Poststimulus-time response patterns in the nuclei of the cat superior olivary complex

Abstract

In this study, the poststimulus-time response patterns from 200 cells in the superior olivary complex have been analyzed. There were 82 from the trapezoid body, 73 from the medial superior olive and 45 from the S-shaped lateral superior olive. On-and off-responses were most commonly observed in the medial superior olive. They were frequency and rise-time-dependent. and binaural stimulation produced different degrees of inhibition for each response. A variety of inhibitory patterns were seen, and these were classified into five categories called burst, onset, repetitive, bilateral, and background inhibition. With the exception of burst inhibition, they were all found most commonly in the medial superior olive, and a neuronal model was constructed to explain these patterns and the binaural interaction that occurred with on-and off responses. Background activity was greater in the trapezoid body and practically absent from the recordings in the S-shaped lateral superior olive. No differences were observed ill the response patterns to different frequencies, intensities, or stimulus durations in the three main subdivisions of the superior olivary complex.