dystonia.)[citation needed] One complex case study found that a ketogenic ... Dopamine agonists: One type of dystonia, dopamine-responsive dystonia, can be completely treated with regular doses of L-DOPA ... dopamine agonists (such as ropinirole and bromocriptine), and muscle relaxants (such as diazepam).[citation needed] Medications ... called myoclonic dystonia where some cases are hereditary and have been associated with a missense mutation in the dopamine-D2 ...
The older typical antipsychotics are primarily dopamine antagonists. Iloperidone has been shown to act as an antagonist at all ... It exhibits high (nM) affinity to serotonin 5HT2A (Ki value of 5.6 nM), dopamine D2 (6.3 nM) and D3 (7.1 nM) and noradrenaline ... Iloperidone exerts its effects by acting upon and antagonizing specific neurotransmitters, particularly multiple dopamine and ... dopamine D1 and histamine H1 receptors. In addition, pharmacogenomic studies identified single nucleotide polymorphisms ...
Dopamine receptor antagonists have sedative and antiemetic properties. Previously, they were used in parallel with opioids to ... an NMDA receptor antagonist, is used primarily for its analgesic effects and in an off-label capacity for its anti-depressant ...
... is the azide derivative of the dopamine antagonist clebopride synthesized in order to label dopamine receptors. It is ... Dopamine antagonists, Organoazides, Chlorobenzenes, Salicylamide ethers, Piperidines, Irreversible antagonists, All stub ... an irreversible dopamine antagonist. Niznik HB, Guan JH, Neumeyer JL, Seeman P (February 1985). "A photoaffinity ligand for ... Wouters W, Van Dun J, Laduron PM (December 1984). "Photoaffinity labelling of dopamine receptors. Synthesis and binding ...
"Dopamine Antagonist - Andre Soriano Bridal Campaign". YouTube. July 26, 2013. "Not For the Classic Princess: Extreme Bridal by ...
As with other dopamine antagonists, zuclopenthixol may sometimes elevate prolactin levels; this may occasionally result in ... Zuclopenthixol is a D1 and D2 antagonist, α1-adrenergic and 5-HT2 antagonist. While it is approved for use in Australia, Canada ... An increase in the incidence of pancreatic islet cell tumours has been observed for some other D2 antagonists. The ... An increase in the incidence of mammary adenocarcinomas is a common finding for D2 antagonists which increase prolactin ...
Antagonists such as dopamine antagonist slow down movement in lab rats. Although they hinder the joining of enzymes to ... Claussen, C. M.; Witte, L. J.; Dafny, N (2015). "Single exposure of dopamine D1 antagonist prevents and D2 antagonist ... For instance, a receptor antagonist is an agent that reduces the response that a ligand produces when the receptor antagonist ... The effects of antagonists can be seen after they have encountered an agonist, and as a result, the effects of the agonist is ...
Arnsten AF, Murphy B, Merchant K (October 2000). "The selective dopamine D4 receptor antagonist, PNU-101387G, prevents stress- ... Mansbach RS, Brooks EW, Sanner MA, Zorn SH (January 1998). "Selective dopamine D4 receptor antagonists reverse apomorphine- ... June 1996). "(S)-(−)-4-[4-[2-(isochroman-1-yl)ethyl]-piperazin-1-yl] benzenesulfonamide, a selective dopamine D4 antagonist". ... August 1997). "Chromeno[3,4-c]pyridin-5-ones: selective human dopamine D4 receptor antagonists as potential antipsychotic ...
Carr KD, Yamamoto N, Omura M, Cabeza de Vaca S, Krahne L (August 2002). "Effects of the D(3) dopamine receptor antagonist, ... Rodríguez-Arias M, Felip CM, Broseta I, Miñarro J (May 1999). "The dopamine D3 antagonist U-99194A maleate increases social ... Rogóz Z, Kłodzińska A, Maj J (2000). "Anxiolytic-like effect of nafadotride and PNU 99194A, dopamine D3 receptor antagonists in ... Gyertyán I, Sághy K (July 2004). "Effects of dopamine D3 receptor antagonists on spontaneous and agonist-reduced motor activity ...
