[Binomial parameters of mediator release in the process of facilitation of neuromuscular transmission]

The dynamics of the end-plate potentials (EPPs) facilitation at paired stimulation of motor nerve was studied in experiments with isolated neuromuscular preparations of the frog musculus sartorius. It was found that the increase in quantum content of EPPs diminished after a single impulse in two exponential phases. The first component, observed immediately after conditioning stimulation, was accompanied by an increase in the binomial parameter n (transmitter available store), and the second one, occuring after 30-60 ms,--by the growth of parameter P (probability of quantum mediator release). The obtained data are discussed in terms of calcium hypothesis of transmitter release.