Selective Impairment in Frequency Discrimination in a Mouse Model of Tinnitus.
Selective Impairment in Frequency Discrimination in a Mouse Model of Tinnitus.
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DOI：
10.1371/journal.pone.0137749
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发表时间：
2015
期刊：
影响因子：
3.7
通讯作者：
Geffen MN
中科院分区：
文献类型：
--
作者：
Mwilambwe-Tshilobo L;Davis AJ;Aizenberg M;Geffen MN
耳鸣是一种听觉障碍，影响着数百万美国人，包括现役军人和退伍军人。它表现为通常限制在特定频率范围内的幻音。由于耳鸣与听力缺陷有关，了解耳鸣如何影响听力感知对于指导治疗以提高这一庞大患者群体的生活质量非常重要。在啮齿动物耳鸣模型中，长时间暴露于音调导致特定频段间隙检测选择性减少。然而，在这些频带内和频带外的声音是否以及如何影响听力，目前还不清楚。我们通过长时间暴露于一个响亮的中频音调来诱导小鼠耳鸣，并在暴露后1、4和8周对小鼠在中频范围和高频范围内的音调是否表现出频率识别灵敏度的变化进行行为分析。一组暴露于音调的小鼠表现出耳鸣样症状，正如间隙检测的选择性缺陷所证明的那样，这种缺陷仅限于高频范围。这些小鼠对中频和高频音调的辨别能力都受损。未表现出耳鸣行为证据的其余音调暴露小鼠在中频范围内表现出暂时的频率识别缺陷，而对照组小鼠则没有受损。我们的研究结果表明，耳鸣的间隙检测高频特异性缺陷与耳鸣频率的频率识别障碍有关。
Tinnitus is an auditory disorder, which affects millions of Americans, including active duty service members and veterans. It is manifested by a phantom sound that is commonly restricted to a specific frequency range. Because tinnitus is associated with hearing deficits, understanding how tinnitus affects hearing perception is important for guiding therapies to improve the quality of life in this vast group of patients. In a rodent model of tinnitus, prolonged exposure to a tone leads to a selective decrease in gap detection in specific frequency bands. However, whether and how hearing acuity is affected for sounds within and outside those frequency bands is not well understood. We induced tinnitus in mice by prolonged exposure to a loud mid-range tone, and behaviorally assayed whether mice exhibited a change in frequency discrimination acuity for tones embedded within the mid-frequency range and high-frequency range at 1, 4, and 8 weeks post-exposure. A subset of tone-exposed mice exhibited tinnitus-like symptoms, as demonstrated by selective deficits in gap detection, which were restricted to the high frequency range. These mice exhibited impaired frequency discrimination both for tones in the mid-frequency range and high-frequency range. The remaining tone exposed mice, which did not demonstrate behavioral evidence of tinnitus, showed temporary deficits in frequency discrimination for tones in the mid-frequency range, while control mice remained unimpaired. Our findings reveal that the high frequency-specific deficits in gap detection, indicative of tinnitus, are associated with impairments in frequency discrimination at the frequency of the presumed tinnitus.