Agonist and antagonist properties at subtypes of dopamine D(2)-like receptor and alpha(1)/alpha(2)-adrenoceptor". The Journal ... Dopamine antagonists such as antipsychotics and metoclopramide counteract some effects of cabergoline. The use of ... Agonist and antagonist properties at serotonin, 5-HT(1) and 5-HT(2), receptor subtypes". The Journal of Pharmacology and ... Youssef MA, van Wely M, Hassan MA, Al-Inany HG, Mochtar M, Khattab S, van der Veen F (March 2010). "Can dopamine agonists ...
... is a dopamine D2 and D3 receptor antagonist. It is more selective than other neuroleptic drugs such as haloperidol and ... This is because dopamine plays a primary role in regulating prolactin release by binding to D2 receptors on prolactin-secreting ... Tiapride is a drug that selectively blocks D2 and D3 dopamine receptors in the brain. It is used to treat a variety of ... Dopamine hyperactivity has been linked with alcohol withdrawal syndrome (AWS), suggesting that tiapride's antidopaminergic ...
Chlorpromazine and haloperidol, both dopamine antagonists, in some cases have worsened PSH symptoms. These drugs are in use ... It may also increase sympathetic inhibition in the brainstem.[medical citation needed] Bromocriptine is a dopamine agonist that ... Other drugs that have been used and have in some cases been helpful are dopamine agonists, other various opiates, ...
"Effects of intrastriatal infusion of D2 and D3 dopamine receptor preferring antagonists on dopamine release in rat dorsal ... UH-232 ((+)-UH232) is a drug which acts as a subtype selective mixed agonist-antagonist for dopamine receptors, acting as a ... Lahti AC, Weiler M, Carlsson A, Tamminga CA (1998). "Effects of the D3 and autoreceptor-preferring dopamine antagonist (+)- ... "The dopamine D3 receptor and autoreceptor preferring antagonists (+)-AJ76 and (+)-UH232; a microdialysis study". European ...
Treatment by serotonin and dopamine antagonists caused a reduction in the behavioral abnormalities. Ataxia, trembling, ... The serotonin and dopamine systems are thought to be involved in the behavioral abnormalities caused by allyl cyanide. ...
Second-line treatments include vitamin B6 +/- doxylamine, antihistamines, dopamine antagonists, and serotonin antagonists. ...
Therefore, CB1 antagonists might indirectly inhibit the dopamine-mediated rewarding properties of food. Peripheral CB1 ... A cannabinoid receptor antagonist, also known simply as a cannabinoid antagonist or as an anticannabinoid, is a type of ... They include antagonists, inverse agonists, and antibodies of CBRs. The discovery of the endocannabinoid system led to the ... CB1 antagonists produce inverse cannabimimetic effects that are opposite in direction from those produced by agonists for these ...
Hence, anticholinergics, antihistamines, dopamine antagonists, serotonin antagonists, and cannabinoids are used as antiemetics ... The chemoreceptor trigger zone at the base of the fourth ventricle has numerous dopamine D2 receptors, serotonin 5-HT3 ...
... pimavanserin is not a dopamine receptor antagonist. Pimavanserin acts as an inverse agonist and antagonist at serotonin 5-HT2A ... dopamine (including D2), muscarinic acetylcholine, histamine, or adrenergic receptors, or to calcium channels. Pimavanserin has ... 5-HT2A antagonists, Atypical antipsychotics, Fluoroarenes, Phenol ethers, Piperidines, Ureas, Breakthrough therapy). ... selectivity for this site over the 5-HT2C receptor and no significant affinity or activity at the 5-HT2B receptor or dopamine ...
