Action potentials. Medical search

Abrupt changes in the membrane potential that sweep along the CELL MEMBRANE of excitable cells in response to excitation stimuli.

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.

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).

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.

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.

Use of electric potential or currents to elicit biological responses.

Ion channels that specifically allow the passage of SODIUM ions. A variety of specific sodium channel subtypes are involved in serving specialized functions such as neuronal signaling, CARDIAC MUSCLE contraction, and KIDNEY function.

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.

A common name used for the genus Cavia. The most common species is Cavia porcellus which is the domesticated guinea pig used for pets and biomedical research.

The hemodynamic and electrophysiological action of the HEART VENTRICLES.

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.

Cell membrane glycoproteins that are selectively permeable to potassium ions. At least eight major groups of K channels exist and they are made up of dozens of different subunits.

The propagation of the NERVE IMPULSE along the nerve away from the site of an excitation stimulus.

The hollow, muscular organ that maintains the circulation of the blood.

An element in the alkali group of metals with an atomic symbol K, atomic number 19, and atomic weight 39.10. It is the chief cation in the intracellular fluid of muscle and other cells. Potassium ion is a strong electrolyte that plays a significant role in the regulation of fluid volume and maintenance of the WATER-ELECTROLYTE BALANCE.

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.

Conical muscular projections from the walls of the cardiac ventricles, attached to the cusps of the atrioventricular valves by the chordae tendineae.

Nerve fibers that are capable of rapidly conducting impulses away from the neuron cell body.

The ability of a substrate to allow the passage of ELECTRONS.

One of the POTASSIUM CHANNEL BLOCKERS, with secondary effect on calcium currents, which is used mainly as a research tool and to characterize channel subtypes.

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.

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)

Projection neurons in the CEREBRAL CORTEX and the HIPPOCAMPUS. Pyramidal cells have a pyramid-shaped soma with the apex and an apical dendrite pointed toward the pial surface and other dendrites and an axon emerging from the base. The axons may have local collaterals but also project outside their cortical region.

The lower right and left chambers of the heart. The right ventricle pumps venous BLOOD into the LUNGS and the left ventricle pumps oxygenated blood into the systemic arterial circulation.

Extensions of the nerve cell body. They are short and branched and receive stimuli from other NEURONS.

A member of the alkali group of metals. It has the atomic symbol Na, atomic number 11, and atomic weight 23.

Modified cardiac muscle fibers composing the terminal portion of the heart conduction system.

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 class of drugs that act by inhibition of potassium efflux through cell membranes. Blockade of potassium channels prolongs the duration of ACTION POTENTIALS. They are used as ANTI-ARRHYTHMIA AGENTS and VASODILATOR AGENTS.

The period of time following the triggering of an ACTION POTENTIAL when the CELL MEMBRANE has changed to an unexcitable state and is gradually restored to the resting (excitable) state. During the absolute refractory period no other stimulus can trigger a response. This is followed by the relative refractory period during which the cell gradually becomes more excitable and the stronger impulse that is required to illicit a response gradually lessens to that required during the resting state.

Potassium channel whose permeability to ions is extremely sensitive to the transmembrane potential difference. The opening of these channels is induced by the membrane depolarization of the ACTION POTENTIAL.

Agents used for the treatment or prevention of cardiac arrhythmias. They may affect the polarization-repolarization phase of the action potential, its excitability or refractoriness, or impulse conduction or membrane responsiveness within cardiac fibers. Anti-arrhythmia agents are often classed into four main groups according to their mechanism of action: sodium channel blockade, beta-adrenergic blockade, repolarization prolongation, or calcium channel blockade.

Striated muscle cells found in the heart. They are derived from cardiac myoblasts (MYOBLASTS, CARDIAC).

Theoretical representations that simulate the behavior or activity of the cardiovascular system, processes, or phenomena; includes the use of mathematical equations, computers and other electronic equipment.

Any disturbances of the normal rhythmic beating of the heart or MYOCARDIAL CONTRACTION. Cardiac arrhythmias can be classified by the abnormalities in HEART RATE, disorders of electrical impulse generation, or impulse conduction.

A class of drugs that act by inhibition of sodium influx through cell membranes. Blockade of sodium channels slows the rate and amplitude of initial rapid depolarization, reduces cell excitability, and reduces conduction velocity.

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.

Elements of limited time intervals, contributing to particular results or situations.

Gated, ion-selective glycoproteins that traverse membranes. The stimulus for ION CHANNEL GATING can be due to a variety of stimuli such as LIGANDS, a TRANSMEMBRANE POTENTIAL DIFFERENCE, mechanical deformation or through INTRACELLULAR SIGNALING PEPTIDES AND PROTEINS.

A group of slow opening and closing voltage-gated potassium channels. Because of their delayed activation kinetics they play an important role in controlling ACTION POTENTIAL duration.

A potassium-selective ion channel blocker. (From J Gen Phys 1994;104(1):173-90)

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)

Neurons which conduct NERVE IMPULSES to the CENTRAL NERVOUS SYSTEM.

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.

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.

Long-lasting voltage-gated CALCIUM CHANNELS found in both excitable and nonexcitable tissue. They are responsible for normal myocardial and vascular smooth muscle contractility. Five subunits (alpha-1, alpha-2, beta, gamma, and delta) make up the L-type channel. The alpha-1 subunit is the binding site for calcium-based antagonists. Dihydropyridine-based calcium antagonists are used as markers for these binding sites.

The muscle tissue of the HEART. It is composed of striated, involuntary muscle cells (MYOCYTES, CARDIAC) connected to form the contractile pump to generate blood flow.

Contractile activity of the MYOCARDIUM.

The chambers of the heart, to which the BLOOD returns from the circulation.

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 opening and closing of ion channels due to a stimulus. The stimulus can be a change in membrane potential (voltage-gated), drugs or chemical transmitters (ligand-gated), or a mechanical deformation. Gating is thought to involve conformational changes of the ion channel which alters selective permeability.

Neurons which activate MUSCLE CELLS.

The small mass of modified cardiac muscle fibers located at the junction of the superior vena cava (VENA CAVA, SUPERIOR) and right atrium. Contraction impulses probably start in this node, spread over the atrium (HEART ATRIUM) and are then transmitted by the atrioventricular bundle (BUNDLE OF HIS) to the ventricle (HEART VENTRICLE).

The hemodynamic and electrophysiological action of the HEART ATRIA.

Optical imaging techniques used for recording patterns of electrical activity in tissues by monitoring transmembrane potentials via FLUORESCENCE imaging with voltage-sensitive fluorescent dyes.

The innermost layer of the heart, comprised of endothelial cells.

Signal transduction mechanisms whereby calcium mobilization (from outside the cell or from intracellular storage pools) to the cytoplasm is triggered by external stimuli. Calcium signals are often seen to propagate as waves, oscillations, spikes, sparks, or puffs. The calcium acts as an intracellular messenger by activating calcium-responsive proteins.

A strain of albino rat developed at the Wistar Institute that has spread widely at other institutions. This has markedly diluted the original strain.

The electrical properties, characteristics of living organisms, and the processes of organisms or their parts that are involved in generating and responding to electrical charges.

A curved elevation of GRAY MATTER extending the entire length of the floor of the TEMPORAL HORN of the LATERAL VENTRICLE (see also TEMPORAL LOBE). The hippocampus proper, subiculum, and DENTATE GYRUS constitute the hippocampal formation. Sometimes authors include the ENTORHINAL CORTEX in the hippocampal formation.

A class of drugs that act by selective inhibition of calcium influx through cellular membranes.

The function of opposing or restraining the excitation of neurons or their target excitable cells.

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.

A conical fibro-serous sac surrounding the HEART and the roots of the great vessels (AORTA; VENAE CAVAE; PULMONARY ARTERY). Pericardium consists of two sacs: the outer fibrous pericardium and the inner serous pericardium. The latter consists of an outer parietal layer facing the fibrous pericardium, and an inner visceral layer (epicardium) resting next to the heart, and a pericardial cavity between these two layers.

An order of the class Amphibia, which includes several families of frogs and toads. They are characterized by well developed hind limbs adapted for jumping, fused head and trunk and webbed toes. The term "toad" is ambiguous and is properly applied only to the family Bufonidae.

The species Oryctolagus cuniculus, in the family Leporidae, order LAGOMORPHA. Rabbits are born in burrows, furless, and with eyes and ears closed. In contrast with HARES, rabbits have 22 chromosome pairs.

An optical isomer of quinine, extracted from the bark of the CHINCHONA tree and similar plant species. This alkaloid dampens the excitability of cardiac and skeletal muscles by blocking sodium and potassium currents across cellular membranes. It prolongs cellular ACTION POTENTIALS, and decreases automaticity. Quinidine also blocks muscarinic and alpha-adrenergic neurotransmission.

Computer-based representation of physical systems and phenomena such as chemical processes.

A condition that is characterized by episodes of fainting (SYNCOPE) and varying degree of ventricular arrhythmia as indicated by the prolonged QT interval. The inherited forms are caused by mutation of genes encoding cardiac ion channel proteins. The two major forms are ROMANO-WARD SYNDROME and JERVELL-LANGE NIELSEN SYNDROME.

Refers to animals in the period of time just after birth.

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.

A family of voltage-gated potassium channels that are characterized by long N-terminal and C-terminal intracellular tails. They are named from the Drosophila protein whose mutation causes abnormal leg shaking under ether anesthesia. Their activation kinetics are dependent on extracellular MAGNESIUM and PROTON concentration.

The time from the onset of a stimulus until a response is observed.

Substances used for their pharmacological actions on any aspect of neurotransmitter systems. Neurotransmitter agents include agonists, antagonists, degradation inhibitors, uptake inhibitors, depleters, precursors, and modulators of receptor function.

An element of the alkaline earth group of metals. It has an atomic symbol Ba, atomic number 56, and atomic weight 138. All of its acid-soluble salts are poisonous.

The domestic cat, Felis catus, of the carnivore family FELIDAE, comprising over 30 different breeds. The domestic cat is descended primarily from the wild cat of Africa and extreme southwestern Asia. Though probably present in towns in Palestine as long ago as 7000 years, actual domestication occurred in Egypt about 4000 years ago. (From Walker's Mammals of the World, 6th ed, p801)

The largest portion of the CEREBRAL CORTEX in which the NEURONS are arranged in six layers in the mammalian brain: molecular, external granular, external pyramidal, internal granular, internal pyramidal and multiform layers.

Cells propagated in vitro in special media conducive to their growth. Cultured cells are used to study developmental, morphologic, metabolic, physiologic, and genetic processes, among others.

A local anesthetic and cardiac depressant used as an antiarrhythmia agent. Its actions are more intense and its effects more prolonged than those of PROCAINE but its duration of action is shorter than that of BUPIVACAINE or PRILOCAINE.

A process leading to shortening and/or development of tension in muscle tissue. Muscle contraction occurs by a sliding filament mechanism whereby actin filaments slide inward among the myosin filaments.

A member of the alkali metals. It has an atomic symbol Cs, atomic number 50, and atomic weight 132.91. Cesium has many industrial applications, including the construction of atomic clocks based on its atomic vibrational frequency.

Sensory ganglia located on the dorsal spinal roots within the vertebral column. The spinal ganglion cells are pseudounipolar. The single primary branch bifurcates sending a peripheral process to carry sensory information from the periphery and a central branch which relays that information to the spinal cord or brain.

The synapse between a neuron and a muscle.

The most common inhibitory neurotransmitter in the central nervous system.

Recording of the moment-to-moment electromotive forces of the HEART as projected onto various sites on the body's surface, delineated as a scalar function of time. The recording is monitored by a tracing on slow moving chart paper or by observing it on a cardioscope, which is a CATHODE RAY TUBE DISPLAY.

A potentially lethal cardiac arrhythmia that is characterized by uncoordinated extremely rapid firing of electrical impulses (400-600/min) in HEART VENTRICLES. Such asynchronous ventricular quivering or fibrillation prevents any effective cardiac output and results in unconsciousness (SYNCOPE). It is one of the major electrocardiographic patterns seen with CARDIAC ARREST.

The smallest difference which can be discriminated between two stimuli or one which is barely above the threshold.

A shaker subfamily of potassium channels that participate in transient outward potassium currents by activating at subthreshold MEMBRANE POTENTIALS, inactivating rapidly, and recovering from inactivation quickly.

An adrenergic beta-antagonist that is used in the treatment of life-threatening arrhythmias.

Regulation of the rate of contraction of the heart muscles by an artificial pacemaker.

Contractile tissue that produces movement in animals.

Pyridines substituted in any position with an amino group. May be hydrogenated, but must retain at least one double bond.

The voltages across pre- or post-SYNAPTIC MEMBRANES.

An element of the alkaline earth family of metals. It has the atomic symbol Sr, atomic number 38, and atomic weight 87.62.

Venoms from jellyfish; CORALS; SEA ANEMONES; etc. They contain hemo-, cardio-, dermo- , and neuro-toxic substances and probably ENZYMES. They include palytoxin, sarcophine, and anthopleurine.

An electrogenic ion exchange protein that maintains a steady level of calcium by removing an amount of calcium equal to that which enters the cells. It is widely distributed in most excitable membranes, including the brain and heart.

Specialized afferent neurons capable of transducing sensory stimuli into NERVE IMPULSES to be transmitted to the CENTRAL NERVOUS SYSTEM. Sometimes sensory receptors for external stimuli are called exteroceptors; for internal stimuli are called interoceptors and proprioceptors.

A superorder of CEPHALOPODS comprised of squid, cuttlefish, and their relatives. Their distinguishing feature is the modification of their fourth pair of arms into tentacles, resulting in 10 limbs.

The physiological mechanisms that govern the rhythmic occurrence of certain biochemical, physiological, and behavioral phenomena.

