Abstract
1) The attitudes of the spike activity and the so-called local response of a single node of Ranvier (Japanese toad) to urethane-Ringer's, low Na+-Ringer's, anisotonic solutions and to stimulating current of a long duration were investigated, to be compared with those to normal Ringer's solution and to short pulse stimulation, respectively.
2) The results obtained were never simple, but it is a fact that they react to those agents in different manners, although not clear whether the difference is essential or only apparent.
3) The spike was often observed to start from the falling phase of the maximal local response.
4) The significance of the ratio of spike height to maximal local response height was discussed.
5) Assuming that urethane is adsorbed by a nodal membrane after Freundlich's adsorption isotherm, it was concluded that the spike activity decreases and the maximal local response activity increases, and that both linearly in proportion to the amount of urethane adsorbed.
