Lifetime and conductance of acetylcholine-activated channels in normal and denervated toad sartorius muscle

P. W. Gage, Owen Hamill

Research output: Contribution to journalArticle

7 Citations (Scopus)

Abstract

The average lifetime and conductance of acetylcholine-activated channels were measured in normal and denervated, voltage-clamped toad sartorius muscle fibres at 10 °C. The null potential was -4 ± 1 mV for subsynaptic channels in normal fibres and -6 ± 3 mV for extrasynaptic channels in denervated fibres. There was a linear relationship between variance of conductance fluctuations and mean conductance for actylcholine-induced currents up to 50 nA, in denervated fibres clamped at -50 mV. The ratio gave a channel conductance of 14 pS. At the same membrane potential, the average lifetime of extrasynaptic channels in denervated fibres was approximately double, whereas channel conductance was approximately half, that of subsynaptic channels in normal fibres: there was little difference in net charge transfer through the two types of channel under similar conditions. Single channel conductance increased, whereas average channel lifetime decreased, as the membrane potential became more positive (depolarized). The effect of potential on channel lifetime and conductance was more pronounced in denervated than in normal fibres.

Original languageEnglish (US)
Pages (from-to)525-538
Number of pages14
JournalJournal of Physiology
VolumeVOL 298
StatePublished - 1980
Externally publishedYes

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Anura
Membrane Potentials
Acetylcholine
Muscles

ASJC Scopus subject areas

  • Physiology

Cite this

Lifetime and conductance of acetylcholine-activated channels in normal and denervated toad sartorius muscle. / Gage, P. W.; Hamill, Owen.

In: Journal of Physiology, Vol. VOL 298, 1980, p. 525-538.

Research output: Contribution to journalArticle

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