Affiliations: Department of Otorhinolaryngology, Gifu University School of Medicine, 40 Tsukasa-machi, Gifu 500, Japan
Note: [*] Reprint address: Mitsuhiro Aoki, MD, PhD, Department of Otorhinolaryngology, Gifu University School of Medicine, 40 Tsukasa-machi, Gifu, 500, Japan; Tel: +81 (58) 265 1241 (ex. 2277); Fax: +81 (58) 262 2461.
Abstract: The involvement of NMDA (N-methyl-D-aspartic acid) receptors in the initial stage of the vestibular compensation was evaluated by examining the effect of MK-801 on this compensation in guinea pigs. MK-801, injected 30 min before induction of unilateral labyrinthectomy by an arsanilate, significantly (P < 0.05) reduced the maximum frequency of the spontaneous nystagmus (SN) towards both the arsanilate-applied and the intact sides. In addition, injection of arsanilate into the opposite middle ear, 60 days subsequent to induction of the unilaterial labyrinthectomy, suppressed the SN towards the second injected side, but had no effect on the SN towards the first injected side. These results suggest that NMDA receptors may be linked to the initiation of the vestibular compensation.