... is a selective dopamine D1 and D5 receptor antagonist. It shows little affinity for either dopamine D2-like or 5-HT2 ... Ecopipam acts as a selective dopamine D1 and D5 receptor antagonist. It is orally active, has an elimination half-life of 10 ... Haney M, Ward AS, Foltin RW, Fischman MW (June 2001). "Effects of ecopipam, a selective dopamine D1 antagonist, on smoked ... Ecopipam (development codes SCH-39166, EBS-101, and PSYRX-101) is a dopamine antagonist which is under development for the ...
... is a drug which acts as a dopamine receptor antagonist selective for the D4 subtype, and has antipsychotic effects in ... Moustgaard A, Hau J, Lind NM (2008). "Effects of dopamine D4 receptor antagonist on spontaneous alternation in rats". ... a novel dopamine D4 receptor antagonist". Trends in Pharmacological Sciences. 18 (6): 186-8. doi:10.1016/s0165-6147(97)01066-3 ... D4 antagonists, Pyrrolopyridines, Phenylpiperazines, Chloroarenes, All stub articles, Nervous system drug stubs). ...
It acts as a selective antagonist on D2 dopamine receptors. It has been used in trials studying Parkinson Disease. Its ... A potent substituted benzamide drug with high affinity for dopamine D-2 receptors in the rat brain". Biochemical Pharmacology. ... Ishibashi K, Ishii K, Oda K, Mizusawa H, Ishiwata K (2010). "Competition between 11C-raclopride and endogenous dopamine in ... Farde L, Gustavsson JP, Jönsson E (1997). "D2 dopamine receptors and personality traits". Nature. 385 (6617): 590. Bibcode: ...
Nociceptin is thought to be an endogenous antagonist of dopamine transport that may act either directly on dopamine or by ... Liu Z, Wang Y, Zhang J, Ding J, Guo L, Cui D, Fei J (March 2001). "Orphanin FQ: an endogenous antagonist of rat brain dopamine ... Antagonists targeting NOP are under investigation for their role as treatments for depression and Parkinson's disease, whereas ... Administration of the NOPr antagonist SB-612,111 has been shown to inhibit this process. More recently a range of selective ...
Treatment for EPS and PDS can both include proton pump inhibitors and dopamine antagonists. Tricyclic antidepressants have also ...
This brake is disrupted through action of a 5-HT2A antagonist, which disinhibits the dopamine neuron, stimulating dopamine ... Miyake, N; Miyamoto, S; Jarskog, LF (October 2012). "New serotonin/dopamine antagonists for the treatment of schizophrenia: are ... The atypical antipsychotics (AAP), also known as second generation antipsychotics (SGAs) and serotonin-dopamine antagonists ( ... "Modulation of striatal dopamine release by 5-HT2A and 5-HT2C receptor antagonists: [11C]raclopride PET studies in the rat". ...
A dopamine antagonist, also known as an anti-dopaminergic and a dopamine receptor antagonist (DRA), is a type of drug which ... Several other dopamine antagonists are antiemetics used in the treatment of nausea and vomiting. Dopamine receptors are all G ... Dopamine+antagonists at the U.S. National Library of Medicine Medical Subject Headings (MeSH) (CS1: long volume value, Articles ... Most antipsychotics are dopamine antagonists, and as such they have found use in treating schizophrenia, bipolar disorder, and ...
Dopamine antagonists. Class Summary. These agents are ergot derivatives and dopamine receptor agonists. They act on ... Semisynthetic ergot alkaloid derivative with strong dopamine D2-receptor agonist and partial dopamine D1-receptor effects. ... Chua ME, Escusa KG, Luna S, Tapia LC, Dofitas B, Morales M. Revisiting oestrogen antagonists (clomiphene or tamoxifen) as ... postsynaptic dopamine receptors while causing no effect on other anterior pituitary functions. Mimic dopamine action of ...
Preclinical studies claim that dopamine D3 receptor (D3R) antagonists are promising. Preclinical studies claim that dopamine D3 ... receptor (D3R) antagonists are promising for the treatment of drug abuse and addiction. BSR in rats (i.e. decreased stimulation ...
