Effects of lesioning the dorsal and intermediate acoustic striae on binaural interaction at the inferior colliculus.

Contralateral clicks normally activate units in the inferior colliculus of rats. Ipsilateral clicks usually inhibit this activity when their intensity just exceeds the contralateral intensity. When the contralateral dorsal and intermediate acoustic striae are lesioned as they pass over the restiform body, ipsilateral clicks inhibit even if they are substantially less intense than contralateral clicks. Contralateral click thresholds for unit activation are elevated by about 10 dB, but this shift in sensitivity cannot account for the marked advantage gained by the ipsilateral inhibitory input. These findings suggest that one or both of these pathways contributes heavily to binaural interaction at the inferior colliculus.