A class of nerve fibers as defined by their nerve sheath arrangement. The AXONS of the unmyelinated nerve fibers are small in diameter and usually several are surrounded by a single MYELIN SHEATH. They conduct low-velocity impulses, and represent the majority of peripheral sensory and autonomic fibers, but are also found in the BRAIN and SPINAL CORD.

The relationship between the dose of an administered drug and the response of the organism to the drug.

A trace element that is a component of vitamin B12. It has the atomic symbol Co, atomic number 27, and atomic weight 58.93. It is used in nuclear weapons, alloys, and pigments. Deficiency in animals leads to anemia; its excess in humans can lead to erythrocytosis.

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.

Clusters of multipolar neurons surrounded by a capsule of loosely organized CONNECTIVE TISSUE located outside the CENTRAL NERVOUS SYSTEM.

A highly neurotoxic polypeptide from the venom of the honey bee (Apis mellifera). It consists of 18 amino acids with two disulfide bridges and causes hyperexcitability resulting in convulsions and respiratory paralysis.

A potent vasodilator agent with calcium antagonistic action. It is a useful anti-anginal agent that also lowers blood pressure.

A superfamily of various freshwater CRUSTACEA, in the infraorder Astacidea, comprising the crayfish. Common genera include Astacus and Procambarus. Crayfish resemble lobsters, but are usually much smaller.

The rate dynamics in chemical or physical systems.

The cochlear part of the 8th cranial nerve (VESTIBULOCOCHLEAR NERVE). The cochlear nerve fibers originate from neurons of the SPIRAL GANGLION and project peripherally to cochlear hair cells and centrally to the cochlear nuclei (COCHLEAR NUCLEUS) of the BRAIN STEM. They mediate the sense of hearing.

Regularly spaced gaps in the myelin sheaths of peripheral axons. Ranvier's nodes allow saltatory conduction, that is, jumping of impulses from node to node, which is faster and more energetically favorable than continuous conduction.

Isopropyl analog of EPINEPHRINE; beta-sympathomimetic that acts on the heart, bronchi, skeletal muscle, alimentary tract, etc. It is used mainly as bronchodilator and heart stimulant.

A local anesthetic of the ester type that has a slow onset and a short duration of action. It is mainly used for infiltration anesthesia, peripheral nerve block, and spinal block. (From Martindale, The Extra Pharmacopoeia, 30th ed, p1016).

A nerve which originates in the lumbar and sacral spinal cord (L4 to S3) and supplies motor and sensory innervation to the lower extremity. The sciatic nerve, which is the main continuation of the sacral plexus, is the largest nerve in the body. It has two major branches, the TIBIAL NERVE and the PERONEAL NERVE.

A chelating agent relatively more specific for calcium and less toxic than EDETIC ACID.

An isoquinoline alkaloid obtained from Dicentra cucullaria and other plants. It is a competitive antagonist for GABA-A receptors.

A shaker subfamily that is prominently expressed in NEURONS and are necessary for high-frequency, repetitive firing of ACTION POTENTIALS.

Drugs that bind to but do not activate excitatory amino acid receptors, thereby blocking the actions of agonists.

The tendency of a phenomenon to recur at regular intervals; in biological systems, the recurrence of certain activities (including hormonal, cellular, neural) may be annual, seasonal, monthly, daily, or more frequently (ultradian).

The nerves outside of the brain and spinal cord, including the autonomic, cranial, and spinal nerves. Peripheral nerves contain non-neuronal cells and connective tissue as well as axons. The connective tissue layers include, from the outside to the inside, the epineurium, the perineurium, and the endoneurium.

The movement of ions across energy-transducing cell membranes. Transport can be active, passive or facilitated. Ions may travel by themselves (uniport), or as a group of two or more ions in the same (symport) or opposite (antiport) directions.

The capacity of the NERVOUS SYSTEM to change its reactivity as the result of successive activations.

The inferior (caudal) ganglion of the vagus (10th cranial) nerve. The unipolar nodose ganglion cells are sensory cells with central projections to the medulla and peripheral processes traveling in various branches of the vagus nerve.

Cells specialized to transduce mechanical stimuli and relay that information centrally in the nervous system. Mechanoreceptor cells include the INNER EAR hair cells, which mediate hearing and balance, and the various somatosensory receptors, often with non-neural accessory structures.

A voltage-gated sodium channel subtype that mediates the sodium ion PERMEABILITY of CARDIOMYOCYTES. Defects in the SCN5A gene, which codes for the alpha subunit of this sodium channel, are associated with a variety of CARDIAC DISEASES that result from loss of sodium channel function.

A major nerve of the upper extremity. In humans, the fibers of the ulnar nerve originate in the lower cervical and upper thoracic spinal cord (usually C7 to T1), travel via the medial cord of the brachial plexus, and supply sensory and motor innervation to parts of the hand and forearm.

Inorganic compounds that contain barium as an integral part of the molecule.

A network of tubules and sacs in the cytoplasm of SKELETAL MUSCLE FIBERS that assist with muscle contraction and relaxation by releasing and storing calcium ions.

The study of PHYSICAL PHENOMENA and PHYSICAL PROCESSES as applied to living things.

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)

Agents that emit light after excitation by light. The wave length of the emitted light is usually longer than that of the incident light. Fluorochromes are substances that cause fluorescence in other substances, i.e., dyes used to mark or label other compounds with fluorescent tags.

Interstitial space between cells, occupied by INTERSTITIAL FLUID as well as amorphous and fibrous substances. For organisms with a CELL WALL, the extracellular space includes everything outside of the CELL MEMBRANE including the PERIPLASM and the cell wall.

Drugs that bind to but do not activate GABA RECEPTORS, thereby blocking the actions of endogenous GAMMA-AMINOBUTYRIC ACID and GABA RECEPTOR AGONISTS.

A heterogenous group of transient or low voltage activated type CALCIUM CHANNELS. They are found in cardiac myocyte membranes, the sinoatrial node, Purkinje cells of the heart and the central nervous system.

A major nerve of the upper extremity. In humans, the fibers of the median nerve originate in the lower cervical and upper thoracic spinal cord (usually C6 to T1), travel via the brachial plexus, and supply sensory and motor innervation to parts of the forearm and hand.

Recording of the changes in electric potential of muscle by means of surface or needle electrodes.

An element with atomic symbol Cd, atomic number 48, and atomic weight 114. It is a metal and ingestion will lead to CADMIUM POISONING.

Annelids of the class Hirudinea. Some species, the bloodsuckers, may become temporarily parasitic upon animals, including man. Medicinal leeches (HIRUDO MEDICINALIS) have been used therapeutically for drawing blood since ancient times.

Characteristic properties and processes of the NERVOUS SYSTEM as a whole or with reference to the peripheral or the CENTRAL NERVOUS SYSTEM.

A potent excitatory amino acid antagonist with a preference for non-NMDA iontropic receptors. It is used primarily as a research tool.

An opisthobranch mollusk of the order Anaspidea. It is used frequently in studies of nervous system development because of its large identifiable neurons. Aplysiatoxin and its derivatives are not biosynthesized by Aplysia, but acquired by ingestion of Lyngbya (seaweed) species.

A malignant form of polymorphic ventricular tachycardia that is characterized by HEART RATE between 200 and 250 beats per minute, and QRS complexes with changing amplitude and twisting of the points. The term also describes the syndrome of tachycardia with prolonged ventricular repolarization, long QT intervals exceeding 500 milliseconds or BRADYCARDIA. Torsades de pointes may be self-limited or may progress to VENTRICULAR FIBRILLATION.

The D-enantiomer is a potent and specific antagonist of NMDA glutamate receptors (RECEPTORS, N-METHYL-D-ASPARTATE). The L form is inactive at NMDA receptors but may affect the AP4 (2-amino-4-phosphonobutyrate; APB) excitatory amino acid receptors.

Nerve structures through which impulses are conducted from a peripheral part toward a nerve center.

A methylpyrrole-carboxylate from RYANIA that disrupts the RYANODINE RECEPTOR CALCIUM RELEASE CHANNEL to modify CALCIUM release from SARCOPLASMIC RETICULUM resulting in alteration of MUSCLE CONTRACTION. It was previously used in INSECTICIDES. It is used experimentally in conjunction with THAPSIGARGIN and other inhibitors of CALCIUM ATPASE uptake of calcium into SARCOPLASMIC RETICULUM.

Branch-like terminations of NERVE FIBERS, sensory or motor NEURONS. Endings of sensory neurons are the beginnings of afferent pathway to the CENTRAL NERVOUS SYSTEM. Endings of motor neurons are the terminals of axons at the muscle cells. Nerve endings which release neurotransmitters are called PRESYNAPTIC TERMINALS.

A cylindrical column of tissue that lies within the vertebral canal. It is composed of WHITE MATTER and GRAY MATTER.

The ability of a substrate to retain an electrical charge.

A voltage-gated potassium channel that is expressed primarily in the HEART.

Methods to induce and measure electrical activities at specific sites in the heart to diagnose and treat problems with the heart's electrical system.

A major class of calcium-activated potassium channels that are found primarily in excitable CELLS. They play important roles in the transmission of ACTION POTENTIALS and generate a long-lasting hyperpolarization known as the slow afterhyperpolarization.

Compounds based on N-phenylacetamide, that are similar in structure to 2-PHENYLACETAMIDES. They are precursors of many other compounds. They were formerly used as ANALGESICS and ANTIPYRETICS, but often caused lethal METHEMOGLOBINEMIA.

Potassium channels where the flow of K+ ions into the cell is greater than the outward flow.

Drugs that block nerve conduction when applied locally to nerve tissue in appropriate concentrations. They act on any part of the nervous system and on every type of nerve fiber. In contact with a nerve trunk, these anesthetics can cause both sensory and motor paralysis in the innervated area. Their action is completely reversible. (From Gilman AG, et. al., Goodman and Gilman's The Pharmacological Basis of Therapeutics, 8th ed) Nearly all local anesthetics act by reducing the tendency of voltage-dependent sodium channels to activate.

The part of the brain that connects the CEREBRAL HEMISPHERES with the SPINAL CORD. It consists of the MESENCEPHALON; PONS; and MEDULLA OBLONGATA.

A family of membrane proteins that selectively conduct SODIUM ions due to changes in the TRANSMEMBRANE POTENTIAL DIFFERENCE. They typically have a multimeric structure with a core alpha subunit that defines the sodium channel subtype and several beta subunits that modulate sodium channel activity.

A highly variable species of the family Ranidae in Canada, the United States and Central America. It is the most widely used Anuran in biomedical research.

The output neurons of the cerebellar cortex.

Electric conductors through which electric currents enter or leave a medium, whether it be an electrolytic solution, solid, molten mass, gas, or vacuum.

A meshlike structure composed of interconnecting nerve cells that are separated at the synaptic junction or joined to one another by cytoplasmic processes. In invertebrates, for example, the nerve net allows nerve impulses to spread over a wide area of the net because synapses can pass information in any direction.

A branch of the tibial nerve which supplies sensory innervation to parts of the lower leg and foot.

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.

A neurotransmitter found at neuromuscular junctions, autonomic ganglia, parasympathetic effector junctions, a subset of sympathetic effector junctions, and at many sites in the central nervous system.

Inorganic compounds derived from hydrochloric acid that contain the Cl- ion.

Mature contractile cells, commonly known as myocytes, that form one of three kinds of muscle. The three types of muscle cells are skeletal (MUSCLE FIBERS, SKELETAL), cardiac (MYOCYTES, CARDIAC), and smooth (MYOCYTES, SMOOTH MUSCLE). They are derived from embryonic (precursor) muscle cells called MYOBLASTS.

Act of eliciting a response from a person or organism through physical contact.

A class of nerve fibers as defined by their structure, specifically the nerve sheath arrangement. The AXONS of the myelinated nerve fibers are completely encased in a MYELIN SHEATH. They are fibers of relatively large and varied diameters. Their NEURAL CONDUCTION rates are faster than those of the unmyelinated nerve fibers (NERVE FIBERS, UNMYELINATED). Myelinated nerve fibers are present in somatic and autonomic nerves.

A calcium channel blocker that is a class IV anti-arrhythmia agent.

Unstriated and unstriped muscle, one of the muscles of the internal organs, blood vessels, hair follicles, etc. Contractile elements are elongated, usually spindle-shaped cells with centrally located nuclei. Smooth muscle fibers are bound together into sheets or bundles by reticular fibers and frequently elastic nets are also abundant. (From Stedman, 25th ed)

A neuromuscular blocker and active ingredient in CURARE; plant based alkaloid of Menispermaceae.

A benzoate-cevane found in VERATRUM and Schoenocaulon. It activates SODIUM CHANNELS to stay open longer than normal.

A family of hexahydropyridines.

A family of delayed rectifier voltage-gated potassium channels that share homology with their founding member, KCNQ1 PROTEIN. KCNQ potassium channels have been implicated in a variety of diseases including LONG QT SYNDROME; DEAFNESS; and EPILEPSY.

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 specialized field of physics and engineering involved in studying the behavior and properties of light and the technology of analyzing, generating, transmitting, and manipulating ELECTROMAGNETIC RADIATION in the visible, infrared, and ultraviolet range.

A phylum of the kingdom Metazoa. Mollusca have soft, unsegmented bodies with an anterior head, a dorsal visceral mass, and a ventral foot. Most are encased in a protective calcareous shell. It includes the classes GASTROPODA; BIVALVIA; CEPHALOPODA; Aplacophora; Scaphopoda; Polyplacophora; and Monoplacophora.

Peripheral AFFERENT NEURONS which are sensitive to injuries or pain, usually caused by extreme thermal exposures, mechanical forces, or other noxious stimuli. Their cell bodies reside in the DORSAL ROOT GANGLIA. Their peripheral terminals (NERVE ENDINGS) innervate target tissues and transduce noxious stimuli via axons to the CENTRAL NERVOUS SYSTEM.

Antiarrhythmic agent pharmacologically similar to LIDOCAINE. It may have some anticonvulsant properties.

