Abstract
The sciatic nerve of a toad was stimulated twice by electrical pulses of short interval successively. The action potentials evoked in that nerve were recorded by the cathod ray oscillograph. One of the stimulating electrodes which was placed near the leading electrode was chosen as the anode of the stimulating current. The nerve was ligated by a thin cotton thread, between the two stimulating electrodes. Thus the effect of the cathodal make excitation could be eliminated from the record, and only the results of the anodal break excitation were registered.
In such a way, the change of the excitability, caused by the anodal break stimulation, was puasued, using the anodal break stimulation as the testing shock, and the so-called recovery curves were treated.
The recovery process pursued by the anodal break excitation showed no difference from that pursued by the cathodal make excitation.
In the cardiac muscle, Brooks et al. have discovered the occurence of the elevation of excitability for the anodal break stimulation at the later period of the relative refractoriness. Such a phenomenon could not be found in the nerve.
