The output neurons of the cerebellar cortex.
Modified cardiac muscle fibers composing the terminal portion of the heart conduction system.
The part of brain that lies behind the BRAIN STEM in the posterior base of skull (CRANIAL FOSSA, POSTERIOR). It is also known as the "little brain" with convolutions similar to those of CEREBRAL CORTEX, inner white matter, and deep cerebellar nuclei. Its function is to coordinate voluntary movements, maintain balance, and learn motor skills.
The superficial GRAY MATTER of the CEREBELLUM. It consists of two main layers, the stratum moleculare and the stratum granulosum.
Mice which carry mutant genes for neurologic defects or abnormalities.
Extensions of the nerve cell body. They are short and branched and receive stimuli from other NEURONS.
Four clusters of neurons located deep within the WHITE MATTER of the CEREBELLUM, which are the nucleus dentatus, nucleus emboliformis, nucleus globosus, and nucleus fastigii.
A part of the MEDULLA OBLONGATA situated in the olivary body. It is involved with motor control and is a major source of sensory input to the CEREBELLUM.
Abrupt changes in the membrane potential that sweep along the CELL MEMBRANE of excitable cells in response to excitation stimuli.
Calcium-binding proteins that are found in DISTAL KIDNEY TUBULES, INTESTINES, BRAIN, and other tissues where they bind, buffer and transport cytoplasmic calcium. Calbindins possess a variable number of EF-HAND MOTIFS which contain calcium-binding sites. Some isoforms are regulated by VITAMIN D.
Slender processes of NEURONS, including the AXONS and their glial envelopes (MYELIN SHEATH). Nerve fibers conduct nerve impulses to and from the CENTRAL NERVOUS SYSTEM.
Impairment of the ability to perform smoothly coordinated voluntary movements. This condition may affect the limbs, trunk, eyes, pharynx, larynx, and other structures. Ataxia may result from impaired sensory or motor function. Sensory ataxia may result from posterior column injury or PERIPHERAL NERVE DISEASES. Motor ataxia may be associated with CEREBELLAR DISEASES; CEREBRAL CORTEX diseases; THALAMIC DISEASES; BASAL GANGLIA DISEASES; injury to the RED NUCLEUS; and other conditions.
A calbindin protein found in many mammalian tissues, including the UTERUS, PLACENTA, BONE, PITUITARY GLAND, and KIDNEYS. In intestinal ENTEROCYTES it mediates intracellular calcium transport from apical to basolateral membranes via calcium binding at two EF-HAND MOTIFS. Expression is regulated in some tissues by VITAMIN D.
Incoordination of voluntary movements that occur as a manifestation of CEREBELLAR DISEASES. Characteristic features include a tendency for limb movements to overshoot or undershoot a target (dysmetria), a tremor that occurs during attempted movements (intention TREMOR), impaired force and rhythm of diadochokinesis (rapidly alternating movements), and GAIT ATAXIA. (From Adams et al., Principles of Neurology, 6th ed, p90)
Specialized junctions at which a neuron communicates with a target cell. At classical synapses, a neuron's presynaptic terminal releases a chemical transmitter stored in synaptic vesicles which diffuses across a narrow synaptic cleft and activates receptors on the postsynaptic membrane of the target cell. The target may be a dendrite, cell body, or axon of another neuron, or a specialized region of a muscle or secretory cell. Neurons may also communicate via direct electrical coupling with ELECTRICAL SYNAPSES. Several other non-synaptic chemical or electric signal transmitting processes occur via extracellular mediated interactions.
A group of dominantly inherited, predominately late-onset, cerebellar ataxias which have been divided into multiple subtypes based on clinical features and genetic mapping. Progressive ataxia is a central feature of these conditions, and in certain subtypes POLYNEUROPATHY; DYSARTHRIA; visual loss; and other disorders may develop. (From Joynt, Clinical Neurology, 1997, Ch65, pp 12-17; J Neuropathol Exp Neurol 1998 Jun;57(6):531-43)
An impulse-conducting system composed of modified cardiac muscle, having the power of spontaneous rhythmicity and conduction more highly developed than the rest of the heart.
CALCIUM CHANNELS located within the PURKINJE CELLS of the cerebellum. They are involved in stimulation-secretion coupling of neurons.
'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.
An electrophysiologic technique for studying cells, cell membranes, and occasionally isolated organelles. All patch-clamp methods rely on a very high-resistance seal between a micropipette and a membrane; the seal is usually attained by gentle suction. The four most common variants include on-cell patch, inside-out patch, outside-out patch, and whole-cell clamp. Patch-clamp methods are commonly used to voltage clamp, that is control the voltage across the membrane and measure current flow, but current-clamp methods, in which the current is controlled and the voltage is measured, are also used.
Diseases that affect the structure or function of the cerebellum. Cardinal manifestations of cerebellar dysfunction include dysmetria, GAIT ATAXIA, and MUSCLE HYPOTONIA.
Use of electric potential or currents to elicit biological responses.
Refers to animals in the period of time just after birth.
A glutamate plasma membrane transporter protein that is primarily expressed in cerebellar PURKINJE CELLS on postsynaptic DENDRITIC SPINES.
A beta-carboline alkaloid isolated from seeds of PEGANUM.
Loss of functional activity and trophic degeneration of nerve axons and their terminal arborizations following the destruction of their cells of origin or interruption of their continuity with these cells. The pathology is characteristic of neurodegenerative diseases. Often the process of nerve degeneration is studied in research on neuroanatomical localization and correlation of the neurophysiology of neural pathways.
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.
A persistent activity-dependent decrease in synaptic efficacy between NEURONS. It typically occurs following repeated low-frequency afferent stimulation, but it can be induced by other methods. Long-term depression appears to play a role in MEMORY.
A heterogenous group of degenerative syndromes marked by progressive cerebellar dysfunction either in isolation or combined with other neurologic manifestations. Sporadic and inherited subtypes occur. Inheritance patterns include autosomal dominant, autosomal recessive, and X-linked.
The voltage differences across a membrane. For cellular membranes they are computed by subtracting the voltage measured outside the membrane from the voltage measured inside the membrane. They result from differences of inside versus outside concentration of potassium, sodium, chloride, and other ions across cells' or ORGANELLES membranes. For excitable cells, the resting membrane potentials range between -30 and -100 millivolts. Physical, chemical, or electrical stimuli can make a membrane potential more negative (hyperpolarization), or less negative (depolarization).
Depolarization of membrane potentials at the SYNAPTIC MEMBRANES of target neurons during neurotransmission. Excitatory postsynaptic potentials can singly or in summation reach the trigger threshold for ACTION POTENTIALS.
A carboxypeptidase that is specific for proteins that contain two ALANINE residues on their C-terminal. Enzymes in this class play an important role in bacterial CELL WALL biosynthesis.
The study of the generation and behavior of electrical charges in living organisms particularly the nervous system and the effects of electricity on living organisms.
Nerve fibers that are capable of rapidly conducting impulses away from the neuron cell body.
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.
The function of opposing or restraining the excitation of neurons or their target excitable cells.
A performance test based on forced MOTOR ACTIVITY on a rotating rod, usually by a rodent. Parameters include the riding time (seconds) or endurance. Test is used to evaluate balance and coordination of the subjects, particular in experimental animal models for neurological disorders and drug effects.
A reflex wherein impulses are conveyed from the cupulas of the SEMICIRCULAR CANALS and from the OTOLITHIC MEMBRANE of the SACCULE AND UTRICLE via the VESTIBULAR NUCLEI of the BRAIN STEM and the median longitudinal fasciculus to the OCULOMOTOR NERVE nuclei. It functions to maintain a stable retinal image during head rotation by generating appropriate compensatory EYE MOVEMENTS.
CALCIUM CHANNELS located in the neurons of the brain.
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.
Cell surface proteins that bind glutamate and act through G-proteins to influence second messenger systems. Several types of metabotropic glutamate receptors have been cloned. They differ in pharmacology, distribution, and mechanisms of action.
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.
Laboratory mice that have been produced from a genetically manipulated EGG or EMBRYO, MAMMALIAN.
Cell-surface proteins that bind glutamate and trigger changes which influence the behavior of cells. Glutamate receptors include ionotropic receptors (AMPA, kainate, and N-methyl-D-aspartate receptors), which directly control ion channels, and metabotropic receptors which act through second messenger systems. Glutamate receptors are the most common mediators of fast excitatory synaptic transmission in the central nervous system. They have also been implicated in the mechanisms of memory and of many diseases.
The capacity of the NERVOUS SYSTEM to change its reactivity as the result of successive activations.
The domestic dog, Canis familiaris, comprising about 400 breeds, of the carnivore family CANIDAE. They are worldwide in distribution and live in association with people. (Walker's Mammals of the World, 5th ed, p1065)
A voltage-gated sodium channel subtype found widely expressed in neurons of the central and peripheral nervous systems. Defects in the SCN8A gene which codes for the alpha subunit of this sodium channel are associated with ATAXIA and cognitive deficits.
Histochemical localization of immunoreactive substances using labeled antibodies as reagents.
A calcium-binding protein that mediates calcium HOMEOSTASIS in KIDNEYS, BRAIN, and other tissues. It is found in well-defined populations of NEURONS and is involved in CALCIUM SIGNALING and NEURONAL PLASTICITY. It is regulated in some tissues by VITAMIN D.
Theoretical representations that simulate the behavior or activity of the neurological system, processes or phenomena; includes the use of mathematical equations, computers, and other electronic equipment.
Reflex closure of the eyelid occurring as a result of classical conditioning.
An aminoperhydroquinazoline poison found mainly in the liver and ovaries of fishes in the order TETRAODONTIFORMES, which are eaten. The toxin causes paresthesia and paralysis through interference with neuromuscular conduction.
Drugs that bind to but do not activate excitatory amino acid receptors, thereby blocking the actions of agonists.
CALCIUM CHANNELS that are concentrated in neural tissue. Omega toxins inhibit the actions of these channels by altering their voltage dependence.
Strains of mice in which certain GENES of their GENOMES have been disrupted, or "knocked-out". To produce knockouts, using RECOMBINANT DNA technology, the normal DNA sequence of the gene being studied is altered to prevent synthesis of a normal gene product. Cloned cells in which this DNA alteration is successful are then injected into mouse EMBRYOS to produce chimeric mice. The chimeric mice are then bred to yield a strain in which all the cells of the mouse contain the disrupted gene. Knockout mice are used as EXPERIMENTAL ANIMAL MODELS for diseases (DISEASE MODELS, ANIMAL) and to clarify the functions of the genes.
Electrical responses recorded from nerve, muscle, SENSORY RECEPTOR, or area of the CENTRAL NERVOUS SYSTEM following stimulation. They range from less than a microvolt to several microvolts. The evoked potential can be auditory (EVOKED POTENTIALS, AUDITORY), somatosensory (EVOKED POTENTIALS, SOMATOSENSORY), visual (EVOKED POTENTIALS, VISUAL), or motor (EVOKED POTENTIALS, MOTOR), or other modalities that have been reported.
Voltage-dependent cell membrane glycoproteins selectively permeable to calcium ions. They are categorized as L-, T-, N-, P-, Q-, and R-types based on the activation and inactivation kinetics, ion specificity, and sensitivity to drugs and toxins. The L- and T-types are present throughout the cardiovascular and central nervous systems and the N-, P-, Q-, & R-types are located in neuronal tissue.
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 number of CELLS of a specific kind, usually measured per unit volume or area of sample.
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.
Intracellular receptors that bind to INOSITOL 1,4,5-TRISPHOSPHATE and play an important role in its intracellular signaling. Inositol 1,4,5-trisphosphate receptors are calcium channels that release CALCIUM in response to increased levels of inositol 1,4,5-trisphosphate in the CYTOPLASM.
A technique for maintenance or growth of animal organs in vitro. It refers to three-dimensional cultures of undisaggregated tissue retaining some or all of the histological features of the tissue in vivo. (Freshney, Culture of Animal Cells, 3d ed, p1)
Elements of limited time intervals, contributing to particular results or situations.
Nerve structures through which impulses are conducted from a peripheral part toward a nerve center.
A strain of albino rat developed at the Wistar Institute that has spread widely at other institutions. This has markedly diluted the original strain.
Mice bearing mutant genes which are phenotypically expressed in the animals.
A shaker subfamily that is prominently expressed in NEURONS and are necessary for high-frequency, repetitive firing of ACTION POTENTIALS.
Most generally any NEURONS which are not motor or sensory. Interneurons may also refer to neurons whose AXONS remain within a particular brain region in contrast to projection neurons, which have axons projecting to other brain regions.
The most common inhibitory neurotransmitter in the central nervous system.
Brief closing of the eyelids by involuntary normal periodic closing, as a protective measure, or by voluntary action.
Electrodes with an extremely small tip, used in a voltage clamp or other apparatus to stimulate or record bioelectric potentials of single cells intracellularly or extracellularly. (Dorland, 28th ed)
3 beta,5,14-Trihydroxy-19-oxo-5 beta-card-20(22)-enolide. The aglycone cardioactive agent isolated from Strophanthus Kombe, S. gratus and other species; it is a very toxic material formerly used as digitalis. Synonyms: Apocymarin; Corchorin; Cynotoxin; Corchorgenin.
A potent excitatory amino acid antagonist with a preference for non-NMDA iontropic receptors. It is used primarily as a research tool.
A technique that localizes specific nucleic acid sequences within intact chromosomes, eukaryotic cells, or bacterial cells through the use of specific nucleic acid-labeled probes.
**Pyridazine** is a heterocyclic organic compound, consisting of a six-membered ring containing two nitrogen atoms, which is a basic structure found in certain pharmaceuticals and natural compounds, though it does not have a specific medical definition itself as a component or condition.
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 relatively common disorder characterized by a fairly specific pattern of tremors which are most prominent in the upper extremities and neck, inducing titubations of the head. The tremor is usually mild, but when severe may be disabling. An autosomal dominant pattern of inheritance may occur in some families (i.e., familial tremor). (Mov Disord 1988;13(1):5-10)
Drugs that bind to but do not activate GABA RECEPTORS, thereby blocking the actions of endogenous GAMMA-AMINOBUTYRIC ACID and GABA RECEPTOR AGONISTS.
The distal terminations of axons which are specialized for the release of neurotransmitters. Also included are varicosities along the course of axons which have similar specializations and also release transmitters. Presynaptic terminals in both the central and peripheral nervous systems are included.
The ability of a substrate to allow the passage of ELECTRONS.
Inorganic or organic derivatives of phosphinic acid, H2PO(OH). They include phosphinates and phosphinic acid esters.
The vestibular part of the 8th cranial nerve (VESTIBULOCOCHLEAR NERVE). The vestibular nerve fibers arise from neurons of Scarpa's ganglion and project peripherally to vestibular hair cells and centrally to the VESTIBULAR NUCLEI of the BRAIN STEM. These fibers mediate the sense of balance and head position.
A neuropeptide toxin from the venom of the funnel web spider, Agelenopsis aperta. It inhibits CALCIUM CHANNELS, P-TYPE by altering the voltage-dependent gating so that very large depolarizations are needed for channel opening. It also inhibits CALCIUM CHANNELS, Q-TYPE.
A class of ionotropic glutamate receptors characterized by their affinity for the agonist AMPA (alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid).
The non-neuronal cells of the nervous system. They not only provide physical support, but also respond to injury, regulate the ionic and chemical composition of the extracellular milieu, participate in the BLOOD-BRAIN BARRIER and BLOOD-RETINAL BARRIER, form the myelin insulation of nervous pathways, guide neuronal migration during development, and exchange metabolites with neurons. Neuroglia have high-affinity transmitter uptake systems, voltage-dependent and transmitter-gated ion channels, and can release transmitters, but their role in signaling (as in many other functions) is unclear.
A member of the alkali group of metals. It has the atomic symbol Na, atomic number 11, and atomic weight 23.

