MODELING OF THE RESPONSE OF MIDBRAIN AUDITORY NEURONS IN THE RAT TO THEIR VOCALIZATION SOUNDS BASED ON FM SENSITIVITIES

Single units were recorded from the inferior colliculus (IC) of anaest hetized rats in response to: (a) an FM tone, the frequency of which wa s randomly varied, and (b) a digitized rat vocalization sound. We hypo thesized that these neurons may have 'orientation-specific' spectrotem poral receptive field (STRF) that can be used to estimate their respon ses to complex communication signals. Based on the FM response, we fir st estimated the cell's STRF which was then convolved with the spectro gram of the rat's vocalization call. A simple convolution gave only cr ude prediction of the cell's response to the vocalization sound. When inhibitory areas were added around certain parts of the STRF, a better match was found. We conclude that for some FM-sensitive neurons of th e IC, STRF with inhibitory areas may account for their responses to vo calization sounds.