GABAergic inhibition increases the neuronal selectivity to natural sounds in the avian auditory forebrain

The influence of the iontophoretically applied GABA antagonist bicuculline-methiodide (BIC) on single cell selectivity to natural sounds in the auditory forebrain was studied in awake chickens. Units in the thalamo-recipient lamina showed no clear changes in neuronal selectivity during BIC application, while cells postsynaptic to this layer displayed a clear loss of response selectivity. The results are discussed in regard to the role of GABA-mediated inhibition in auditory processing within the telencephalon.