ventral cochlear nucleus

The anteroventral cochlear nucleus (aVCN) (or accessory), placed between the two divisions of the cochlear nerve, is on the ventral aspect of the inferior peduncle. Auditory nerve fibers enter the brain through the nerve root in the ventral cochlear nucleus (VCN). There auditory nerve fibers bifurcate, the ascending branch innervating the anteroventral cochlear nucleus and the descending branch innervating the posteroventral cochlear nucleus and then continuing to the dorsal cochlear nucleus. The orderly innervation by auditory nerve fibers gives the AVCN a tonotopic organization along the dorso-ventral axis. Fibers that carry information from the apex of the cochlea that are tuned to low frequencies contact neurons in the ventral part of aVCN; those that carry information from the base of the cochlea that are tuned to high frequencies contact neurons in the dorsal part of the aVCN. Several populations of neurons populate the aVCN. Bushy cells receive input from auditory nerve fibers through particularly large endings called end bulbs of Held. They contact stellate cells through more conventional boutons.