Ionic currents underlying spontaneous action potentials in isolated cerebellar Purkinje neurons. (1/1885)

Acutely dissociated cell bodies of mouse Purkinje neurons spontaneously fired action potentials at approximately 50 Hz (25 degrees C). To directly measure the ionic currents underlying spontaneous activity, we voltage-clamped the cells using prerecorded spontaneous action potentials (spike trains) as voltage commands and used ionic substitution and selective blockers to isolate individual currents. The largest current flowing during the interspike interval was tetrodotoxin-sensitive sodium current (approximately -50 pA between -65 and -60 mV). Although the neurons had large voltage-dependent calcium currents, the net current blocked by cobalt substitution for calcium was outward at all times during spike trains. Thus, the electrical effect of calcium current is apparently dominated by rapidly activated calcium-dependent potassium currents. Under current clamp, all cells continued firing spontaneously (though approximately 30% more slowly) after block of T-type calcium current by mibefradil, and most cells continued to fire after block of all calcium current by cobalt substitution. Although the neurons possessed hyperpolarization-activated cation current (Ih), little current flowed during spike trains, and block by 1 mM cesium had no effect on firing frequency. The outward potassium currents underlying the repolarization of the spikes were completely blocked by 1 mM TEA. These currents deactivated quickly (<1 msec) after each spike. We conclude that the spontaneous firing of Purkinje neuron cell bodies depends mainly on tetrodotoxin-sensitive sodium current flowing between spikes. The high firing rate is promoted by large potassium currents that repolarize the cell rapidly and deactivate quickly, thus preventing strong hyperpolarization and restoring a high input resistance for subsequent depolarization.  (+info)

Cerebellar Purkinje cell simple spike discharge encodes movement velocity in primates during visuomotor arm tracking. (2/1885)

Pathophysiological, lesion, and electrophysiological studies suggest that the cerebellar cortex is important for controlling the direction and speed of movement. The relationship of cerebellar Purkinje cell discharge to the control of arm movement parameters, however, remains unclear. The goal of this study was to examine how movement direction and speed and their interaction-velocity-modulate Purkinje cell simple spike discharge in an arm movement task in which direction and speed were independently controlled. The simple spike discharge of 154 Purkinje cells was recorded in two monkeys during the performance of two visuomotor tasks that required the animals to track targets that moved in one of eight directions and at one of four speeds. Single-parameter regression analyses revealed that a large proportion of cells had discharge modulation related to movement direction and speed. Most cells with significant directional tuning, however, were modulated at one speed, and most cells with speed-related discharge were modulated along one direction; this suggested that the patterns of simple spike discharge were not adequately described by single-parameter models. Therefore, a regression surface was fitted to the data, which showed that the discharge could be tuned to specific direction-speed combinations (preferred velocities). The overall variability in simple spike discharge was well described by the surface model, and the velocities corresponding to maximal and minimal discharge rates were distributed uniformly throughout the workspace. Simple spike discharge therefore appears to integrate information about both the direction and speed of arm movements, thereby encoding movement velocity.  (+info)

Comparative effects of methylmercury on parallel-fiber and climbing-fiber responses of rat cerebellar slices. (3/1885)

The environmental neurotoxicant methylmercury (MeHg) causes profound disruption of cerebellar function. Previous studies have shown that acute exposure to MeHg impairs synaptic transmission in both the peripheral and central nervous systems. However, the effects of MeHg on cerebellar synaptic function have never been examined. In the present study, effects of acute exposure to MeHg on synaptic transmission between parallel fibers or climbing fibers and Purkinje cells were compared in 300- to 350-microm cerebellar slices by using extracellular and intracellular microelectrode-recording techniques. Field potentials of parallel-fiber volleys (PFVs) and the associated postsynaptic responses (PSRs) were recorded in the molecular layer by stimulating the parallel fibers in transverse cerebellar slices. The climbing-fiber responses were also recorded in the molecular layer by stimulating white matter in sagittal cerebellar slices. At 20, 100, and 500 microM, MeHg reduced the amplitude of both PFVs and the associated PSRs to complete block, however, it blocked PSRs more rapidly than PFVs. MeHg also decreased the amplitudes of climbing-fiber responses to complete block. For all responses, an initial increase in amplitude preceded MeHg-induced suppression. Intracellular recordings of excitatory postsynaptic potentials of Purkinje cells were compared before and after MeHg. At 100 microM and 20 microM, MeHg blocked the Na+-dependent, fast somatic spikes and Ca++-dependent, slow dendritic spike bursts. MeHg also hyperpolarized and then depolarized Purkinje cell membranes, suppressed current conduction from parallel fibers or climbing fibers to dendrites of Purkinje cells, and blocked synaptically activated local responses. MeHg switched the pattern of repetitive firing of Purkinje cells generated spontaneously or by depolarizing current injection at Purkinje cell soma from predominantly Na+-dependent, fast somatic spikes to predominantly Ca++-dependent, low amplitude, slow dendritic spike bursts. Thus, acute exposure to MeHg causes a complex pattern of effects on cerebellar synaptic transmission, with apparent actions on both neuronal excitability and chemical synaptic transmission.  (+info)

Effect of riluzole on the neurological and neuropathological changes in an animal model of cardiac arrest-induced movement disorder. (4/1885)

Posthypoxic myoclonus and seizures precipitate as secondary neurological consequences in ischemic/hypoxic insults of the central nervous system. Neuronal hyperexcitation may be due to excessive activation of glutamatergic neurotransmission, an effect that has been shown to follow ischemic/hypoxic events. Therefore, riluzole, an anticonvulsant that inhibits the release of glutamate by stabilizing the inactivated state of activated voltage-sensitive sodium channels, was tested for its antimyoclonic and neuroprotective properties in the cardiac arrest-induced animal model of posthypoxic myoclonus. Riluzole (4-12 mg/kg i.p.) dose-dependently attenuated the audiogenic seizures and action myoclonus seen in this animal model. Histological examination using Nissl staining and the novel Fluoro-Jade histochemistry in cardiac-arrested animals showed an extensive neuronal degeneration in the hippocampus and cerebellum. Riluzole treatment almost completely prevented the neuronal degeneration in these brain areas. The neuroprotective effect was more pronounced in hippocampal pyramidal neurons and cerebellar Purkinje cells. These effects were seen at therapeutically relevant doses of riluzole, and the animals tolerated the treatment well. These findings indicate that the pathogenesis of posthypoxic myoclonus and seizure may involve excessive activation of glutamate neurotransmission, and that riluzole may serve as an effective pharmacological agent with neuroprotective potential for the treatment of neurological conditions associated with cardiac arrest in humans.  (+info)

Molecular identification of human G-substrate, a possible downstream component of the cGMP-dependent protein kinase cascade in cerebellar Purkinje cells. (5/1885)

G-substrate, an endogenous substrate for cGMP-dependent protein kinase, exists almost exclusively in cerebellar Purkinje cells, where it is possibly involved in the induction of long-term depression. A G-substrate cDNA was identified by screening expressed sequence tag databases from a human brain library. The deduced amino acid sequence of human G-substrate contained two putative phosphorylation sites (Thr-68 and Thr-119) with amino acid sequences [KPRRKDT(p)PALH] that were identical to those reported for rabbit G-substrate. G-substrate mRNA was expressed almost exclusively in the cerebellum as a single transcript. The human G-substrate gene was mapped to human chromosome 7p15 by radiation hybrid panel analysis. In vitro translation products of the cDNA showed an apparent molecular mass of 24 kDa on SDS/PAGE which was close to that of purified rabbit G-substrate (23 kDa). Bacterially expressed human G-substrate is a heat-stable and acid-soluble protein that cross-reacts with antibodies raised against rabbit G-substrate. Recombinant human G-substrate was phosphorylated efficiently by cGMP-dependent protein kinase exclusively at Thr residues, and it was recognized by antibodies specific for rabbit phospho-G-substrate. The amino acid sequences surrounding the sites of phosphorylation in G-substrate are related to those around Thr-34 and Thr-35 of the dopamine- and cAMP-regulated phosphoprotein DARPP-32 and inhibitor-1, respectively, two potent inhibitors of protein phosphatase 1. However, purified G-substrate phosphorylated by cGMP-dependent protein kinase inhibited protein phosphatase 2A more effectively than protein phosphatase 1, suggesting a distinct role as a protein phosphatase inhibitor.  (+info)

Patterns of spontaneous purkinje cell complex spike activity in the awake rat. (6/1885)

The olivocerebellar system is known to generate periodic synchronous discharges that result in synchronous (to within 1 msec) climbing fiber activation of Purkinje cells (complex spikes) organized in parasagittally oriented strips. These results have been obtained primarily in anesthetized animals, and so the question remains whether the olivocerebellar system generates such patterns in the awake animal. To this end, multiple electrode recordings of crus 2a complex spike activity were obtained in awake rats conditioned to execute tongue movements in response to a tone. After removal of all movement- and tone-related activity, the remaining data were examined to characterize spontaneous complex spike activity in the alert animal. Spontaneous complex spikes occurred at an average firing rate of 1 Hz and a clear approximately 10 Hz rhythmicity. Analysis of the autocorrelograms using a rhythm index indicated that the large majority of Purkinje cells displayed rhythmicity, similar to that in the anesthetized preparation. In addition, the patterns of synchronous complex spike activity were also similar to those observed in the anesthetized preparation (i.e., simultaneous activity was found predominantly among Purkinje cells located within the same parasagittally oriented strip of cortex). The results provide unequivocal evidence that the olivocerebellar system is capable of generating periodic patterns of synchronous activity in the awake animal. These findings support the extrapolation of previous results obtained in the anesthetized preparation to the waking state and are consistent with the timing hypothesis concerning the role of the olivocerebellar system in motor coordination.  (+info)

Presynaptic strontium dynamics and synaptic transmission. (7/1885)

Strontium can replace calcium in triggering neurotransmitter release, although peak release is reduced and the duration of release is prolonged. Strontium has therefore become useful in probing release, but its mechanism of action is not well understood. Here we study the action of strontium at the granule cell to Purkinje cell synapse in mouse cerebellar slices. Presynaptic residual strontium levels were monitored with fluorescent indicators, which all responded to strontium (fura-2, calcium orange, fura-2FF, magnesium green, and mag-fura-5). When calcium was replaced by equimolar concentrations of strontium in the external bath, strontium and calcium both entered presynaptic terminals. Contaminating calcium was eliminated by including EGTA in the extracellular bath, or by loading parallel fibers with EGTA, enabling the actions of strontium to be studied in isolation. After a single stimulus, strontium reached higher peak free levels than did calcium (approximately 1.7 times greater), and decayed more slowly (half-decay time 189 ms for strontium and 32 ms for calcium). These differences in calcium and strontium dynamics are likely a consequence of greater strontium permeability through calcium channels, lower affinity of the endogenous buffer for strontium, and less efficient extrusion of strontium. Measurements of presynaptic divalent levels help to explain properties of release evoked by strontium. Parallel fiber synaptic currents triggered by strontium are smaller in amplitude and longer in duration than those triggered by calcium. In both calcium and strontium, release consists of two components, one more steeply dependent on divalent levels than the other. Strontium drives both components less effectively than does calcium, suggesting that the affinities of the sensors involved in both phases of release are lower for strontium than for calcium. Thus, the larger and slower strontium transients account for the prominent slow component of release triggered by strontium.  (+info)

Influence of the sodium pump on intercellular communication in heart fibres: effect of intracellular injection of sodium ion on electrical coupling. (8/1885)

1. The effect of intracellular sodium injection on the electrical coupling between cardiac Purkinje cells was investigated. 2. It was found that an increase in the intracellular sodium concentration produces uncoupling in about 500 sec and increases the input resistance of the injected cell. Both effects were completely reversible. 3. Inhibition of the sodium pump by ouabain (6-8 x 10(7) M) also causes electrical uncoupling. 4. The decoupling of heart cells achieved by sodium injection was considerably accelerated in fibres treated with ouabain. 5. The influence of sodium injection on cell communication seems to be related to the intracellular calcium concentration 6. The above results indicate that the maintenance of a low intracellular sodium concentration by the sodium pump is essential for the preservation of a high junctional conductance in cardiac fibres.  (+info)

Purkinje cells are a type of neuron located in the cerebellar cortex, which is the outer layer of the cerebellum, a part of the brain that plays a crucial role in motor control and coordination. These cells have large branching dendrites and receive input from many other neurons, particularly granule cells. The axons of Purkinje cells form the principal output pathway of the cerebellar cortex, synapsing with deep cerebellar nuclei. They are named after Johannes Evangelista Purkinje, a Czech physiologist who first described them in 1837.

Purkinje fibers are specialized cardiac muscle fibers that are located in the subendocardial region of the inner ventricular walls of the heart. They play a crucial role in the electrical conduction system of the heart, transmitting electrical impulses from the bundle branches to the ventricular myocardium, which enables the coordinated contraction of the ventricles during each heartbeat.

These fibers have a unique structure that allows for rapid and efficient conduction of electrical signals. They are larger in diameter than regular cardiac muscle fibers, have fewer branching points, and possess more numerous mitochondria and a richer blood supply. These features enable Purkinje fibers to conduct electrical impulses at faster speeds, ensuring that the ventricles contract simultaneously and forcefully, promoting efficient pumping of blood throughout the body.

The cerebellum is a part of the brain that lies behind the brainstem and is involved in the regulation of motor movements, balance, and coordination. It contains two hemispheres and a central portion called the vermis. The cerebellum receives input from sensory systems and other areas of the brain and spinal cord and sends output to motor areas of the brain. Damage to the cerebellum can result in problems with movement, balance, and coordination.

The cerebellar cortex is the outer layer of the cerebellum, which is a part of the brain that plays a crucial role in motor control, balance, and coordination of muscle movements. The cerebellar cortex contains numerous small neurons called granule cells, as well as other types of neurons such as Purkinje cells, basket cells, and stellate cells. These neurons are organized into distinct layers and microcircuits that process information related to motor function and possibly other functions such as cognition and emotion. The cerebellar cortex receives input from various sources, including the spinal cord, vestibular system, and cerebral cortex, and sends output to brainstem nuclei and thalamus, which in turn project to the cerebral cortex. Damage to the cerebellar cortex can result in ataxia, dysmetria, dysdiadochokinesia, and other motor symptoms.

Neurologic mutant mice are genetically engineered or spontaneously mutated rodents that are used as models to study various neurological disorders and conditions. These mice have specific genetic modifications or mutations that affect their nervous system, leading to phenotypes that resemble human neurological diseases.

Some examples of neurologic mutant mice include:

1. Alzheimer's disease models: Mice that overexpress genes associated with Alzheimer's disease, such as the amyloid precursor protein (APP) or presenilin 1 (PS1), to study the pathogenesis and potential treatments of this disorder.
2. Parkinson's disease models: Mice that have genetic mutations in genes associated with Parkinson's disease, such as alpha-synuclein or parkin, to investigate the mechanisms underlying this condition and develop new therapies.
3. Huntington's disease models: Mice that carry an expanded CAG repeat in the huntingtin gene to replicate the genetic defect seen in humans with Huntington's disease and study disease progression and treatment strategies.
4. Epilepsy models: Mice with genetic mutations that cause spontaneous seizures or increased susceptibility to seizures, used to investigate the underlying mechanisms of epilepsy and develop new treatments.
5. Stroke models: Mice that have surgical induction of stroke or genetic modifications that increase the risk of stroke, used to study the pathophysiology of stroke and identify potential therapeutic targets.

Neurologic mutant mice are essential tools in biomedical research, allowing scientists to investigate the complex interactions between genes and the environment that contribute to neurological disorders. These models help researchers better understand disease mechanisms, develop new therapies, and test their safety and efficacy before moving on to clinical trials in humans.

Dendrites are the branched projections of a neuron that receive and process signals from other neurons. They are typically short and highly branching, increasing the surface area for receiving incoming signals. Dendrites are covered in small protrusions called dendritic spines, which can form connections with the axon terminals of other neurons through chemical synapses. The structure and function of dendrites play a critical role in the integration and processing of information in the nervous system.

The cerebellar nuclei are clusters of neurons located within the white matter of the cerebellum, a region of the brain responsible for motor coordination, balance, and fine movement regulation. There are four main pairs of cerebellar nuclei: the fastigial, interpositus, dentate, and vestibular nuclei. These nuclei receive input from various parts of the cerebellar cortex and project to different areas of the brainstem and thalamus, contributing to the regulation of muscle tone, posture, and movement.

The olivary nucleus is a structure located in the medulla oblongata, which is a part of the brainstem. It consists of two main parts: the inferior olive and the accessory olive. The inferior olive is further divided into several subnuclei.

