title: Localization of gamma-aminobutyric acid A receptor subunits in the rat spiral ganglion and organ of Corti.
abstract: Gamma-aminobutyric acid (GABA) is thought to be the major inhibitory neurotransmitter in the central nervous system. Although it is distributed in the olivo-cochlear bundles, which constitute the mammalian cochlear efferent system, its function in the cochlea is still obscure. In this study, we investigated the localization of GABAa receptor subunits (alpha1-6, beta1-3, gamma) in the rat cochlea in order to determine the role of GABA in the cochlea. Most spiral ganglion cells were intensely immunolabeled with all the anti-GABAa receptor subunit antibodies. In the organ of Corti, punctate immunoreactivities were observed in inner hair cell regions corresponding to the distribution of GABA. These data suggest that GABAa receptor was present in afferent nerve terminals in inner hair cell regions, and that GABA regulated afferent nerve transmission contacting efferent nerve endings by means of the axo-dendritic synapse function.
authors.affiliation: Department of Otorhinolaryngology, Hirosaki University School of Medicine, Hirosaki, Japan.
authors.forename: Youhei
authors.initials: Y
authors.lastname: Yamamoto
authors.forename: Atsushi
authors.initials: A
authors.lastname: Matsubara
authors.forename: Kenji
authors.initials: K
authors.lastname: Ishii
authors.forename: Kimitoshi
authors.initials: K
authors.lastname: Makinae
authors.forename: Akira
authors.initials: A
authors.lastname: Sasaki
authors.forename: Hideichi
authors.initials: H
authors.lastname: Shinkawa
mesh_terms: D000818:Animals; D000906:Antibodies / Q000276:immunology; D003712:Dendrites / Q000276:immunology / Q000378:metabolism; D006199:Hair Cells, Auditory, Inner / Q000166:cytology / Q000276:immunology / Q000378:metabolism; D007150:Immunohistochemistry; D008297:Male; D009475:Neurons, Afferent / Q000276:immunology / Q000378:metabolism; D009925:Organ of Corti / Q000166:cytology / Q000276:immunology / Q000378:metabolism*; D051381:Rats; D017208:Rats, Wistar; D018079:Receptors, GABA / Q000276:immunology / Q000378:metabolism / Q000502:physiology*; D013136:Spiral Ganglion / Q000166:cytology / Q000276:immunology / Q000378:metabolism*; D013569:Synapses / Q000276:immunology / Q000378:metabolism; D009435:Synaptic Transmission / Q000502:physiology
chemical_list: D000906:Antibodies; D018079:Receptors, GABA