[Trace postsynaptic reactions in neuromuscular junctions].

Factors which control the duration of postsynaptic responses in neuromuscular junctions are discussed together with a possibility of origin of trace postsynaptic reactions (potentiation and desensitization). In experiments on nerve-muscle preparations of various vertebrates (lamprey, frog, chicken, rat), the key role of functional activity of acetylcholinesterase was revealed in regulation of the duration of both short- and long-living postsynaptic responses. The significance of sufficient activity of acetylcholinesterase for normal realization of neuromuscular transmission presumably increases in the course of evolution of vertebrates. An analysis of possible molecular nature of trace reactions on the postsynaptic membrane was carried out.