The olivary nucleus plays an important role in the coordination of movements, particularly in the regulation of fine motor control and rhythmic movements. It receives input from various sources, including the cerebellum, spinal cord, and other brainstem nuclei, and sends output to the cerebellum via the climbing fibers.

Damage to the olivary nucleus can result in a variety of neurological symptoms, including ataxia (loss of coordination), tremors, and dysarthria (speech difficulties). Certain neurodegenerative disorders, such as multiple system atrophy, may also affect the olivary nucleus and contribute to its degeneration.

An action potential is a brief electrical signal that travels along the membrane of a nerve cell (neuron) or muscle cell. It is initiated by a rapid, localized change in the permeability of the cell membrane to specific ions, such as sodium and potassium, resulting in a rapid influx of sodium ions and a subsequent efflux of potassium ions. This ion movement causes a brief reversal of the electrical potential across the membrane, which is known as depolarization. The action potential then propagates along the cell membrane as a wave, allowing the electrical signal to be transmitted over long distances within the body. Action potentials play a crucial role in the communication and functioning of the nervous system and muscle tissue.

Calbindins are a family of calcium-binding proteins that are widely distributed in various tissues, including the gastrointestinal tract, brain, and kidney. They play important roles in regulating intracellular calcium levels and modulating calcium-dependent signaling pathways. Calbindin D28k, one of the major isoforms, is particularly abundant in the central nervous system and has been implicated in neuroprotection, neuronal plasticity, and regulation of neurotransmitter release. Deficiencies or alterations in calbindins have been associated with various pathological conditions, including neurological disorders and cancer.

Nerve fibers are specialized structures that constitute the long, slender processes (axons) of neurons (nerve cells). They are responsible for conducting electrical impulses, known as action potentials, away from the cell body and transmitting them to other neurons or effector organs such as muscles and glands. Nerve fibers are often surrounded by supportive cells called glial cells and are grouped together to form nerve bundles or nerves. These fibers can be myelinated (covered with a fatty insulating sheath called myelin) or unmyelinated, which influences the speed of impulse transmission.

Ataxia is a medical term that refers to a group of disorders affecting coordination, balance, and speech. It is characterized by a lack of muscle control during voluntary movements, causing unsteady or awkward movements, and often accompanied by tremors. Ataxia can affect various parts of the body, such as the limbs, trunk, eyes, and speech muscles. The condition can be congenital or acquired, and it can result from damage to the cerebellum, spinal cord, or sensory nerves. There are several types of ataxia, including hereditary ataxias, degenerative ataxias, cerebellar ataxias, and acquired ataxias, each with its own specific causes, symptoms, and prognosis. Treatment for ataxia typically focuses on managing symptoms and improving quality of life, as there is no cure for most forms of the disorder.

S100 calcium binding protein G, also known as calgranulin A or S100A8, is a member of the S100 family of proteins. These proteins are characterized by their ability to bind calcium ions and play a role in intracellular signaling and regulation of various cellular processes.

S100 calcium binding protein G forms a heterodimer with S100 calcium binding protein B (S100A9) and is involved in the inflammatory response, immune function, and tumor growth and progression. The S100A8/A9 heterocomplex has been shown to play a role in neutrophil activation and recruitment, as well as the regulation of cytokine production and cell proliferation.

Elevated levels of S100 calcium binding protein G have been found in various inflammatory conditions, such as rheumatoid arthritis, Crohn's disease, and psoriasis, as well as in several types of cancer, including breast, lung, and colon cancer. Therefore, it has been suggested that S100 calcium binding protein G may be a useful biomarker for the diagnosis and prognosis of these conditions.

Cerebellar ataxia is a type of ataxia, which refers to a group of disorders that cause difficulties with coordination and movement. Cerebellar ataxia specifically involves the cerebellum, which is the part of the brain responsible for maintaining balance, coordinating muscle movements, and regulating speech and eye movements.

The symptoms of cerebellar ataxia may include:

* Unsteady gait or difficulty walking
* Poor coordination of limb movements
* Tremors or shakiness, especially in the hands
* Slurred or irregular speech
* Abnormal eye movements, such as nystagmus (rapid, involuntary movement of the eyes)
* Difficulty with fine motor tasks, such as writing or buttoning a shirt

Cerebellar ataxia can be caused by a variety of underlying conditions, including:

* Genetic disorders, such as spinocerebellar ataxia or Friedreich's ataxia
* Brain injury or trauma
* Stroke or brain hemorrhage
* Infections, such as meningitis or encephalitis
* Exposure to toxins, such as alcohol or certain medications
* Tumors or other growths in the brain

Treatment for cerebellar ataxia depends on the underlying cause. In some cases, there may be no cure, and treatment is focused on managing symptoms and improving quality of life. Physical therapy, occupational therapy, and speech therapy can help improve coordination, balance, and communication skills. Medications may also be used to treat specific symptoms, such as tremors or muscle spasticity. In some cases, surgery may be recommended to remove tumors or repair damage to the brain.

A synapse is a structure in the nervous system that allows for the transmission of signals from one neuron (nerve cell) to another. It is the point where the axon terminal of one neuron meets the dendrite or cell body of another, and it is here that neurotransmitters are released and received. The synapse includes both the presynaptic and postsynaptic elements, as well as the cleft between them.

At the presynaptic side, an action potential travels down the axon and triggers the release of neurotransmitters into the synaptic cleft through exocytosis. These neurotransmitters then bind to receptors on the postsynaptic side, which can either excite or inhibit the receiving neuron. The strength of the signal between two neurons is determined by the number and efficiency of these synapses.

Synapses play a crucial role in the functioning of the nervous system, allowing for the integration and processing of information from various sources. They are also dynamic structures that can undergo changes in response to experience or injury, which has important implications for learning, memory, and recovery from neurological disorders.

Spinocerebellar ataxias (SCAs) are a group of genetic disorders that affect the cerebellum, which is the part of the brain responsible for coordinating muscle movements. SCAs are characterized by progressive problems with balance, speech, and coordination. They are caused by mutations in various genes that result in the production of abnormal proteins that accumulate in neurons, leading to their degeneration.

There are over 40 different types of SCAs, each caused by a different genetic mutation. Some of the more common types include SCA1, SCA2, SCA3, SCA6, and SCA7. The symptoms and age of onset can vary widely depending on the type of SCA.

In addition to problems with coordination and balance, people with SCAs may also experience muscle weakness, stiffness, tremors, spasticity, and difficulty swallowing or speaking. Some types of SCAs can also cause visual disturbances, hearing loss, and cognitive impairment. Currently, there is no cure for SCAs, but treatments such as physical therapy, speech therapy, and medications can help manage the symptoms.

The heart conduction system is a group of specialized cardiac muscle cells that generate and conduct electrical impulses to coordinate the contraction of the heart chambers. The main components of the heart conduction system include:

1. Sinoatrial (SA) node: Also known as the sinus node, it is located in the right atrium near the entrance of the superior vena cava and functions as the primary pacemaker of the heart. It sets the heart rate by generating electrical impulses at regular intervals.
2. Atrioventricular (AV) node: Located in the interatrial septum, near the opening of the coronary sinus, it serves as a relay station for electrical signals between the atria and ventricles. The AV node delays the transmission of impulses to allow the atria to contract before the ventricles.
3. Bundle of His: A bundle of specialized cardiac muscle fibers that conducts electrical impulses from the AV node to the ventricles. It divides into two main branches, the right and left bundle branches, which further divide into smaller Purkinje fibers.
4. Right and left bundle branches: These are extensions of the Bundle of His that transmit electrical impulses to the respective right and left ventricular myocardium. They consist of specialized conducting tissue with large diameters and minimal resistance, allowing for rapid conduction of electrical signals.
5. Purkinje fibers: Fine, branching fibers that arise from the bundle branches and spread throughout the ventricular myocardium. They are responsible for transmitting electrical impulses to the working cardiac muscle cells, triggering coordinated ventricular contraction.

In summary, the heart conduction system is a complex network of specialized muscle cells responsible for generating and conducting electrical signals that coordinate the contraction of the atria and ventricles, ensuring efficient blood flow throughout the body.

Calcium channels, P-type, are a specific type of voltage-gated calcium channel found in excitable cells such as neurons and muscle cells. They are named "P-type" because they were initially identified in Purkinje cells of the cerebellum. These channels play a crucial role in various cellular processes, including neurotransmitter release, muscle contraction, and gene expression.

P-type calcium channels are characterized by their unique biophysical properties, such as slow voltage-dependent activation and inactivation, as well as sensitivity to the drug felodipine. They are composed of several subunits, including the pore-forming α1 subunit, which contains the voltage sensor and the selectivity filter for calcium ions. The α1 subunit is associated with accessory subunits, such as β, γ, and δ, that modulate the channel's properties and trafficking to the cell membrane.

P-type calcium channels are important targets for therapeutic interventions in various diseases, including neurological disorders, cardiovascular diseases, and cancer. For example, drugs that block P-type calcium channels have been used to treat hypertension and angina, while activators of these channels have shown promise in treating neurodegenerative disorders such as 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.

Patch-clamp techniques are a group of electrophysiological methods used to study ion channels and other electrical properties of cells. These techniques were developed by Erwin Neher and Bert Sakmann, who were awarded the Nobel Prize in Physiology or Medicine in 1991 for their work. The basic principle of patch-clamp techniques involves creating a high resistance seal between a glass micropipette and the cell membrane, allowing for the measurement of current flowing through individual ion channels or groups of channels.

There are several different configurations of patch-clamp techniques, including:

1. Cell-attached configuration: In this configuration, the micropipette is attached to the outer surface of the cell membrane, and the current flowing across a single ion channel can be measured. This configuration allows for the study of the properties of individual channels in their native environment.
2. Whole-cell configuration: Here, the micropipette breaks through the cell membrane, creating a low resistance electrical connection between the pipette and the inside of the cell. This configuration allows for the measurement of the total current flowing across all ion channels in the cell membrane.
3. Inside-out configuration: In this configuration, the micropipette is pulled away from the cell after establishing a seal, resulting in the exposure of the inner surface of the cell membrane to the solution in the pipette. This configuration allows for the study of the properties of ion channels in isolation from other cellular components.
4. Outside-out configuration: Here, the micropipette is pulled away from the cell after establishing a seal, resulting in the exposure of the outer surface of the cell membrane to the solution in the pipette. This configuration allows for the study of the properties of ion channels in their native environment, but with the ability to control the composition of the extracellular solution.

Patch-clamp techniques have been instrumental in advancing our understanding of ion channel function and have contributed to numerous breakthroughs in neuroscience, pharmacology, and physiology.

Cerebellar diseases refer to a group of medical conditions that affect the cerebellum, which is the part of the brain located at the back of the head, below the occipital lobe and above the brainstem. The cerebellum plays a crucial role in motor control, coordination, balance, and some cognitive functions.

Cerebellar diseases can be caused by various factors, including genetics, infections, tumors, stroke, trauma, or degenerative processes. These conditions can result in a wide range of symptoms, such as:

1. Ataxia: Loss of coordination and unsteady gait
2. Dysmetria: Inability to judge distance and force while performing movements
3. Intention tremors: Shaking or trembling that worsens during purposeful movements
4. Nystagmus: Rapid, involuntary eye movement
5. Dysarthria: Speech difficulty due to muscle weakness or incoordination
6. Hypotonia: Decreased muscle tone
7. Titubation: Rhythmic, involuntary oscillations of the head and neck
8. Cognitive impairment: Problems with memory, attention, and executive functions

Some examples of cerebellar diseases include:

1. Ataxia-telangiectasia
2. Friedrich's ataxia
3. Multiple system atrophy (MSA)
4. Spinocerebellar ataxias (SCAs)
5. Cerebellar tumors, such as medulloblastomas or astrocytomas
6. Infarctions or hemorrhages in the cerebellum due to stroke or trauma
7. Infections, such as viral encephalitis or bacterial meningitis
8. Autoimmune disorders, like multiple sclerosis (MS) or paraneoplastic syndromes
9. Metabolic disorders, such as Wilson's disease or phenylketonuria (PKU)
10. Chronic alcoholism and withdrawal

Treatment for cerebellar diseases depends on the underlying cause and may involve medications, physical therapy, surgery, or supportive care to manage symptoms and improve quality of life.

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.

"Newborn animals" refers to the very young offspring of animals that have recently been born. In medical terminology, newborns are often referred to as "neonates," and they are classified as such from birth until about 28 days of age. During this time period, newborn animals are particularly vulnerable and require close monitoring and care to ensure their survival and healthy development.

The specific needs of newborn animals can vary widely depending on the species, but generally, they require warmth, nutrition, hydration, and protection from harm. In many cases, newborns are unable to regulate their own body temperature or feed themselves, so they rely heavily on their mothers for care and support.

In medical settings, newborn animals may be examined and treated by veterinarians to ensure that they are healthy and receiving the care they need. This can include providing medical interventions such as feeding tubes, antibiotics, or other treatments as needed to address any health issues that arise. Overall, the care and support of newborn animals is an important aspect of animal medicine and conservation efforts.

Excitatory Amino Acid Transporter 4 (EAAT4) is a type of glutamate transporter protein that is primarily found in the central nervous system, particularly in the Purkinje cells of the cerebellum. Glutamate is the primary excitatory neurotransmitter in the brain, and EAAT4 plays a crucial role in regulating its levels in the synaptic cleft (the narrow gap between neurons where neurotransmission occurs) by efficiently transporting glutamate back into the presynaptic neuron or nearby glial cells after it has been released. This helps to terminate the excitatory signal and prevent overstimulation of the postsynaptic neuron, which could lead to excitotoxicity and neurodegeneration if left unchecked.

EAAT4 is a subtype of the EAAT family, which includes five members (EAAT1-5) with different expression patterns, substrate affinities, and transport mechanisms. EAAT4 has a high affinity for glutamate and is primarily responsible for maintaining low basal levels of extracellular glutamate in the cerebellum. Mutations in the gene that encodes EAAT4 (SLC1A6) have been associated with certain neurological disorders, such as episodic ataxia type 6 and spinocerebellar ataxia type 12, highlighting the importance of proper glutamate transport and regulation in maintaining normal cerebellar function.

Harmane, also known as harmaline, is a naturally occurring psychoactive compound found in several plants, including the seeds of the Syrian rue (Peganum harmala) and the bark of the African pinwheel cactus (Adenium obesum). It is an alkaloid with beta-carboline structure.

In a medical context, harmaline has been studied for its potential effects on the central nervous system. It acts as a reversible monoamine oxidase inhibitor (MAOI), which means it can increase the levels of certain neurotransmitters in the brain by preventing their breakdown. This property has led to some research into its use as a treatment for depression and other neurological disorders, although it is not currently approved for medical use in this capacity due to potential side effects and toxicity concerns.

It's important to note that harmaline can have dangerous interactions with certain medications and foods, particularly those containing tyramine, which can lead to a hypertensive crisis. Therefore, its use should only be under the supervision of a qualified medical professional.

Nerve degeneration, also known as neurodegeneration, is the progressive loss of structure and function of neurons, which can lead to cognitive decline, motor impairment, and various other symptoms. This process occurs due to a variety of factors, including genetics, environmental influences, and aging. It is a key feature in several neurological disorders such as Alzheimer's disease, Parkinson's disease, Huntington's disease, and multiple sclerosis. The degeneration can affect any part of the nervous system, leading to different symptoms depending on the location and extent of the damage.

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.

Long-term synaptic depression (LTSD) is a form of prolonged decrease in the strength of synaptic transmission between neurons, which results from specific patterns of synaptic activity. It is characterized by a reduction in the amplitude and/or frequency of excitatory postsynaptic potentials (EPSPs) or currents (EPSCs), reflecting a decrease in the efficiency of neurotransmitter release and/or decreased responsiveness of the postsynaptic neuron.

LTSD typically requires prolonged periods of low-frequency stimulation (1-5 Hz) and can last for hours to days, depending on the synapse and organism. The underlying mechanisms involve changes in both presynaptic and postsynaptic elements, including alterations in the number and function of neurotransmitter receptors, modifications in the release probability of neurotransmitters, and structural remodeling of the synaptic connections.

LTSD is thought to play a crucial role in various forms of synaptic plasticity, learning, and memory processes, particularly those involving the extinction or weakening of synaptic connections. Dysregulation of LTSD has been implicated in several neurological and psychiatric disorders, such as Alzheimer's disease, Parkinson's disease, epilepsy, and depression.

