The utricle also contributes to the sense of equilibrium, sensing position in space and stimulated by gravity, centrifugal force, and linear movements. There are about 30,000 afferent neurons that innervate roughly half as many hair cells in each cochlea. Each afferent neuron derives from many outer hair cells and each outer hair cell is innervated from many different afferent neurons. The fibers of the cochlear nerve pass to the dorsal and ventral cochlear nuclei. Most fibers from the nuclei cross the midline and travel superiorly to the contralateral inferior colliculus, with some ascending ipsilaterally.
Further crossovers occur at the nuclei of the lateral lemniscus and inferior colliculi.
The pathway then runs to the medial geniculate body and continues to the auditory cortex of the temporal lobe. The neural fibers of the vestibular nerve go to one of four vestibular nuclei and are widely distributed from there. Pathways travel to the spinal cord, cerebellum, and other parts of the central nervous system.