BALDERRAMA-TRAPAGA, Jorge Arturo and APARICIO-NARANJO, Carlos Fernando. Effects of dopamine agonists and antagonists in ... The cumulative body of empirical evidence shows that dopamine agonists and antagonists (e.g., Methylphenidate and Haloperidol, ... Keywords : Methylphenidate; Haloperidol; Choice; Motivation; Reinforcement; Rats; Laboratory research; Dopamine; Dopamine ... The anhedonia hypothesis maintains that pleasure for food-reward is determined by dopamine activity in the brain. ...
Dopamine antagonists. Class Summary. These agents are ergot derivatives and dopamine receptor agonists. They act on ... Semisynthetic ergot alkaloid derivative with strong dopamine D2-receptor agonist and partial dopamine D1-receptor effects. ... Chua ME, Escusa KG, Luna S, Tapia LC, Dofitas B, Morales M. Revisiting oestrogen antagonists (clomiphene or tamoxifen) as ... postsynaptic dopamine receptors while causing no effect on other anterior pituitary functions. Mimic dopamine action of ...
T1 - Attempts to develop super- or subsensitivity of retinal dopamine receptors after various treatments with antagonists or ... Attempts to develop super- or subsensitivity of retinal dopamine receptors after various treatments with antagonists or ... title = "Attempts to develop super- or subsensitivity of retinal dopamine receptors after various treatments with antagonists ... Attempts to develop super- or subsensitivity of retinal dopamine receptors after various treatments with antagonists or ...
H2 Receptor Antagonist. *Antacids. *Proton Pump Inhibitors. *Dopamine Antagonist. *Prokinetic Agents. *Calcium Channel Blockers ...
... dopamine receptor antagonists (e.g., metoclopramide, prochlorperazine); and sympathomimetics (often used in combination with ...
Amisulpride is in a class of medications called dopamine receptor antagonists. It works by blocking the action of dopamine, a ...
Dopamine-2 Receptor Antagonist Oral Feb. 26, 2020 In Use 70934-0580-10 70934-0580 Prednisone Prednisone 10.0 mg/1 Hormonal ... 5HT3 Receptor Antagonist Oral Aug. 18, 2020 Aug. 31, 2023 In Use ... 5HT3 Receptor Antagonist Oral Feb. 7, 2022 Nov. 30, 2024 In Use ... 5HT3 Receptor Antagonist Oral July 13, 2021 Jan. 31, 2025 In Use ... 5HT3 Receptor Antagonist Oral Aug. 31, 2020 May 31, 2025 In Use ... 5HT3 Receptor Antagonist Oral April 22, 2021 Feb. 28, 2025 In Use ...
Bupropion is a dopamine and norepinephrine reuptake inhibitor with nicotine receptor antagonist properties. It reduces craving ... Bupropion is a dopamine and norepinephrine reuptake inhibitor with nicotine receptor antagonist properties. It reduces craving ...
2021). Striatal TRPV1 activation by acetaminophen ameliorates dopamine D2 receptor antagonist-induced orofacial dyskinesia. JCI ... 2010). Association of methotrexate and tumour necrosis factor antagonists with risk of infectious outcomes including ...
Catecholamines typically secreted are norepinephrine and epinephrine; some tumors produce dopamine. [8] ... Dopamine antagonists: Eg, metoclopramide [11] * Cold medications * Beta blockers [11] * Drugs that inhibit catecholamine ...
Conventional antipsychotic drugs are dopamine antagonists; through their binding to dopamine receptors, mainly the D2 receptor ... However, because these drugs only alter dopamine levels, they are active against only the positive symptoms of the disorder and ... Dopamine has an important role in the etiology of psychotic disorders such as schizophrenia. ... Atypical antipsychotic drugs block not only dopamine receptors, but also serotonin receptors, mainly the 5HT2A receptor.5 Due ...
