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. 1980 Jan;298:525–538. doi: 10.1113/jphysiol.1980.sp013099

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

P W Gage, O P Hamill
PMCID: PMC1279134  PMID: 6767026

Abstract

1. The average lifetime and conductance of acetylcholine-activated channels were measured in normal and denervated, voltage-clamped toad sartorius muscle fibres at 10 degrees C. 2. The null potential was -4 +/- 1 mV for subsynaptic channels in normal fibres and -6 +/- 3 mV for extrasynaptic channels in denervated fibres. 3. There was a linear relationship between variance of conductance fluctuations and mean conductance for acetylcholine-induced currents up to 50 nA, in denervated fibres clamped at -50 mV. The ratio gave a channel conductance of 14 pS. 4. 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. 5. 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.

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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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