Neural Mechanism of Corticofugal Modulation of Tuning Property in Frequency Domain of Bat’s Auditory System

摘要

It is quite important for sensory processing to understand how feedback modulates the information processing in early brain areas in order to extract behaviorally-relevant features of stimulus. The auditory system of bats provides an ideal system for clarifying the mechanism of the adaptive processing by feedback. To investigate this mechanism, we developed a neural network model of bat’s auditory system for detecting Doppler-shifted frequency of sound echoes. Using the model, we demonstrate the receptive field modulation of cortical neurons and the modulation of the feedback to IC neurons, evoked by an electric stimulation and a GABA antagonist. Our model reproduces qualitatively the experimental results of best frequency (BF) shifts by Xiao and Suga (Proc Natl Acad Sci USA 99(24):15743–15748, 2002). We also show how the modulations cause the BF shifts of cortical and subcortical neurons. Furthermore we investigate the neuronal characteristics required for enhancing BF shifts.