Synaptic plasticity determines the character of interaural-time-difference representation

Abstract

Neuronal activity of cells in the first binaural brainstem nucleus, in mammals the MSO, depends on interaural time differences (ITDs). The neurons thereby resolve disparities of about 10 μs . Based on a computational model for the development of synaptic couplings, we give restrictions for a recently proposed coding hypothesis based on a monotonic dependence of the firing rate upon the ITD. We find that synaptic plasticity at MSO neurons with high best frequencies favors a rate-place code with a high variability of the tuning curves, as in the classical Jeffress model, whereas low best frequencies give rise to monotonic ITD dependence.