Cochlear ganglion cells in the alligator lizard. 1983

M J Mulroy

Two types of ganglion cells are present in the cochlear ganglion of the alligator lizard. Myelinated cells are the predominant type but a small population of unmyelinated cells is also present. Ganglion cells are reconstructed and morphometrically analyzed from serial light and electron micrographs. The results are interpreted to indicate that the unmyelinated ganglion cells are degenerating neurons. No normal population of unmyelinated nerve fibers was found. The anatomy of the cochlear nerve of the lizard is described and compared with the mammalian auditory nerve.

UI MeSH Term Description Entries
D008116 Lizards Reptiles within the order Squamata that generally possess limbs, moveable EYELIDS, and EXTERNAL EAR openings, although there are some species which lack one or more of these structures. Chameleons,Geckos,Chameleon,Gecko,Lizard
D008854 Microscopy, Electron Microscopy using an electron beam, instead of light, to visualize the sample, thereby allowing much greater magnification. The interactions of ELECTRONS with specimens are used to provide information about the fine structure of that specimen. In TRANSMISSION ELECTRON MICROSCOPY the reactions of the electrons that are transmitted through the specimen are imaged. In SCANNING ELECTRON MICROSCOPY an electron beam falls at a non-normal angle on the specimen and the image is derived from the reactions occurring above the plane of the specimen. Electron Microscopy
D009186 Myelin Sheath The lipid-rich sheath surrounding AXONS in both the CENTRAL NERVOUS SYSTEMS and PERIPHERAL NERVOUS SYSTEM. The myelin sheath is an electrical insulator and allows faster and more energetically efficient conduction of impulses. The sheath is formed by the cell membranes of glial cells (SCHWANN CELLS in the peripheral and OLIGODENDROGLIA in the central nervous system). Deterioration of the sheath in DEMYELINATING DISEASES is a serious clinical problem. Myelin,Myelin Sheaths,Sheath, Myelin,Sheaths, Myelin
D009413 Nerve Fibers, Myelinated A class of nerve fibers as defined by their structure, specifically the nerve sheath arrangement. The AXONS of the myelinated nerve fibers are completely encased in a MYELIN SHEATH. They are fibers of relatively large and varied diameters. Their NEURAL CONDUCTION rates are faster than those of the unmyelinated nerve fibers (NERVE FIBERS, UNMYELINATED). Myelinated nerve fibers are present in somatic and autonomic nerves. A Fibers,B Fibers,Fiber, Myelinated Nerve,Fibers, Myelinated Nerve,Myelinated Nerve Fiber,Myelinated Nerve Fibers,Nerve Fiber, Myelinated
D003051 Cochlea The part of the inner ear (LABYRINTH) that is concerned with hearing. It forms the anterior part of the labyrinth, as a snail-like structure that is situated almost horizontally anterior to the VESTIBULAR LABYRINTH. Cochleas
D003056 Cochlear Nerve The cochlear part of the 8th cranial nerve (VESTIBULOCOCHLEAR NERVE). The cochlear nerve fibers originate from neurons of the SPIRAL GANGLION and project peripherally to cochlear hair cells and centrally to the cochlear nuclei (COCHLEAR NUCLEUS) of the BRAIN STEM. They mediate the sense of hearing. Acoustic Nerve,Auditory Nerve,Acoustic Nerves,Auditory Nerves,Cochlear Nerves,Nerve, Acoustic,Nerve, Auditory,Nerve, Cochlear,Nerves, Acoustic,Nerves, Auditory,Nerves, Cochlear
D000818 Animals Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA. Animal,Metazoa,Animalia
D001489 Basilar Membrane A basement membrane in the cochlea that supports the hair cells of the ORGAN OF CORTI, consisting keratin-like fibrils. It stretches from the SPIRAL LAMINA to the basilar crest. The movement of fluid in the cochlea, induced by sound, causes displacement of the basilar membrane and subsequent stimulation of the attached hair cells which transform the mechanical signal into neural activity. Basilar Membranes,Membrane, Basilar,Membranes, Basilar
D013136 Spiral Ganglion The sensory ganglion of the COCHLEAR NERVE. The cells of the spiral ganglion send fibers peripherally to the cochlear hair cells and centrally to the COCHLEAR NUCLEI of the BRAIN STEM. Ganglion of Corti,Auditory Ganglion,Spiral Ganglia,Auditory Ganglions,Ganglia, Spiral,Ganglion, Auditory,Ganglion, Spiral,Ganglions, Auditory
D014725 Vestibular Nerve The vestibular part of the 8th cranial nerve (VESTIBULOCOCHLEAR NERVE). The vestibular nerve fibers arise from neurons of Scarpa's ganglion and project peripherally to vestibular hair cells and centrally to the VESTIBULAR NUCLEI of the BRAIN STEM. These fibers mediate the sense of balance and head position. Scarpa's Ganglion,Ganglion, Scarpa's,Nerve, Vestibular,Nerves, Vestibular,Scarpa Ganglion,Scarpas Ganglion,Vestibular Nerves
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