Abstract
An attempt was made to analyse the factors which might determine the time course of the end-plate current. The end-plate current was measured by clamping the membrane potential of the crayfish muscle fiber. The calculated glutamate-induced current was in good agreement with the observations obtained, suggesting that the presented kinetic model explained well the practical phenomenon. The kinetic model could be applied also to explain the depolarization change induced by prolonged application of glutamate. The semilogarithmic plots of the falling phase of calculated glutamate-induced currents gave an approximately straight line. The slope of the line yielded an apparent desensitization rate constant, and the relationship between the true and apparent desensitization rate constants was determined, but it was suggested that the desensitization rate could not be determined from the slope of the decay of glutamate-induced current alone.