Abstract : The spontaneous frequency of discharge of the red nucleus neurones has been evaluated in the rat before and after total and bilateral destruction of the inferior olive by 3-acetylpyridine. The suppression of the inferior olive increasing the cerebellar inhibition, produces, as a consequence, a consequence, a disfacilitation of the activity of the red nucleus neurones. The process persists for a few days, then a progressive compensation takes place. A month later the average frequency of discharge is recovered but a normal unit activity and motor behaviour are not restaured.