Cochlear nucleus
The cochlear nuclei (CN) are located at the dorso-lateral side of the brainstem, spanning the junction of the pons and medulla.The auditory nerve fibers form a highly organized system of connections according to their peripheral innervation of the cochlea.The mid frequency projections end up in between the two extremes; in this way the tonotopic organization that is established in the cochlea is preserved in the cochlear nuclei.The inferior colliculus receives direct, monosynaptic projections from the superior olivary complex, the contralateral dorsal acoustic stria, some classes of stellate neurons of the VCN, as well as from the different nuclei of the lateral lemniscus.Two types of principal cells convey information out of the dorsal cochlear nucleus (DCN) to the contralateral inferior colliculus.Acoustic input is also conveyed through inhibitory interneurons (tuberculoventral cells of the DCN and "wide band inhibitors" in the VCN).The information is used by higher brainstem regions to achieve further computational objectives (such as sound source location or improvement in signal-to-noise ratio).This article incorporates text in the public domain from page 788 of the 20th edition of Gray's Anatomy (1918) Young ED, Spirou GA, Rice JJ, Voigt HF (June 1992).