[Analysis of the dynamics of the facilitation of end-plate potentials in frogs]

Within 60 msec after presentation of conditioned stimulus the facilitation of the e.p.p. second response declined by two phases. The 1st phase corresponded to the 1st component of facilitation while the 2nd phase followed in 5--10 msec reaching the maximum within 15 msec and then declining with the time constant of 20--50 msec. During repeated stimulation the 1st phase accumulated linearly while the 2nd one exponentially. Tetraethylammonium and three-ethylcholine increased the quantum content e.p.p. and the facilitation but had no effect upon the time constant of the facilitation decline.