title: Downregulation of N-methyl-D-aspartate receptor ζ1 subunit (GluN1) gene in inferior colliculus with aging.
abstract: Presbycusis is the impairment of auditory function associated with aging, which stems from peripheral cochlear lesions and degeneration of the central auditory process. The effect of age-induced peripheral hearing loss on the central auditory process is not fully understood. C57Bl/6 (C57) mice present accelerated peripheral hearing loss, which is well developed by middle-age and mimics the human presbycusis pattern. The aim of this study was to elucidate the molecular effects of peripheral hearing loss in the inferior colliculus (IC) with age between young and middle-aged C57 mice using cDNA microarray. Glutamate receptor ionotropic NMDA ζ1 (GluN1) exhibited the greatest decrease in the middle-aged group as determined using cDNA microarray and by further assessment using real-time PCR (qPCR). Histological assessment with in situ hybridization of GluN1 showed significantly decreased expression in all IC subdivisions of the middle-aged group. GluN1 is a receptor for excitatory neurotransmission, and significant downregulation of this gene may be subsequent to the decline of afferent input from the cochlea in aging C57 mice. Consequently, using the combination of microarray, qPCR, and in situ hybridization, we showed that the decline of GluN1 in the IC of aging animals might have a key role in the pathogenesis of presbycusis.
authors.affiliation: Department of Otolaryngology, Kansai Medical University, Takii Hospital, 10-15 Fumizono-cho, Moriguchi, Osaka 570-8506, Japan.
authors.forename: Yasunori
authors.initials: Y
authors.lastname: Osumi
authors.forename: Seiji Bruce
authors.initials: SB
authors.lastname: Shibata
authors.forename: Seiji
authors.initials: S
authors.lastname: Kanda
authors.forename: Masao
authors.initials: M
authors.lastname: Yagi
authors.forename: Hisashi
authors.initials: H
authors.lastname: Ooka
authors.forename: Takashi
authors.initials: T
authors.lastname: Shimano
authors.forename: Mikiya
authors.initials: M
authors.lastname: Asako
authors.forename: Kohei
authors.initials: K
authors.lastname: Kawamoto
authors.forename: Hiromichi
authors.initials: H
authors.lastname: Kuriyama
authors.forename: Toshiya
authors.initials: T
authors.lastname: Inoue
authors.forename: Toshimasa
authors.initials: T
authors.lastname: Nishiyama
authors.forename: Toshio
authors.initials: T
authors.lastname: Yamashita
authors.forename: Koichi
authors.initials: K
authors.lastname: Tomoda
mesh_terms: D000375:Aging / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D000818:Animals; D003051:Cochlea / Q000378:metabolism / Q000473:pathology / Q000503:physiopathology; D015536:Down-Regulation / Q000502:physiology*; D016057:Evoked Potentials, Auditory, Brain Stem / Q000502:physiology; D005260:Female; D007245:Inferior Colliculi / Q000378:metabolism* / Q000503:physiopathology; D051379:Mice; D011304:Presbycusis / Q000235:genetics / Q000378:metabolism* / Q000503:physiopathology; D016194:Receptors, N-Methyl-D-Aspartate / Q000235:genetics / Q000378:metabolism*
chemical_list: C409466:NR1 NMDA receptor; D016194:Receptors, N-Methyl-D-Aspartate