title: NMDA and AMPA receptor subunit protein expression in the rat vestibular nucleus following unilateral labyrinthectomy.
abstract: We examined the expression of the NR1 and NR2A subunits of the N-methyl-D-aspartate (NMDA) receptor, and the GluR2 subunit of the alpha-amino-3-hydroxy-5-methyl-4-isoxazole propionate (AMPA) receptor, in the ipsilateral and contralateral vestibular nucleus complexes (VNCs) at 10 h and 2 weeks following unilateral vestibular deafferentation (UVD) in rats, in order to directly test the hypothesis that the behavioural recovery following UVD ('vestibular compensation') is associated with an up-regulation of NMDA receptors. We found no significant changes in NR1 or NR2A expression at 10 hs or 2 weeks post-op. compared to sham and anesthetic controls. We did find a significant (p < 0.01 and p < 0.05) increase in GluR2 expression in both VNCs at 10 h but not 2 weeks post-op. compared to sham and anesthetic controls; however, comparison over time post-UVD failed to detect a significant difference, suggesting that it was small and transient at best. These results add further evidence to the conclusion that NMDA receptors do not undergo up-regulation in the ipsilateral VNC during vestibular compensation.
authors.affiliation: Vestibular Research Group, Dept. of Pharmacology and Toxicology, School of Medical Sciences, University of Otago, Dunedin, New Zealand.
authors.forename: Jaimee
authors.initials: J
authors.lastname: King
authors.forename: Yiwen
authors.initials: Y
authors.lastname: Zheng
authors.forename: Ping
authors.initials: P
authors.lastname: Liu
authors.forename: Cynthia L
authors.initials: CL
authors.lastname: Darlington
authors.forename: Paul F
authors.initials: PF
authors.lastname: Smith
mesh_terms: D000818:Animals; D015153:Blotting, Western; D003714:Denervation; D007758:Ear, Inner / Q000601:surgery*; D007839:Functional Laterality; D051381:Rats; D017208:Rats, Wistar; D018091:Receptors, AMPA / Q000032:analysis / Q000096:biosynthesis*; D016194:Receptors, N-Methyl-D-Aspartate / Q000032:analysis / Q000096:biosynthesis*; D014726:Vestibular Nuclei / Q000737:chemistry / Q000378:metabolism*
chemical_list: C409466:NR1 NMDA receptor; C120997:NR2A NMDA receptor; D018091:Receptors, AMPA; D016194:Receptors, N-Methyl-D-Aspartate