[Characteristics of post-spike and lateral inhibition in neurons of the primary auditory cortex in the cat].

In experiments on cats anaesthetized with nembutal it was shown by intracellular recordings that neurons located in the primary auditory cortex respond to characteristic frequency tones or to electrical stimulation of spiral ganglion fibres innervating the centre of the neuronal receptive field by a short latency spike response followed by long-lasting (20-250 ms) poststimulus inhibition. The cause of this inhibition is an IPSP originating in the studied neuron after the spike. On the basis of close connection between poststimulus inhibition and preceding spike activity the conclusion is made that the inhibition is created by a recurrent mechanism. When tones of noncharacteristic frequencies were used or peripheral parts of the receptive field were stimulated, responses in form of EPSP-IPSP developed. They were followed by depression of neuronal background activity and its responses to test stimuli. It was shown that these effects are produced by the mechanism of lateral inhibition. The characteristics of these two kinds of inhibition are presented.