文摘
The features of synaptic organization of tonic motor units in vertebrates, which are widely represented in amphibians and reptiles but preserved only as muscular systems serving sensory organs in mammals, are reviewed. Based on the previous classical works, the comparative description of innervation and neurotransmitter secretion of tonic muscular systems is given. The data on synaptic organization of tonic muscles obtained in the studies that were continued after a 20-year break and published in the past few years are discussed.