Vestibulo-Ocular Reflex (VOR)

The Vestibulo-ocular Reflex (VOR) maintains eye fixation on an object as the head turns. The turning causes movement of hair cells in the horizontal semicircular canals with respect to the fluid. This polarizes the hair cells, leading to an altered frequency of action potential discharge of cranial nerve VIII.

Axons entering the medial vestibular nucleus synapse with neurons that send their axons to the contralateral abducens nucleus. This nucleus consists of neurons whose axons comprise cranial nerve VI and innervate the lateral rectus muscle. Other cranial nerve VIII axons enter the lateral vestibular nucleus. These neurons relay to the ipsilateral ocular motor nucleus whose neurons form the axons of cranial nerve III which innervates the medial rectus nucleus muscle.