title: Aging effects on vestibulo-ocular responses in C57BL/6 mice: comparison with alteration in auditory function.
abstract: Age-related changes in auditory function are well documented in animal models; however, this is not the case as regards vestibular function. In this study, we evaluated age-related changes in vestibulo-ocular responses in C57BL/6 mice that are considered as a model of presbycusis. The functional data were substantiated by the findings of histological analysis of vestibular and auditory peripherals. The gain in vestibulo-ocular reflex, which reflects functionality of the vestibular system, increased in an age-dependent manner until 12 weeks and exhibited limited functional loss due to aging after 24 weeks. By contrast, no alteration in the thresholds of the auditory brainstem response (ABR) was observed from 3 to 12 weeks of age; however, ABR thresholds were significantly elevated from age 24 weeks and onwards. Histological analysis demonstrated that the degeneration of auditory peripherals was closely related with functional loss due to aging. Vestibular peripherals also exhibited age-related degeneration morphologically, although age-related dysfunction was not apparent. Age-related changes in the vestibular function of C57BL/6 mice followed a different time course when compared to changes in auditory function. These findings indicate that mechanisms for age-related changes in vestibular function differ from those of auditory function.
authors.affiliation: Department of Otolaryngology, Aichi Medical University, Aichi, Japan.
authors.forename: Atsushi
authors.initials: A
authors.lastname: Shiga
authors.forename: Takayuki
authors.initials: T
authors.lastname: Nakagawa
authors.forename: Meiho
authors.initials: M
authors.lastname: Nakayama
authors.forename: Tsuyoshi
authors.initials: T
authors.lastname: Endo
authors.forename: Fukuichiro
authors.initials: F
authors.lastname: Iguchi
authors.forename: Tae-Soo
authors.initials: TS
authors.lastname: Kim
authors.forename: Yasushi
authors.initials: Y
authors.lastname: Naito
authors.forename: Juichi
authors.initials: J
authors.lastname: Ito
mesh_terms: D000367:Age Factors; D000375:Aging / Q000502:physiology*; D000818:Animals; D016022:Case-Control Studies; D004195:Disease Models, Animal; D007758:Ear, Inner / Q000503:physiopathology*; D016057:Evoked Potentials, Auditory, Brain Stem; D007150:Immunohistochemistry; D051379:Mice; D008810:Mice, Inbred C57BL; D011304:Presbycusis / Q000503:physiopathology; D012027:Reflex, Vestibulo-Ocular / Q000502:physiology*