Metoclopramide is a dopamine antagonist that stimulates upper gastrointestinal motility, increases gastroesophageal sphincter ... Dopamine is used in the treatment of cardiogenic shock, CHF, and following cardiac surgery. It has 3 different actions at 3 ... Dopamine receptors: applications in clinical cardiology. Circulation. 1985 Aug. 72(2):245-8. [QxMD MEDLINE Link]. ... Patients with Parkinson disease who take dopamine (combination of L-dopa and carbidopa) must stay on their usual medication ...
Treatment of psychogenic feather picking in psittacine birds with a dopamine antagonist. J. Small Anim. Pract. 34: 564-566. ... 2 while the dopamine antagonist haloperidol results in suppression of spontaneously occurring stereotyped behavior.16 ... Use of narcotic antagonists to modify stereotypic self-licking, self-chewing and scratching behavior in dogs. J. Am. Vet. Med. ... Beta-endorphin antagonists have high first-pass metabolism and a short half-life, and most are only effective as injectables. ...
Other dopamine antagonists, when administered to pregnant animals, have caused negative effects on learning and motor ... Medicinal products with dopamine receptor antagonistic properties have been associated with the induction of tardive dyskinesia ... Current or past use of medicinal products with alpha 1a-adrenergic antagonist effect should be made known to the ophthalmic ... Even though paliperidone is a strong D2-antagonist, which is believed to relieve the positive symptoms of schizophrenia, it ...
Dopamine Receptor Antagonism: Loxitane acts as a dopamine receptor antagonist, specifically targeting D2 receptors in the brain ... The efficacy of Loxitane in mental health treatment lies in its ability to antagonize dopamine receptors in the brain, ... Serotonin Receptor Blockade: In addition to dopamine receptors, Loxitane also affects serotonin receptors, known to play a role ... Loxapine works by blocking dopamine receptors in the brain, which helps alleviate symptoms of psychosis.. **Key Differences:** ...
... were not antagonized by the dopamine receptor antagonist haloperidol in rats. In addition, alpha-methyl-p-tyrosine, a dopamine ... modafinil binds to the dopamine reuptake site and causes an increase in extracellular dopamine, but no increase in dopamine ... Modafinil is not a direct- or indirect-acting dopamine receptor agonist. However, in vitro, modafinil binds to the dopamine ... This activity has been associated in vivo with increased extracellular dopamine levels in some brain regions of animals. In ...
Major contributions included the discovery of the first selective antagonists for the dopamine D4 receptor, the development of ... The biological targets have included both receptors and enzymes such as GPCR & chemokine antagonists and lipase & protease ...
Literature References: Combined serotonin (5HT2) and dopamine (D2) receptor antagonist. Prepn: FR 1334944 (1963 to Wander); ...
Allosteric interactions between agonists and antagonists within the adenosine A2A receptor-dopamine D2 receptor heterotetramer ... Dopamine D(4) receptor, but not the ADHD-associated D(4.7) variant, forms functional heteromers with the dopamine D(2S) ... Dopamine D1-histamine H3 receptor heteromers provide a selective link to the map-kinase signalling in gabaergic neurons of the ... Cocaine inhibits dopamine D2 receptor signaling via sigma-1-D2 receptor heteromers. Navarro Brugal, Gemma; Moreno Guillén, ...
... whereas an antagonist of the 5-HT receptor produces an agonistic effect on the activity of the dopamine system, resulting in an ... 9. Ji XY, Wu M, Zhang X, Dopamine level in the stratium exhibits circadian rhythms in the rat model of Tourette syndrome: Int J ... An agonist of the 5-HT receptor exerts an inhibitory effect on the activity of the dopamine system, resulting in decreased ... Aripiprazole is a partial agonist of 5-HT2C receptors, while risperidone is a 5-HT2C receptor antagonist at low doses, they are ...
Three dopamine agonists, pramipexole, ropinirole, and rotigotine (used as a patch), are effective and have few serious adverse ... The mechanism is unclear but may involve abnormalities in dopamine neurotransmission in the central nervous system (CNS). PLMD ... With use of stimulants, certain antidepressants, or dopamine antagonists. *. During pregnancy. *. In patients with chronic ...
