Single channel properties of synaptic acetylcholine receptors in dystrophic fibers

✍ Scribed by Christine Brennan; Leslie P. Henderson

• Book ID: 102954304
• Publisher: John Wiley and Sons
• Year: 1993
• Tongue: English
• Weight: 625 KB
• Volume: 16
• Category: Article
• ISSN: 0148-639X
• DOI: 10.1002/mus.880160513

✦ Synopsis

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.