Spinocerebellar degenerations (SCDs) are a group of genetic disorders that primarily affect the cerebellum, the part of the brain responsible for coordinating muscle movements, and the spinal cord. These conditions are characterized by progressive degeneration or loss of nerve cells in the cerebellum and/or spinal cord, leading to various neurological symptoms.

SCDs are often inherited in an autosomal dominant manner, meaning that only one copy of the altered gene from either parent is enough to cause the disorder. The most common type of SCD is spinocerebellar ataxia (SCA), which includes several subtypes (SCA1, SCA2, SCA3, etc.) differentiated by their genetic causes and specific clinical features.

Symptoms of spinocerebellar degenerations may include:

1. Progressive ataxia (loss of coordination and balance)
2. Dysarthria (speech difficulty)
3. Nystagmus (involuntary eye movements)
4. Oculomotor abnormalities (problems with eye movement control)
5. Tremors or other involuntary muscle movements
6. Muscle weakness and spasticity
7. Sensory disturbances, such as numbness or tingling sensations
8. Dysphagia (difficulty swallowing)
9. Cognitive impairment in some cases

The age of onset, severity, and progression of symptoms can vary significantly among different SCD subtypes and individuals. Currently, there is no cure for spinocerebellar degenerations, but various supportive treatments and therapies can help manage symptoms and improve quality of life.

Membrane potential is the electrical potential difference across a cell membrane, typically for excitable cells such as nerve and muscle cells. It is the difference in electric charge between the inside and outside of a cell, created by the selective permeability of the cell membrane to different ions. The resting membrane potential of a typical animal cell is around -70 mV, with the interior being negative relative to the exterior. This potential is generated and maintained by the active transport of ions across the membrane, primarily through the action of the sodium-potassium pump. Membrane potentials play a crucial role in many physiological processes, including the transmission of nerve impulses and the contraction of muscle cells.

Excitatory postsynaptic potentials (EPSPs) are electrical signals that occur in the dendrites and cell body of a neuron, or nerve cell. They are caused by the activation of excitatory synapses, which are connections between neurons that allow for the transmission of information.

When an action potential, or electrical impulse, reaches the end of an axon, it triggers the release of neurotransmitters into the synaptic cleft, the small gap between the presynaptic and postsynaptic membranes. The excitatory neurotransmitters then bind to receptors on the postsynaptic membrane, causing a local depolarization of the membrane potential. This depolarization is known as an EPSP.

EPSPs are responsible for increasing the likelihood that an action potential will be generated in the postsynaptic neuron. When multiple EPSPs occur simultaneously or in close succession, they can summate and cause a large enough depolarization to trigger an action potential. This allows for the transmission of information from one neuron to another.

It's important to note that there are also inhibitory postsynaptic potentials (IPSPs) which decrease the likelihood that an action potential will be generated in the postsynaptic neuron, by causing a local hyperpolarization of the membrane potential.

A Serine-type D-Ala-D-Ala Carboxypeptidase is a type of enzyme that specifically catalyzes the cleavage of the peptide bond at the carboxyl terminus of a polypeptide, where the penultimate residue is D-alanine and the ultimate residue is D-alanine. This enzyme plays an essential role in bacterial cell wall biosynthesis and is a crucial target for antibiotics such as vancomycin and teicoplanin, which inhibit its activity by binding to the D-Ala-D-Ala motif of the peptidoglycan precursor. The serine residue in the active site of this enzyme is involved in the catalytic mechanism, hence the name "serine-type" carboxypeptidase.

Electrophysiology is a branch of medicine that deals with the electrical activities of the body, particularly the heart. In a medical context, electrophysiology studies (EPS) are performed to assess abnormal heart rhythms (arrhythmias) and to evaluate the effectiveness of certain treatments, such as medication or pacemakers.

During an EPS, electrode catheters are inserted into the heart through blood vessels in the groin or neck. These catheters can record the electrical activity of the heart and stimulate it to help identify the source of the arrhythmia. The information gathered during the study can help doctors determine the best course of treatment for each patient.

In addition to cardiac electrophysiology, there are also other subspecialties within electrophysiology, such as neuromuscular electrophysiology, which deals with the electrical activity of the nervous system and muscles.

An axon is a long, slender extension of a neuron (a type of nerve cell) that conducts electrical impulses (nerve impulses) away from the cell body to target cells, such as other neurons or muscle cells. Axons can vary in length from a few micrometers to over a meter long and are typically surrounded by a myelin sheath, which helps to insulate and protect the axon and allows for faster transmission of nerve impulses.

Axons play a critical role in the functioning of the nervous system, as they provide the means by which neurons communicate with one another and with other cells in the body. Damage to axons can result in serious neurological problems, such as those seen in spinal cord injuries or neurodegenerative diseases like multiple sclerosis.

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.

Neural inhibition is a process in the nervous system that decreases or prevents the activity of neurons (nerve cells) in order to regulate and control communication within the nervous system. It is a fundamental mechanism that allows for the balance of excitation and inhibition necessary for normal neural function. Inhibitory neurotransmitters, such as GABA (gamma-aminobutyric acid) and glycine, are released from the presynaptic neuron and bind to receptors on the postsynaptic neuron, reducing its likelihood of firing an action potential. This results in a decrease in neural activity and can have various effects depending on the specific neurons and brain regions involved. Neural inhibition is crucial for many functions including motor control, sensory processing, attention, memory, and emotional regulation.

The Rotarod performance test is not a medical diagnosis or condition, but rather a laboratory test used in both preclinical research and clinical settings to evaluate various aspects of motor function and balance in animals, including mice and rats. The test is often used to assess the neurological status, sensorimotor function, and coordination abilities of animals following drug treatments, surgical interventions, or in models of neurodegenerative diseases.

In this test, a rodent is placed on a rotating rod with a diameter that allows the animal to comfortably grip it. The rotation speed gradually increases over time, and the researcher records how long the animal can maintain its balance and stay on the rod without falling off. This duration is referred to as the "latency to fall" or "rotarod performance."

The Rotarod performance test offers several advantages, such as its sensitivity to various neurological impairments, ease of use, and ability to provide quantitative data for statistical analysis. It can help researchers evaluate potential therapeutic interventions, monitor disease progression, and investigate the underlying mechanisms of motor function and balance in health and disease.

A vestibulo-ocular reflex (VOR) is a automatic motion of the eyes that helps to stabilize images on the retina during head movement. It is mediated by the vestibular system, which includes the semicircular canals and otolith organs in the inner ear.

When the head moves, the movement is detected by the vestibular system, which sends signals to the oculomotor nuclei in the brainstem. These nuclei then generate an eye movement that is equal and opposite to the head movement, allowing the eyes to remain fixed on a target while the head is moving. This reflex helps to maintain visual stability during head movements and is essential for activities such as reading, walking, and driving.

The VOR can be tested clinically by having the patient follow a target with their eyes while their head is moved passively. If the VOR is functioning properly, the eyes should remain fixed on the target despite the head movement. Abnormalities in the VOR can indicate problems with the vestibular system or the brainstem.

Calcium channels, Q-type, are a type of voltage-gated calcium channel found in various tissues, including the brain and heart. They are called "Q-type" because they exhibit a distinctive "q-wave" in their current trace during electrical activity. These channels play important roles in regulating physiological processes such as neurotransmitter release, hormone secretion, and cardiac muscle contraction.

The pore-forming subunit of Q-type calcium channels is the CaV2.1 (or α1A) subunit, which is encoded by the CACNA1A gene. These channels are activated by depolarization of the cell membrane and allow the influx of calcium ions into the cell. The resulting increase in intracellular calcium concentration triggers various downstream signaling pathways that mediate the physiological responses mentioned above.

Dysfunction of Q-type calcium channels has been implicated in several neurological and cardiovascular disorders, including migraine, epilepsy, cerebellar ataxia, and hypertension. Therefore, understanding the structure, function, and regulation of these channels is an important area of research for developing new therapeutic strategies to treat these conditions.

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.

Metabotropic glutamate receptors (mGluRs) are a type of G protein-coupled receptor (GPCR) that are activated by the neurotransmitter glutamate, which is the primary excitatory neurotransmitter in the central nervous system. There are eight different subtypes of mGluRs, labeled mGluR1 through mGluR8, which are classified into three groups (Group I, II, and III) based on their sequence homology, downstream signaling pathways, and pharmacological properties.

Group I mGluRs include mGluR1 and mGluR5, which are primarily located postsynaptically in the central nervous system. Activation of Group I mGluRs leads to increased intracellular calcium levels and activation of protein kinases, which can modulate synaptic transmission and plasticity.

Group II mGluRs include mGluR2 and mGluR3, which are primarily located presynaptically in the central nervous system. Activation of Group II mGluRs inhibits adenylyl cyclase activity and reduces neurotransmitter release.

Group III mGluRs include mGluR4, mGluR6, mGluR7, and mGluR8, which are also primarily located presynaptically in the central nervous system. Activation of Group III mGluRs inhibits adenylyl cyclase activity and voltage-gated calcium channels, reducing neurotransmitter release.

Overall, metabotropic glutamate receptors play important roles in modulating synaptic transmission and plasticity, and have been implicated in various neurological disorders, including epilepsy, pain, anxiety, depression, and neurodegenerative diseases.

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.

Transgenic mice are genetically modified rodents that have incorporated foreign DNA (exogenous DNA) into their own genome. This is typically done through the use of recombinant DNA technology, where a specific gene or genetic sequence of interest is isolated and then introduced into the mouse embryo. The resulting transgenic mice can then express the protein encoded by the foreign gene, allowing researchers to study its function in a living organism.

The process of creating transgenic mice usually involves microinjecting the exogenous DNA into the pronucleus of a fertilized egg, which is then implanted into a surrogate mother. The offspring that result from this procedure are screened for the presence of the foreign DNA, and those that carry the desired genetic modification are used to establish a transgenic mouse line.

Transgenic mice have been widely used in biomedical research to model human diseases, study gene function, and test new therapies. They provide a valuable tool for understanding complex biological processes and developing new treatments for a variety of medical conditions.

Glutamate receptors are a type of neuroreceptor in the central nervous system that bind to the neurotransmitter glutamate. They play a crucial role in excitatory synaptic transmission, plasticity, and neuronal development. There are several types of glutamate receptors, including ionotropic and metabotropic receptors, which can be further divided into subclasses based on their pharmacological properties and molecular structure.

Ionotropic glutamate receptors, also known as iGluRs, are ligand-gated ion channels that directly mediate fast synaptic transmission. They include N-methyl-D-aspartate (NMDA) receptors, α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptors, and kainite receptors.

Metabotropic glutamate receptors, also known as mGluRs, are G protein-coupled receptors that modulate synaptic transmission through second messenger systems. They include eight subtypes (mGluR1-8) that are classified into three groups based on their sequence homology, pharmacological properties, and signal transduction mechanisms.

Glutamate receptors have been implicated in various physiological processes, including learning and memory, motor control, sensory perception, and emotional regulation. Dysfunction of glutamate receptors has also been associated with several neurological disorders, such as epilepsy, Alzheimer's disease, Parkinson's disease, and psychiatric conditions like schizophrenia and depression.

Neuronal plasticity, also known as neuroplasticity or neural plasticity, refers to the ability of the brain and nervous system to change and adapt as a result of experience, learning, injury, or disease. This can involve changes in the structure, organization, and function of neurons (nerve cells) and their connections (synapses) in the central and peripheral nervous systems.

Neuronal plasticity can take many forms, including:

* Synaptic plasticity: Changes in the strength or efficiency of synaptic connections between neurons. This can involve the formation, elimination, or modification of synapses.
* Neural circuit plasticity: Changes in the organization and connectivity of neural circuits, which are networks of interconnected neurons that process information.
* Structural plasticity: Changes in the physical structure of neurons, such as the growth or retraction of dendrites (branches that receive input from other neurons) or axons (projections that transmit signals to other neurons).
* Functional plasticity: Changes in the physiological properties of neurons, such as their excitability, responsiveness, or sensitivity to stimuli.

Neuronal plasticity is a fundamental property of the nervous system and plays a crucial role in many aspects of brain function, including learning, memory, perception, and cognition. It also contributes to the brain's ability to recover from injury or disease, such as stroke or traumatic brain injury.

I believe there might be a misunderstanding in your question. "Dogs" is not a medical term or condition. It is the common name for a domesticated carnivore of the family Canidae, specifically the genus Canis, which includes wolves, foxes, and other extant and extinct species of mammals. Dogs are often kept as pets and companions, and they have been bred in a wide variety of forms and sizes for different purposes, such as hunting, herding, guarding, assisting police and military forces, and providing companionship and emotional support.

If you meant to ask about a specific medical condition or term related to dogs, please provide more context so I can give you an accurate answer.

NAV1.6, also known as SCN8A, is a gene that encodes for the α subunit of a voltage-gated sodium channel, specifically Nav1.6. This channel plays a crucial role in the initiation and propagation of action potentials in neurons. It has a predominant expression in the central and peripheral nervous system, including the nodes of Ranvier in myelinated axons.

Nav1.6 voltage-gated sodium channels are responsible for the rapid upstroke of the action potential and contribute to the generation of repetitive firing in some neuronal populations. Mutations in the SCN8A gene have been associated with various neurological disorders, such as epilepsy, intellectual disability, and movement disorders.

In summary, NAV1.6 voltage-gated sodium channels are essential for normal neuronal excitability and function, and their dysfunction can lead to a range of neurological symptoms.

Immunohistochemistry (IHC) is a technique used in pathology and laboratory medicine to identify specific proteins or antigens in tissue sections. It combines the principles of immunology and histology to detect the presence and location of these target molecules within cells and tissues. This technique utilizes antibodies that are specific to the protein or antigen of interest, which are then tagged with a detection system such as a chromogen or fluorophore. The stained tissue sections can be examined under a microscope, allowing for the visualization and analysis of the distribution and expression patterns of the target molecule in the context of the tissue architecture. Immunohistochemistry is widely used in diagnostic pathology to help identify various diseases, including cancer, infectious diseases, and immune-mediated disorders.

Calbindin 1 is a calcium-binding protein that belongs to the family of EF-hand proteins. It is also known as calbindin D-28k, due to its molecular weight of approximately 28 kilodaltons. This protein is widely distributed in various tissues and organisms but is particularly abundant in the nervous system, where it plays crucial roles in calcium homeostasis, neuroprotection, and signal transduction.

In neurons, calbindin 1 is primarily located in the cytoplasm and dendrites, with lower concentrations found in the axons and nerve terminals. It helps regulate intracellular calcium levels by binding to calcium ions (Ca2+) with high affinity and capacity, thereby preventing rapid fluctuations in Ca2+ concentration that could trigger cellular damage or dysfunction.

Calbindin 1 has been implicated in several neuronal processes, including neurotransmitter release, synaptic plasticity, and neuronal excitability. Additionally, it is believed to provide neuroprotection against various insults, such as oxidative stress, glutamate excitotoxicity, and calcium overload, which are associated with neurological disorders like Alzheimer's disease, Parkinson's disease, and epilepsy.

In summary, calbindin 1 is a calcium-binding protein that plays essential roles in maintaining calcium homeostasis, neuroprotection, and neuronal signaling within the nervous system.

Neurological models are simplified representations or simulations of various aspects of the nervous system, including its structure, function, and processes. These models can be theoretical, computational, or physical and are used to understand, explain, and predict neurological phenomena. They may focus on specific neurological diseases, disorders, or functions, such as memory, learning, or movement. The goal of these models is to provide insights into the complex workings of the nervous system that cannot be easily observed or understood through direct examination alone.

Eyelid conditioning, also known as eyelid classical conditioning or Ursinus' phenomenon, is a type of reflex conditioning that involves associating a neutral stimulus with the natural act of blinking. This concept was first described by Russian physiologist Ivan Pavlov and later studied in detail by German ophthalmologist Hermann Ludwig Ferdinand von Helmholtz and Austrian physician Sigmund Exner.

In this procedure, a conditioned stimulus (like a sound or light) is repeatedly presented just before the unconditioned stimulus (such as a puff of air directed at the eye), which naturally triggers the blink reflex. Over time, the subject begins to associate the conditioned stimulus with the blinking response and will start to blink even when only the conditioned stimulus is presented, without the presence of the unconditioned stimulus. This learning process is an example of classical conditioning and can be used in various research and clinical applications.

