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Single channel properties of synaptic acetylcholine receptors in dystrophic fibers
Author(s) -
Brennan Christine,
Henderson Leslie P.
Publication year - 1993
Publication title -
muscle and nerve
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.025
H-Index - 145
eISSN - 1097-4598
pISSN - 0148-639X
DOI - 10.1002/mus.880160513
Subject(s) - acetylcholine receptor , neurotransmission , acetylcholine , hyperpolarization (physics) , electrophysiology , neuromuscular transmission , endocrinology , time constant , medicine , biophysics , receptor , chemistry , membrane potential , neuromuscular junction , biology , neuroscience , anatomy , stereochemistry , engineering , nuclear magnetic resonance spectroscopy , electrical engineering
Neuromuscular transmission in dystrophic mice has been extensively studied through analysis of nerve‐evoked endplate potentials. In the present study, single channel ACh‐induced activity recorded from endplates of fast twitch muscle fibers from mdx and dy dystrophic mice, was compared with activity recorded from wild‐type fiber endplates to ascertain whether expression of these phenotypes leads to changes in ACh receptor properties and synaptic transmission. An 89 pS class of ACh‐induced events predominated in recordings from wild‐type and both strains of dystrophic mice. The mean open times for this class of events was well described by two exponential components, one with a voltage‐independent time constant of ∼ 0.3 ms and the other with a time constant of 2–5 ms which increased e‐fold with ∼ 120 mV of hyperpolarization. The expression of the mdx or the dy phenotype was not associated with significant differences in the conductance, distribution of open durations, or the voltage‐dependence of the mean open time for this class of ACh‐induced events. © 1993 John Wiley & Soncs, Inc.