Central vestibular compensation. Effect of the bilateral labyrinthectomy on neural activity in the medial vestibular nucleus.

An attempt was made to reconstruct the central events that occurred in the various stages of vestibular compensation after a bilateral labyrinthectomy in the cat. Bilateral labyrinthectomized cats showed no nystagmus, but had unsteady head movements and wide gaits. Neural activity in both sides of the medial vestibular nuclei (MVN) was depressed during the critical stage of compensation; however, the neural activity was full and normal during the acute and compensated stage. The experimental results suggest that removing crossed inhibitory influence and reducing the cerebellar inhibitory influence by bilateral labyrinthectomy enhances the process of recovering neural activity in the vestibular nuclei during central compensation, and that the contralateral vestibular end organ is not a source of the driving force responsible for regeneration of electrical activity in the deafferented MVN after a unilateral labyrinthectomy.