Tetrodotoxin (TTX) is a potent neurotoxin that is primarily found in certain species of pufferfish, blue-ringed octopuses, and other marine animals. It blocks voltage-gated sodium channels in nerve cell membranes, leading to muscle paralysis and potentially respiratory failure. TTX has no known antidote, and medical treatment focuses on supportive care for symptoms. Exposure can occur through ingestion, inhalation, or skin absorption, depending on the route of toxicity.

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.

Calcium channels, N-type ( Cav2.2) are voltage-gated calcium channels found in excitable cells such as neurons and cardiac myocytes. They play a crucial role in regulating various cellular functions, including neurotransmitter release, gene expression, and cell excitability.

N-type calcium channels are composed of five subunits: an alpha1 (Cav2.2) subunit that forms the ion-conducting pore, and four auxiliary subunits (alpha2delta, beta, and gamma) that modulate channel function and stability. The alpha1 subunit contains the voltage sensor and the selectivity filter for calcium ions.

N-type calcium channels are activated by depolarization of the cell membrane and mediate a rapid influx of calcium ions into the cytoplasm. This calcium influx triggers neurotransmitter release from presynaptic terminals, regulates gene expression in the nucleus, and contributes to the electrical excitability of neurons.

N-type calcium channels are also targets for various drugs and toxins that modulate their activity. For example, the peptide toxin from cone snail venom, known as ω-conotoxin MVIIA (Ziconotide), specifically binds to N-type calcium channels and inhibits their activity, making it a potent analgesic for treating chronic pain.

A "knockout" mouse is a genetically engineered mouse in which one or more genes have been deleted or "knocked out" using molecular biology techniques. This allows researchers to study the function of specific genes and their role in various biological processes, as well as potential associations with human diseases. The mice are generated by introducing targeted DNA modifications into embryonic stem cells, which are then used to create a live animal. Knockout mice have been widely used in biomedical research to investigate gene function, disease mechanisms, and potential therapeutic targets.

Evoked potentials (EPs) are medical tests that measure the electrical activity in the brain or spinal cord in response to specific sensory stimuli, such as sight, sound, or touch. These tests are often used to help diagnose and monitor conditions that affect the nervous system, such as multiple sclerosis, brainstem tumors, and spinal cord injuries.

There are several types of EPs, including:

1. Visual Evoked Potentials (VEPs): These are used to assess the function of the visual pathway from the eyes to the back of the brain. A patient is typically asked to look at a patterned image or flashing light while electrodes placed on the scalp record the electrical responses.
2. Brainstem Auditory Evoked Potentials (BAEPs): These are used to evaluate the function of the auditory nerve and brainstem. Clicking sounds are presented to one or both ears, and electrodes placed on the scalp measure the response.
3. Somatosensory Evoked Potentials (SSEPs): These are used to assess the function of the peripheral nerves and spinal cord. Small electrical shocks are applied to a nerve at the wrist or ankle, and electrodes placed on the scalp record the response as it travels up the spinal cord to the brain.
4. Motor Evoked Potentials (MEPs): These are used to assess the function of the motor pathways in the brain and spinal cord. A magnetic or electrical stimulus is applied to the brain or spinal cord, and electrodes placed on a muscle measure the response as it travels down the motor pathway.

EPs can help identify abnormalities in the nervous system that may not be apparent through other diagnostic tests, such as imaging studies or clinical examinations. They are generally safe, non-invasive procedures with few risks or side effects.

Calcium channels are specialized proteins that span the membrane of cells and allow calcium ions (Ca²+) to flow in and out of the cell. They are crucial for many physiological processes, including muscle contraction, neurotransmitter release, hormone secretion, and gene expression.

There are several types of calcium channels, classified based on their biophysical and pharmacological properties. The most well-known are:

1. Voltage-gated calcium channels (VGCCs): These channels are activated by changes in the membrane potential. They are further divided into several subtypes, including L-type, P/Q-type, N-type, R-type, and T-type. VGCCs play a critical role in excitation-contraction coupling in muscle cells and neurotransmitter release in neurons.
2. Receptor-operated calcium channels (ROCCs): These channels are activated by the binding of an extracellular ligand, such as a hormone or neurotransmitter, to a specific receptor on the cell surface. ROCCs are involved in various physiological processes, including smooth muscle contraction and platelet activation.
3. Store-operated calcium channels (SOCCs): These channels are activated by the depletion of intracellular calcium stores, such as those found in the endoplasmic reticulum. SOCCs play a critical role in maintaining calcium homeostasis and signaling within cells.

Dysregulation of calcium channel function has been implicated in various diseases, including hypertension, arrhythmias, migraine, epilepsy, and neurodegenerative disorders. Therefore, calcium channels are an important target for drug development and therapy.

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.

"Cell count" is a medical term that refers to the process of determining the number of cells present in a given volume or sample of fluid or tissue. This can be done through various laboratory methods, such as counting individual cells under a microscope using a specialized grid called a hemocytometer, or using automated cell counters that use light scattering and electrical impedance techniques to count and classify different types of cells.

Cell counts are used in a variety of medical contexts, including hematology (the study of blood and blood-forming tissues), microbiology (the study of microscopic organisms), and pathology (the study of diseases and their causes). For example, a complete blood count (CBC) is a routine laboratory test that includes a white blood cell (WBC) count, red blood cell (RBC) count, hemoglobin level, hematocrit value, and platelet count. Abnormal cell counts can indicate the presence of various medical conditions, such as infections, anemia, or leukemia.

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.

Inositol 1,4,5-trisphosphate receptors (IP3Rs) are a type of calcium ion channel found in the endoplasmic reticulum (ER) membrane of many cell types. They play a crucial role in intracellular calcium signaling and are activated by the second messenger molecule, inositol 1,4,5-trisphosphate (IP3).

IP3 is produced by enzymatic cleavage of the membrane lipid phosphatidylinositol 4,5-bisphosphate (PIP2) in response to extracellular signals such as hormones and neurotransmitters. When IP3 binds to the IP3R, it triggers a conformational change that opens the channel, allowing calcium ions to flow from the ER into the cytosol. This increase in cytosolic calcium can then activate various cellular processes such as gene expression, protein synthesis, and cell survival or death pathways.

There are three isoforms of IP3Rs (IP3R1, IP3R2, and IP3R3) that differ in their tissue distribution, regulation, and sensitivity to IP3. Dysregulation of IP3R-mediated calcium signaling has been implicated in various pathological conditions, including neurological disorders, cardiovascular diseases, and cancer.

Organ culture techniques refer to the methods used to maintain or grow intact organs or pieces of organs under controlled conditions in vitro, while preserving their structural and functional characteristics. These techniques are widely used in biomedical research to study organ physiology, pathophysiology, drug development, and toxicity testing.

Organ culture can be performed using a variety of methods, including:

1. Static organ culture: In this method, the organs or tissue pieces are placed on a porous support in a culture dish and maintained in a nutrient-rich medium. The medium is replaced periodically to ensure adequate nutrition and removal of waste products.
2. Perfusion organ culture: This method involves perfusing the organ with nutrient-rich media, allowing for better distribution of nutrients and oxygen throughout the tissue. This technique is particularly useful for studying larger organs such as the liver or kidney.
3. Microfluidic organ culture: In this approach, microfluidic devices are used to create a controlled microenvironment for organ cultures. These devices allow for precise control over the flow of nutrients and waste products, as well as the application of mechanical forces.

Organ culture techniques can be used to study various aspects of organ function, including metabolism, secretion, and response to drugs or toxins. Additionally, these methods can be used to generate three-dimensional tissue models that better recapitulate the structure and function of intact organs compared to traditional two-dimensional cell cultures.

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.

Afferent pathways, also known as sensory pathways, refer to the neural connections that transmit sensory information from the peripheral nervous system to the central nervous system (CNS), specifically to the brain and spinal cord. These pathways are responsible for carrying various types of sensory information, such as touch, temperature, pain, pressure, vibration, hearing, vision, and taste, to the CNS for processing and interpretation.

The afferent pathways begin with sensory receptors located throughout the body, which detect changes in the environment and convert them into electrical signals. These signals are then transmitted via afferent neurons, also known as sensory neurons, to the spinal cord or brainstem. Within the CNS, the information is further processed and integrated with other neural inputs before being relayed to higher cognitive centers for conscious awareness and response.

Understanding the anatomy and physiology of afferent pathways is essential for diagnosing and treating various neurological conditions that affect sensory function, such as neuropathies, spinal cord injuries, and brain disorders.

"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.

A "mutant strain of mice" in a medical context refers to genetically engineered mice that have specific genetic mutations introduced into their DNA. These mutations can be designed to mimic certain human diseases or conditions, allowing researchers to study the underlying biological mechanisms and test potential therapies in a controlled laboratory setting.

Mutant strains of mice are created through various techniques, including embryonic stem cell manipulation, gene editing technologies such as CRISPR-Cas9, and radiation-induced mutagenesis. These methods allow scientists to introduce specific genetic changes into the mouse genome, resulting in mice that exhibit altered physiological or behavioral traits.

These strains of mice are widely used in biomedical research because their short lifespan, small size, and high reproductive rate make them an ideal model organism for studying human diseases. Additionally, the mouse genome has been well-characterized, and many genetic tools and resources are available to researchers working with these animals.

Examples of mutant strains of mice include those that carry mutations in genes associated with cancer, neurodegenerative disorders, metabolic diseases, and immunological conditions. These mice provide valuable insights into the pathophysiology of human diseases and help advance our understanding of potential therapeutic interventions.

Shaw potassium channels, also known as KCNA4 channels, are a type of voltage-gated potassium channel that is encoded by the KCNA4 gene in humans. These channels play a crucial role in regulating the electrical excitability of cells, particularly in the heart and nervous system.

Shaw channels are named after James E. Shaw, who first identified them in 1996. They are composed of four subunits that arrange themselves to form a central pore through which potassium ions can flow. The channels are activated by depolarization of the cell membrane and help to repolarize the membrane during action potentials.

Mutations in the KCNA4 gene have been associated with various cardiac arrhythmias, including familial atrial fibrillation and long QT syndrome type 3. These conditions can cause irregular heart rhythms and may increase the risk of sudden cardiac death. Therefore, understanding the function and regulation of Shaw potassium channels is important for developing therapies to treat these disorders.

Interneurons are a type of neuron that is located entirely within the central nervous system (CNS), including the brain and spinal cord. They are called "inter" neurons because they connect and communicate with other nearby neurons, forming complex networks within the CNS. Interneurons receive input from sensory neurons and/or other interneurons and then send output signals to motor neurons or other interneurons.

Interneurons are responsible for processing information and modulating neural circuits in the CNS. They can have either excitatory or inhibitory effects on their target neurons, depending on the type of neurotransmitters they release. Excitatory interneurons release neurotransmitters such as glutamate that increase the likelihood of an action potential in the postsynaptic neuron, while inhibitory interneurons release neurotransmitters such as GABA (gamma-aminobutyric acid) or glycine that decrease the likelihood of an action potential.

Interneurons are diverse and can be classified based on various criteria, including their morphology, electrophysiological properties, neurochemical characteristics, and connectivity patterns. They play crucial roles in many aspects of CNS function, such as sensory processing, motor control, cognition, and emotion regulation. Dysfunction or damage to interneurons has been implicated in various neurological and psychiatric disorders, including epilepsy, Parkinson's disease, schizophrenia, and autism spectrum disorder.

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.

Blinking is the rapid and repetitive closing and reopening of the eyelids. It is a normal physiological process that helps to keep the eyes moist, protected and comfortable by spreading tears over the surface of the eye and removing any foreign particles or irritants that may have accumulated on the eyelid or the conjunctiva (the mucous membrane that covers the front of the eye and lines the inside of the eyelids).

Blinking is controlled by the facial nerve (cranial nerve VII), which sends signals to the muscles that control the movement of the eyelids. On average, people blink about 15-20 times per minute, but this rate can vary depending on factors such as mood, level of attention, and visual tasks. For example, people tend to blink less frequently when they are concentrating on a visual task or looking at a screen, which can lead to dry eye symptoms.

A microelectrode is a small electrode with dimensions ranging from several micrometers to a few tens of micrometers in diameter. They are used in various biomedical applications, such as neurophysiological studies, neuromodulation, and brain-computer interfaces. In these applications, microelectrodes serve to record electrical activity from individual or small groups of neurons or deliver electrical stimuli to specific neural structures with high spatial resolution.

Microelectrodes can be fabricated using various materials, including metals (e.g., tungsten, stainless steel, platinum), metal alloys, carbon fibers, and semiconductor materials like silicon. The design of microelectrodes may vary depending on the specific application, with some common types being sharpened metal wires, glass-insulated metal microwires, and silicon-based probes with multiple recording sites.

The development and use of microelectrodes have significantly contributed to our understanding of neural function in health and disease, enabling researchers and clinicians to investigate the underlying mechanisms of neurological disorders and develop novel therapies for conditions such as Parkinson's disease, epilepsy, and hearing loss.

Strophanthidin is not a commonly used medical term, but it is a chemical compound that comes from the seeds of certain plants in the strokehantus family. It's a cardiac glycoside, meaning it has a toxic effect on the heart muscle and can affect its rhythm. In the past, it was used as a medication to treat heart failure and arrhythmias, but it has largely been replaced by other drugs that are safer and more effective.

In modern medical practice, Strophanthidin is not typically used clinically due to its narrow therapeutic index, potential for toxicity, and the availability of safer alternatives. It's important to note that the use of Strophanthidin or any other cardiac glycoside should be under the close supervision of a healthcare professional.

6-Cyano-7-nitroquinoxaline-2,3-dione is a chemical compound that is commonly used in research and scientific studies. It is a member of the quinoxaline family of compounds, which are aromatic heterocyclic organic compounds containing two nitrogen atoms.

The 6-Cyano-7-nitroquinoxaline-2,3-dione compound has several notable features, including:

* A quinoxaline ring structure, which is made up of two benzene rings fused to a pyrazine ring.
* A cyano group (-CN) at the 6th position of the quinoxaline ring.
* A nitro group (-NO2) at the 7th position of the quinoxaline ring.
* Two carbonyl groups (=O) at the 2nd and 3rd positions of the quinoxaline ring.

This compound is known to have various biological activities, such as antimicrobial, antifungal, and anticancer properties. However, its use in medical treatments is not widespread due to potential toxicity and lack of comprehensive studies on its safety and efficacy. As with any chemical compound, it should be handled with care and used only under appropriate laboratory conditions.

In situ hybridization (ISH) is a molecular biology technique used to detect and localize specific nucleic acid sequences, such as DNA or RNA, within cells or tissues. This technique involves the use of a labeled probe that is complementary to the target nucleic acid sequence. The probe can be labeled with various types of markers, including radioisotopes, fluorescent dyes, or enzymes.

During the ISH procedure, the labeled probe is hybridized to the target nucleic acid sequence in situ, meaning that the hybridization occurs within the intact cells or tissues. After washing away unbound probe, the location of the labeled probe can be visualized using various methods depending on the type of label used.

In situ hybridization has a wide range of applications in both research and diagnostic settings, including the detection of gene expression patterns, identification of viral infections, and diagnosis of genetic disorders.

I apologize for any confusion, but "Pyridazines" is not a medical term. It is a chemical term that refers to a class of heterocyclic organic compounds which contain a six-membered ring with two nitrogen atoms. These types of compounds are often used in the synthesis of various pharmaceuticals and agrochemicals, but "Pyridazines" itself is not a medical concept or diagnosis. If you have any questions related to medicine or health, I would be happy to try to help answer those for you.

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.

Essential tremor is a type of involuntary tremor, or shaking, that primarily affects the hands and arms. It can also affect the head, vocal cords, and other parts of the body. Essential tremor is often confused with Parkinson's disease, as they share some similar symptoms, but essential tremor is generally not associated with other neurological conditions.

The tremors associated with essential tremor typically occur when a person is performing voluntary movements, such as writing, eating, or using tools. The shaking may also occur at rest, but this is less common. Essential tremor usually worsens with stress, fatigue, and age.

While the exact cause of essential tremor is not known, it appears to have a genetic component, as it tends to run in families. In some cases, essential tremor may be related to alcohol use or other factors. There is no cure for essential tremor, but medications and lifestyle changes can help manage the symptoms and improve quality of life.