Chemicals that bind to and remove ions from solutions. Many chelating agents function through the formation of COORDINATION COMPLEXES with METALS.

The 10th cranial nerve. The vagus is a mixed nerve which contains somatic afferents (from skin in back of the ear and the external auditory meatus), visceral afferents (from the pharynx, larynx, thorax, and abdomen), parasympathetic efferents (to the thorax and abdomen), and efferents to striated muscle (of the larynx and pharynx).

A subgroup of cyclic nucleotide-regulated ION CHANNELS of the superfamily of pore-loop cation channels that are opened by hyperpolarization rather than depolarization. The ion conducting pore passes SODIUM, CALCIUM, and POTASSIUM cations with a preference for potassium.

Treatment process involving the injection of fluid into an organ or tissue.

A delayed rectifier subtype of shaker potassium channels that is commonly mutated in human episodic ATAXIA and MYOKYMIA.

Venoms from snakes of the family Elapidae, including cobras, kraits, mambas, coral, tiger, and Australian snakes. The venoms contain polypeptide toxins of various kinds, cytolytic, hemolytic, and neurotoxic factors, but fewer enzymes than viper or crotalid venoms. Many of the toxins have been characterized.

Lanthanum. The prototypical element in the rare earth family of metals. It has the atomic symbol La, atomic number 57, and atomic weight 138.91. Lanthanide ion is used in experimental biology as a calcium antagonist; lanthanum oxide improves the optical properties of glass.

A non-essential amino acid naturally occurring in the L-form. Glutamic acid is the most common excitatory neurotransmitter in the CENTRAL NERVOUS SYSTEM.

The study of the electrical activity and characteristics of the HEART; MYOCARDIUM; and CARDIOMYOCYTES.

Theoretical representations that simulate the behavior or activity of biological processes or diseases. For disease models in living animals, DISEASE MODELS, ANIMAL is available. Biological models include the use of mathematical equations, computers, and other electronic equipment.

Clusters of neuronal cell bodies in invertebrates. Invertebrate ganglia may also contain neuronal processes and non-neuronal supporting cells. Many invertebrate ganglia are favorable subjects for research because they have small numbers of functional neuronal types which can be identified from one animal to another.

A species of the family Ranidae occurring in a wide variety of habitats from within the Arctic Circle to South Africa, Australia, etc.

A group of cardiac arrhythmias in which the cardiac contractions are not initiated at the SINOATRIAL NODE. They include both atrial and ventricular premature beats, and are also known as extra or ectopic heartbeats. Their frequency is increased in heart diseases.

Ganglia of the sympathetic nervous system including the paravertebral and the prevertebral ganglia. Among these are the sympathetic chain ganglia, the superior, middle, and inferior cervical ganglia, and the aorticorenal, celiac, and stellate ganglia.

The excitable plasma membrane of a muscle cell. (Glick, Glossary of Biochemistry and Molecular Biology, 1990)

A methylxanthine naturally occurring in some beverages and also used as a pharmacological agent. Caffeine's most notable pharmacological effect is as a central nervous system stimulant, increasing alertness and producing agitation. It also relaxes SMOOTH MUSCLE, stimulates CARDIAC MUSCLE, stimulates DIURESIS, and appears to be useful in the treatment of some types of headache. Several cellular actions of caffeine have been observed, but it is not entirely clear how each contributes to its pharmacological profile. Among the most important are inhibition of cyclic nucleotide PHOSPHODIESTERASES, antagonism of ADENOSINE RECEPTORS, and modulation of intracellular calcium handling.

Semidomesticated variety of European polecat much used for hunting RODENTS and/or RABBITS and as a laboratory animal. It is in the subfamily Mustelinae, family MUSTELIDAE.

A species of the family Ranidae (true frogs). The only anuran properly referred to by the common name "bullfrog", it is the largest native anuran in North America.

The number of times the HEART VENTRICLES contract per unit of time, usually per minute.

The thin layer of GRAY MATTER on the surface of the CEREBRAL HEMISPHERES that develops from the TELENCEPHALON and folds into gyri and sulchi. It reaches its highest development in humans and is responsible for intellectual faculties and higher mental functions.

Further evidence that prostaglandins inhibit the release of noradrenaline from adrenergic nerve terminals by restriction of availability of calcium. (1/21346)

1 Guinea-pig vasa deferentia were continuously superfused after labelling the transmitter stores with [3H](-)-noradrenaline. Release of [3H]-(-)-noradrenaline was induced by transmural nerve stimulation. 2 Prostglandin E2 (14 nM) drastically reduced the release of [3H]-(-)-noradrenaline, while tetraethylammonium (2 mM), rubidium (6 mM), phenoxybenzamine (3 muM) each in the presence or absence of Uptake 1 or 2 blockade, and prolonged pulse duration (from 0.5 to 2.0 ms) all significantly increased the release of [3H]-(-)-noradrenaline per nerve impulse. 3 The inhibitory effect of prostaglandin E2 on evoked release of [3H]-(-)-noradrenaline was significantly reduced by tetraethylammonium, rubidium and prolonged pulse duration, whilst it was actually enhanced by phenoxybenzamine. This indicates that increased release of noradrenaline per nerve impulse does not per se counteract the inhibitory effect of prostaglandin E2. 4 It is concluded that tetraethylammonium, rubidium and prolonged pulse duration counteracted the inhibitory effect of prostaglandin E2 on T3H]-(-)-noradrenaline release by promoting calcium influx during the nerve action potential. The results are consistent with, and add more weight to the view that prostaglandins inhibit the release of noradrenaline by restriction of calcium availability. (+info)

Effect of electrotonic potentials on pacemaker activity of canine Purkinje fibers in relation to parasystole. (2/21346)

Isolated false tendons excised form dog hearts were mounted in a three-chamber tissue bath. Isotonic sucrose solution was perfused in the central chamber to provide a region of depressed conductivity between the fiber segments in chambers 1 and 3, which were perfused with Tyrode's solution. The electrotonic influence of spontaneous or driven responses evoked in chamber 3 during the first half of the spontaneous cycle of a chamber 1 peacemaker delayed the next spontaneous discharge. This effect changed to acceleration when the chamber 3 segment fired during the second half of the spontaneous cycle. We found that subthreshold depolarizing current pulses 50-300 msec applied across the sucrose gap caused similar degrees of delay or acceleration. Furthermore, hyperpolarizing currents caused the reverse pattern. The results indicate that the discharge pattern of a parasystolic focus may be altered by the electrotonic influence of activity in the surrounding tissue. The significance of these findings is considered in relation to the mechanism of production of parasystolic rhythms. (+info)

Low resting potential and postnatal upregulation of NMDA receptors may cause Cajal-Retzius cell death. (3/21346)

Using in situ patch-clamp techniques in rat telencephalic slices, we have followed resting potential (RP) properties and the functional expression of NMDA receptors in neocortical Cajal-Retzius (CR) cells from embryonic day 18 to postnatal day 13, the time around which these cells normally disappear. We find that throughout their lives CR cells have a relatively depolarized RP (approximately -50 mV), which can be made more hyperpolarized (approximately -70 mV) by stimulation of the Na/K pump with intracellular ATP. The NMDA receptors of CR cells are subjected to intense postnatal upregulation, but their similar properties (EC50, Hill number, sensitivity to antagonists, conductance, and kinetics) throughout development suggest that their subunit composition remains relatively homogeneous. The low RP of CR cells is within a range that allows for the relief of NMDA channels from Mg2+ blockade. Our findings are consistent with the hypothesis that CR cells may degenerate and die subsequent to uncontrolled overload of intracellular Ca2+ via NMDA receptor activation by ambient glutamate. In support of this hypothesis we have obtained evidence showing the protection of CR cells via in vivo blockade of NMDA receptors with dizocilpine. (+info)

Activity-dependent metaplasticity of inhibitory and excitatory synaptic transmission in the lamprey spinal cord locomotor network. (4/21346)

Paired intracellular recordings have been used to examine the activity-dependent plasticity and neuromodulator-induced metaplasticity of synaptic inputs from identified inhibitory and excitatory interneurons in the lamprey spinal cord. Trains of spikes at 5-20 Hz were used to mimic the frequency of spiking that occurs in network interneurons during NMDA or brainstem-evoked locomotor activity. Inputs from inhibitory and excitatory interneurons exhibited similar activity-dependent changes, with synaptic depression developing during the spike train. The level of depression reached was greater with lower stimulation frequencies. Significant activity-dependent depression of inputs from excitatory interneurons and inhibitory crossed caudal interneurons, which are central elements in the patterning of network activity, usually developed between the fifth and tenth spikes in the train. Because these interneurons typically fire bursts of up to five spikes during locomotor activity, this activity-dependent plasticity will presumably not contribute to the patterning of network activity. However, in the presence of the neuromodulators substance P and 5-HT, significant activity-dependent metaplasticity of these inputs developed over the first five spikes in the train. Substance P induced significant activity-dependent depression of inhibitory but potentiation of excitatory interneuron inputs, whereas 5-HT induced significant activity-dependent potentiation of both inhibitory and excitatory interneuron inputs. Because these metaplastic effects are consistent with the substance P and 5-HT-induced modulation of the network output, activity-dependent metaplasticity could be a potential mechanism underlying the coordination and modulation of rhythmic network activity. (+info)

Ionic currents underlying spontaneous action potentials in isolated cerebellar Purkinje neurons. (5/21346)

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)

Somatic recording of GABAergic autoreceptor current in cerebellar stellate and basket cells. (6/21346)

Patch-clamp recordings were performed from stellate and basket cells in rat cerebellar slices. Under somatic voltage clamp, short depolarizing pulses were applied to elicit action potentials in the axon. After the action potential, a bicuculline- and Cd2+-sensitive current transient was observed. A similar response was obtained when eliciting axonal firing by extracellular stimulation. With an isotonic internal Cl- solution, the peak amplitude of this current varied linearly with the holding potential, yielding an extrapolated reversal potential of -20 to 0 mV. Unlike synaptic or autaptic GABAergic currents obtained in the same preparation, the current transient had a slow rise-time and a low variability between trials. This current was blocked when 10 mM BAPTA was included in the recording solution. In some experiments, the current transient elicited axonal action potentials. The current transient was reliably observed in animals aged 12-15 d, with a mean amplitude of 82 pA at -70 mV, but was small and rare in the age group 29-49 d. Numerical simulations could account for all properties of the current transient by assuming that an action potential activates a distributed GABAergic conductance in the axon. The actual conductance is probably restricted to release sites, with an estimated mean presynaptic current response of 10 pA per site (-70 mV, age 12-15 d). We conclude that in developing rats, stellate and basket cell axons have a high density of GABAergic autoreceptors and that a sizable fraction of the corresponding current can be measured from the soma. (+info)

Inducible genetic suppression of neuronal excitability. (7/21346)

Graded, reversible suppression of neuronal excitability represents a logical goal of therapy for epilepsy and intractable pain. To achieve such suppression, we have developed the means to transfer "electrical silencing" genes into neurons with sensitive control of transgene expression. An ecdysone-inducible promoter drives the expression of inwardly rectifying potassium channels in polycistronic adenoviral vectors. Infection of superior cervical ganglion neurons did not affect normal electrical activity but suppressed excitability after the induction of gene expression. These experiments demonstrate the feasibility of controlled ion channel expression after somatic gene transfer into neurons and serve as the prototype for a novel generalizable approach to modulate excitability. (+info)

Cerebellar Purkinje cell simple spike discharge encodes movement velocity in primates during visuomotor arm tracking. (8/21346)

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)

There are many different types of cardiac arrhythmias, including:

1. Tachycardias: These are fast heart rhythms that can be too fast for the body's needs. Examples include atrial fibrillation and ventricular tachycardia.
2. Bradycardias: These are slow heart rhythms that can cause symptoms like fatigue, dizziness, and fainting. Examples include sinus bradycardia and heart block.
3. Premature beats: These are extra beats that occur before the next regular beat should come in. They can be benign but can also indicate an underlying arrhythmia.
4. Supraventricular arrhythmias: These are arrhythmias that originate above the ventricles, such as atrial fibrillation and paroxysmal atrial tachycardia.
5. Ventricular arrhythmias: These are arrhythmias that originate in the ventricles, such as ventricular tachycardia and ventricular fibrillation.

Cardiac arrhythmias can be diagnosed through a variety of tests including electrocardiograms (ECGs), stress tests, and holter monitors. Treatment options for cardiac arrhythmias vary depending on the type and severity of the condition and may include medications, cardioversion, catheter ablation, or implantable devices like pacemakers or defibrillators.

The QT interval is a measure of the time it takes for the ventricles to recover from each heartbeat and prepare for the next one. In people with LQTS, this recovery time is prolonged, which can disrupt the normal rhythm of the heart and increase the risk of arrhythmias.

LQTS is caused by mutations in genes that encode proteins involved in the cardiac ion channels, which regulate the flow of ions into and out of the heart muscle cells. These mutations can affect the normal functioning of the ion channels, leading to abnormalities in the electrical activity of the heart.

Symptoms of LQTS can include palpitations, fainting spells, and seizures. In some cases, LQTS can be diagnosed based on a family history of the condition or after a sudden death in an otherwise healthy individual. Other tests, such as an electrocardiogram (ECG), echocardiogram, and stress test, may also be used to confirm the diagnosis.

Treatment for LQTS typically involves medications that regulate the heart's rhythm and reduce the risk of arrhythmias. In some cases, an implantable cardioverter-defibrillator (ICD) may be recommended to monitor the heart's activity and deliver an electric shock if a potentially life-threatening arrhythmia is detected. Lifestyle modifications, such as avoiding stimuli that trigger symptoms and taking precautions during exercise and stress, may also be recommended.

