[Activity of neurons of the motor zone of the cortex during elaboration of a local instrumental defensive reflex in the rabbit].

During instrumental defensive reaction of wrist extension in response to a sound (conditioned) stimulus, two types of neuronal responses in the rabbit motor cortex were discovered. The first type was recorded in cells with activity not connected with electromyographic activity of wrist extensors. The reaction consisted in the appearance of inhibitory response at the place of the cancelled electrocutaneous stimulation at animal's performance of conditioned reaction to sound. The second type of responses was shown for a neurone with the activity significantly related to electromyographic activity. In this case the conditioned motor response was accompanied by enhancement of the cellular activation reaction to sound and the increase of spike activity in interstimuli intervals.