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.

Presynaptic terminals, also known as presynaptic boutons or nerve terminals, refer to the specialized structures located at the end of axons in neurons. These terminals contain numerous small vesicles filled with neurotransmitters, which are chemical messengers that transmit signals between neurons.

When an action potential reaches the presynaptic terminal, it triggers the influx of calcium ions into the terminal, leading to the fusion of the vesicles with the presynaptic membrane and the release of neurotransmitters into the synaptic cleft, a small gap between the presynaptic and postsynaptic terminals.

The released neurotransmitters then bind to receptors on the postsynaptic terminal, leading to the generation of an electrical or chemical signal that can either excite or inhibit the postsynaptic neuron. Presynaptic terminals play a crucial role in regulating synaptic transmission and are targets for various drugs and toxins that modulate neuronal communication.

Electric conductivity, also known as electrical conductance, is a measure of a material's ability to allow the flow of electric current through it. It is usually measured in units of Siemens per meter (S/m) or ohm-meters (Ω-m).

In medical terms, electric conductivity can refer to the body's ability to conduct electrical signals, which is important for various physiological processes such as nerve impulse transmission and muscle contraction. Abnormalities in electrical conductivity can be associated with various medical conditions, including neurological disorders and heart diseases.

For example, in electrocardiography (ECG), the electric conductivity of the heart is measured to assess its electrical activity and identify any abnormalities that may indicate heart disease. Similarly, in electromyography (EMG), the electric conductivity of muscles is measured to diagnose neuromuscular disorders.

I'm sorry for any confusion, but "Phosphinic Acids" is not a recognized medical term. Phosphinic acids are chemical compounds that contain a phosphorus atom bonded to two organic groups and one hydroxyl group, making them a subclass of organophosphorus compounds. They are widely used in the production of various chemicals, but they do not have specific relevance to medical definitions or terminology. If you have any questions related to medicine or health, I'd be happy to try to help answer those!

The vestibular nerve, also known as the vestibulocochlear nerve or cranial nerve VIII, is a pair of nerves that transmit sensory information from the balance-sensing structures in the inner ear (the utricle, saccule, and semicircular canals) to the brain. This information helps the brain maintain balance and orientation of the head in space. The vestibular nerve also plays a role in hearing by transmitting sound signals from the cochlea to the brain.

Omega-Agatoxin IVA is a specific type of neurotoxin that is derived from the venom of the funnel web spider, Agelenopsis aperta. It is known to selectively target and block P/Q-type voltage-gated calcium channels, which are found in the presynaptic terminals of neurons. These channels play a crucial role in the release of neurotransmitters, the chemical signals that neurons use to communicate with each other.

By blocking these channels, omega-Agatoxin IVA can prevent the release of neurotransmitters and interfere with the normal functioning of the nervous system. It is a valuable tool in neuroscience research for studying the role of calcium channels in various physiological processes and has been used to investigate conditions such as pain, epilepsy, and neurological disorders.

It's important to note that while omega-Agatoxin IVA has potential therapeutic applications, it is primarily used for research purposes and should be handled with care due to its potent neurotoxic effects.

AMPA (α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid) receptors are ligand-gated ion channels found in the postsynaptic membrane of excitatory synapses in the central nervous system. They play a crucial role in fast synaptic transmission and are responsible for the majority of the fast excitatory postsynaptic currents (EPSCs) in the brain.

AMPA receptors are tetramers composed of four subunits, which can be any combination of GluA1-4 (previously known as GluR1-4). When the neurotransmitter glutamate binds to the AMPA receptor, it causes a conformational change that opens the ion channel, allowing the flow of sodium and potassium ions. This leads to depolarization of the postsynaptic membrane and the generation of an action potential if the depolarization is sufficient.

In addition to their role in synaptic transmission, AMPA receptors are also involved in synaptic plasticity, which is the ability of synapses to strengthen or weaken over time in response to changes in activity. This process is thought to underlie learning and memory.

Neuroglia, also known as glial cells or simply glia, are non-neuronal cells that provide support and protection for neurons in the nervous system. They maintain homeostasis, form myelin sheaths around nerve fibers, and provide structural support. They also play a role in the immune response of the central nervous system. Some types of neuroglia include astrocytes, oligodendrocytes, microglia, and ependymal cells.

Sodium is an essential mineral and electrolyte that is necessary for human health. In a medical context, sodium is often discussed in terms of its concentration in the blood, as measured by serum sodium levels. The normal range for serum sodium is typically between 135 and 145 milliequivalents per liter (mEq/L).

Sodium plays a number of important roles in the body, including:

* Regulating fluid balance: Sodium helps to regulate the amount of water in and around your cells, which is important for maintaining normal blood pressure and preventing dehydration.
* Facilitating nerve impulse transmission: Sodium is involved in the generation and transmission of electrical signals in the nervous system, which is necessary for proper muscle function and coordination.
* Assisting with muscle contraction: Sodium helps to regulate muscle contractions by interacting with other minerals such as calcium and potassium.

Low sodium levels (hyponatremia) can cause symptoms such as confusion, seizures, and coma, while high sodium levels (hypernatremia) can lead to symptoms such as weakness, muscle cramps, and seizures. Both conditions require medical treatment to correct.