... commented that the dopamine D3 receptor antagonists have shown greater promise for this application than agents affecting D2. ... So, you can try to manipulate either side of this equation, and impact dopamine release without necessarily targeting dopamine ... Brady explained that disulfiram also increases central dopamine transmission by inhibiting dopamine b-hydroxylase. ... Targeting GABA and dopamine. The g-aminobutyric acid-ergic (GABA-ergic) system was described by Brady as a counterbalance to ...
... it acts more like a dopamine antagonist. This raises the question of whether a different antipsychotic might perform just as ...
Dopamine Antagonists -- See Also the narrower term Olanzapine 1 Dopamine-D2 Receptor -- See Receptors, Dopamine D2 A subfamily ... Dopamine -- therapeutic use 2 Dopaminergic Agents -- See Dopamine Agents Any drugs that are used for their effects on dopamine ... Dopamine. 19 Dopamine -- adverse effects : Progress in dopamine research in schizophrenia : a guide for physicians / edited by ... Drugs that bind to and activate dopamine receptors 1 Dopamine Receptor Agonists -- See Dopamine Agonists Drugs that bind to and ...
... quinolizines as D1 Dopamine Antagonists. Deborah L. Minor, Steven D. Wyrick, Paul S. Charifson, Val J. Watts, Richard B. ... quinolizines as D1 Dopamine Antagonists. / Minor, Deborah L.; Wyrick, Steven D.; Charifson, Paul S. et al. In: Journal of ... quinolizines as D1 Dopamine Antagonists. In: Journal of Medicinal Chemistry. 1994 ; Vol. 37, No. 25. pp. 4317-4328. ... quinolizines as D1 Dopamine Antagonists. Journal of Medicinal Chemistry. 1994 Dec 1;37(25):4317-4328. doi: 10.1021/jm00051a008 ...
  • A dopamine antagonist, also known as an anti-dopaminergic and a dopamine receptor antagonist (DRA), is a type of drug which blocks dopamine receptors by receptor antagonism. (wikipedia.org)
  • Dopamine receptors are all G protein-coupled receptors, and are divided into two classes based on which G-protein they are coupled to. (wikipedia.org)
  • The D1-like class of dopamine receptors is coupled to Gαs/olf and stimulates adenylate cyclase production, whereas the D2-like class is coupled to Gαi/o and thus inhibits adenylate cyclase production. (wikipedia.org)
  • Furthermore, most effective antipsychotics block D2 receptors, suggesting a role for dopamine in schizophrenia. (wikipedia.org)
  • They inhibit dopaminergic neurotransmission in the brain by blocking about 72% of the D2 dopamine receptors. (wikipedia.org)
  • They act on postsynaptic dopamine receptors while causing no effect on other anterior pituitary functions. (medscape.com)
  • Attempts to develop super- or subsensitivity of retinal dopamine receptors after various treatments with antagonists or agonists. (edu.sa)
  • A subfamily of G-PROTEIN-COUPLED RECEPTORS that bind the neurotransmitter DOPAMINE and modulate its effects. (edu.au)
  • This combination shows an effect on the dopaminergic receptors without causing any release of the chemical dopamine. (drugcarts.com)
  • This dramatic increase coincides with the introduction of a range of new neurochemical and pharmacological tools for the study of dopamine neurons and their function in the brain, as well as the identification of the dopamine receptors, their pharmacology, and their role in mediating the antipsychotic action of neuroleptics [12,13]. (lu.se)
  • DA released from receptor (type I) cells during chemostimulation is predominantly inhibitory, acting via pre- and post-synaptic dopamine D2 receptors (D2R) on type I cells and afferent (petrosal) terminals respectively. (mcmaster.ca)
  • These agents are ergot derivatives and dopamine receptor agonists. (medscape.com)
  • The cumulative body of empirical evidence shows that dopamine agonists and antagonists (e.g. (bvsalud.org)
  • However, patients with LID receive combination therapies that often include dopamine agonists. (lu.se)
