Turner J G, Willott J F
Department of Psychology, Northern Illinois University, DeKalb 60115, USA.
Hear Res. 1998 Apr;118(1-2):101-13. doi: 10.1016/s0378-5955(98)00024-0.
The effects of exposure to an augmented acoustic environment (AAE) on auditory function were evaluated using DBA/2J (DBA) mice, a strain that exhibits high-frequency hearing loss beginning around the time of weaning/adolescence (between 3-4 weeks of age) and becoming severe by 2-3 months of age. Mice were exposed 12 h per night for 10 nights to a 70 dB SPL broad-band noise AAE at one of three age periods ranging from the onset of hearing loss (25-35 days of age) to more severe degrees of hearing loss (35-45 days and 45-55 days); control mice did not receive the AAE. C57BL/6J (C57) mice of the same ages provided normal-hearing. age-matched mice in both exposed and control conditions. The auditory brainstem response (ABR), acoustic startle response amplitude, and prepulse inhibition (PPI) were used to assess the auditory system. The AAE had significant effects on DBA mice, but had no effect on normal-hearing C57 mice. For the most part, AAE exposure resulted in improved auditory performance in DBA mice (better PPI, lower ABR thresholds, bigger startle amplitudes). However, the age of the mice and/or severity of hearing loss proved to be an important variable; improvement of PPI occurred only when the AAE was initiated later in the course of hearing loss (35 days of age or older); in contrast to this, beneficial effects on ABR thresholds occurred only when the AAE was initiated early in the course of hearing loss (< 45 days of age).
使用DBA/2J（DBA）小鼠评估暴露于增强声学环境（AAE）对听觉功能的影响。DBA小鼠品系在断奶/青春期左右（3 - 4周龄）开始出现高频听力损失，并在2 - 3个月龄时变得严重。小鼠在三个年龄阶段之一，从听力损失开始（25 - 35日龄）到更严重的听力损失程度（35 - 45日龄和45 - 55日龄），每晚暴露于70 dB SPL宽带噪声AAE 12小时，持续10晚；对照小鼠未接受AAE。相同年龄的C57BL/6J（C57）小鼠提供听力正常的、与暴露和对照条件下年龄匹配的小鼠。使用听觉脑干反应（ABR）、听觉惊吓反应幅度和前脉冲抑制（PPI）来评估听觉系统。AAE对DBA小鼠有显著影响，但对听力正常的C57小鼠没有影响。在大多数情况下，AAE暴露导致DBA小鼠的听觉性能改善（更好的PPI、更低的ABR阈值、更大的惊吓幅度）。然而，小鼠的年龄和/或听力损失的严重程度被证明是一个重要变量；仅当在听力损失过程后期（35日龄或更大）开始AAE时，PPI才会改善；与此相反，对ABR阈值的有益影响仅在听力损失过程早期（<45日龄）开始AAE时出现。