In summary, Long QT syndrome is a rare inherited disorder that affects the electrical activity of the heart, leading to an abnormal prolongation of the QT interval and an increased risk of irregular and potentially life-threatening heart rhythms. It is important for individuals with LQTS to be closely monitored by a healthcare provider and to take precautions to manage their condition and reduce the risk of complications.

In Vfib, the electrical activity of the heart becomes disorganized, leading to a fibrillatory pattern of contraction. This means that the ventricles are contracting in a rapid, unsynchronized manner, rather than the coordinated, synchronized contractions that occur in normal heart function.

Vfib can be caused by a variety of factors, including coronary artery disease, heart attack, cardiomyopathy, and electrolyte imbalances. It can also be triggered by certain medications, such as digoxin, or by electrical shocks to the heart.

Symptoms of Vfib include palpitations, shortness of breath, chest pain, and loss of consciousness. If not treated promptly, Vfib can lead to cardiac arrest and death.

Treatment of Vfib typically involves electrical cardioversion, which involves delivering an electric shock to the heart to restore a normal heart rhythm. In some cases, medications may also be used to help regulate the heart rhythm. In more severe cases, surgery or other interventions may be necessary to address any underlying causes of Vfib.

Overall, ventricular fibrillation is a serious medical condition that requires prompt treatment to prevent complications and ensure effective cardiac function.

Torsades de pointes is often associated with certain medications, such as antiarrhythmics, beta blockers, and cardiac glycosides, as well as with underlying heart conditions, such as coronary artery disease, hypertension, and heart failure. The condition can cause the heart to beat in an irregular and disorganized manner, which can lead to ineffective pumping of blood and can ultimately result in cardiac arrest and death.

Torsades de pointes is typically diagnosed based on the patient's medical history, physical examination, and results of electrocardiogram (ECG) tests. Treatment for the condition may involve stopping any medications that may be contributing to the arrhythmia, administering anti-arrhythmic drugs, and in some cases, implanting a cardioverter-defibrillator (ICD) to regulate the heart's rhythm.

In summary, torsades de pointes is a serious and potentially life-threatening arrhythmia that can be caused by various medications and underlying heart conditions. It is important for healthcare providers to be aware of this condition and to take appropriate measures to diagnose and treat it promptly in order to prevent complications and improve patient outcomes.

There are several types of premature complexes, including:

1. Premature atrial complex (PAC): An extra heartbeat that originates in the atria, usually due to a rapid or irregular heart rate.
2. Premature ventricular complex (PVC): An extra heartbeat that originates in the ventricles, which can be more serious than PACs and may require further evaluation.
3. Premature nodal rhythm: A condition where the AV node (the electrical pathway between the atria and ventricles) fires prematurely, causing a rapid heart rate.

PCCs can be diagnosed using electrocardiography (ECG), which records the electrical activity of the heart. Treatment options for PCCs depend on the underlying cause and may include medications to regulate the heart rhythm, cardioversion (a procedure that restores a normal heart rhythm using electrical shock), or catheter ablation (a minimally invasive procedure that destroys the abnormal electrical pathway).

Tachycardia, ventricular can be classified into several types based on its duration and the presence of other symptoms. These include:

1. Paroxysmal ventricular tachycardia (PVT): This is a rapid heart rate that occurs in episodes lasting less than 30 seconds and may be accompanied by palpitations, shortness of breath, or dizziness.
2. Sustained ventricular tachycardia: This is a rapid heart rate that persists for more than 30 seconds and may require medical intervention to return the heart to normal rhythm.
3. Ventricular fibrillation (VF): This is a life-threatening condition in which the ventricles are unable to pump blood effectively due to rapid, disorganized electrical activity.

Symptoms of tachycardia, ventricular may include:

* Palpitations or rapid heartbeat
* Shortness of breath
* Dizziness or lightheadedness
* Chest pain or discomfort
* Fatigue or weakness

Diagnosis of tachycardia, ventricular is typically made based on a physical examination, medical history, and results of diagnostic tests such as electrocardiogram (ECG), echocardiogram, or stress test. Treatment options may include medications to regulate heart rhythm, cardioversion to restore normal heart rhythm, and in some cases, implantation of a cardioverter-defibrillator (ICD) to prevent sudden death.

In summary, tachycardia, ventricular is a rapid heart rate that originates in the ventricles and can be caused by a variety of conditions. It is important to seek medical attention if symptoms persist or worsen over time. With proper diagnosis and treatment, it is possible to manage the condition and improve quality of life.

There are several risk factors for developing AF, including:

1. Age: The risk of developing AF increases with age, with the majority of cases occurring in people over the age of 65.
2. Hypertension (high blood pressure): High blood pressure can damage the heart and increase the risk of developing AF.
3. Heart disease: People with heart disease, such as coronary artery disease or heart failure, are at higher risk of developing AF.
4. Diabetes mellitus: Diabetes can increase the risk of developing AF.
5. Sleep apnea: Sleep apnea can increase the risk of developing AF.
6. Certain medications: Certain medications, such as thyroid medications and asthma medications, can increase the risk of developing AF.
7. Alcohol consumption: Excessive alcohol consumption has been linked to an increased risk of developing AF.
8. Smoking: Smoking is a risk factor for many cardiovascular conditions, including AF.
9. Obesity: Obesity is a risk factor for many cardiovascular conditions, including AF.

Symptoms of AF can include:

1. Palpitations (rapid or irregular heartbeat)
2. Shortness of breath
3. Fatigue
4. Dizziness or lightheadedness
5. Chest pain or discomfort

AF can be diagnosed with the help of several tests, including:

1. Electrocardiogram (ECG): This is a non-invasive test that measures the electrical activity of the heart.
2. Holter monitor: This is a portable device that records the heart's rhythm over a 24-hour period.
3. Event monitor: This is a portable device that records the heart's rhythm over a longer period of time, usually 1-2 weeks.
4. Echocardiogram: This is an imaging test that uses sound waves to create pictures of the heart.
5. Cardiac MRI: This is an imaging test that uses magnetic fields and radio waves to create detailed pictures of the heart.

Treatment for AF depends on the underlying cause and may include medications, such as:

1. Beta blockers: These medications slow the heart rate and reduce the force of the heart's contractions.
2. Antiarrhythmics: These medications help regulate the heart's rhythm.
3. Blood thinners: These medications prevent blood clots from forming and can help reduce the risk of stroke.
4. Calcium channel blockers: These medications slow the entry of calcium into the heart muscle cells, which can help slow the heart rate and reduce the force of the heart's contractions.

In some cases, catheter ablation may be recommended to destroy the abnormal electrical pathway causing AF. This is a minimally invasive procedure that involves inserting a catheter through a vein in the leg and guiding it to the heart using x-ray imaging. Once the catheter is in place, energy is applied to the abnormal electrical pathway to destroy it and restore a normal heart rhythm.

It's important to note that AF can increase the risk of stroke, so anticoagulation therapy may be recommended to reduce this risk. This can include medications such as warfarin or aspirin, or in some cases, implantable devices such as a left atrial appendage closure device.

In conclusion, atrial fibrillation is a common heart rhythm disorder that can increase the risk of stroke and heart failure. Treatment options depend on the underlying cause and may include medications, cardioversion, catheter ablation, or anticoagulation therapy. It's important to work closely with a healthcare provider to determine the best course of treatment for AF.

1) They share similarities with humans: Many animal species share similar biological and physiological characteristics with humans, making them useful for studying human diseases. For example, mice and rats are often used to study diseases such as diabetes, heart disease, and cancer because they have similar metabolic and cardiovascular systems to humans.

2) They can be genetically manipulated: Animal disease models can be genetically engineered to develop specific diseases or to model human genetic disorders. This allows researchers to study the progression of the disease and test potential treatments in a controlled environment.

3) They can be used to test drugs and therapies: Before new drugs or therapies are tested in humans, they are often first tested in animal models of disease. This allows researchers to assess the safety and efficacy of the treatment before moving on to human clinical trials.

4) They can provide insights into disease mechanisms: Studying disease models in animals can provide valuable insights into the underlying mechanisms of a particular disease. This information can then be used to develop new treatments or improve existing ones.

5) Reduces the need for human testing: Using animal disease models reduces the need for human testing, which can be time-consuming, expensive, and ethically challenging. However, it is important to note that animal models are not perfect substitutes for human subjects, and results obtained from animal studies may not always translate to humans.

6) They can be used to study infectious diseases: Animal disease models can be used to study infectious diseases such as HIV, TB, and malaria. These models allow researchers to understand how the disease is transmitted, how it progresses, and how it responds to treatment.

7) They can be used to study complex diseases: Animal disease models can be used to study complex diseases such as cancer, diabetes, and heart disease. These models allow researchers to understand the underlying mechanisms of the disease and test potential treatments.

8) They are cost-effective: Animal disease models are often less expensive than human clinical trials, making them a cost-effective way to conduct research.

9) They can be used to study drug delivery: Animal disease models can be used to study drug delivery and pharmacokinetics, which is important for developing new drugs and drug delivery systems.

10) They can be used to study aging: Animal disease models can be used to study the aging process and age-related diseases such as Alzheimer's and Parkinson's. This allows researchers to understand how aging contributes to disease and develop potential treatments.

Peripheral Nervous System Diseases can result from a variety of causes, including:

1. Trauma or injury
2. Infections such as Lyme disease or HIV
3. Autoimmune disorders such as Guillain-Barré syndrome
4. Genetic mutations
5. Tumors or cysts
6. Toxins or poisoning
7. Vitamin deficiencies
8. Chronic diseases such as diabetes or alcoholism

Some common Peripheral Nervous System Diseases include:

1. Neuropathy - damage to the nerves that can cause pain, numbness, and weakness in the affected areas.
2. Multiple Sclerosis (MS) - an autoimmune disease that affects the CNS and PNS, causing a range of symptoms including numbness, weakness, and vision problems.
3. Peripheral Neuropathy - damage to the nerves that can cause pain, numbness, and weakness in the affected areas.
4. Guillain-Barré syndrome - an autoimmune disorder that causes muscle weakness and paralysis.
5. Charcot-Marie-Tooth disease - a group of inherited disorders that affect the nerves in the feet and legs, leading to muscle weakness and wasting.
6. Friedreich's ataxia - an inherited disorder that affects the nerves in the spine and limbs, leading to coordination problems and muscle weakness.
7. Chronic Inflammatory Demyelinating Polyneuropathy (CIDP) - an autoimmune disorder that causes inflammation of the nerves, leading to pain, numbness, and weakness in the affected areas.
8. Amyotrophic Lateral Sclerosis (ALS) - a progressive neurological disease that affects the nerve cells responsible for controlling voluntary muscle movement, leading to muscle weakness, atrophy, and paralysis.
9. Spinal Muscular Atrophy - an inherited disorder that affects the nerve cells responsible for controlling voluntary muscle movement, leading to muscle weakness and wasting.
10. Muscular Dystrophy - a group of inherited disorders that affect the nerve cells responsible for controlling voluntary muscle movement, leading to muscle weakness and wasting.

It's important to note that this is not an exhaustive list and there may be other causes of muscle weakness. If you are experiencing persistent or severe muscle weakness, it is important to see a healthcare professional for proper evaluation and diagnosis.

There are several types of channelopathies, including:

1. Long QT syndrome: This is a condition that affects the ion channels in the heart, leading to abnormal heart rhythms and increased risk of sudden death.
2. Short QT syndrome: This is a rare condition that has the opposite effect of long QT syndrome, causing the heart to beat too quickly.
3. Catecholaminergic polymorphic ventricular tachycardia (CPVT): This is a rare disorder that affects the ion channels in the heart, leading to abnormal heart rhythms and increased risk of sudden death.
4. Brugada syndrome: This is a condition that affects the ion channels in the heart, leading to abnormal heart rhythms and increased risk of sudden death.
5. Wolff-Parkinson-White (WPW) syndrome: This is a condition that affects the ion channels in the heart, leading to abnormal heart rhythms and increased risk of sudden death.
6. Neuromuscular disorders: These are disorders that affect the nerve-muscle junction, leading to muscle weakness and wasting. Examples include muscular dystrophy and myasthenia gravis.
7. Dystrophinopathies: These are a group of disorders that affect the structure of muscle cells, leading to muscle weakness and wasting. Examples include Duchenne muscular dystrophy and Becker muscular dystrophy.
8. Myotonia: This is a condition that affects the muscles, causing them to become stiff and rigid.
9. Hyperkalemic periodic paralysis: This is a rare condition that causes muscle weakness and paralysis due to abnormal potassium levels in the body.
10. Hypokalemic periodic paralysis: This is a rare condition that causes muscle weakness and paralysis due to low potassium levels in the body.
11. Thyrotoxic periodic paralysis: This is a rare condition that causes muscle weakness and paralysis due to an overactive thyroid gland.
12. Hyperthyroidism: This is a condition where the thyroid gland becomes overactive, leading to increased heart rate, weight loss, and muscle weakness.
13. Hypothyroidism: This is a condition where the thyroid gland becomes underactive, leading to fatigue, weight gain, and muscle weakness.
14. Pituitary tumors: These are tumors that affect the pituitary gland, which regulates hormone production in the body.
15. Adrenal tumors: These are tumors that affect the adrenal glands, which produce hormones such as cortisol and aldosterone.
16. Carcinoid syndrome: This is a condition where cancer cells in the digestive system produce hormones that can cause muscle weakness and wasting.
17. Multiple endocrine neoplasia (MEN): This is a genetic disorder that affects the endocrine system and can cause tumors to grow in the thyroid, adrenal, and parathyroid glands.

These are just some of the many potential causes of muscle weakness. It's important to see a healthcare professional for an accurate diagnosis and appropriate treatment.

