Three separate experiments are proposed: 1) The influence of asymmetric stimulation of the peripheral vestibular system induced by a unilateral plug of the horizontal semicircular canal on the binding of 3H-diazepam to the vestibular nuclei will be studied in order to test the hypothesis that exclusive stimulation of secondary vestibular cells by a GABA-ergic pathway leads to increased post-synaptic GABA receptors. 2) The role of the cerebellum in the compensation of asymmetric vestibuloocular reflexes will be studied. Rabbits which have received total cerebellectomies will subsequently be used in an experiment in which the time course of induction and compensation for asymmetry of the horizontal vestibuloocular reflex is studied. The asymmetry will be induced by plugging unilaterally a horizontal semicircular canal. 3) The vestibularly- and visually-evoked activity of cells of the medial accessory division of the inferior olive of rabbits will be investigated with microelectrode techniques.