[Neurotrophic control of frog skeletal muscle following parenteral administration of colchicine].

A study was made of the membrane potential, electric properties and membrane sensitivity of individual muscle fibers to acetylcholine, as well as of electrophysiological characteristics of evoked and spontaneous transmitter release in myoneural synapses of the frog sartorius muscle after parenteral administration of colchicine. After two weeks the decrease in the membrane potential and appearance of junctional sensitivity of muscle fibers to acetylcholine were observed without any changes in the electrical properties of the electrogenic membrane. Concurrently the number of synapses with low values of the quantum composition of EPP increased. Meanwhile spontaneous transmitter release was not affected. It is suggested that denervation-like changes in the muscle were caused by the direct action of the alkaloid on nerve terminals but not on the muscle.