title: Recent advances in the development and function of type II spiral ganglion neurons in the mammalian inner ear.
abstract: In hearing, mechanically sensitive hair cells (HCs) in the cochlea release glutamate onto spiral ganglion neurons (SGNs) to relay auditory information to the central nervous system (CNS). There are two main SGN subtypes, which differ in morphology, number, synaptic targets, innervation patterns and firing properties. About 90-95% of SGNs are the type I SGNs, which make a single bouton connection with inner hair cells (IHCs) and have been well described in the canonical auditory pathway for sound detection. However, less attention has been given to the type II SGNs, which exclusively innervate outer hair cells (OHCs). In this review, we emphasize recent advances in the molecular mechanisms that control how type II SGNs develop and form connections with OHCs, and exciting new insights into the function of type II SGNs.
authors.affiliation: Department of Biology, Georgetown University, Washington, DC, USA. Electronic address: kz115@georgetown.edu.
authors.forename: Kaidi D
authors.initials: KD
authors.lastname: Zhang
authors.affiliation: Department of Biology, Georgetown University, Washington, DC, USA.
authors.forename: Thomas M
authors.initials: TM
authors.lastname: Coate
mesh_terms: D000818:Animals; D002454:Cell Differentiation; D019070:Cell Lineage / Q000502:physiology; D036386:Ephrin-A5 / Q000235:genetics / Q000378:metabolism; D018507:Gene Expression Regulation, Developmental; D018698:Glutamic Acid / Q000378:metabolism; D006198:Hair Cells, Auditory / Q000166:cytology / Q000378:metabolism*; D006309:Hearing / Q000502:physiology*; D006801:Humans; D008322:Mammals; D040542:Mechanotransduction, Cellular; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism; D009419:Nerve Tissue Proteins / Q000235:genetics / Q000378:metabolism; D011956:Receptors, Cell Surface / Q000235:genetics / Q000378:metabolism; D011984:Sensory Receptor Cells / Q000166:cytology / Q000378:metabolism*; D013136:Spiral Ganglion / Q000166:cytology / Q000378:metabolism*
chemical_list: D036386:Ephrin-A5; D008565:Membrane Proteins; D009419:Nerve Tissue Proteins; C492112:Plxna3 protein, mouse; D011956:Receptors, Cell Surface; C491229:Sema3f protein, mouse; D018698:Glutamic Acid
keywords: Afferent innervation; Cochlea; Hair cell; Inner ear; Spiral ganglion