Potassium currents contributing to action potential repolarization in dissociated cultured rat superior cervical sympathetic neurones. 1991

S J Marsh, and D A Brown
Department of Pharmacology, University College London, U.K.

Pharmacological blocking agents were used to assess the contributions of different K(+)-currents to spike-repolarization and early spike-afterhyperpolarization recorded in dissociated, tissue-cultured rat superior cervical sympathetic neurones using both patch-clamp and impalement microelectrode techniques. Effects of 4-aminopyridine (4-AP) and tetraethylammonium (TEA), in concentrations which selectively reduced the delayed rectifier current IK(DR) and Ca(2+)-activated K(+)-current IK(Ca, fast), respectively, indicated that IK(DR) made a significant contribution to both spike repolarization and spike afterhyperpolarization under all recording conditions, whereas the contribution of IK(Ca,fast) depended on the level of intracellular Ca(2+)-buffering. No evidence for a significant role for the transient current IK(A) could be adduced in these experiments.

UI MeSH Term Description Entries
D007700 Kinetics The rate dynamics in chemical or physical systems.
D009474 Neurons 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. Nerve Cells,Cell, Nerve,Cells, Nerve,Nerve Cell,Neuron
D002104 Cadmium An element with atomic symbol Cd, atomic number 48, and atomic weight 112.41. It is a metal and ingestion will lead to CADMIUM POISONING.
D002118 Calcium A basic element found in nearly all 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. Coagulation Factor IV,Factor IV,Blood Coagulation Factor IV,Calcium-40,Calcium 40,Factor IV, Coagulation
D002478 Cells, Cultured 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. Cultured Cells,Cell, Cultured,Cultured Cell
D002712 Chlorides Inorganic compounds derived from hydrochloric acid that contain the Cl- ion. Chloride,Chloride Ion Level,Ion Level, Chloride,Level, Chloride Ion
D004533 Egtazic Acid A chelating agent relatively more specific for calcium and less toxic than EDETIC ACID. EGTA,Ethylene Glycol Tetraacetic Acid,EGATA,Egtazic Acid Disodium Salt,Egtazic Acid Potassium Salt,Egtazic Acid Sodium Salt,Ethylene Glycol Bis(2-aminoethyl ether)tetraacetic Acid,Ethylenebis(oxyethylenenitrile)tetraacetic Acid,GEDTA,Glycoletherdiamine-N,N,N',N'-tetraacetic Acid,Magnesium-EGTA,Tetrasodium EGTA,Acid, Egtazic,EGTA, Tetrasodium,Magnesium EGTA
D005728 Ganglia, Sympathetic 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. Celiac Ganglia,Sympathetic Ganglia,Celiac Ganglion,Ganglion, Sympathetic,Ganglia, Celiac,Ganglion, Celiac,Sympathetic Ganglion
D000200 Action Potentials Abrupt changes in the membrane potential that sweep along the CELL MEMBRANE of excitable cells in response to excitation stimuli. Spike Potentials,Nerve Impulses,Action Potential,Impulse, Nerve,Impulses, Nerve,Nerve Impulse,Potential, Action,Potential, Spike,Potentials, Action,Potentials, Spike,Spike Potential
D000818 Animals Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA. Animal,Metazoa,Animalia

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