MODEL-CALCULATIONS OF THE EFFECTS OF WIDE-BAND INHIBITORS IN THE DORSAL COCHLEAR NUCLEUS

In two previous papers [Reed and Blum, J. Acoust. Sec. Am. 97, 425-438 (1995), Blum et al., J. Acoust. Sec. Am. 98, 181-191 (1995)] a comput ational model for signal processing in the dorsal cochlear nucleus (DC N) was developed. In those modelling studies, stellate cells inhibited only type II cells. In this study, the effect of including wide-band inhibitory (WBI) connections from stellate cells to type IV cells, as proposed by Nelken and Young [J. Neurophysiol. 71, 2446-2462 (1994)], is examined. Inclusion of the WBI connections improves the fit to the experimental pure tone response maps for both the ''standard'' and ''n on-standard'' cells examined by Spirou and Young [J. Neurophysiol. 66, 1750-1768 (1991)]. Thus, these modelling studies support the hypothes is of Nelken and Young [J. Neurophysiol. 71, 2446-2462 (1994)]. The de gree of improvement is greatest for cells with prominent upper inhibit ory sidebands. The qualitative features of the pure tone response map and the theoretical model allow one to deduce the probable frequency b ias of the type II to type IV and stellate to type IV connections. (C) 1997 Acoustical Society of America. [S0001-4966(97)02310-2] PACS numb ers: 43.64.Qh, 43.64.Bt, 43.64.Fy [RDF].