The action potential in a normal skeletal muscle cell is similar to the action potential in neurons. Action potentials result ... of Arizona A cartoon illustrating the action potential Action potential propagation Production of the action potential: voltage ... The cardiac action potential differs from the neuronal action potential by having an extended plateau, in which the membrane is ... Action potentials in neurons are also known as "nerve impulses" or "spikes", and the temporal sequence of action potentials ...

https://en.wikipedia.org/wiki/Action_potential

... the atrial action potential are action potentials that occur in the heart atrium. They are similar to ventricular action ... Cardiac action potential Vigmond E.J, Tsoi V, Yin Y, Page P, & Vinet A. (2009). Estimating Atrial Action Potential Duration ... Also, in comparison to the ventricular action potential, atrial action potentials have a more gradual repolarization period. ... Action potentials, All stub articles, Muscle stubs). ... potential with the exception of having a more narrow phase 2 ( ...

https://en.wikipedia.org/wiki/Atrial_action_potential

A pacemaker action potential is the kind of action potential that provides a reference rhythm for the network. This contrasts ... Some pacemaker action generate rhythms for the heart beat (sino-atrial node) or the circadian rhythm in the suprachiasmatic ... with pacemaker potential or current which drives rhythmic modulation of firing rate. ...

https://en.wikipedia.org/wiki/Pacemaker_action_potential

The action potential pulse is a model of the speed an action potential that is dynamically dependent upon the position and ... The action potential pulse model takes into account entropy and the conduction speed of the action potential along an axon. It ... In addition a soliton pulse is known to flow at the same rate and follow the action potential. From measurements of the speed ... An action potential pulse is a mathematically and experimentally correct Synchronized Oscillating Lipid Pulse coupled with an ...

https://en.wikipedia.org/wiki/Action_potential_pulse

This current is observed in human and dog action potentials, but not in guinea pig action potentials. Repolarization is ... which is close to the potassium reversal potential. When an action potential is generated, the membrane potential rises above ... Cardiac action potential (Articles lacking sources from December 2009, All articles lacking sources, Cardiac electrophysiology ... The beginning of the action potential, phase 0, specialized membrane proteins (voltage-gated sodium channels) in the cell ...

https://en.wikipedia.org/wiki/Ventricular_action_potential

... of a cardiac action potential Interactive mathematical models of cardiac action potential and other generic action potentials ( ... The cardiac action potential differs from action potentials found in other types of electrically excitable cells, such as ... Unlike the action potential in skeletal muscle cells, the cardiac action potential is not initiated by nervous activity. ... Outlined below are the five phases of the ventricular myocyte action potential, with reference also to the SAN action potential ...

https://en.wikipedia.org/wiki/Cardiac_action_potential

The compound muscle action potential (CMAP) or compound motor action potential is an electromyography investigation (electrical ... have prolonged compound muscle action potential. Goodman BP; et al. (2009). "Prolonged compound muscle action potential ... v t e (Articles using infobox templates with no data rows, Neurophysiology, Action potentials, All stub articles, Medical ... The CMAP idealizes the summation of a group of almost simultaneous action potentials from several muscle fibers in the same ...

https://en.wikipedia.org/wiki/Compound_muscle_action_potential

As an example, the cardiac action potential illustrates how differently shaped action potentials can be generated on membranes ... Op-amp circuits that realize the FHN and van der Pol models of the action potential have been developed by Keener. A hybrid of ... The simplest models of the action potential are the "flush and fill" models (also called "integrate-and-fire" models), in which ... In neurophysiology, several mathematical models of the action potential have been developed, which fall into two basic types. ...

https://en.wikipedia.org/wiki/Quantitative_models_of_the_action_potential

However, all action potentials are begun by electrotonic potentials depolarizing the membrane above the threshold potential ... Action potential, a propagated impulse. Electrotonic potentials represent changes to the neuron's membrane potential that do ... longer neurons utilize electrotonic potentials to trigger the action potential. Electrotonic potentials have an amplitude that ... Electrotonic potentials are conducted faster than action potentials, but attenuate rapidly so are unsuitable for long-distance ...

https://en.wikipedia.org/wiki/Electrotonic_potential

Spike potentials are one of the action potentials, which occur in electrical activity of smooth muscle contraction in animals. ... These are true action potentials. In the human gut they occur automatically when the resting membrane potential of the ... The spike potentials last 10 to 40 times as long in gastrointestinal muscle as the action potentials in large nerve fibers, ... During cortical reaction in fertilisation[circular reference]of sperm with secondary oocyte spike potential reaches above +30 ...

https://en.wikipedia.org/wiki/Spike_potential

Postsynaptic potentials are graded potentials, and should not be confused with action potentials although their function is to ... Action potentials are not graded; they are all-or-none responses. Postsynaptic potentials begin to be terminated when the ... Action potential Electrophysiology Goldman equation Membrane potential Nernst equation Neuron Neurotransmission Postsynaptic ... as the potential comes closer to zero. This is an excitatory postsynaptic potential (EPSP), as it brings the neuron's potential ...

https://en.wikipedia.org/wiki/Postsynaptic_potential

... the threshold potential is the critical level to which a membrane potential must be depolarized to initiate an action potential ... The action potential is recorded downstream from the triggering impulse. The stimulus is automatically decreased in steps of a ... The signals can only continue along the neuron to cause an action potential further down if they are strong enough to make it ... The threshold value controls whether or not the incoming stimuli are sufficient to generate an action potential. It relies on a ...

https://en.wikipedia.org/wiki/Threshold_potential

... that explained the resting potential of nerve and muscle as a diffusion potential. Action potential Depolarization ... During the action potential, these weights change. If the conductances of Na+ and Cl− are zero, the membrane potential reduces ... as opposed to the specific dynamic electrochemical phenomena called action potential and graded membrane potential. Apart from ... usually the resting potential can be no more negative than the potassium equilibrium potential. The resting potential can be ...

https://en.wikipedia.org/wiki/Resting_potential

... reverse potential of the postsynaptic potential, action potential threshold voltage, ionic permeability of the ion channel, as ... If the electrochemical potential of the ion is more negative than that of the action potential threshold then the resultant ... To generate an action potential, the postsynaptic membrane must depolarize-the membrane potential must reach a voltage ... IPSPs always want to keep the membrane potential more negative than the action potential threshold and can be seen as a " ...

https://en.wikipedia.org/wiki/Inhibitory_postsynaptic_potential

... the membrane potential) that occurs between the end of one action potential and the beginning of the next action potential. ... to reach the threshold potential and consequently fire the next action potential; thus, the pacemaker potential is what drives ... The threshold potential is the potential an excitable cell membrane, such as a myocyte, must reach in order to induce an action ... Pacemaker action potential Graded potential Berne, Robert; Matthew Levy; Bruce Koeppen; Bruce Stanton (2004). Physiology. ...

https://en.wikipedia.org/wiki/Pacemaker_potential

... can work to trigger an action potential either within the same neuron or on an adjacent cell. Within the ... A receptor potential, also known as a generator potential, a type of graded potential, is the transmembrane potential ... where they elicit an action potential. Resting potential Action potential Merriam-Webster Online Dictionary. http://www.merriam ... The magnitude of the receptor potential determines the frequency with which action potentials are generated, and is controlled ...

https://en.wikipedia.org/wiki/Receptor_potential

Uterine muscle seems to generate action potentials spontaneously. In gastrointestinal smooth muscle, the slow-wave threshold ... A slow-wave potential is a not rhythmic electrophysiological event in the gastrointestinal tract. The normal conduction of slow ... Another potential coupling mechanism is the "Peg and Socket" theory which demonstrates that the membranes of smooth muscle ... In the human enteric nervous system, the slow-wave threshold is the slow-wave potential which must be reached before a slow ...

https://en.wikipedia.org/wiki/Slow-wave_potential

A variation potential, like an action potential, is a temporary change in the membrane potential of the plant cell by ... Unlike action potentials, variation potentials are not all or nothing. Depolarization of a variation potential is determined by ... the other two being action potential (AP) and wound potential (WP) (also unique to plants). Variation potentials are ... Variation potentials are distinct from action potentials in their cause of stimulation. Depolarization arises from an increase ...

https://en.wikipedia.org/wiki/Variation_potential

TRP ion channels convert energy into action potentials in somatosensory nociceptors. Thermo-TRP channels have a C-terminal ... Transient receptor potential channels (TRP channels) are a group of ion channels located mostly on the plasma membrane of ... TRPV2 is a potential biomarker and therapeutic target in triple negative breast cancer.[citation needed] TRPM family of ion ... Only a single TRPN, N for "no mechanoreceptor potential C," or "nompC", is known to be broadly expressed in animals (although ...

https://en.wikipedia.org/wiki/Transient_receptor_potential_channel

In this state, the cell fires action potentials independent of synaptic input. The PICs can be turned off via the activation of ... v t e (Electrophysiology, Action potentials, All stub articles, Neuroscience stubs). ... have also been shown to exhibit plateau potentials. Plateau potentials are also seen in the cortical, and hippocampal pyramidal ... Plateau potentials are of particular importance to spinal cord motor systems. PICs are set up by the influence of descending ...

https://en.wikipedia.org/wiki/Plateau_potentials

... these subthreshold membrane potential oscillations do not trigger action potentials, since the firing of an action potential is ... they are able to still impact action potential outcomes. Neurons display, beyond synaptic and action potentials, rhythmic ... Neurons produce action potentials when their membrane potential increases past a critical threshold. In order for neurons to ... Subthreshold membrane potential oscillations are membrane oscillations that do not directly trigger an action potential since ...

https://en.wikipedia.org/wiki/Subthreshold_membrane_potential_oscillations

... plays a major role in the action potentials of some algae, but plays a negligible role in the action potentials of most animals ... Although the membrane potential changes about 100 mV during an action potential, the concentrations of ions inside and outside ... The resting potential in excitable cells (capable of producing action potentials) is usually near -60 mV-more depolarized ... Cells may draw on the energy they store in the resting potential to drive action potentials or other forms of excitation. These ...

https://en.wikipedia.org/wiki/Membrane_potential

When an action potential fires at the dendritic spine where the action potential is initiated from the presynaptic terminal to ... The action potential actually occurs because of the synaptic potential across the membrane of the neuron. The potential ... Synaptic potentials, unlike action potentials, degrade quickly as they move away from the synapse. This is the case for both ... Synaptic potential refers to the potential difference across the postsynaptic membrane that results from the action of ...

https://en.wikipedia.org/wiki/Synaptic_potential

It gradually returns to resting potential and is ready for another action potential to occur. During the action potential ... It is important to note that EPPs are not action potentials, but that they trigger action potentials. In a normal muscular ... an action potential occurs and causes a sharp spike in membrane polarity. There are five phases of an action potential: ... When an action potential propagates down a nerve and reaches the axon terminal of the motor neuron, the change in membrane ...

https://en.wikipedia.org/wiki/End-plate_potential

The unfiltered signal reflects the sum of action potentials from cells within approximately 50-350 μm from the tip of the ... The fast fluctuations are mostly caused by the short inward and outward currents of action potentials, while the direct ... activity-dependent phase-precession of action potentials". Hippocampus. 8 (3): 244-61. doi:10.1002/(SICI)1098-1063(1998)8:3. ... contribution of action potentials is minimal in the LFP. The LFP is thus composed of the more sustained currents in the tissue ...

https://en.wikipedia.org/wiki/Local_field_potential

Depolarizing local potentials sum together, and if the voltage reaches the threshold potential, an action potential occurs in ... They include diverse potentials such as receptor potentials, electrotonic potentials, subthreshold membrane potential ... Graded potentials that make the membrane potential more negative, and make the postsynaptic cell less likely to have an action ... thus making the postsynaptic cell more likely to have an action potential, are called excitatory postsynaptic potentials (EPSPs ...

https://en.wikipedia.org/wiki/Graded_potential

... decreasing the probability of an action potential firing as the voltage becomes more negative (for an action potential to fire ... an action potential). Some neurons also generate subthreshold membrane potential oscillations. These signals are generated and ... the neuron generates an all-or-nothing electrochemical pulse called an action potential. This potential travels rapidly along ... When an action potential reaches the axon terminal, it opens voltage-gated calcium channels, allowing calcium ions to enter the ...

https://en.wikipedia.org/wiki/Neuron

The four commonly recognized propagation methods include action potentials (APs), variation potentials (VPs), local electric ... These action potentials can influence processes such as actin-based cytoplasmic streaming, plant organ movements, wound ... Pickard BG (1973). "Action Potentials in Higher Plants". Botanical Review. 39 (2): 172-201. doi:10.1007/BF02859299. JSTOR ... APs allow for the movement of signaling ions and molecules from the pre-potential cell to the post-potential cell(s). These ...

https://en.wikipedia.org/wiki/Plant_perception_(physiology)

The first is the action potential and the second is the variation potential. Similar to action potentials in animals, action ... Sir John Burdon-Sanderson described action potentials and their long-distance propagation throughout plants. Action potentials ... Variation potentials are slower than action potentials, are not considered "all or nothing," and they themselves can trigger ... That is to say, it is not always the case that a plant responds with an action potential or variation potential. However, when ...

https://en.wikipedia.org/wiki/Plant_communication

Parsing action and cognition: Using the lateralized readiness potential to quantify perceptual/cognitive slowing in older ... In neuroscience, the lateralized readiness potential (LRP) is an event-related brain potential, or increase in electrical ... That means it can be used to access whether the brain is simulating an action even when the action is never carried out and ... the readiness potential. Vaughan, Costa, and Ritter (1968) noted that the readiness potential was larger contralateral to the ...

https://en.wikipedia.org/wiki/Lateralized_readiness_potential

The potential water yield, and thus the supply contracts, of the Melones Project were calculated based on stream flow data ... The Wild and Scenic Rivers Act "prohibits federal support for actions such as the construction of dams or other instream ... One potential solution has been outlined in a 2016 agreement between the Bureau of Reclamation, the local water districts and a ... "Chapter 2: Water Resources" (PDF). Draft Revised Substitute Environmental Document in Support of Potential Changes to the Water ...

