Vestibular compensation in glutamate receptor delta-2 subunit knockout mice: dynamic property of vestibulo-ocular reflex.
The delta-2 subunit of the glutamate receptor delta subfamily is selectively localised in cerebellar Purkinje cells. Delta-2 knock-out mice have defects in Purkinje cell synapse formation, as well as cerebellar long- term depression. In order to elucidate the roles of neural transmission around Purkinje cells in vestibular compensation, the gain and phase of the vestibulo-ocular reflex were measured before and after unilateral vestibular differentiation in delta-2 knock-out mice. After unilateral injury of the inner ear, gain decreased and then recovered in both knock-out mice and wild-type mice. However, recovery of VOR gain after unilateral vestibular differentiation was slower in knock-out mice than in wild-type mice. The knock-out mice displayed lower VOR gain than wild-type mice during the period between the 1st and the 2nd postoperative weeks. The results suggest that the cerebellum is necessary for augmentation of vestibulo-ocular reflex gain during the partially compensated stage of vestibular compensation after unilateral vestibular differentiation.
Murai
Norihiko
N
Department of Otolaryngology and Head and Neck Surgery, Kyoto University Hospital, Shogoinkawahara-cho 54, Sakyo-ku, 606-8507 Kyoto, Japan. murai@ent.kuhp.kyoto-u.ac.jp
Tsuji
Jun
J
Ito
Juichi
J
Mishina
Masayoshi
M
Hirano
Tomoo
T
D000222:Adaptation, Physiological / Q000502:physiology; D000704:Analysis of Variance; D000818:Animals; D002531:Cerebellum / Q000502:physiology; D051379:Mice; D018345:Mice, Knockout; D008817:Mice, Mutant Strains; D009759:Nystagmus, Pathologic / Q000503:physiopathology; D011689:Purkinje Cells / Q000502:physiology*; D017470:Receptors, Glutamate / Q000737:chemistry / Q000235:genetics*; D012027:Reflex, Vestibulo-Ocular / Q000502:physiology*; D014722:Vestibule, Labyrinth / Q000502:physiology
D017470:Receptors, Glutamate