Superior-olivary response patterns to monaural and binaural clicks.

Abstract

This study presents responses to dichotic clicks obtained from neurons of the medial superior-olivary nucleus of anesthetized cats. The neurons described in this study evidenced interactive patterns to both time and intensity differences by changes in their probabilities of response and by shifts in their latency. These findings suggest a complex synaptic organization of neurons, some of which are responsive to large and some to small interaural time differences. The former neurons that show interactions to large time differences (ca. 10.0 msec) respond consistently to both monaural left and right clicks. Binaural clicks, however, significantly decrease the probability of firing in response to stimulation of the lagging ear. Some of the latter neurons that show interactions to small time differences (ca. 0–2.0 msec) fire only once, while others discharge twice to a monaural click; these single and double responders exhibit changes in latency and probability of their firings upon binaural stimulation and, in the case of the double responders, alterations in both spikes occur upon appropriate stimulation.