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. 1986 Jun;49(6):1243–1247. doi: 10.1016/S0006-3495(86)83754-7

Single transient K channels in mammalian sensory neurons.

H Kasai, M Kameyama, K Yamaguchi, J Fukuda
PMCID: PMC1329709  PMID: 2424519

Abstract

A single-channel recording of the transient outward current (A-current) was obtained from dorsal root ganglion cells in culture using patch-clamp techniques. Depolarization of the membrane patch elicited pulse like current of a uniform amplitude in an outward direction, of which the unitary conductance was 20 pS. Alteration of extracellular ionic compositions indicated that the charge carriers were K ions. A systematic study was made on the voltage-dependence of the ensemble average current; (a) the activation started at a potential around -60 mV; (b) the time course of the activation was relatively rapid; (c) the channel was completely inactivated at a potential positive to -40 mV. Two time constants (tau f = 100 ms and tau s = 4,000 ms) were detected in the decay of the current indicating that the channels had two different states of inactivation. A convulsant, 4-aminopyridine (4-AP), acted on the channel only from the intracellular side of the membrane. 4-AP (5 mM) reduced not only mean open time (by 50%) but also the single-channel conductance (by 20%). The properties of the channel were independent of Ca ions in the intracellular space.

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Selected References

These references are in PubMed. This may not be the complete list of references from this article.

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