Studies on rats showed that complete neurotoxin lesioning of the inferior olive obviated the possibility of developing and restoring previously learned operant balance reflexes. Motor deficit and compensatory-restorative processes in rats treated with 3-acetylpyridine and high section of the dorsolateral funiculus of the spinal cord depended directly on the level of disruption of the inferior olive. Prolonged observation of rats with incomplete lesions to the inferior olive revealed improvements in the compensation of motor lesions and stabilization of operant reflexes.