https://en.wikipedia.org/wiki/New_Melones_Dam

His personality and action was mythologized during his life and after his death. Supporters consider him a symbol of Greek ... to assess the potential for the development of a guerrilla movement against the occupation forces in this area. His proposals ... The Communist Party was always suspicious of Velouchiotis's actions even though he had been the founder of ELAS because of his ... These confessions were often publicly published listing both the actions for which the signatory had confessed, as well as ...

https://en.wikipedia.org/wiki/Aris_Velouchiotis

Coghlan described Shane's actions towards Roxy as brutal and cruel. A romance develops between Roxy and Kyle Canning (Chris ... Anderson also thought that Amy is "a little bit intimidated by Roxy", but they had the "potential to make peace, because they ... She told Inside Soap's Alice Penwill that some of Roxy's past questionable actions have caught up with her and she needs a ... Going forward, we see the potential for lots of fun in that relationship, but also some conflict..." Roxy later shares "a ...

https://en.wikipedia.org/wiki/Roxy_Willis

Every action he does stems from that." In another interview, he stated of their relationship: "I think Fen's first love is ... After being reunited with his family, Michael and Lauren later mention that Fen had gone to Arizona to visit potential colleges ...

https://en.wikipedia.org/wiki/Fenmore_Baldwin

... "potential misuse" of his research at the time, referring to it as his "real failure," and to the work he did as, "political ... although Whatsapp denied that any action was taken on Wylie's account. Wylie authored a book about the subject matter: Wylie, ...

https://en.wikipedia.org/wiki/Christopher_Wylie

We call on all parties to cease military action, protect civilians, respect international law and engage in dialogue to de- ... the nations expressed their concern for the situation and its potential to cause instability. France: The French minister of ...

https://en.wikipedia.org/wiki/Battle_of_Tripoli_(2018)

"Introduction Ecumenical Decade: Churches in Solidarity With Women," Into Action, New York, U.S. Office of the World Council of ... an influential urban analysis of demographic change and its potential effect on congregational strategy and development. She ...

https://en.wikipedia.org/wiki/Eunice_Blanchard_Poethig

Years later, she enumerated a set of proper procedures concerning the delivery of potential heirs, perhaps informed by the ... and could pursue any legal action as any "single unmarried person might or may do at any time", despite still being married. ... and was looking to secure his son's future by betrothing him to a conveniently wealthy ward whose children could be potential ...

https://en.wikipedia.org/wiki/Lady_Margaret_Beaufort

Although it would appear that there is an open-ended potential for the Commonwealth to encroach on areas of traditional State ... The reserve powers may also include the power to dismiss a Prime Minister who is engaging in persistent illegal action ( ... majority upheld the validity of the WorkChoices legislation against all the challenges that had been made to it in an action ...

https://en.wikipedia.org/wiki/Australian_constitutional_law

... an action which prompted widespread criticism. Lai was allowed bail on 12 August, but on 3 December, Lai was accused of fraud ... of the relationship between corporate investment and the lure to Western companies of Chinese markets and the potential for ...

https://en.wikipedia.org/wiki/Jimmy_Lai

Prior to the video of the action being released, some of the militants and supporters had claimed that Finicum was cooperating ... about 1,500 potential jurors were summoned and asked to complete questionnaires that would be reviewed by the attorneys and ... At the meeting, a "committee of safety" was organized by Bundy and Payne to orchestrate direct action against the Hammond ... The FBI later confirmed this action. The militants were able to maintain contact with Oregon Public Broadcasting from January ...

https://en.wikipedia.org/wiki/Occupation_of_the_Malheur_National_Wildlife_Refuge

2010s action adventure films, 2010s fantasy action films, 2010s fantasy adventure films, American action adventure films, ... The post-credits scene of Dead Men teases a potential plot involving Davy Jones, who appears in some form while Will and ... He is also being eyed to helm a potential sixth Pirates movie. Schaffer, Sandy (August 6, 2018). "Disney Is Still Developing ... "in the middle of a big action scene, you need to be able to lean on the characters and find the heart of that story, and ...

https://en.wikipedia.org/wiki/Pirates_of_the_Caribbean:_Dead_Men_Tell_No_Tales

DeConcini began the meeting by saying, "We wanted to meet with you because we have determined that potential actions of yours ... and said Keating's contributions made no difference to their actions. The senators' initial defense of their actions rested on ... "actions were not improper nor attended with gross negligence and did not reach the level of requiring institutional action ... The new FHLBB chair was M. Danny Wall, who was more sympathetic to Keating and took no action on the report, saying its ...

https://en.wikipedia.org/wiki/Keating_Five

Autonomy refers here to the need to feel free to decide one's course of action. Competence refers to the need to have the ... Indigenous peoples are acutely aware of this potential, and so are working with various partners to decolonize the digital ... To this end, recent class actions and regulation efforts Tech firms can be promising examples in the context of pushing the ... In 2018, the Swiss government launched a Digital Self-Determination network in response to the action plan for the Federal ...

https://en.wikipedia.org/wiki/Digital_self-determination

This is a school which cares for each pupil as an individual, fostering academic potential and social development in a ... but this was prevented by the actions of pupils, parents, staff and administrators at Vantis Business Recovery Services who ...

https://en.wikipedia.org/wiki/Wood-Dene_School

As people learn how to access their full potential more consistently, HR adherents say, they get better results with less ... Shinnyo-en Foundation: Health Realization Principles in Action[permanent dead link]. Spotlight Archive. 2006. Retrieved Oct. 19 ... assuming the potential in others, displaying common sense, and listening respectfully to all. Facilitators ideally teach in the ... An Inside-Out Model of Prevention and Resiliency in Action through Health Realization, NEHRI Publications 1998. Kelley, T., op ...

https://en.wikipedia.org/wiki/Health_realization

Her plan is to actually kidnap other people with psionic potential and use their harvested mental energy to enslave the world ... 4) #23 Action Comics #42. DC Comics. Blackhawk #38. Quality Comics. Justice League Adventures #6 Justice League Unlimited #29 ... A different version of Queen Bee named Lisa Raven first appears in Action Comics #42 (November 1941). Lissa Raven was the ...

https://en.wikipedia.org/wiki/Queen_Bee_(comics)

... is a multiplayer team-based first-person action video game, developed as a total conversion ... "potential". Stating that "the rampant silliness and absurd title hide a remarkably robust and satisfying melee game", the ...

https://en.wikipedia.org/wiki/Pirates,_Vikings_and_Knights_II

Either Empire or Colley's Maze War is the first networked multiplayer action game. It was ported to Trek82, Trek83, ROBOTREK, ... As PLATO IV reached production quality, William Norris (CDC) became increasingly interested in it as a potential product. His ... Deihl, Ned C.; Radocy, Rudolf E. (1969). "Computer-Assisted Instruction: Potential for Instrumental Music Education". Council ...

https://en.wikipedia.org/wiki/PLATO_(computer_system)

... or to take action to overthrow him. In my view, the latter course, with all of its risks, is the correct one. Indeed, the ... is clearly another instance where neoconservatives place a watchdog in potential trouble spots in the government to ensure that ... in the Middle East and suggested that such an action would be "wise, moral and unpopular (among some of our allies)". He went ... praised the presentation given by then Secretary of State Colin Powell in which he outlined the case for military action ...

https://en.wikipedia.org/wiki/Eliot_A._Cohen

One twist to the action sequence was the inclusion of a 3-D capability known as "depths". Each "depth" was a separate 2-D side- ... or potential allies, has a major outcome during the next turn. When the turn ends, thread is fought. If the player has chosen ... It also had the option of periodic action sequences in which the player has to fight the Thread directly. The game is divided ... The release of the famed Temple of Apshai in 1979 took the company away from its hardcore market into a more action-oriented ...

https://en.wikipedia.org/wiki/Dragonriders_of_Pern_(video_game)

Conducting negotiations with potential users and concludes licensing agreements with them for the use of works TALI manages in ... Enforcing members' rights, which includes taking legal action against users who violate these rights. Lobbying for legislation ...

https://en.wikipedia.org/wiki/Tali_Rights

Despite Theodore's actions and the overthrow of his daughter and son-in-law, Akropolites reports that John Asen II remained ... This was the customary Byzantine punishment for treason and means of sidelining potential political rivals. According to a ... According to Philip Van Tricht, Theodore's actions were motivated by several factors, which led him to regard Peter as a threat ... whose actions had deepened the rift between Greeks and Latins further. Whatever the true course of events, Theodore's ...

https://en.wikipedia.org/wiki/Theodore_Komnenos_Doukas

Mahwah's actions in passing a township ordinance to bar nonresidents of New Jersey from its parks, and the hostility of some ... Nobile, Tom; Burrow, Megan (September 5, 2017). "Teaneck plans to welcome Upper Saddle River group's potential protest". ... In response to the council's action, the Bergen-Rockland Eruv Association (of which the South Monsey group is a part) and ... The case, filed in state court in Hackensack, sought nullification of the council's actions, statutory penalties, attorney's ...

https://en.wikipedia.org/wiki/2017–2018_Bergen_County_eruv_controversy

Ever since September 11, many actions have been taken to improve border security in the United States. The creation of the ... which makes them a primary point of entry for potential terrorists.[original research?] For example, in May 2012, the C.I.A. ... attacks of September 11th have served to heighten awareness about the supply system's vulnerability to terrorist actions. Drugs ...

https://en.wikipedia.org/wiki/United_States_border_security_concerns

The action sequences were inspired by the Japanese Super Sentai series. The layouts for the backgrounds were made to match the ... Meanwhile, two dwarves, Unico and Auros, were discussing between themselves of the potentials of Nathan and Marco as champions ...

https://en.wikipedia.org/wiki/Pikyaw

Nam S, Kim D, Cheng JQ, Zhang S, Lee JH, Buettner R, Mirosevich J, Lee FY, Jove R (October 2005). "Action of the Src family ... Amsberg GK, Koschmieder S (2013). "Profile of bosutinib and its clinical potential in the treatment of chronic myeloid leukemia ... migration and invasive potential. So the use of a tyrosine kinase inhibitor is a possible way of reducing the progression of ... and metastatic potential of tumors. EGFR activates c-Src while EGF also increases the activity of c-Src. In addition, ...

https://en.wikipedia.org/wiki/Proto-oncogene_tyrosine-protein_kinase_Src

Estimates from recent literature are cited, giving a potential of up to 5 GtCO2 per year for BECCS and up to 3.6 GtCO2 per year ... Examples of actions consistent with the 1.5 °C pathway include "shifting to low- or zero-emission power generation, such as ... "Australia is not on track to reach 2030 Paris target (but the potential is there)". The Conversation. Retrieved 2018-10-18. " ... The report describes several proposals for solar radiation management (SRM). It concludes that SRMs have potential to limit ...

https://en.wikipedia.org/wiki/Special_Report_on_Global_Warming_of_1.5_°C

Obama said, "We're also seeing expanded opportunity for women to reach their full potential around the world. That's in large ... "Implementation Plan of the National Action Plan on Women, Peace and Security". Published: 2012. Accessed on: January 17, 2014. ... including Secretarial Policy Guidance on Gender Equality and the National Action Plan on Women, Peace and Security. Their work ...

https://en.wikipedia.org/wiki/Melanne_Verveer

Their existence is a potential source of conflict between factions fighting for a share of the revenue, which may take the form ... Bannon, Ian; Collier, Paul (eds.), Natural Resources and Violent Conflict: Options and Actions. World Bank (2003), p.3. Dreher ... From 2018 onward, a discussion emerged concerning the potential for a resource curse related to critical materials for ... as oil revenues have the potential to alter the balance of power between regimes and their opponents, rendering bargains in the ...

https://en.wikipedia.org/wiki/Resource_curse

When these signs and symptoms occur, take action to reduce fatigue and potential safety risks:. *Have the responder take a ... Take Action to Reduce Fatigue and Potential Safety Risks. ...

https://www.cdc.gov/niosh/emres/longhourstraining/signs.html

The study of motor unit action potential (MUAP) activityfrom electromyographic signals is an important stage onneurological ... Determining Feature Relevance for the Grouping of Motor Unit Action Potentials through Generative Topographic Mapping A.O. ... The study of motor unit action potential (MUAP) activity from electromyographic signals is an important stage on neurological ... corresponding to the hyperpolarization period in the physisiological process of generation of muscle fibre action potentials ...

https://actapress.com/Abstract.aspx?paperId=23105

... Biophys J. 1996 Feb;70(2):1069-81. ... During trains of action potentials, [Ca2+]i increased and rapidly reached a steady state (time constant , 200 ms), fluctuating ... A single action potential evoked a transient increase of intradendritic calcium concentration ([Ca2+]i) that was reduced in ... Thus, the mean dendritic [Ca2+]i encodes the action potential frequency during physiological patterns of electrical activity ...

https://pubmed.ncbi.nlm.nih.gov/8789126/?dopt=Abstract

... For Immediate Release: Sept. 22, 2020 ... Alexis McGill Johnson, president of the Planned Parenthood Action Fund:. "We know whoever this president puts forward will be ... Planned Parenthood Action Fund is an independent, nonpartisan, not-for-profit membership organization formed as the advocacy ... The Planned Parenthood Action Fund works to advance access to sexual health care and defend reproductive rights. ...

https://www.plannedparenthoodaction.org/pressroom/planned-parenthood-action-fund-statement-on-potential-supreme-court-nomination

Study calls for action to explore potential impacts of decommissioned offshore structures. The research comes at a time when ... Study calls for action to explore potential impacts of decommissioned offshore structures 9 May 2023 ... Home / Press office / Study calls for action to explore potential impacts of decommissioned offshore structures. ... To counter that, scientists have called for urgent global action so that the construction of future artificial structures - or ...

https://www.plymouth.ac.uk/news/study-calls-for-action-to-explore-potential-impacts-of-decommissioned-offshore-structures

