RESPONSE OF NEURONS OF THE SUPERIOR OLIVARY COMPLEX OF THE CAT TO ACOUSTIC STIMULI OF LONG DURATION

Abstract

Most superior olivary neurons respond in a sustained fashion to maintained stimuli. These neurons could be divided into two groups. The first group resemble in their properties neurons encountered in other brainstem auditory nuclei; the characteristics of the second group are similar to those ascribed to olivo-cochlear fibers. For all neurons, there were systematic relations between discharge rate, on the one hand, and stimulus intensity and duration, on the other. The distributions of interspike-intervals occurring during sustained discharge were investigated. There are systematic differences in the distributions derived from a single unit firing at different discharge rates and striking differences in the distributions derived from different units firing at the same discharge rate. A theoretical model was presented by means of which it was shown that the differences in the distributions derived from a single neuron could be interpreted as reflecting differences in mean excitatory input, whereas the differences in the distributions derived from different neurons were just those which would be expected if neurons differed in their recovery from preceding activity.