Novel approach to a quantitative treatment of the quantal transmitter release at the frog neuromuscular junction.

To explain the discrepancy between estimates of parameters of quantal transmitter release received by different techniques the paper postulates a novel concept for quanta mobilization, which assumes that a quantum emitted by a vesicle transiently acquires a transition state in which it is immediately available for release. The working particle model is formulated in terms of probabilities of inter-state quanta transitions. The parameters of the model are determined by fitting solutions to the experimental curves representing short-term changes of synaptic efficacy at the frog neuromuscular junction as well as taking into account the morphologically estimated number of releasable vesicles. The value of the model is demonstrated by successful prediction of the estimates of the parameters of the quantal transmitter release suggested by evidence received from different lines of research.