کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
4356142 1615664 2008 12 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Effects of exposing C57BL/6J mice to high- and low-frequency augmented acoustic environments: Auditory brainstem response thresholds, cytocochleograms, anterior cochlear nucleus morphology and the role of gonadal hormones
موضوعات مرتبط
علوم زیستی و بیوفناوری علم عصب شناسی سیستم های حسی
پیش نمایش صفحه اول مقاله
Effects of exposing C57BL/6J mice to high- and low-frequency augmented acoustic environments: Auditory brainstem response thresholds, cytocochleograms, anterior cochlear nucleus morphology and the role of gonadal hormones
چکیده انگلیسی

Gonadectomized and intact adult C57BL/6J (B6) mice of both sexes were exposed for 12 h nightly to an augmented acoustic environment (AAE): repetitive bursts of a 70 dB SPL noise band. The high-frequency AAE (HAAE) was a half-octave band centered at 20 kHz; the low-frequency AAE (LAAE) was a 2–8 kHz band. The effects of sex, gonadectomy, and AAE treatment on genetic progressive hearing loss (a trait of B6 mice) were evaluated by obtaining auditory brainstem response (ABR) thresholds at ages 3-, 6-, and 9-months. At 9-months of age, hair cell counts (cytocochleograms) were obtained, and morphometric measures of the anteroventral cochlear nucleus (AVCN) were obtained. LAAE treatment caused elevation in ABR thresholds (8–24 kHz), with the highest thresholds occurring in intact females. LAAE treatment caused some loss of outer hair cells in the basal half of the cochlea (in addition to losses normally occurring in B6 mice), with intact females losing more cells than intact males. The loss of AVCN neurons and shrinkage of tissue volume that typically occur in 9-month-old B6 mice was lessened by LAAE treatment in intact (but not gonadectomized) male mice, whereas the degenerative changes were exacerbated in intact (but not gonadectomized) females. These LAAE effects were prominent in, but not restricted to, the tonotopic low-frequency (ventral) AVCN. HAAE treatment resulted in some loss of neurons in the high-frequency (dorsal) AVCN. In general, LAAE treatment plus male gonadal hormones (intact males) had an ameliorative effect whereas HAAE or LAAE treatment plus ovarian hormones (intact females) had a negative effect on age-related changes in the B6 auditory system.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Hearing Research - Volume 235, Issues 1–2, January 2008, Pages 60–71
نویسندگان
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