... By Oliver Morrison 25-Mar-2022. - ... "This action will only set the stage for even bigger crises down the road," warned Benton. "We dont have to knee jerk and ... Action is needed in three areas therefore if we are serious about tackling food resilience, he explained. ... "This crisis has the potential to be far more disruptive than the 2010/11 food price hike because the food, fertilizer and ...

https://www.foodnavigator.com/Article/2022/03/25/This-food-price-crisis-could-be-worse-than-in-2011-what-are-the-potential-action-areas

Action Potential Initiation; Dendritic Action Potentials; Active Dendrites; Action Potentials; Synaptic Integration; ... CA1 pyramidal neuron: action potential backpropagation (Gasparini & Migliore 2015). Download zip file Help downloading and ... 1 . Gasparini S,Migliore M (2015) Action Potential Backpropagation Encyclopedia of Computational Neuroscience, (Jaeger D:Jung R ... and the timing of synaptic input with backpropagating action potentials (fig 4) affects membrane voltage trajectories. ...

https://senselab.med.yale.edu/ModelDB/ShowModel?model=148646&file=%2FGaspariniMigliore2015%2Ffixnseg.hoc

... to positive regulation of voltage-gated potassium channel activity involved in ventricular cardiac muscle cell action potential ... to positive regulation of voltage-gated potassium channel activity involved in ventricular cardiac muscle cell action potential ... to positive regulation of voltage-gated potassium channel activity involved in ventricular cardiac muscle cell action potential ... positive regulation of voltage-gated potassium channel activity involved in ventricular cardiac muscle cell action potential ...

https://rgd.mcw.edu/rgdweb/report/annotation/main.html?term=GO:1903762&id=1586262

ACTION POTENTIAL SPORTS AND NEUROLOGICAL REHAB featuring . Aged Care Accommodation. ...

https://www.lacartes.com/search/w/businesses/q/Action-Potential---Sports-and-Neurological-Rehab/c/Accommodations/c2/Aged-Care-Accommodation/page/

The High Court recently released four related judgments in the class action brought against Southern Response by two of its ... Class action update: High Court sets rules for communicating with potential class members ... Class action update: High Court sets rules for communicating with potential class members. ... the plaintiffs in that action must be taken to have accepted the risk there would not be a funding order in the class action ...

https://www.bellgully.com/insights/class-action-update-high-court-sets-rules-for-communicating-with-potential-class-members/

7 Strategies to Stop Self-Sabotage and Reach your Potential. This is a guest post from Ronald Cain. Ronald taught English in ... Moving People to Action. Challenging and Supporting People to do the Most Important Work of their Lives ... This bubble - my comfort zone - was holding me back from reaching my potential. In that year I vowed to burst out of this ...

https://conorneill.com/2021/01/19/7-strategies-to-stop-self-sabotage-and-reach-your-potential/

Recent data suggests that this input consists largely of bursts of action potentials (APs). We investigated the origin of these ... Recent data suggests that this input consists largely of bursts of action potentials (APs). We investigated the origin of these ...

https://unsworks.unsw.edu.au/entities/publication/dd2a7f31-300a-4078-b512-800ef022621c

6 degrees (1) Abhishek Chari (11) About Us (1) acquired (1) action potentials (1) activating (1) acute stress (1) adrenaline (1 ... Posts about action potentials written by IndSciComm ...

https://indscicomm.blog/tag/action-potentials/

... used for the simulation of single fiber action potentials, Medical & biological engineering & computing, vol. 28, no. 5, pp. ... used for the simulation of single fiber action potentials. Medical & biological engineering & computing, 28(5), 492-497. ... used for the simulation of single fiber action potentials. In: Medical & biological engineering & computing. 1990 ; Vol. 28, No ... used for the simulation of single fiber action potentials. / van Veen, B.K.; Rutten, Wim; Wallinga, W. ...

https://research.utwente.nl/en/publications/the-influence-of-an-frequency-dependent-medium-around-a-network-m

A Message from President Judd Regarding Potential Congressional Actions. Jun 21, 2018. ... Two Congressional actions currently under consideration raise significant concerns. One involves the fundamental freedoms and ... The status of many Dreamers has been protected by the Deferred Action for Childhood Arrival (DACA) program, which the current ... Sarah Lawrence College is that of monitoring federal and state policy debates and resulting regulatory and legislative actions ...

https://www.sarahlawrence.edu/news-events/news/2018-06-21-a-message-from-president-judd-regarding-potential-congressional-actions-nb.html

Intermittent Fasting and Brain Health: Efficacy and Potential Mechanisms of Action. Nikita Francis 1, 2, *. ... Recommended citation: Francis N. Intermittent Fasting and Brain Health: Efficacy and Potential Mechanisms of Action. OBM ... Ku M, Ramos MJ, Feng J. Therapeutic fasting as a potential effective treatment for type 2 diabetes: A 4-month case study. ... A metabolic regulating device based on the actions of human growth hormone and of insulin, singly and together, on the human ...

https://www.lidsen.com/journals/geriatrics/geriatrics-04-02-121

Compound Motor Action Potentials During a Modest Nerve Crush. Hamad, Mohammed Nazmy; Boroda, Nickolas; Echenique, Diego ... Compound Motor Action Potentials During a Modest Nerve Crush. ... The instantaneous compound motor action potential (CMAP) is ... axonotmesis; compound motor action potential (CMAP); controlled compression parameters; controlled crush parameters; force- ...

https://pesquisa.bvsalud.org/portal/resource/pt/mdl-35431816

Class action lawsuit - Traders from across US are banding together to accuse JP Morgan Chase (JPM) of manipulating the precious ... JP Morgan Faces Potential Class Action Lawsuit. Home Market Insight Gold JP Morgan Faces Potential… ... Class Action Lawsuit: concept for legal class action lawsuit. A combined case seeking class action status would include anyone ... JP Morgan Faces Potential Class Action Lawsuit After Guilty Pleas By a Former Metals Trader. The comments below are an edited ...

https://bmg-group.com/jp-morgan-faces-potential-class-action-lawsuit/

by Action Potential Actually, Ive already done primary care. Theres a complicated explanation behind why this extra month ... This entry was posted in things ive learned, Unhelpful Advice For Med School by Action Potential. Bookmark the permalink. 5 ...

https://apotential.wordpress.com/2013/03/18/5-things-ive-learned-on-primary-care/

What is an action potential in a neuron?. An action potential is a rapid rise and subsequent fall in voltage or membrane ... What initiates an action potential?. An action potential is a rapid sequence of changes in the voltage across a membrane. In ... What causes an action potential?. Action potentials are caused when different ions cross the neuron membrane. A stimulus first ... What are the 5 steps of action potential?. The course of the action potential can be divided into five parts: the rising phase ...

https://www.theburningofrome.com/blog/what-is-an-action-potential-in-a-neuron/

Charles Krauthammer Calls Potential Obama Immigration Action An Impeachable Offense. November 14, 2014. Paige Lavender ... Fox News contributor Charles Krauthammer said potential action by President Barack Obama on immigration may be "an impeachable ... offense." Fox News reported Wednesday Obama would announce the use of executive action on a 10-point immigration plan as early ... a senior administration official told The Huffington Post Wednesday the president had yet to decide on immigration action. ...

https://vaticancatholic.com/charles-krauthammer-calls-potential-obama-immigration-action-impeachable-offense/

When an insect visits the trap and tilts the mechanosensors on the inner surface, action potentials (APs) are fired. After a ... The Venus flytrap Dionaea muscipula counts prey-induced action potentials to induce sodium uptake. ... for the flytrap to recognize an encaged object as potential food, thus making it worthwhile activating the glands. By applying ...

https://figshare.utas.edu.au/articles/journal_contribution/The_Venus_flytrap_Dionaea_muscipula_counts_prey-induced_action_potentials_to_induce_sodium_uptake/22938185

1 Action Potential in the Neuron. *2 014 The Journey Down the Axon*2.1 Why is action potential unidirectional?*2.1.1 Why cant ... Why is action potential propagation is one way in its movement along a neuron?. *Action potential propagation is one way in its ... Why does the action potential only move down the axon and not backwards?. The action potential only moves down the axon and not ... Why does the action potential only move away from the cell body?. The action potential only moves away from the cell body ...

https://theclassicwanderer.com/travel-blog/why-do-action-potentials-travel-in-one-direction.html

Potential Compensation for a Whistleblower Qui Tam Action. By Hennig, Ruiz & Singh October 31, 2018 ... Compensation for Qui Tam Actions. To give employees a reason to start these lawsuits, many times the employee receives a ...

https://www.employmentattorneyla.com/blog/2018/october/potential-compensation-for-a-whistleblower-qui-t/

Potential of Integrated Data to Engage Communities in Collective Action Presentation by Claudia Coulton ...

https://www.neighborhoodindicators.org/library/catalog/potential-integrated-data-engage-communities-collective-action

This side event showcased the potential for stepping up implementation of NbS across multiple policy sectors and saw the launch ... Unlocking Natures Potential to Combat Climate Change - The Case for Nature for Climate Action: Country Experiences, Lessons ... She stressed the need for concrete actions on the ground, as well as equity and fairness in finance "so we can address this ... This side event showcased the potential for stepping up implementation of NbS across multiple policy sectors and saw the launch ...

https://enb.iisd.org/events/unlocking-natures-potential-combat-climate-change-case-nature-climate-action-country

title = "Cochlear threshold assessment using tone-derived action potentials",. abstract = "An evoked-potential technique has ... Salt, Alec N. ; Vora, Arti R. / Cochlear threshold assessment using tone-derived action potentials. In: International Journal ... Cochlear threshold assessment using tone-derived action potentials. / Salt, Alec N.; Vora, Arti R. In: International Journal of ... Salt, A. N., & Vora, A. R. (1990). Cochlear threshold assessment using tone-derived action potentials. International Journal of ...

https://profiles.wustl.edu/en/publications/cochlear-threshold-assessment-using-tone-derived-action-potential

Action potential. An action potential (or nerve impulse) is a transient alteration of the transmembrane voltage (or membrane ... Action potentials play multiple roles in several types of excitable cells such as neurons, myocytes, and electrocytes. The best ... known action potentials are pulse-like waves of voltage that travel along axons of neurons. ... potential) across an excitable membrane generated by the activity of voltage-gated ion channels embedded in the membrane. ...

https://phys.org/tags/nerve+impulses/sort/date/all/

Trumps Potential Trade Actions Against China and Their Implications. China Briefing: Trumps Potential Trade Actions Against ... China Briefing: Trumps Potential Trade Actions Against China and Their Implications. * 1 February 2018 ... China-Briefing-Trumps-Potential-Trade-Actions-Against-China-and-Their-Implications.jpg 1 February 2018. 29 July 2019. In his ... Tariff on Chinese tech imports. Section 301 of the US Trade Act allowed the president to take action against unfair trade ...

https://www.blackpeakgroup.com/2018/02/china-briefing-trumps-potential-trade-actions-against-china-and-their-implications/

Efficient parameterization of cardiac action potential models using a genetic algorithm Submitted by vibhaadmin on Mon, 09/25/ ... We assess performance by evaluating the parameter values obtained, action potentials at fit and non-fit cycle lengths, and ... We also fit the models to action potentials recorded experimentally using microelectrodes and analyze performance. We find that ... in which we attempt to find parameter values that match model-derived action potential data from several cycle lengths. ...

http://cyberheart.cs.stonybrook.edu/efficient-parameterization-cardiac-action-potential-models-using-genetic-algorithm

In neurons, the rapid rise in potential, depolarization, is an all-or-nothing event that is initiated by the opening of sodium ion channels within the plasma membrane. (theburningofrome.com)
What happens during depolarization in an action potential? (theburningofrome.com)
During an action potential, the depolarization is so large that the potential difference across the cell membrane briefly reverses polarity, with the inside of the cell becoming positively charged. (theburningofrome.com)
An action potential is generated in the following steps: depolarization, repolarization, hyperpolarization and a refactory period. (theburningofrome.com)
First, action potentials are generated by the depolarization of the cell membrane, which causes a change in voltage across the membrane. (theclassicwanderer.com)

An action potential is a rapid rise and subsequent fall in voltage or membrane potential across a cellular membrane with a characteristic pattern. (theburningofrome.com)
When the membrane potential of the axon hillock of a neuron reaches threshold, a rapid change in membrane potential occurs in the form of an action potential. (theburningofrome.com)
This moving change in membrane potential has three phases. (theburningofrome.com)
During the rising phase the membrane potential depolarizes (becomes more positive). (theburningofrome.com)
The reason for this is that the action potential is caused by a change in the membrane potential. (theclassicwanderer.com)
The ions will flow until the membrane potential is restored to its original state. (theclassicwanderer.com)
The restoration of the membrane potential is called the repolarization. (theclassicwanderer.com)
An action potential (or nerve impulse ) is a transient alteration of the transmembrane voltage (or membrane potential ) across an excitable membrane generated by the activity of voltage-gated ion channels embedded in the membrane. (phys.org)
Abrupt changes in the membrane potential that sweep along the CELL MEMBRANE of excitable cells in response to excitation stimuli. (bvsalud.org)

Stimulus starts the rapid change in voltage or action potential. (theburningofrome.com)
This means that once a cell has reached its threshold voltage, it will generate an action potential regardless of the strength of the stimulus. (theclassicwanderer.com)

One reason action potentials cannot travel backwards is because they are generated by the opening of voltage-gated sodium channels. (theclassicwanderer.com)
If action potentials could travel backwards, the cell would never reach its threshold voltage and the sodium channels would never open. (theclassicwanderer.com)

This is why we can see action potentials generated by very weak stimuli, such as when we first touch something. (theclassicwanderer.com)
If action potentials could travel backwards, then we would not see this all-or-none behavior, and action potentials would be generated only by very strong stimuli. (theclassicwanderer.com)
Evoked potentials are the electrical signals generated by the nervous system in response to sensory stimuli. (medscape.com)
Auditory, visual, and somatosensory stimuli are used commonly for clinical evoked potential studies. (medscape.com)

