Vestibular unitary responses to visual stimulation in the rabbit.

Vestibular nucleus (VN) neurons, identified by sinusoidal rotation about the vertical axis, were tested for their response to moving visual field, and to electric stimulation on the optic chiasm (OX) and super colliculus (SC). Incremental responses during the rotation were inhibited by visual stimulus in cerebellectomized animals. Single-pulse stimulation applied to the OX was ineffective in producing a positive response in these neurons as well or in any other unit. Thus, such a visual pathway to VN must be located inside the brainstem and contains multi-synapses. Effects of repetitive stimulations (60 Hz) to OX and SC were more predominant in the cerebellectomized animal than in the intact animal. Cerebellar inhibitory control on visual-vestibular kinkage was suggested.