Denervation supersensitivity as a model for the neural control of muscle.

A review about the neural regulation of the membrane distribution of muscle acetylcholine receptors is presented on the basis of author's and literature data. The main evidence in support of the role of nerve impulses and of chemical factors ("trophic" factors, acetylcholine, nerve breakdown products) as neural signals involved in the origin of denervation supersensitivity, is concisely described and evaluated. The contribution of breakdown products of the nerve, their interaction with muscle inactivity are illustrated and a unifying hypothesis on the neural control of extrajunctional and junctional acetylcholine receptors is presented.