<P> The cochlear nerve (also auditory or acoustic nerve) is one of two parts of the vestibulocochlear nerve, a cranial nerve present in amniotes, the other part being the vestibular nerve . The cochlear nerve carries auditory sensory information from the cochlea of the inner ear directly to the brain . The other portion of the vestibulocochlear nerve is the vestibular nerve, which carries spatial orientation information to the brain from the semicircular canals, also known as semicircular ducts . </P> <P> In terms of anatomy, an auditory nerve fiber is either bipolar or unipolar, with its distal projection being called the peripheral process, and its central projection being called the axon; these two projections are also known as the "peripheral axon" and the "central axon", respectively . The peripheral process is sometimes referred to as a dendrite, although that term is somewhat inaccurate . Unlike the typical dendrite, the peripheral process generates and conducts action potentials, which then "jump" across the cell body (or soma) and continue to propagate along the central axon . In this respect, auditory nerve fibers are somewhat unusual in that action potentials pass through the soma . Both the peripheral process and the axon are myelinated . </P> <P> In humans, there are on average 30,000 nerve fibers within the cochlear nerve . The number of fibers varies significantly across species; the domestic cat, for example, has an average of 50,000 fibers . The peripheral axons of auditory nerve fibers form synaptic connections with the hair cells of the cochlea via ribbon synapses using the neurotransmitter glutamate . The central axons form synaptic connections with cells in the cochlear nucleus of the brainstem . </P> <P> The cell bodies of the cochlear nerve lie within the cochlea and collectively form the spiral ganglion, named for the spiral shape it shares with the cochlea . These central axons exit the cochlea at its base and form a nerve trunk, which, in humans, is approximately one inch long . This travels in parallel with the vestibular nerves through the internal auditory canal, through which it connects to the brainstem . There, its fibers synapse with the cell bodies of the cochlear nucleus . </P>

Where does the cochlear nerve transmit impulses to