  • BACKGROUND: Nicotine receptor partial agonists may help people to stop smoking by a combination of maintaining moderate levels of dopamine to counteract withdrawal symptoms (acting as an agonist) and reducing smoking satisfaction (acting as an antagonist). (who.int)
  • These include α-2 adrenergic agonists, such as clonidine and guanfacine , and dopamine antagonists (antipsychotics). (medscape.com)
  • the dopamine hypersensitivity hypothesis and the serotonin-dopamine antagonist hypothesis. (who.int)
  • The neuroleptic-induced TD with those who did serotonin-dopamine antagonist hypothesis not develop it under comparatively similar maintains that drugs which have a high conditions. (who.int)
  • The functional effect was correlated to a recovery of dopamine, but not noradrenaline, content in the brain, suggesting that depletion of dopamine, rather than noradrenaline or serotonin, was the cause of the akinetic state in reserpine-treated animals. (lu.se)
  • Depression is a treatable condition by the said drugs "antidepressants" that act on key brain neurotransmitter systems, particularly those involving serotonin and norepinephrine, and to a lesser extent dopamine and melatonin. (univ-tours.fr)
  • Concomitant treatment with dopamine antagonists such as metoclopramide may result in diminution of the effects of both drugs on the gastrointestinal tract. (janusinfo.se)
  • Bupropion is a dopamine and norepinephrine reuptake inhibitor with nicotine receptor antagonist properties. (cdc.gov)
  • Most antipsychotics are dopamine antagonists, and as such they have found use in treating schizophrenia, bipolar disorder, and stimulant psychosis. (wikipedia.org)
  • Dopamine as an independent neurotransmitter in the nervous system was discovered in Lund by the pharmacologist Arvid Carlsson in 1957, working at the Department of Pharmacology at Sölvegatan 10 in Lund (the current Geocentrum building). (lu.se)
  • The discovery of dopamine as a neurotransmitter in the brain was one of the seminal events in the development of modern neuroscience. (lu.se)
  • Cessation of these opioid medications leaves the brain with a deficit of dopamine, the neurotransmitter associated with pleasure and reward. (thecolemaninstitute.com)
  • The mechanism is unclear but may involve abnormalities in dopamine neurotransmission in the central nervous system (CNS). (msdmanuals.com)
  • In comparisons of ill and well GW veterans, magnetic resonance spectroscopy found metabolite abnormalities in basal ganglia associated with increased central dopamine turnover, and cholinergic challenge with physostigmine caused abnormal cholinergic response in caudate, putamen and globus pallidus. (cdc.gov)
  • Conclusion: Repetitive exposure to AChE-inhibitors causes dopamine neurotransmission abnormalities, possibly contributing to brain dysfunction in GWI. (cdc.gov)
  • In particular, compounds modulating D1 receptor signaling had a stronger effect in the L-dopa-only group, whereas both amantadine and the selective NMDA antagonist MK801 produced a markedly larger antidyskinetic effect in L-dopa-ropinirole cotreated animals. (lu.se)
  • He noted that he has used dopamine blockers to treat hundreds of children with Tourette syndrome and has never had a case of tardive dyskinesia . (medscape.com)
  • Domperidone is a Dopamine-2 receptor antagonist that acts as a prokinetic that works on the upper digestive tract allow food easily through the stomach. (drugcarts.com)
  • Mechanisms of dysregulation of dopamine neurotransmission by cholinesterase-inhibitors: implications for Gulf War Illness. (cdc.gov)
  • From these findings, we hypothesized that Gulf War Illness (GWI) involves dysregulation of dopamine neurotransmission in the mesocorticolimbic reward and motor circuitry of the basal ganglia, which contributes emotional and visceral nervous system processing. (cdc.gov)
  • BACKGROUND: Pituitary pars intermedia dysfunction (PPID), a neurodegenerative disease leading to reduced dopamine production, is a common disease in aged horses. (bvsalud.org)
