Abstract
Sartorius nerve-sartorius muscle preparations were made from Bufo vulgaris, and two stimuli were given at various intervals to lead and record the action potentials. As long as the intervals ranged between 3.5 msec and 9.8 msec (6.1 msec in average), no action potential of the muscle were recorded. As the absolute refractory periods of the muscle fibres and that of the nerve fibres have already elapsed in most cases at this moment, the absolute refractory period observed in this kind of complex excitable tissue is the absolute refractory period of the end-plate. When the absolute refractory period of the end-plate has elapsed, the action potential induced by the first stimulus is much larger than that induced by the second stimulus. Further, the action potential induced by the maximal stimulus given through the governing nerve of the muscle, is 1/5-1/6 of the action potential of the muscle induced by the maximal direct stimul
In view of the above facts, the authors recorded that there exist many end-plates which are first facilitated by two or three nerve impulses in addition to those facilitated by a single nerve impulse.
