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. 2006 Nov;221(1-2):73-81.
doi: 10.1016/j.heares.2006.07.016. Epub 2006 Sep 14.

Effects of exposing gonadectomized and intact C57BL/6J mice to a high-frequency augmented acoustic environment: Auditory brainstem response thresholds and cytocochleograms

James F Willott  1 , Justine VandenBosche, Toru Shimizu, Da-Lian Ding, Richard Salvi
Affiliations

Effects of exposing gonadectomized and intact C57BL/6J mice to a high-frequency augmented acoustic environment: Auditory brainstem response thresholds and cytocochleograms

James F Willott et al. Hear Res. 2006 Nov.

Abstract

Gonadectomized and surgically intact adult C57BL/6J (B6) mice of both sexes were exposed for 12h nightly to a high-frequency augmented acoustic environment (AAE): repetitive bursts of a half-octave noise band centered at 20 kHz, 70 dB SPL. The effects of sex, gonadectomy, and AAE treatment on genetic progressive hearing loss (exhibited by B6 mice) were evaluated by obtaining auditory brainstem response thresholds at ages 3-, 6-, and 9-months; hair cell counts (cytocochleograms) were obtained at 9 months. A sex difference in the rate of genetic progressive hearing loss in B6 mice (observed by earlier studies) was confirmed, with females exhibiting a faster rate of threshold elevations and more severe loss of hair cells at age 9 months. Gonadectomy had no consistent effects on the rate or severity of hearing loss in non-exposed mice of either sex. An unexpected finding was that the high-frequency AAE treatment caused additional ABR threshold elevations and hair cell loss. In an earlier study, the same high-frequency AAE treatment on DBA/2J mice ameliorated hearing loss. The most severe AAE-induced losses occurred in surgically intact females, suggesting a potentiating effect of ovarian hormone(s).

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Figures

Figure 1
Figure 1
ABR thresholds for all mice at all three ages (means and standard errors). The frequency band of the AAE noise is shown by the shaded bar. Green symbols = males, black symbols = females; square symbols = gonadectomized. Round symbols = intact; unfilled symbols = AAE-exposed, filled symbols = nonexposed controls.
Figure 2
Figure 2
ABR thresholds (means and standard errors) as a function of age for each stimulus frequency. Green symbols = males, black symbols = females; square symbols = gonadectomized. Round symbols = intact; unfilled symbols = AAE-exposed, filled symbols = nonexposed controls.
Figure 3
Figure 3
ABR thresholds for 14-month-old mice. In these older mice, females have significantly higher thresholds at 8, 12, and 16 kHz.
Figure 4
Figure 4
Cytocochleograms (% missing hair cells) for all groups.
See this image and copyright information in PMC

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References

    1. Arnold AP. Genetically triggered sexual differentiation of brain and behavior. Horm Behav. 1996;30:495–505. - PubMed
    1. Belisle S, Bellabarba D, Lehoux JG. Age-dependent, ovary-independent decrease in the nuclear binding kinetics of estrogen receptors in the brain of the C57BL/6J mouse. Amer J Obstet Gynecol. 1985;153:394–401. - PubMed
    1. Bergman MD, Karelus KK, felicio LS, Nelson JF. Differential effects of aging on estrogen receptor dynamics in hypothalamus, pituitary and uterus of the C57BL/6J mouse. J Steroid Biochem. 1989;33:1027–1033. - PubMed
    1. Bittar RS, Cruz OL, Lorenzi MC, Marone SA, Miniti A. bregm1. Morphological and functional study of the cochlea after administration of estrogen and progesterone in the guinea pig. Int Tinnitus J. 7:41–45. - PubMed
    1. Coleman JR, Campbell D, Cooper WA, Welsh MG, Moyer J. Auditory brainstem responses after ovariectomy and estrogen replacement in rat. Hear Res. 1994;80:209–215. - PubMed

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