This tonotopic organization is preserved because only a few inner hair cells synapse on the dendrites of a nerve cell in the spiral ganglion, and the axon from that nerve cell synapses on only a very few dendrites in the cochlear nucleus. 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 axons from the higher frequency organ of corti hair cells project to the dorsal portion of the ventral cochlear nucleus and the dorsal-medial portions of the dorsal cochlear nucleus. Axons from the spiral ganglion cells of the lower frequencies innervate the ventrolateral portions of the ventral cochlear nucleus and lateral-ventral portions of the dorsal cochlear nucleus. The auditory nerve fibers form a highly organized system of connections according to their peripheral innervation of the cochlea. The major input to the cochlear nucleus is from the auditory nerve, a part of cranial nerve VIII (the vestibulocochlear nerve). The VCN is further divided by the nerve root into the posteroventral cochlear nucleus (PVCN) and the anteroventral cochlear nucleus (AVCN).The dorsal cochlear nucleus (DCN), also known as the tuberculum acusticum or acoustic tubercle, curves over the VCN and wraps around the cerebellar peduncle.The ventral cochlear nucleus(VCN) on the ventral aspect of the brain stem, ventrolateral to the inferior peduncle.The cochlear nuclei (CN) are located at the dorso-lateral side of the brainstem, spanning the junction of the pons and medulla. The outputs from the cochlear nuclei are received in higher regions of the auditory brainstem. All acoustic information thus enters the brain through the cochlear nuclei, where the processing of acoustic information begins. Auditory nerve fibers, fibers that travel through the auditory nerve (also known as the cochlear nerve or eighth cranial nerve) carry information from the inner ear, the cochlea, on the same side of the head, to the nerve root in the ventral cochlear nucleus.Īt the nerve root the fibers branch to innervate the ventral cochlear nucleus and the deep layer of the dorsal cochlear nucleus. ![]() The ventral cochlear nucleus is unlayered whereas the dorsal cochlear nucleus is layered. doi:10.The cochlear nuclear ( CN) complex comprises two cranial nerve nuclei in the human brainstem, the ventral cochlear nucleus (VCN) and the dorsal cochlear nucleus (DCN). Cochlear nerve aplasia and hypoplasia: Predictors of cochlear implant success. Peng KA, Kuan EC, Hagan S, Wilkinson EP, Miller ME. Diagnosis and management of acute cerebellar infarction. Wright J, Huang C, Strbian D, Sundararajan S. ![]() Pathology of the vestibulocochlear nerve. Case report: Rare presentation of AICA syndrome. Neuro-otological aspects of cerebellar stroke syndrome. Association of multiple sclerosis and sudden sensorineural hearing loss. How the ear works.Ītula S, Sinkkonen ST, Saat R, Sairanen T, Atula T. Neuroanatomy, cranial nerve 8 (vestibulocochlear).
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