  • Lindqvist, Tor Magnusson and Bertil Waldeck, made the seminal observations that during the subsequent years would lead to the unravelling of dopamine as a transmitter in the central nervous system, independent of its role as a precursor in noradrenaline and adrenaline synthesis. (lu.se)
  • In their 1957 and 1958 papers [1.2], (Carlsson et al 1957) (Carlsson et al 1958) Carlsson and co-workers made the intriguing observation that the akinetic effects of reserpine could be reversed by an intravenous injection of the dopamine (and noradrenaline) precursor, 3,4- dihydroxyphenylalanine (DOPA). (lu.se)
  • Semisynthetic ergot alkaloid derivative with strong dopamine D2-receptor agonist and partial dopamine D1-receptor effects. (medscape.com)
  • Dopamine receptor antagonists are used for some diseases such as schizophrenia, bipolar disorder, nausea and vomiting. (wikipedia.org)
  • Dopamine is a major transmitter in the extrapyramidal system of the brain, and important in regulating movement. (edu.au)
  • The anhedonia hypothesis maintains that pleasure for food-reward is determined by dopamine activity in the brain. (bvsalud.org)
  • Dopamine (DA) is a well-studied neurochemical in the mammalian carotid body (CB), a chemosensory organ involved in O2 and CO2/H+ homeostasis. (mcmaster.ca)
  • Amisulpride is in a class of medications called dopamine receptor antagonists. (medlineplus.gov)
  • Several other dopamine antagonists are antiemetics used in the treatment of nausea and vomiting. (wikipedia.org)
  • It works by blocking the action of dopamine, a natural substance that may cause nausea and vomiting. (medlineplus.gov)
  • However, DA strongly inhibited [Ca2+]i elevations (Δ[Ca2+]i) evoked by the P2Y2R agonist UTP (100 μM), an effect opposed by the D2/3R antagonist, sulpiride (1-10 μM). (mcmaster.ca)
  • The experimental device will take the opportunity to submit P2X7 knockout mouse to UCMS protocol, to assess the effect of specific P2X7 antagonists and test whose role in neurogenesis, microglial activation and endothelial changes induced by UCMS mice, will also be evaluated. (univ-tours.fr)
  • In addition, dopamine research has been unique within the neurosciences in the way it has bridged basic science and clinical practice. (lu.se)
  • Activation of the D1 dopamine receptor/cAMP/PKA cascade is regulated by the neuronal protein kinase, Cdk5. (cdc.gov)
  • Not only is there a lack of dopamine to contend with, but many patients who have been using opioids for an extended time have not focused on other important aspects of their health. (thecolemaninstitute.com)
  • Mimic dopamine action of inhibition of prolactin release. (medscape.com)
  • This unique mechanism of action allows aripiprazole to help regulate the activity of dopamine and other neurotransmitters, which can help to improve symptoms of several mental health conditions. (azspills.com)
  • The treatment is based on administration of the dopamine agonist pergolide. (bvsalud.org)
  • Treatment of striatal slices with CP induced a dose-dependent increase in phospho-Ser845 GluR1 and phospho-Thr34 DARPP-32, which was blocked by a D1 antagonist. (cdc.gov)
  • Finally, treatment of mice with a chronic low-dose combination of CP and PB reduced concentrations of dopamine and its metabolites DOPAC and HVA, and increased dopamine turnover, in the olfactory bulb. (cdc.gov)
  • Alpha-naphthoflavone acts as an antagonist of 2,3,7, 8-tetrachlorodibenzo-p-dioxin by forming an inactive complex with the Ah receptor. (aspetjournals.org)
  • BACKGROUND: Current models of levodopa (L-dopa)-induced dyskinesia (LID) are obtained by treating dopamine-depleted animals with L-dopa. (lu.se)
  • The number of papers published on dopamine that year, as listed in PubMed, was 234. (lu.se)
  • Number of publications per year from 1945 to 2006 on the topics of Dopamine and of related classical neurotransmitters. (lu.se)