In the ventral cochlear nucleus ( VCN ), auditory nerve fibers enter the brain via the nerve root in the VCN. The ventral cochlear nucleus is divided into the anterior ventral (anteroventral) cochlear nucleus (AVCN) and the posterior ventral (posteroventral) cochlear nucleus (PVCN). In the VCN, auditory nerve fibers bifurcate, the ascending branch innervates the AVCN and the descending branch innervates the PVCN and then continue to the dorsal cochlear nucleus . The orderly innervation by auditory nerve fibers gives the AVCN a tonotopic organization along the dorsoventral axis. Fibers that carry information from the apex of the cochlea that are tuned to low frequencies contact neurons in the ventral part of the 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.
14-443: VCN may refer to: The ventral cochlear nucleus Acrylonitrile , also called vinyl cyanide Vancouver Community Network Video Core Next – brand for some ASIC related to video compression and decompression by AMD Virtual Card Number - see Controlled Payment Number Topics referred to by the same term [REDACTED] This disambiguation page lists articles associated with
28-418: 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 . In mammals, cochlear nerve fibers are classified as either type I or type II. In mammals, the axons from each cochlear nerve terminate in
42-408: A single calyx of Held , and several smaller collaterals synapse ipsilaterally in the posterior (PPO) and dorsolateral periolivary (DLPO) nuclei, lateral superior olive (LSO), and lateral nucleus of the trapezoid body (LNTB); contralaterally in the dorsomedial periolivary nucleus (DMPO), ventral nucleus of the trapezoid body (VNTB), nucleus paragigantocellularis lateralis (PGL), and ventral nucleus of
56-547: Is 'choppers'. They have an intrinsical rhythm, and will fire action potentials with this rhythm once activated by the right sound. The anteroventral cochlear nucleus (AVCN) (or accessory ), is placed between the two divisions of the cochlear nerve , and is on the ventral aspect of the inferior peduncle . [REDACTED] This article incorporates text in the public domain from page 788 of the 20th edition of Gray's Anatomy (1918) Cochlear nerve The cochlear nerve (also auditory nerve or acoustic nerve )
70-483: Is either bipolar or unipolar , with its distal projection being called the peripheral process , and its proximal 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
84-506: 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. In terms of anatomy, an auditory nerve fiber
98-455: The branching, tree-like, nature of their dendritic fields, visible using Golgi's method , they receive large end bulbs of Held from auditory nerve fibers. Bushy cells are of three subtypes that project to different target nuclei in the superior olivary complex. Globular bushy cells project large axons to the contralateral medial nucleus of the trapezoid body (MNTB), in the superior olivary complex where they synapse onto principal cells via
112-527: 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 . 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
126-419: The cochlea are transmitted electrically to specific positions in the cochlear nuclei. The axons from the low-frequency region of the cochlea project to the ventral portion of the dorsal cochlear nucleus and the ventrolateral portions of the anteroventral cochlear nucleus. The axons from the high-frequency region project to the dorsal portion of the anteroventral cochlear nucleus and the uppermost dorsal portions of
140-457: The cochlear nuclear complex that is ipsilaterally located in the medulla of the brainstem. The cochlear nucleus is the first 'relay station' of the central auditory system and receives mainly ipsilateral afferent input. The three major components of the cochlear nuclear complex are (see figure below): Each of the three cochlear nuclei are organized to sort sound according to a specific spacial arrangement . As such, sound frequencies detected by
154-413: 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. 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
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#1732898508762168-511: The ipsilateral lateral superior olive. They project neither to the medial superior olives or to the medial nucleus of the trapezoid body. Multipolar cells fall into two distinct groups. Those whose axons project out of the AVCN through the trapezoid body, T stellate cells, have longer dendrites than bushy cells that characteristically lie in line with fascicles of auditory nerve fibers. These principal cells are excitatory. Another name for these cells
182-732: The lateral lemniscus (VNLL). Axons always send a collateral into the MNTB, but do not necessarily give rise to collaterals that innervate each of the other nuclei. Spherical bushy cells project ipsilaterally to the LSO, bilaterally to the medial superior olive (MSO) and LNTB, and contralaterally to the VNTB and VNLL. The most important purpose of these projections seems to be to imbue the MSO and LSO with their interaural time and level sensitivities (respectively). Small spherical Small spherical bushy cells likely project to
196-669: The title VCN . If an internal link led you here, you may wish to change the link to point directly to the intended article. Retrieved from " https://en.wikipedia.org/w/index.php?title=VCN&oldid=933232770 " Category : Disambiguation pages Hidden categories: Short description is different from Wikidata All article disambiguation pages All disambiguation pages Ventral cochlear nucleus The anterior cochlear nucleus contains several cell types, which correspond fairly well with different physiological unit types. Additionally, these cell types generally have specific projection patterns. Named due to
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