[Electrophysiologic effects of stimulating the vestibular nuclei on the sensomotor cortex of cats].

The evoked potentials in the anterior suprasylvian and posterior sigmoid gyri to the bulbar vestibular nuclei stimulation were recorded in relaxed anesthetized cats. Neuronal discharges of 70 units in the forelimb cortical zone in the posterior sigmoid gyrus were also recorded. 26 neurons responded to the vestibular nuclei stimulation, 6 of them were identified as cortico-rubral neurons. All of them were activated by the radial-nerve muscle branch stimulation. There was no neurons characterized by the muscle-vestibular convergence from the pyramidal tract neurons. The muscle-vestibular afferent system projection to the cortico-rubral neurons is supposed to play a major role in the tonic muscle coordination of the forelimbs.