Peripheral vestibular disorder induced by (+/-)-alpha-amino-3-hydroxy-5-methyl-isoxazole-4-propionic acid (AMPA).
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 9 h after the infusion and disappeared within 18 h. 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.
Shimogori
Hiroaki
H
Department of Otolaryngology, Yamaguchi University School of Medicine, 1-1-1 Minamikogushi, Ube, Yamaguchi 755-8505, Japan. shio-h@yamaguchi-u.ac.jp
Yamashita
Hiroshi
H
D018750:6-Cyano-7-nitroquinoxaline-2,3-dione / Q000494:pharmacology; D000818:Animals; D002150:Caloric Tests; D004195:Disease Models, Animal; D018690:Excitatory Amino Acid Agonists / Q000633:toxicity*; D018691:Excitatory Amino Acid Antagonists / Q000494:pharmacology; D006168:Guinea Pigs; D008297:Male; D009759:Nystagmus, Pathologic / Q000139:chemically induced / Q000503:physiopathology; D015837:Vestibular Diseases / Q000139:chemically induced* / Q000503:physiopathology*; D018350:alpha-Amino-3-hydroxy-5-methyl-4-isoxazolepropionic Acid / Q000633:toxicity*
D018690:Excitatory Amino Acid Agonists; D018691:Excitatory Amino Acid Antagonists; D018750:6-Cyano-7-nitroquinoxaline-2,3-dione; D018350:alpha-Amino-3-hydroxy-5-methyl-4-isoxazolepropionic Acid