Deafness induced up-regulation of GluR2/3 and NR1 in the spiral ganglion cells of the rat cochlea.
Expressions of AMPA (GluR2, GluR3, and GluR4) and NMDA (NR1 and NR2) glutamate receptors in the spiral ganglion cells of the cochlea were analyzed both at protein and mRNA levels in control and deaf rats between week 0 (P14) and week 8 (P70) after deafness induced by a daily injection of kanamycin at P0-P14. In the deaf rats, significant up-regulations of GluR2, GluR3, and NR1 in the surviving spiral ganglion cells were observed, while expressions of GluR4 and NR2 were fairly constant. In contrast, in the control rats, the expressions of all these glutamate receptor subtypes were stable. These results suggest that drastic alterations in the diversity of GluR2/GluR3/NR1 receptor complexes in the surviving spiral ganglion cells, which result in alterations in Ca2+ permeability, may contribute to the deafness-related alterations in the structure and function of the cochlea.
Hasegawa
T
T
Department of Otolaryngology and Sensory Organ Surgery, Osaka University Graduate School of Medicine, Suita, Japan.
Doi
K
K
Fuse
Y
Y
Fujii
K
K
Uno
Y
Y
Nishimura
H
H
Kubo
T
T
D000367:Age Factors; D000818:Animals; D000831:Animals, Newborn; D002452:Cell Count / Q000706:statistics & numerical data; D003638:Deafness / Q000139:chemically induced / Q000378:metabolism* / Q000503:physiopathology; D007608:Kainic Acid / Q000494:pharmacology; D009410:Nerve Degeneration / Q000139:chemically induced / Q000378:metabolism / Q000503:physiopathology; D016133:Polymerase Chain Reaction / Q000379:methods; D012333:RNA, Messenger / Q000187:drug effects / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D018091:Receptors, AMPA / Q000187:drug effects / Q000235:genetics / Q000378:metabolism*; D016194:Receptors, N-Methyl-D-Aspartate / Q000187:drug effects / Q000235:genetics / Q000378:metabolism*; D013136:Spiral Ganglion / Q000187:drug effects / Q000378:metabolism* / Q000473:pathology / Q000503:physiopathology; D015854:Up-Regulation / Q000187:drug effects / Q000502:physiology
C409466:NR1 NMDA receptor; C120997:NR2A NMDA receptor; D012333:RNA, Messenger; D018091:Receptors, AMPA; D016194:Receptors, N-Methyl-D-Aspartate; C104723:glutamate receptor ionotropic, AMPA 3; C104724:glutamate receptor ionotropic, AMPA 4; C104722:glutamate receptor ionotropic, AMPA 2; D007608:Kainic Acid