Comparison of reactions of neurons in various neocortical areas of rabbits to conditioned positive and inhibitory stimuli.

Abstract

1. The average time of coupled reaction of simultaneously recorded pairs of neurons in the visual and sensorimotor regions of the cortex is similar during the action of the conditioned stimulus, the combined application of conditioned and unconditioned stimuli, and during the inhibitory stimulus. The scatter of values for the time of the similar reaction is greater during the inhibitory stimulus than during reinforcing stimuli. 2. In some neurons of the visual and sensorimotor areas of the cortex there is an increase in the phasicity and simultaneously in the similarity of reactions during the action of an inhibitory stimulus compared with the conditional stimulus; in other pairs of neurons the reactions are attenuated and the similarity of the responses declines. 3. The frequency of appearance of intervals of coupled excitation after the conditioned stimulus corresponds to 4.3 Hz, it increases to 5.9 during the combined action of the conditioned and unconditioned stimuli, and declines to 3.6 Hz after the inhibitory stimulus. 4. The sequential engagement in coupled activity of various groups of neurons in various areas of the cortex is observed after stimulus action. The foregoing sequence of engagement in combined activity changes depending upon the character of the stimulus.