This change in potential is caused by the movement of ions through special channels in the cell membrane. (theclassicwanderer.com)
Once an action potential is generated, it will be propagated along the cell membrane until it reaches the end of the neuron. (theclassicwanderer.com)

Subtraction of the masked AP waveform from the unmasked AP yields a derived potential, provided the continuous tone is above the threshold of cochlear sensitivity. (wustl.edu)
This relation between the loss in compound action potential (CAP) sensitivity and the noise duty cycle (or rest period) was abolished by the presence of CO. The cochlear microphonic (CM) amplitude revealed similar results to those seen using the CAP. (cdc.gov)

Action potentials play multiple roles in several types of excitable cells such as neurons, myocytes, and electrocytes. (phys.org)

This model entry recreates figures 2 and 4 from the paper illustrating how conductance densities of voltage gated channels (fig 2) and the timing of synaptic input with backpropagating action potentials (fig 4) affects membrane voltage trajectories. (yale.edu)
An association has been curated linking Rnf207 and positive regulation of voltage-gated potassium channel activity involved in ventricular cardiac muscle cell action potential repolarization in Rattus norvegicus. (mcw.edu)
An action potential is a rapid sequence of changes in the voltage across a membrane. (theburningofrome.com)
This change in voltage is called an action potential.The action potential travels down the axon to the axon terminal. (theclassicwanderer.com)
The best known action potentials are pulse-like waves of voltage that travel along axons of neurons. (phys.org)

Action potentials are caused when different ions cross the neuron membrane. (theburningofrome.com)

What is an action potential in a neuron? (theburningofrome.com)
These neurotransmitters cross the synapse and bind to receptors on the dendrites of the next neuron, initiating a new action potential.In this way, action potentials can travel long distances, from the brain to the toes, and allow us to interact with our environment. (theclassicwanderer.com)
Why is action potential propagation is one way in its movement along a neuron? (theclassicwanderer.com)

Comparative epidemiology of two potential hazards: threshold for public health action. (cdc.gov)

At the axon terminal, the action potential triggers the release of chemical signals, called neurotransmitters. (theclassicwanderer.com)

The study of motor unit action potential (MUAP) activity from electromyographic signals is an important stage on neurological investigations that aim to understand the state of the neuromuscular system. (actapress.com)

Somatosensory evoked potentials (SEPs) consist of a series of waves that reflect sequential activation of neural structures along the somatosensory pathways. (medscape.com)

In May 2018, Mr and Mrs Ross commenced a funded class action on behalf of the 3,000 customers who settled with Southern Response following the Canterbury earthquakes (the Ross class action ). (bellgully.com)

Compound Motor Action Potentials During a Modest Nerve Crush. (bvsalud.org)
The instantaneous compound motor action potential (CMAP) is monitored in situ and in real- time , allowing the characterization of neuromuscular response during and after injury . (bvsalud.org)

A single action potential evoked a transient increase of intradendritic calcium concentration ([Ca2+]i) that was reduced in size and prolonged when the Fura-2 concentration was increased from 20 to 250 microM. (nih.gov)

Draft guidance manual for the assessment of joint toxic action of chemical mixtures. (cdc.gov)
2000. Evaluating noncancer effects of trichloroethylene: Dosimetry, mode of action, and risk assessment. (cdc.gov)

Francis N. Intermittent Fasting and Brain Health: Efficacy and Potential Mechanisms of Action. (lidsen.com)

The experimental results of the analysis of a data set consisting of MUAPs measured from the surface of the First Dorsal Interosseous, a hand muscle, indicate that the MUAP features corresponding to the hyperpolarization period in the physisiological process of generation of muscle fibre action potentials are consistently estimated as the most relevant and, therefore, as those that should be paid preferential attention for the interpretation of the MUAP groupings. (actapress.com)
When an insect visits the trap and tilts the mechanosensors on the inner surface, action potentials (APs) are fired. (edu.au)
Particle penetration through intact skin and a method for determining potential exposure through surface contamination. (cdc.gov)

In November 2020, the Supreme Court ruled that the Ross class action could be brought on an opt-out basis (see our update on that decision here ). (bellgully.com)
Meanwhile, in a separate claim brought against Southern Response by Mr and Mrs Dodds, the Court of Appeal ruled in September 2020 that Southern Response misled customers about their earthquake insurance entitlements, in the same way as that alleged in the Ross class action. (bellgully.com)

We will give strong preference to papers that emphasize an alteration (or a potential alteration) in the fundamental disease course of Alzheimer's disease, vascular aging diseases, osteoarthritis, osteoporosis, skin aging, immune senescence, and other age-related diseases. (lidsen.com)

Examples of cells that signal via action potentials are neurons and muscle cells. (theburningofrome.com)
Each muscle fiber that contracts will produce an action potential. (medlineplus.gov)
The presence, size, and shape of the wave form of the action potential produced on the oscilloscope, provides information about the ability of the muscle to respond to nervous stimulation. (medlineplus.gov)

NYSDOH have determined that current and potential future exposures to arsenic in shallow residential soil arsenic exposure? (cdc.gov)
Wash hands after outdoor activities to help reduce the ATSDR will coordinate with state and federal partners potential for exposure. (cdc.gov)
contaminants of concerns in soil), evaluate the public health implications of additional sampling results, and · Properly maintain water treatment systems in recommend public health actions to reduce exposure, as accordance with the manufacturer's specification. (cdc.gov)
Public health officials and project managers concerned with appropriate actions to take at hazardous waste sites may want information on levels of exposure associated with more subtle effects in humans or animals (LOAEL) or exposure levels below which no adverse effects (NOAEL) have been observed. (cdc.gov)

This is the latest study involving the University of Plymouth to examine the potential ecological impacts of both the construction and adaptation of coastal and ocean structures. (plymouth.ac.uk)

The technique involves recording the cochlear action potential (AP) response to a suprathreshold probe tone, first in the absence and then in the presence of a continuous masking tone at the same frequency. (wustl.edu)

abstract = "An evoked-potential technique has been evaluated which detects whether the cochlea responds to a continuous, low level tone. (wustl.edu)

This side event showcased the potential for stepping up implementation of NbS across multiple policy sectors and saw the launch of a new UN Environmental Programme (UNEP) report , and a new initiative to coordinate global efforts to advance NbS. (iisd.org)
Moderator Inka Gnittke, BMUV , Germany, introduced the event by highlighting the new Enhancing Nature-based Solutions for an Accelerated Climate Transformation (ENACT) initiative to coordinate action on biodiversity and NbS, which was launched by Germany, the Egyptian COP 27 Presidency, and International Union for Conservation of Nature (IUCN). (iisd.org)

The Action Fund engages in educational, advocacy and electoral activity, including grassroots organizing, legislative advocacy, and voter education. (plannedparenthoodaction.org)
Among my responsibilities as the president of Sarah Lawrence College is that of monitoring federal and state policy debates and resulting regulatory and legislative actions that could have substantial consequences for the College. (sarahlawrence.edu)

Two Congressional actions currently under consideration raise significant concerns. (sarahlawrence.edu)

1984. The reversal potential of excitatory amino acid action on granule cells of the rat dentate gyrus. (cdc.gov)

Why Do Action Potentials Travel In One Direction? (theclassicwanderer.com)
This means that once the action potential is triggered, it will always travel in the same direction. (theclassicwanderer.com)
Why can't action potentials travel backwards? (theclassicwanderer.com)

Washington - Planned Parenthood Action Fund President Alexis McGill Johnson released the following statement after President Donald Trump announced he intends to nominate someone to fill Justice Ruth Bader Ginsburg's seat on the Supreme Court on Saturday. (plannedparenthoodaction.org)

The High Court recently released four related judgments in the class action brought against Southern Response by two of its customers, Mr and Mrs Ross. (bellgully.com)
The Court rejected the plaintiffs' request that Southern Response be restrained from communicating with potential class members while the plaintiffs sought to build their class by spending opt-out notices. (bellgully.com)
Finally, action potential propagation is one way because it is an all-or-none response. (theclassicwanderer.com)

The Planned Parenthood Action Fund works to advance access to sexual health care and defend reproductive rights. (plannedparenthoodaction.org)

Recent data suggests that this input consists largely of bursts of action potentials (APs). (edu.au)

The niques and consumption mores, African cas ava - imported from Brazil by the potential health impact of phytocomplexes fo d has some common basic features.3 Portuguese) are very common. (who.int)
The purpose of this Health Alert Network (HAN) Health Update is to inform clinicians and public health agencies about the potential for new clusters or outbreaks of mpox cases and to provide resources on clinical evaluation, treatment, vaccination, and testing. (cdc.gov)
The aim of the grant is to promote health research as a tool for national development programming, and to increase the use of evidence-based action and health planning for provision of equitable health care. (who.int)
Health for All and the Global Plan of Action for Workers' Health. (who.int)

To counter that, scientists have called for urgent global action so that the construction of future artificial structures - or the decommissioning of existing ones - doesn't create an additional ecological burden on areas of the planet already being severely impacted by the effects of climate change. (plymouth.ac.uk)

another reason is that action potentials are all-or-none events. (theclassicwanderer.com)

Lemke highlighted Germany's pledge to increase financing for international action on biodiversity by EUR 1.5 billion and urged reflecting NbS in Nationally Determined Contributions (NDCs) and in the closing declaration of COP 27. (iisd.org)

Following the Supreme Court's decision, the next step in the class action is for class members notices to be issued, advising class members of the class action and how to opt out. (bellgully.com)
A combined case seeking class action status would include anyone who purchased or sold futures contracts or an option on NYMEX platinum or palladium or COMEX silver or gold between (at least) January 1, 2009, and December 31, 2015. (bmg-group.com)
Edmonds admitted that he and other co-conspirators at JPM fraudulently manipulated the precious metals market from 2009 to 2015, the same timeframe covered in the class action suits. (bmg-group.com)

The action potential is unidirectional because it is an all-or-none event. (theclassicwanderer.com)

This food price crisis could be worse than in 2011… what are the potential action areas? (foodnavigator.com)

2000. Mode of action of liver tumor induction by trichloroethylene and its metabolites, trichloroacetate and dichloroacetate. (cdc.gov)

What are the 5 steps of action potential? (theburningofrome.com)
What are the steps of an action potential? (theburningofrome.com)

But wheat and mil et) - often the main dish at vegetal microRNAs and synergistic action even though each region of Africa has its lunch, is prevalent in the Sahara.Along the of plant bioactive components on endoge- own distinctive dishes, preparation tech- Ivory Coast ro t crops, (primarily yam and nous human microRNA regulation. (who.int)

"This crisis has the potential to be far more disruptive than the 2010/11 food price hike because the food, fertilizer and energy disruptions are potentially much bigger," warned Professor Tim Benton, Director of the Environment and Society Programme at Chatham House. (foodnavigator.com)

Anatomy70

Organisms18

Diseases7

Chemicals and Drugs98

Analytical, Diagnostic and Therapeutic Techniques and Equipment17

Psychiatry and Psychology3

Phenomena and Processes34

Disciplines and Occupations5

Technology, Industry, Agriculture1

Information Science1

Further evidence that prostaglandins inhibit the release of noradrenaline from adrenergic nerve terminals by restriction of availability of calcium. (1/21346)

Effect of electrotonic potentials on pacemaker activity of canine Purkinje fibers in relation to parasystole. (2/21346)

Low resting potential and postnatal upregulation of NMDA receptors may cause Cajal-Retzius cell death. (3/21346)

Activity-dependent metaplasticity of inhibitory and excitatory synaptic transmission in the lamprey spinal cord locomotor network. (4/21346)

Ionic currents underlying spontaneous action potentials in isolated cerebellar Purkinje neurons. (5/21346)

Somatic recording of GABAergic autoreceptor current in cerebellar stellate and basket cells. (6/21346)

Inducible genetic suppression of neuronal excitability. (7/21346)

Cerebellar Purkinje cell simple spike discharge encodes movement velocity in primates during visuomotor arm tracking. (8/21346)

Action Potentials

Electrophysiology

Membrane Potentials

Patch-Clamp Techniques

Tetrodotoxin

Electric Stimulation

Sodium Channels

Calcium

Guinea Pigs

Ventricular Function

Neurons

Potassium Channels

Neural Conduction

Heart

Potassium

Heart Conduction System

Papillary Muscles

Axons

Electric Conductivity

4-Aminopyridine

Synaptic Transmission

Microelectrodes

Pyramidal Cells

Heart Ventricles

Dendrites

Sodium

Purkinje Fibers

Synapses

Potassium Channel Blockers

Tetraethylammonium Compounds

Refractory Period, Electrophysiological

Potassium Channels, Voltage-Gated

Anti-Arrhythmia Agents

Myocytes, Cardiac

Models, Cardiovascular

Arrhythmias, Cardiac

Sodium Channel Blockers

Excitatory Postsynaptic Potentials

Time Factors

Ion Channels

Delayed Rectifier Potassium Channels

Tetraethylammonium

Dogs

Neurons, Afferent

Evoked Potentials

Calcium Channels

Models, Neurological

Calcium Channels, L-Type

Myocardium

Myocardial Contraction

Heart Atria

Rats, Sprague-Dawley

Ion Channel Gating

Motor Neurons

Sinoatrial Node

Atrial Function

Voltage-Sensitive Dye Imaging

Endocardium

Calcium Signaling

Rats, Wistar

Electrophysiological Phenomena

Hippocampus

Calcium Channel Blockers

Neural Inhibition

Interneurons

Pericardium

Anura

Rabbits

Quinidine

Computer Simulation

Long QT Syndrome

Animals, Newborn

Presynaptic Terminals

Ether-A-Go-Go Potassium Channels

Reaction Time

Neurotransmitter Agents

Barium

Cats

Neocortex

Cells, Cultured