A model of selective processing of auditory-nerve inputs by stellate cells of the antero-ventral cochlear nucleus

Abstract

Stellate cells in the cat antero-ventral cochlear nucleus (AVCN) maintain a robust rate-place representation of vowel spectra over a wide range of stimulus levels. This rate-place representation resembles that of low threshold, high spontaneous rate (SR) auditory nerve fibers (ANFs) at low stimulus levels, and that of high threshold, low-medium SR ANFs at high stimulus levels. One hypothesis accounting for this phenomenon is that AVCN stellate cells selectively process inputs from different SR population of ANFs in a level-dependent fashion. In this paper, we investigate a neural mechanism that can support selective processing of ANF inputs by stellate cells. We study a physiologically detailed compartmental model of stellate cells. The model reproduces PST histograms and rate-versus-level functions measured in real cells. These results indicate that simple and plausible distribution patterns of excitatory and inhibitory inputs within the stellate cell dendritic tree can support level dependent selective processing. Factors affecting selective processing are identified. This study thus represents a first step towards the development of a computational model of the AVCN stellate cell receptive field.