[Effect of penicillin on the discrimination function of the auditory cortex neurons in the cat]

Responses and receptive fields of neurons in auditory cortex (AI) were studied in acute nembutal-anaesthetized cats before and during ionophoretic application of penicillin. Frequency and duration of impulse responses to tone bursts were increased during application in the majority (83%) of neurons. Increase of receptive fields and decline of frequency selectivity were found in 80% of neurons. The data obtained are regarded as proofs of decisive role of GABA-ergic inhibition in formation of functional receptive fields of auditory cortical neurons.