[Responses of sensomotor cortex neurons of rats to stimulation of the midbrain reticular formation].

High frequency stimulation of the mesencephalic reticular formation produces significant inhibition of neuronal activity in the sensorimotor cortex, the effect being equally observed in both hemispheres. In case of low frequency stimulation, marked difference was observed between the reaction of ipsi- and contralateral neurons. Under these conditions, contralateral neurons produce mainly facilitation responses. In both hemispheres evident predominance of tonic effects was observed which revealed itself in the continuation of the reaction in the poststimulation period. Single shocks applied to the midbrain reticular formation elicited in the cortex the evoked potentials of two types: one with a constant and the other with varying latent periods. The former exhibited a latency of 4-18 msec. Responses with varying latencies were predominant. In general, latent periods were longer in contralateral hemisphere.