THE ELECTRIC RESPONSES OF THE TAIL PILOMOTORS AND NICTITATING MEMBRANE OF THE CAT

Abstract

Cocaine, veratrine, 933F or ergotoxine was injected into cats in order to separate out various components in the electrograms and to examine the relations between electric and mechanical events. The pilo-motor electrogram exhibits 7 components which may vary independently. Components 1-5 show no correlation with the mechanogram. Components 6 and 7 vary, as a rule, with contraction. Component 6 coincides with the development of the mechanical response; it is interpreted as correlated with the chemical changes associated with this development. Component 7 outlasts contraction; it is assumed to correspond to recovery processes. Both slow components 6 and 7 can be recorded from "diphasic" leads, thus proving that they correspond to an asymmetric change in each muscular cell. The first 2 components of the membrane electrogram are similar to those of the pilomotors[long dash]they are monophasic waves of opposite polarity. The membrane has at least one component never encountered in the pilomotors, the rhythmic component. Components 1 and 2 may develop, in response to additional stimuli, during the course of the rhythmic component. These several components are therefore independent. The discussion is concerned with the methods for the study of the 2 smooth muscles, with the significance of their electrograms and the features in which they differ from that of striated muscle and with the heterogeneity of smooth muscles as a class.