Peripheral vestibular disorder induced by (+/-)-alpha-amino-3-hydroxy-5-methyl-isoxazole-4-propionic acid (AMPA).

摘要

An intracochlear infusion of (+/-)-alpha-amino-3-hydroxy-5-methyl-isoxazole-4-propionic acid (AMPA) was done in guinea pigs with a syringe pump and peripheral vestibular disorder was induced. Spontaneous nystagmus toward the intact side reached a peak 9h after the infusion and disappeared within 18h. As a control, artificial perilymph was infused and animals had no nystagmus. The nystagmus frequency was decreased by simultaneous infusion of 6-cyano-7-nitroquinoxaline-2,3-dione (CNQX) in a dose-dependent manner. In the animals treated with AMPA or AMPA + CNQX, caloric tests performed 1 week after treatment revealed a partial dysfunction of vestibular periphery. These results indicate that the nystagmus observed is induced by AMPA via AMPA receptors and that AMPA-induced vestibular disorder is partial. This animal model may be a candidate for pharmacological study of inner ear diseases induced by glutamate excitotoxicity.