Hamann Ingo, Gleich Otto, Klump Georg M, Kittel Malte C, Boettcher Flint A, Schmiedt Richard A, Strutz Jürgen
HNO-Klinik, ENT-Department, University of Regensburg, Franz-Josef-Strauss-Allee 11, 93042 Regensburg, Germany.
Hear Res. 2002 Sep;171(1-2):82-95. doi: 10.1016/s0378-5955(02)00454-9.
Age-dependent hearing loss has been well documented in gerbils exceeding 2 years of age using physiological methods (e.g. [Mills et al. (1990) Hear. Res. 46, 201-210]). We determined behavioral thresholds for broad-band noise and pure-tone pulses in gerbils as a function of age. Contrary to expectations based on previously published physiological data, we found no significant (broad-band noise and 10 kHz) or only a very small hearing loss (7 dB at 2 kHz) in 30-36-month-old animals. In animals over 3 years of age we observed an increased spread of thresholds and threshold shifts exceeding 20 dB in some individuals. Behavioral thresholds of old gerbils from two breeding colonies (University of Regensburg and Medical University of South Carolina) were similar. Data from individual animals where thresholds were determined physiologically and behaviorally indicate that results from auditory brainstem response measurements show no shift at 18 months while subsequent measurements at 28-29 months revealed age-dependent threshold shifts of 10-15 dB. In contrast, thresholds determined by behavioral methods in these same individuals at 31-33 months of age remained stable.
使用生理学方法（例如[米尔斯等人（1990年），《听觉研究》46卷，201 - 210页]），已充分证明超过2岁的沙鼠存在年龄依赖性听力损失。我们确定了沙鼠对宽带噪声和纯音脉冲的行为阈值作为年龄的函数。与基于先前发表的生理学数据的预期相反，我们发现在30 - 36月龄的动物中没有显著的（宽带噪声和10千赫）或仅有非常小的听力损失（2千赫时为7分贝）。在3岁以上的动物中，我们观察到阈值范围增加，并且在一些个体中阈值变化超过20分贝。来自两个繁殖群体（雷根斯堡大学和南卡罗来纳医科大学）的老年沙鼠的行为阈值相似。对个体动物进行生理学和行为学阈值测定的数据表明，听觉脑干反应测量结果在18个月时没有变化，而随后在28 - 29个月时的测量显示出年龄依赖性阈值变化为10 - 15分贝。相比之下，这些相同个体在31 - 33月龄时通过行为学方法测定的阈值保持稳定。