Purkinje cells migrate toward the outer surface of the cerebellar cortex and form the Purkinje cell layer. Purkinje cells are ... input to the Purkinje cell, with basket cells synapsing on the Purkinje cell axon initial segment and stellate cells onto the ... Purkinje cells are found within the Purkinje layer in the cerebellum. Purkinje cells are aligned like dominos stacked one in ... with up to 200,000 parallel fibers forming a Granule-cell-Purkinje-cell synapse with a single Purkinje cell. Canonically, each ...
... cell to Purkinje-cell synapses or gcPc synapses are the junctions that form the synapse in the cerebellum between granule cells ... The cerebellar parallel fiber system contains the synapses be- tween the granule cells and the Purkinje cells (gcPc synapses), ... "Properties of unitary granule cell-->Purkinje cell synapses in adult rat cerebellar slices". Journal of Neuroscience. 22 (22): ... and Purkinje cells. These synapses are thought to be a storage site for the information that is required for motor coordination ...
"Purkinje cell model". YouTube Video. 2007-12-25. Archived from the original on 2021-12-21. Retrieved 2007-12-25. "Who's News: ...
Kruithof curve Dark adaptation Dark adaptor goggles Skot (unit) Nox (unit) "Purkinje cell". Dictionary.com Unabridged (Online ... The Purkinje effect or Purkinje phenomenon (Czech: [ˈpurkɪɲɛ] ; sometimes called the Purkinje shift, often pronounced / ... The Purkinje effect occurs at the transition between primary use of the photopic (cone-based) and scotopic (rod-based) systems ... The Purkinje shift is the relation between the absorption maximum of rhodopsin, reaching a maximum at about 500 nanometres (2.0 ...
Zoghbi, Huda Y; Mehta, Arpan R (September 2021). "Purkinje cells and their trees". The Lancet Neurology. 20 (9): 706. doi: ... Cell. 178 (5): 1159-1175.e17. doi:10.1016/j.cell.2019.07.043. PMC 6726125. PMID 31442405 - via Elsevier Science Direct. Kavli ... The MECP2 protein binds methylated cytosine (5-methylcytosine) in CpG sites, and is indispensable for almost all brain cells. ... the formation of secretory cells in the gut., and neonatal respiratory rhythm and chemosensitivity in the adult brain by ...
D) Higher magnification of (C) showing Purkinje cell. (E) Dendrite of the Purkinje cell. Drawing of the neural circuitry of the ... 1900 Drawing of Purkinje cells (A) and granule cells (B) from pigeon cerebellum by Santiago Ramón y Cajal, 1899. Instituto ... Purkinje cell of the human cerebellum. Golgi method. -a, axon; b, recurrent collateral; c and d, spaces in the dendritic ... The catalog for the exhibition featured Cajal's drawing of the Purkinje Cell on the front cover. The National Institutes of ...
By recording from the Purkinje cells of conscious monkeys learning a manual task, Gilbert and Thach tested and confirmed ... Gilbert, P.F.C.; Thach, W.T. (June 1977). "Purkinje cell activity during motor learning". Brain Research. 128 (2): 309-328. doi ...
Mammalian Purkinje-cell protein-2 (Pcp2). It may function as a cell-type specific modulator for G protein-mediated cell ... It is uniquely expressed in cerebellar Purkinje cells and in retinal bipolar neurons. Eukaryotic Rap1GAP. A GTPase activator ... In heterotrimeric G-protein signalling, cell surface receptors (GPCRs) are coupled to membrane-associated heterotrimers ...
Neurohistological biomarkers of Purkinje cell loss". Annals of the New York Academy of Sciences. 801: 217-26. doi:10.1111/j. ... Work in the laboratory of Mark Molliver at Johns Hopkins indicated degeneration of cerebellar Purkinje cells observed in rats ... O'Hearn E, Molliver ME (July 1993). "Degeneration of Purkinje cells in parasagittal zones of the cerebellar vermis after ...
Later inverse stochastic resonance has been confirmed in Purkinje cells of cerebellum, where it could play the role for ... "Inverse Stochastic Resonance in Cerebellar Purkinje Cells". PLOS Computational Biology. 12 (8): e1005000. Bibcode:2016PLSCB.. ... 14 cells in 12 animals were tested, and all showed an increased SNR at a particular level of noise, meeting the requirements ... At the optimum level of noise, the cells were more likely to spike, resulting in spikes with more information and more precise ...
Somat Cell Mol Genet. 22 (3): 167-75. doi:10.1007/BF02369907. PMID 8914602. S2CID 41800640. "Entrez Gene: PCP4 Purkinje cell ... Purkinje cell protein 4 is a protein that in humans is encoded by the PCP4 gene. Also known as PEP-19, PCP4 is a 7.6 kDa ... PCP4 is abundant in Purkinje cells of the cerebellum, and plays an important role in synaptic plasticity. PCP4 knockout mice ... Hu YH, Warnatz HJ, Vanhecke D, Wagner F, Fiebitz A, Thamm S, Kahlem P, Lehrach H, Yaspo ML, Janitz M (2006). "Cell array-based ...
Single neurons in vitro including cerebellar Purkinje cells and squid giant axon could also demonstrate the inverse stochastic ... "Inverse Stochastic Resonance in Cerebellar Purkinje Cells". PLOS Computational Biology. 12 (8): e1005000. Bibcode:2016PLSCB.. ...
Recordings from Purkinje cells show that the olive is depressed during the Purkinje cell CR. Taken together, results from ... Purkinje cell CRs reappeared rapidly, mirroring the "savings" phenomenon demonstrated at the behavioral level. Purkinje cell ... Purkinje cells of the cerebellar cortex tonically inhibit deep nuclear cells. Therefore, an LTD-mediated decrease in PC ... This pause response, called a Purkinje cell CR, was also obtained when direct mossy fibre stimulation was used as the CS and ...
Wadiche JI, Jahr CE (October 2001). "Multivesicular release at climbing fiber-Purkinje cell synapses". Neuron. 32 (2): 301-313 ... It has also been proposed and then refuted at the ribbon synapses formed between inner hair cell and spiral ganglion neurons. ... Fuchs PA (July 2005). "Time and intensity coding at the hair cell's ribbon synapse". The Journal of Physiology. 566 (Pt 1): 7- ... September 2014). "Uniquantal release through a dynamic fusion pore is a candidate mechanism of hair cell exocytosis". Neuron. ...
Purkinje cells are especially susceptible to ethanol excitotoxicity. Impairment of Purkinje synapses is a component of ... "Lingo-1 expression is increased in essential tremor cerebellum and is present in the basket cell pinceau". Acta ...
Porras-Garcia ME, Ruiz R, Pérez-Villegas EM, Armengol JÁ (2013). "Motor learning of mice lacking cerebellar Purkinje cells". ... the postnatal survival of Purkinje cells in the mouse disclose a longitudinal pattern of differentially sensitive cells". Dev ... "Progressive Purkinje cell degeneration in tambaleante mutant mice is a consequence of a missense mutation in HERC1 E3 ubiquitin ... mutant mice are characterized by Purkinje cell loss. In addition to the cerebellum, Herc1tbl mutants had lower dendritic spine ...
High levels of mRNA in cerebellar Purkinje cells". FEBS Lett. 347 (1): 69-72. doi:10.1016/0014-5793(94)00509-5. PMID 8013665. ... 2004). "SEREX identification of new tumour-associated antigens in cutaneous T-cell lymphoma". Br. J. Dermatol. 150 (2): 252-8. ... which mobilizes intracellular calcium and acts as a second messenger mediating cell responses to various stimulation. GRCh38: ...
... and another type of study have observed strong immunoreaction against 5-HT2A receptor protein in rat Purkinje cells. In the ... "Serotonin2A receptor-like immunoreactivity in rat cerebellar Purkinje cells". Neuroscience Letters. 252 (1): 72-74. doi:10.1016 ...
It develops when the neurons known as Purkinje cells, located in the cerebellum of the brain, begin to die off. These cells ... Put simply, without Purkinje cells, an animal loses its sense of space and distance, making balance and coordination difficult ... In a few breeds, such as the Beagle, Rough Collie, and Miniature Poodle, Purkinje cells begin to die off at or shortly before ... However, it was discovered that in horses, the die-off of purkinje cells began after the animal was born, rather than occurring ...
For example, backward propagation of action potentials is very limited in cerebellar Purkinje cells but is quite prevalent in ... Electrophysiological properties of in vitro purkinje cell dendrites in mammalian cerebellar slices. Journal of Physiology 305: ... "Dendritic spikes and their inhibition in alligator Purkinje cells". Science. 160 (3832): 1132-1135. Bibcode:1968Sci...160.1132L ... For example, Mitral cells seem to serve both as projection neurons and as local interneurons. If the axonal output of a mitral ...
Others are studies of neurons, such as Purkinje cells. These studies used GENESIS to simulate Purkinje cells and could be ... The axon is a key component of nerve cells over which information is transmitted from one part of the neuron (e.g., the cell ... "Nerve cells are capable of communicating with each other in such a highly structured manner as to form neuronal networks. To ... The cell body or soma contains the nucleus and the other organelles necessary for cellular function. ...
Purkinje cell and granule cell degeneration results in ataxia. Despite normal Reln mRNA levels, Dab1-scm mutants have defective ... Cell ectopias are identical with targeted disruption of Dab1. Dab1-scm mutants have a widespread gait obvious to the naked eye ... Birthdate and cell marker analysis of scrambler: a novel mutation affecting cortical development with a reeler-like phenotype. ... Dab1-scm homozygous mutants possess a reeler-like phenotype with respect to cell malpositioning in cerebellar cortex, ...
Excitation of cerebellar Purkinje cells by the climbing fibers. Nature 203: 245-246, 1964 Illustration and text: cere/text/p3/ ... They terminate directly on Purkinje cells as the climbing fiber input system. This article incorporates text in the public ...
In the rat cerebellum, the protein has also been found in the Golgi cells of the granular layer, and in the Purkinje cells. In ... Maeshima T, Shiga T, Ito R, Okado N (December 2004). "Expression of serotonin2A receptors in Purkinje cells of the developing ... "Serotonin2A receptor-like immunoreactivity in rat cerebellar Purkinje cells". Neuroscience Letters. 252 (1): 72-74. doi:10.1016 ... doi:10.1016/j.cell.2021.03.043. PMC 8122087. PMID 33915107. Chambers JJ, Kurrasch-Orbaugh DM, Parker MA, Nichols DE (March 2001 ...
Some special cells present only in the cerebellum, Purkinje cells, have been reported to be part of this problems. Increasing ... Large numbers of T cells, B cells, and other immune cells concentrated around blood vessels. Inactive layer: Again activated ... living cells The functional characterization shows that T cells releasing Th2 cytokines and helping B cells dominate the T-cell ... T-cells attack is followed by leaks in the blood-brain barrier where T-cells infiltrate causing the known demyelination. Human ...
In the cerebellum Purkinje cells and interneuronal Golgi cells predominate. Glial cells are the supporting cells of the neurons ... The two main types of cells in the brain are neurons, also known as nerve cells, and glial cells also known as neuroglia. ... and ependymal cells, known collectively as macroglia, and the smaller scavenger cells known as microglia. Glial stem cells are ... Brain cell types are the functional neurons, and supporting glia. Neurons, also called nerve cells, are the functional ...
... which activated Purkinje cells, also activated the basket cells which subsequently inhibited the effect of Purkinje cells on ... Later using electron microscopy, it was confirmed that the basket cell axon projects on the axon hillock of Purkinje cells in ... where the presynaptic basket cell axons were found to inhibit the terminal output of postsynaptic Purkinje cells through the ... Dizon MJ, Khodakhah K (July 2011). "The role of interneurons in shaping Purkinje cell responses in the cerebellar cortex". The ...
Good CH (2007). "Endocannabinoid-dependent regulation of feedforward inhibition in cerebellar Purkinje cells". Journal of ... A related study found that endocannabinoids affect taste perception in taste cells. In taste cells, endocannabinoids were shown ... and bone marrow cells. These receptors have also been implicated in the migration of B cells into the marginal zone and the ... Based on the cell, these effects may result in the on-site synthesis of endogenous cannabinoids anandamide or 2-AG by a process ...
"Encoding of action by the Purkinje cells of the cerebellum". Nature. 526 (7573): 439-442. Bibcode:2015Natur.526..439H. doi: ... An important discovery was regarding how cells in the cerebellum are organized into populations that make predictions and learn ...
Good CH (2007). "Endocannabinoid-dependent regulation of feedforward inhibition in cerebellar Purkinje cells". Journal of ... Parkinson's disease is at least in part related to dropping out of dopaminergic cells in deep-brain nuclei, primarily the ... Noradrenaline is often released steadily so that it can prepare the supporting glial cells for calibrated responses. Despite ... a neuromodulator that boosts the function of multiple cell types to optimize CNS performance". Neurochem. Res. 37 (11): 2496- ...
Purkinje cells migrate toward the outer surface of the cerebellar cortex and form the Purkinje cell layer. Purkinje cells are ... input to the Purkinje cell, with basket cells synapsing on the Purkinje cell axon initial segment and stellate cells onto the ... Purkinje cells are found within the Purkinje layer in the cerebellum. Purkinje cells are aligned like dominos stacked one in ... with up to 200,000 parallel fibers forming a Granule-cell-Purkinje-cell synapse with a single Purkinje cell. Canonically, each ...
c Image of a dendritic shaft (Den) of Purkinje cell double-labelled for GABAB1 (10 nm) and CaV2.1 (5 nm) on the P-face in the ... Differential association of GABAB receptors with their effector ion channels in Purkinje cells. *Original Article ... In situ hybridization and immunohistochemical studies have shown that Purkinje cells (PCs), the output neurons of the ... Vigot R, Batini C (1997) GABAB receptor activation of Purkinje cells in cerebellar slices. Neurosci Res 29:151-160 ...
Dendritic spines of rat cerebellar Purkinje cells: serial electron microscopy with reference to their biophysical ... Dendritic spines of rat cerebellar Purkinje cells: serial electron microscopy with reference to their biophysical ... Dendritic spines of rat cerebellar Purkinje cells: serial electron microscopy with reference to their biophysical ... Dendritic spines of rat cerebellar Purkinje cells: serial electron microscopy with reference to their biophysical ...
... high expression in hippocampal CA3 pyramidal cells and cerebellar Purkinje cells (Shiraishi et al., 2004). In Purkinje cells, ... 4 total 61 cells; alone: 15.5 ± 5.1% oscillatory cells and 25.9 ± 4.9% persistent cells, n = 4 total 58 cells). The cells ... oscillatory cells and 41.7 ± 4.3% persistent cells) (Fig. 11B). The cells expressing wild-type Homer3-expressing cells ... 1988) Cell-specific localization of the alpha-subunit of calcium/calmodulin-dependent protein kinase II in Purkinje cells in ...
Effect of diphenylhydantoin on gamma aminobutyric acid (GABA) and succinate activity in rat Purkinje cells. ... Effect of diphenylhydantoin on gamma aminobutyric acid (GABA) and succinate activity in rat Purkinje cells. ...
Cell Type(s):. Cerebellum Purkinje GABA cell; Abstract integrate-and-fire leaky neuron; Abstract integrate-and-fire adaptive ... The parameters of the model were tuned to the Purkinje cell of cerebellum to reproduce the inhibiion of these cells by noisy ... Recurrent amplification of grid-cell activity (DAlbis and Kempter 2020). Robust transmission in the inhibitory Purkinje Cell ... Recurrent amplification of grid-cell activity (DAlbis and Kempter 2020). Robust transmission in the inhibitory Purkinje Cell ...
Robust transmission in the inhibitory Purkinje Cell to Cerebellar Nuclei pathway (Abbasi et al 2017). Robust transmission in ... Robust transmission in the inhibitory Purkinje Cell to Cerebellar Nuclei pathway (Abbasi et al 2017). Robust transmission in ... Robust transmission in the inhibitory Purkinje Cell to Cerebellar Nuclei pathway (Abbasi et al 2017). Robust transmission in ... Robust transmission in the inhibitory Purkinje Cell to Cerebellar Nuclei pathway (Abbasi et al 2017). Robust transmission in ...
PURKINJE FIBERS OF THE HEART EXAMINED WITH THE PEROXIDASE REACTION , Journal of Cell Biology, Volume 37, Issue 2, 1 May 19 ... Joachim R. Sommer, Edward A. Johnson; PURKINJE FIBERS OF THE HEART EXAMINED WITH THE PEROXIDASE REACTION . J Cell Biol 1 May ... A Comparative Study of Purkinje Fibers and Ventricular Fibers Intermediate (skeletin) filaments in heart Purkinje fibers. A ... PURKINJE FIBERS OF THE HEART EXAMINED WITH THE PEROXIDASE REACTION Joachim R. Sommer, Joachim R. Sommer ...
Alcohol exposure on postnatal day 5 induces Purkinje cell loss and evidence of Purkinje cell degradation in lobule I of rat ... Curcumin alters motor coordination but not total number of Purkinje cells in the cerebellum of adolescent male Wistar rats ... Curcumin alters motor coordination but not total number of Purkinje cells in the cerebellum of adolescent male Wistar rats. ... Goodlett CR, Eilers AT . Alcohol-induced Purkinje cell loss with a single binge exposure in neonatal rats: a stereological ...
Hirano, A., & Dembitzer, H. M. (1975). Aberrant development of the Purkinje cell dendritic spine. Advances in neurology, 12, ... Aberrant development of the Purkinje cell dendritic spine. / Hirano, A.; Dembitzer, H. M. In: Advances in neurology, Vol. 12, ... Hirano, A. ; Dembitzer, H. M. / Aberrant development of the Purkinje cell dendritic spine. In: Advances in neurology. 1975 ; ... Hirano, A & Dembitzer, HM 1975, Aberrant development of the Purkinje cell dendritic spine., Advances in neurology, vol. 12, ...
Here we use recordings from visualized rat cerebellar Purkinje cell axons to localize the site of initiation to a well-defined ... Here we use recordings from visualized rat cerebellar Purkinje cell axons to localize the site of initiation to a well-defined ... The main panel shows the morphology of the reconstructed Purkinje cell, with voltage in each section coded by color. The ... Results from a simulation in the Purkinje cell model (same as in Supplementary Video 1), plotting action potential amplitude in ...
Add color and vibe to that blank wall of your room with this stunning watercolor print. Our designs display sharp vivid images with a high degree of color accuracy and re
Blood London have been providing Purkinje Cell Antibody (Hu and Yo) on a self-referral basis to patients in Central and Greater ...
In paired recordings of connected basket cell-Purkinje cell synapses, depolarizations of 10-30 mV applied to the basket cell ... In basket and stellate cells, NMDA induced an even larger mIPSC frequency increase than in Purkinje cells, whereas mEPSCs were ... In Purkinje cells, application of NMDA enhanced the frequency of miniature IPSCs (mIPSCs) but not that of miniature EPSCs ( ... and that the corresponding receptors are most likely located in the axonal domain of the cell. ...
Heterogeneity in Purkinje cells arises early in development, with molecularly distinct embryonic cell clusters present soon ... Traditional methods have characterized cerebellar development and cell types, including Purkinje cell subtypes, based on ... However, recent single-cell RNA sequencing studies provide vastly increased resolution of the whole cerebellar transcriptome. ... Here we draw together the results of multiple single-cell transcriptomic studies in developing and adult cerebellum in both ...
Purkinje (c) Leeuwenhoek (d) Robert Brown Ans : (c) Leeuwenhoek ... Living cells were discovered by : (a) Robert Hooke (b) ... Living cells were discovered by : (a) Robert Hooke (b) Purkinje (c) Leeuwenhoek (d) Robert Brown. 28. Living cells were ...
Principle branch dynamics governing shape characteristics of cerebellar Purkinje cell dendrites. Kazuto Fujishima, Ryota Horie ... Principle branch dynamics governing shape characteristics of cerebellar Purkinje cell dendrites. In: Development. 2012 ; Vol. ... Principle branch dynamics governing shape characteristics of cerebellar Purkinje cell dendrites. / Fujishima, Kazuto; Horie, ... title = "Principle branch dynamics governing shape characteristics of cerebellar Purkinje cell dendrites", ...
Mostafa, Mohamed Hisham Atwa, "Ultrastructural Study of the Purkinje Cells of Hamster Cerebellar Cortex after Chronic Alcohol ... Ultrastructural Study of the Purkinje Cells of Hamster Cerebellar Cortex after Chronic Alcohol Administration. ...
... brush-like basket cell axons in contact with Purkinje cell bodies (shown above in c; the Purkinje cell bodies are indicated by ... Innervation of Purkinje Cells. Purkinje cells are the main source of cerebellar output, and as such, they must be tightly ... giant Purkinje cells (a). Meanwhile, climbing fibers transmit signals from the inferior olivary nucleus to Purkinje cells. Each ... bipolar cells (not pictured here) and ganglion cells (o), amacrine cells and horizontal cells (a,b) seemed to defy his law of ...
... Silvestri, L; ... we apply recent advances in optical microscopy and image analysis to characterize the spatial distribution of Purkinje cells ( ... we apply recent advances in optical microscopy and image analysis to characterize the spatial distribution of Purkinje cells ( ... Quantitative neuroanatomy of all Purkinje cells with light sheet microscopy and high-throughput image analysis, ,,FRONTIERS IN ...
... at parallel fibre-Purkinje cell synapses. Moreover, developmental elimination of surplus climbing fibres-a model for activity- ... 1b) or in Purkinje cell density (calculated as number of PCs/length of the Purkinje cell layer (mm); WT: 28.6±1.4 cells/mm; n=4 ... The Purkinje cell shown corresponds to the wild-type Purkinje cell in (c). Scale bar, 20 μm. The quantification of dendritic ... 7a,b). In wild-type mice 38.18% of Purkinje cells received one CF input, 50.91% of Purkinje cells received two CF inputs and ...
... suggesting that the NMDAR in Purkinje cells, but not in other cells, is directly involved in Purkinje cell viability. The ... suggesting that the NMDAR in Purkinje cells, but not in other cells, is directly involved in Purkinje cell viability. The ... suggesting that the NMDAR in Purkinje cells, but not in other cells, is directly involved in Purkinje cell viability. The ... suggesting that the NMDAR in Purkinje cells, but not in other cells, is directly involved in Purkinje cell viability. The ...
Purkinje cells destroyed. Plaques of encephalomalacia in brains of patients dying late in disease. (17, 18) ...
