[Electrophysiologic characteristics of the inhibitory neuromuscular synapses of the crayfish with different rhythms of activity].

By means of intracellular recording, the IPSP's parameters and the characteristics of inhibitory neuromuscular transmission in the dactylopod-opener muscle, were studied at different rhythms of activity. The presynaptic character of the high-frequency (pessimal) blockade of inhibitory system was shown. Transformation of the stimulation rhythm was correlated with the drop in the velocity of conduction along the inhibitory axon and/or its branches. At high-frequency stimulation, the mean quantae content of IPSP's on the potentiation plateau prior to transformation was lower than at lower frequencies. No signs of the depletion of the mediator store was revealed during the high-frequency activity. The mechanism of the inhibitory mediator secretion seems to be more reliable than the function of conduction of the presynaptic neural impulse.