Abstract: | The comparative study, when stimulation is increased, of the amplitude changes shown by the negative waves of dorsal root potentials, indicates that the N1 and N2 waves are evoked by A alpha cutaneous afferent, whereas N3 wave is due to A alpha, A beta and perhaps A delta cutaneous afferents. On the other hand, a possible inhibitory action of N1, N2 negative complex on N3 wave is postulated. |