... cell transplantation ameliorates motor function deterioration of spinocerebellar ataxia by rescuing cerebellar Purkinje cells. ... cell transplantation ameliorates motor function deterioration of spinocerebellar ataxia by rescuing cerebellar Purkinje cells ...
Dendritic glutamate release produces autocrine activation of mGluR1 in cerebellar Purkinje cells. ... Dendritic glutamate release produces autocrine activation of mGluR1 in cerebellar Purkinje cells. Together they form a unique ...
MF, mossy fiber; CF, climbing fiber; GC, granule cell; PF, parallel fiber; PC, Purkinje cell; Golgi, Golgi cell; IN, inhibitory ... MF, mossy fiber; CF, climbing fiber; GC, granule cell; PF, parallel fiber; PC, Purkinje cell; Golgi, Golgi cell; IN, inhibitory ... Purkinje cell; IN, inhibitory interneuron; LTD, long-term depression. White cells: excitatory neurons, gray cells: inhibitory ... Purkinje cells have an inherent vulnerability of excitotoxicity-induced cell death. Thus, auto-antibodies-induced synaptic ...
Aim of this study was to investigate the alterations of intrinsic membrane properties and of synaptic inputs in Purkinje cells ... PCs were recorded by whole-cell patch-clamp in cerebellar slices from wild-type and APP/PS1 mice. In APP/PS1 PCs, evoked action ...
A Simplified Method for Generating Purkinje Cells from Human-Induced Pluripotent Stem Cells ... A Simplified Method for Generating Purkinje Cells from Human-Induced Pluripotent Stem Cells ...
Long-term climbing fibre activity induces transcription of microRNAs in cerebellar Purkinje cells. ... Long-term climbing fibre activity induces transcription of microRNAs in cerebellar Purkinje cells. Together they form a unique ...
N2 - An examination of the anatomy of the atrial, ventricular and Purkinje cells reveals that the internal composition of all ... AB - An examination of the anatomy of the atrial, ventricular and Purkinje cells reveals that the internal composition of all ... Legato, M. J. (1973). Ultrastructure of the atrial, ventricular, and Purkinje cell, with special reference to the genesis of ... Ultrastructure of the atrial, ventricular, and Purkinje cell, with special reference to the genesis of arrhythmias. / Legato, M ...
  • Purkinje cells, or Purkinje neurons, are a class of GABAergic inhibitory neurons located in the cerebellum. (wikipedia.org)
  • Purkinje cells are found within the Purkinje layer in the cerebellum. (wikipedia.org)
  • The Purkinje layer of the cerebellum, which contains the cell bodies of the Purkinje cells and Bergmann glia, express a large number of unique genes. (wikipedia.org)
  • The parameters of the model were tuned to the Purkinje cell of cerebellum to reproduce the inhibiion of these cells by noisy current injections. (yale.edu)
  • The micrograph of the three layers of cerebellum (Light microscopy, ×100) The Purkinje cells counted were those having nucleoli clearly visible (as indicated by arrows). (jcimjournal.com)
  • Here we draw together the results of multiple single-cell transcriptomic studies in developing and adult cerebellum in both mouse and human. (ox.ac.uk)
  • In this paper, we apply recent advances in optical microscopy and image analysis to characterize the spatial distribution of Purkinje cells (PCs) across the whole cerebellum. (unicatt.it)
  • We find that in patDp/+ mice delay eyeblink conditioning-a form of cerebellum-dependent motor learning-is impaired, and observe deregulation of a putative cellular mechanism for motor learning, long-term depression (LTD) at parallel fibre-Purkinje cell synapses. (nature.com)
  • Aim of this study was to investigate the alterations of intrinsic membrane properties and of synaptic inputs in Purkinje cells (PCs) of the cerebellum, where only soluble Aβ is present. (nih.gov)
  • In addition, FACL4 was highly expressed in both adult and newborn mouse brain especially in the granule cells of the dentate gyrus and the pyramidal cell layer of CA1 in hippocampus, and the granular cell layer and Purkinje cells of the cerebellum. (nih.gov)
  • The combined neuronal activity of two seemingly opposite types of Purkinje cell in the brain's cerebellum has been found to be required to control the jerky eye movements known as saccades in monkeys. (natureasia.com)
  • To gain insight into the genetic and molecular mechanisms that might link the cerebellum to ASD, we analysed the transcriptome dynamics of a developing cell population highly enriched for Purkinje cells of the mouse cerebellum across multiple timepoints. (ox.ac.uk)
  • Notably, histopathological examinations highlighted a sparse and disorganized Purkinje cell layer in the cerebellum. (elsevierpure.com)
  • Dystrophin was expressed in all hippocampal pyramidal subfields and in the molecular-, Purkinje-, and granular cell layer of the cerebellum. (frontiersin.org)
  • In rat hippocampus and cerebellum there were neither differences in dystrophin positive cell types, nor in the regional dystrophin distribution between AK and control animals. (frontiersin.org)
  • Pathophysiological links to autism include effects such as hyperserotoninemia, decreased T-cell proliferative function and activation, increased soluble IL-2 levels in serum, decreased CD8+ cells, decreased NK cells, development of anti-brain autoantibodies, decreased cerebellum volume and Purkinje cell number, and increased brain size. (cdc.gov)
  • These cells are some of the largest neurons in the human brain (Betz cells being the largest), with an intricately elaborate dendritic arbor, characterized by a large number of dendritic spines. (wikipedia.org)
  • One illustrative example is the Purkinje cell protein 4 (PCP4) in knockout mice, which exhibit impaired locomotor learning and markedly altered synaptic plasticity in Purkinje neurons. (wikipedia.org)
  • PCP4 accelerates both the association and dissociation of calcium (Ca2+) with calmodulin (CaM) in the cytoplasm of Purkinje cells, and its absence impairs the physiology of these neurons. (wikipedia.org)
  • Further evidence points yet towards the possibility of a common stem cell ancestor among Purkinje neurons, B-lymphocytes and aldosterone-producing cells of the human adrenal cortex. (wikipedia.org)
  • In situ hybridization and immunohistochemical studies have shown that Purkinje cells (PCs), the output neurons of the cerebellar cortex, are the neuron type with the highest levels of GABA B receptors (Bowery et al. (springer.com)
  • Figure 3: A model of action potential initiation in Purkinje neurons. (nature.com)
  • The cell bodies shown above are surrounded by "receptive nets" (A, B) formed by their own dendrites and the axons of neurons originating in the thoracic spinal cord. (nih.gov)
  • This vectorized representation of the cell population allows a thorough characterization of the complex three-dimensional distribution of the neurons, highlighting the presence of gaps inside the lamellar organization of PCs, whose density is believed to play a significant role in autism spectrum disorders. (unicatt.it)
  • Uninjured transgenic Purkinje cells displayed normal morphology, indicating that transgene expression does not modify the normal phenotype of these neurons. (nin.nl)
  • Finally, although only a moderate Purkinje cell loss occurred in wild-type cerebella after axotomy, a considerable number of injured transgenic neurons degenerated, but they could be partially rescued by the different transplants placed into the lesion site. (nin.nl)
  • snRNA-seq data mining and in situ hybridization in humans show that PRDM13 is expressed at early stages in the progenitors of the cerebellar ventricular zone, which gives rise to cerebellar GABAergic neurons, including Purkinje cells. (elsevierpure.com)
  • ATP7A increases in CA2 hippocampal pyramidal and cerebellar Purkinje neurons but decreases in other cell populations postnatally. (medscape.com)
  • Schlief et al found that copper is protective and copper chelation exacerbates NMDA-mediated excitotoxic cell death in hippocampal neurons. (medscape.com)
  • We examined the capacity of this protein to increase the regenerative potential of injured adult central axons, by inducing targeted B-50/GAP-43 overexpression in Purkinje cells, which normally show poor regenerative capabilities. (nin.nl)
  • These parallel fibers make relatively weaker excitatory (glutamatergic) synapses to spines in the Purkinje cell dendrite, whereas climbing fibers originating from the inferior olivary nucleus in the medulla provide very powerful excitatory input to the proximal dendrites and cell soma. (wikipedia.org)
  • Canonically, each adult Purkinje cell receives approximately 500 climbing fiber synapses, all originating from a single climbing fiber from the inferior olive. (wikipedia.org)
  • In paired recordings of connected basket cell-Purkinje cell synapses, depolarizations of 10-30 mV applied to the basket cell soma enhanced the frequency of postsynaptic mIPSCs, suggesting that somatic depolarization was partially transmitted to the terminals in the presence of tetrodotoxin. (ox.ac.uk)
  • C ) Cerebellar tissue from Control and Ttbk2 c.mut mice at 3 months after loss of Ttbk2 , immunostained for Calbindin to label Purkinje cells (red) and VGLUT2 to show climbing fiber synapses (green). (elifesciences.org)
  • Electrical synapses are important where __________ activity among a group of cells are a major function. (flashcardmachine.com)
  • Single-cell recordings provided the first strong evidence for mammalian electrical synapses in the __________ nucleus of cranial nerve __________, the __________ nucleus, and the __________ __________ nucleus. (flashcardmachine.com)
  • synapses use neurotransmitter to carry information from cell to cell. (flashcardmachine.com)
  • However, multi-innervation has now been found that "occurs" in mice among the subset of Purkinje cells with multiple primary dendrites, a dendritic motif that is uncommon in rodents but "predominant" in humans. (wikipedia.org)
  • Purkinje-specific gene markers were also proposed by comparing the transcriptome of Purkinje-deficient mice with that of wild-type mice. (wikipedia.org)
  • There is evidence in mice and humans that bone marrow cells either fuse with or generate cerebellar Purkinje cells, and it is possible that bone marrow cells, either by direct generation or by cell fusion, could play a role in repair of central nervous system damage. (wikipedia.org)
  • In cultures from normal mice, NMDA-mediated currents were detected in all identified Purkinje cells at 4 d in vitro (div). After 14 d, however, NMDA responses were reduced in amplitude, whereas the responses to kainate and glutamate increased steadily in amplitude. (elsevierpure.com)
  • Purkinje cell survival was correspondingly poorer in cultures from the NR1-/- mice than in wild-type controls, suggesting that NMDAR activity enhances the survival of Purkinje cells in vitro. (elsevierpure.com)
  • Feeder layers of cerebellar granule cells derived from wild-type or NR1-/- mice promoted survival of Purkinje cells to a similar degree, suggesting that the NMDAR in Purkinje cells, but not in other cells, is directly involved in Purkinje cell viability. (elsevierpure.com)
  • PCs were recorded by whole-cell patch-clamp in cerebellar slices from wild-type and APP/PS1 mice. (nih.gov)
  • Thus, transgenic mice were produced in which B-50/GAP-43 overexpression was driven by the Purkinje cell-specific L7 promoter. (nin.nl)
  • Nevertheless, despite these growth phenomena, which never occurred in wild-type mice, the severed transgenic axons were not able to regenerate, either spontaneously or into embryonic neural or Schwann cell grafts placed into the lesion site. (nin.nl)
  • We have used serial electron microscopy and 3-dimensional reconstructions of dendritic spines from Purkinje spiny branchlets of normal adult rats to evaluate 2 questions about the relationship of spine geometry to synaptic efficacy. (jneurosci.org)
  • In Purkinje cells, Homer3 is distributed throughout the dendrites, axons, and soma, but the most remarkable accumulation of Homer3 was observed in dendritic spines. (jneurosci.org)
  • Both basket and stellate cells (found in the cerebellar molecular layer) provide inhibitory (GABAergic) input to the Purkinje cell, with basket cells synapsing on the Purkinje cell axon initial segment and stellate cells onto the dendrites. (wikipedia.org)
  • the dendritic arbor, the cell body, and the axon. (nih.gov)
  • By contrast, after axotomy numerous transgenic Purkinje cells exhibited profuse sprouting along the axon and at its severed end. (nin.nl)
  • Purkinje cells send inhibitory projections to the deep cerebellar nuclei, and constitute the sole output of all motor coordination in the cerebellar cortex. (wikipedia.org)
  • Further maturation was observed following dissociation and co-culture of these cerebellar progenitors with mouse cerebellar cells, with 10% of human cells staining positive for the Purkinje cell marker calbindin by day 70 of differentiation. (ox.ac.uk)
  • During early development Purkinje cells arise in the ventricular zone in the neural tube, the nervous system´s precursor in the embryo. (wikipedia.org)
  • Purkinje cells are specifically generated from progenitors in the ventricular neuroepithelium of the embryonic cerebellar primordium. (wikipedia.org)
  • Neurogenin2, together with neurogenin1, are transiently expressed in restricted domains of the ventricular neuroepithelium during the time-window of Purkinje cell genesis. (wikipedia.org)
  • An examination of the anatomy of the atrial, ventricular and Purkinje cells reveals that the internal composition of all cardiac myofibers is qualitatively the same: all have a single nucleus, sarcomeric and mitochondrial units, and a well developed sarcoplasmic reticulum. (johnshopkins.edu)
  • By day 35 of differentiation, subpopulations of cells representative of the two cerebellar germinal zones, the rhombic lip (Atoh1-positive) and ventricular zone (Ptf1a-positive), could be identified, with the latter giving rise to cells positive for Purkinje cell progenitor-specific markers, including Lhx5, Kirrel2, Olig2 and Skor2. (ox.ac.uk)
  • Furthermore, both robust phosphorylation of Homer3 and its dissociation from metabotropic glutamate receptor 1α (mGluR1α) were triggered by depolarization in primary cultured Purkinje cells, and these events were inhibited by CaMKII inhibitor. (jneurosci.org)
  • Here, we analysed the distribution of GABA B receptors using highly sensitive SDS-digested freeze-fracture replica labelling in mouse cerebellar Purkinje cells. (springer.com)
  • Parallel fibers pass orthogonally through the Purkinje neuron's dendritic arbor, with up to 200,000 parallel fibers forming a Granule-cell-Purkinje-cell synapse with a single Purkinje cell. (wikipedia.org)
  • This is because Drosophila genes controlling fundamental cellular functions, such as cell growth and death, are quite identical to those found in human cells. (ataxia.org)
  • Purkinje cells migrate toward the outer surface of the cerebellar cortex and form the Purkinje cell layer. (wikipedia.org)
  • In basket and stellate cells, NMDA induced an even larger mIPSC frequency increase than in Purkinje cells, whereas mEPSCs were again not affected. (ox.ac.uk)
  • The results demonstrate that NMDARs transiently produce membrane current in Purkinje cells and may serve as one of the epigenetic factors that support the survival of Purkinje cells in vitro. (elsevierpure.com)
  • There are important differences, however, in the extent and distribution of the cell membrane and its derivatives in the myofiber. (johnshopkins.edu)
  • are proteins and __________ are tubes in the cell membrane. (flashcardmachine.com)
  • Recent advances in induced pluripotent stem cell (iPSC) technology offer the opportunity to generate multiple neuronal subtypes for study in vitro. (ox.ac.uk)
  • We found that Homer3, the predominant isoform in Purkinje cells, is phosphorylated by calcium/calmodulin-dependent protein kinase II (CaMKII) both in vitro and in vivo . (jneurosci.org)
  • The establishment of a reliable model for the study of Purkinje cells in vitro is of particular importance, given their central role in cerebellar function and pathology. (ox.ac.uk)
  • Stimulation of postsynaptic GABA B receptors generally triggers inhibition of adenylate cyclase and activation of G protein-gated inwardly rectifying K + (GIRK/Kir3) channels, leading to cell hyperpolarisation (Kaupmann et al. (springer.com)
  • In this study, we revealed that Homer3 was phosphorylated by calcium/calmodulin-dependent protein kinase II (CaMKII) in Purkinje cells, and the phosphorylation reduces the affinity for Homer target molecules, resulting in change of the solubility. (jneurosci.org)
  • The adaptor protein Grb2 is able to enhance the activity of the cytoplasmic tyrosine kinase Btk through a novel mechanism, revealing a new role for Grb2 in B-cell signaling. (elifesciences.org)
  • The Menkes protein is also in retinal pigment epithelial cells and the neurosensory retina. (medscape.com)
  • The Menkes protein is synthesized as a single-chain polypeptide localized to the trans-Golgi network in cells. (medscape.com)
  • Purkinje cells show two distinct forms of electrophysiological activity: Simple spikes occur at rates of 17 - 150 Hz (Raman and Bean, 1999), either spontaneously or when Purkinje cells are activated synaptically by the parallel fibers, the axons of the granule cells. (wikipedia.org)
  • The epithelial cells that line the intestine have been found to sense tight attachment of bacteria, and to respond by producing proteins that shape the effector functions of the immune system's T H 17 cells. (natureasia.com)
  • Similar experimental protocols were also applied to the detailed biophysical model of Purkinje cells, de Shutter & Bower (1994) model. (yale.edu)
  • Here we use recordings from visualized rat cerebellar Purkinje cell axons to localize the site of initiation to a well-defined anatomical structure: the first node of Ranvier, which normally forms at the first axonal branch point. (nature.com)
  • Presynaptic effects of NMDA in cerebellar Purkinje cells and interneurons. (ox.ac.uk)
  • We conclude that activation of NMDARs in interneurons exerts complex presynaptic effects, and that the corresponding receptors are most likely located in the axonal domain of the cell. (ox.ac.uk)
  • Mammalian embryonic research has detailed the neurogenic origins of Purkinje cells. (wikipedia.org)
  • Heterogeneity in Purkinje cells arises early in development, with molecularly distinct embryonic cell clusters present soon after Purkinje cell specification. (ox.ac.uk)
  • Most cases of this condition result from new (de novo) mutations in the gene that occur during the formation of reproductive cells (eggs or sperm) in an affected individual's parent or in early embryonic development. (medlineplus.gov)
  • This spatio-temporal distribution pattern suggests that neurogenins are involved in the specification of phenotypically heterogeneous Purkinje cell subsets, ultimately responsible for constructing the framework of the cerebellar topography. (wikipedia.org)
  • In Purkinje cells, application of NMDA enhanced the frequency of miniature IPSCs (mIPSCs) but not that of miniature EPSCs (mEPSCs). (ox.ac.uk)
  • Here, we describe a simplified method for the reproducible generation of Purkinje cells from human iPSCs. (ox.ac.uk)
  • Together, these findings suggested that Homer3 in Purkinje cells might function as a reversible coupler regulated by CaMKII phosphorylation and that the phosphorylation is capable of regulating the postsynaptic molecular architecture in response to synaptic activity. (jneurosci.org)
  • These results suggest that the phosphorylation may regulate postsynaptic molecular architecture and Ca 2+ signaling of Purkinje cells in response to synaptic activity. (jneurosci.org)
  • The quantitative approach presented here can be extended to study the distribution of different types of cell in many brain regions and across the whole encephalon, providing a robust base for building realistic computational models of the brain, and for unbiased morphological tissue screening in presence of pathologies and/or drug treatments. (unicatt.it)
  • Description: A sandwich ELISA for quantitative measurement of Human Cathepsin Antibodies in samples from blood, plasma, serum, cell culture supernatant and other biological fluids. (iowaodes.com)
  • 1994. Inhibition of Na+-glucose cotransport in kidney cortical cells by cadmium and copper: Protection by zinc. (cdc.gov)
  • The present study aimed at investigating the effects of curcumin on the motor coordination and the estimate of the total number of cerebellar Purkinje cells of adolescent Wistar rats exposed to ethanol. (jcimjournal.com)
  • We also show that loss of function of prdm13 in zebrafish leads to a reduction in Purkinje cells numbers and a complete absence of the inferior olive nuclei. (elsevierpure.com)
  • The system is formed by Purkinje cells (PC), the Deep Cerebellar Nucleus (DCN) and Inferior Olive (IO). (tudelft.nl)
  • Conflicting evidence exists concerning the activity of NMDA receptors (NMDARs) in cerebellar Purkinje cells and their possible functions. (elsevierpure.com)
  • A gene expression signature in developing Purkinje cells predicts autism and intellectual disability co-morbidity status. (ox.ac.uk)
  • MicrocircuitDB: Inverse stochastic resonance of cerebellar Purkinje cell (Buchin et al. (yale.edu)
  • ISR of Purkinje cells This is the code used to generate the plots of adaptive exponential integrate-and-fire model and Bower-de-Shutter model describing the activity of the cerevellar Purkinje cells. (yale.edu)
  • At 7 div, the number of surviving Purkinje cells was less in cultures treated with NMDA antagonists, and their survival was dose-dependent. (elsevierpure.com)
  • The addition of moderate doses of NMDA promoted the survival of wild- type Purkinje cells in the presence of tetrodotoxin. (elsevierpure.com)
  • This protocol, which incorporates modifications designed to enhance cell survival and maturation and improve the ease of handling, should serve to make existing models more accessible, in order to enable future advances in the field. (ox.ac.uk)
  • However, to date, only a handful of studies have generated Purkinje cells from human pluripotent stem cells, with most of these protocols proving challenging to reproduce. (ox.ac.uk)
  • This ASD-associated gene cluster was specific to developing Purkinje cells and not detected in the mouse neocortex during the same developmental period, in which we identified a distinct temporally regulated ASD gene module. (ox.ac.uk)