The Biochemical Properties and Regulation of Acetylcholine Receptors in Normal and Denervated Muscle

Mammalian skeletal muscle fibers have two populations of acetylcholine receptors that are distinguished by their location on the fiber surface and by their independent modes of regulation. One population, which binds the acetylcholine released by nerve terminals and thus mediates neuromuscular transmission, occurs in the folds of muscle membrane immediately underlying the nerve terminals (Porter et al. 1973; Fertuck and Salpeter 1974; Daniels and Vogel 1975). It is not known when these receptors first appear during development, but in the adult, their number appears to be relatively constant and is little affected by denervation or by muscle activity (Frank et al. 1975).