BEHAVIORAL ASSESSMENTS OF HEARING LOSS

听力损失的行为评估

• 批准号: 6087150
• 负责人: CYNTHIA A PROSEN
• 金额: $ 13.02万
• 依托单位: NORTHERN MICHIGAN UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2000
• 资助国家: 美国
• 起止时间: 2000-04-01 至 2004-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6087150
• 关键词: acetylcholine; acoustic nerve; afferent nerve; auditory feedback; auditory nuclei; auditory threshold; behavioral /social science research tag; biological models; cochlea; disease /disorder onset; ear hair cell; early diagnosis; efferent nerve; gene targeting; genetic strain; genetically modified animals; histology; laboratory mouse; nicotinic receptors; noise; olivocochlear bundle; psychophysiology; sensorineural hearing loss; sound frequency; acetylcholine; acoustic nerve; afferent nerve; auditory feedback; auditory nuclei; auditory threshold; behavioral /social science research tag; biological models; cochlea; disease /disorder onset; ear hair cell; early diagnosis; efferent nerve; gene targeting; genetic strain; genetically modified animals; histology; laboratory mouse; nicotinic receptors; noise; olivocochlear bundle; psychophysiology; sensorineural hearing loss; sound frequency

DESCRIPTION: (Adapted from the Investigator's Abstract) The long-term objective of this research project is to investigate perceptual, anatomical, and physiological consequences of sensorineural hearing loss (SNHL). The first specific aim will examine auditory deficits in C57BL/6J mice which serve as an animal model of presbycusis, the progressive loss of high-frequency hearing that afflicts most adult humans. When outer hair cells are lost in the progression of SNHL, the resulting disturbance of active cochlear mechanics is presumed to decrease auditory sensitivity and frequency tuning. This interpretation will be tested in detail by correlating behavioral measures of absolute threshold and frequency resolution at various stages of hearing loss with structural changes in the cochlea, auditory nerve, and cochlear nucleus. It is hypothesized that the onset of behaviorally-assessed perceptual deficits will be correlated with ultrastructural changes of the peripheral innervation before gross cochlear degeneration leads to significant hair cell loss. These findings may lead to a better understanding of the importance of early clinical interventions for the treatment of profound SNHL. Olivocochlear efferent fibers that project from the auditory brainstem to the cochlea terminate upon outer hair cells; for this reason, the most common patterns of SNHL disrupt both afferent and efferent processes in the auditory periphery. The second specific aim will isolate the discrete functional consequences of a compromised efferent feedback system by measuring the hearing thresholds of alpha-9 knockout mice in quiet and in continuo9us background noise. Recent physiological studies have shown that these mutant mice exhibit normal afferent responses but no obvious cochlear efferent activity because cholinergic olivocochlear projections cannot function in the absence of alpha-9 acetylchol9ne receptors. Based on the results of previous olivocochlear lesioning experiments in other species, it is hypothesized that genetically de-efferented mice will be more sensitive to noise masking effects than normal controls. These studies may explain why current hearing aid designs fail to function effectively in the presence of environmental noise.

描述：（根据调查员的摘要进行了改编）长期目标 该研究项目是研究感知，解剖学和 感官听力损失（SNHL）的生理后果。第一个 具体目的将检查C57BL/6J鼠标中的听觉缺陷 长老会的动物模型，高频听力的进行性丧失 这会困扰大多数成年人。当外毛细胞丢失时 SNHL的进展，主动人工耳蜗机械师的扰动是 假定会降低听觉灵敏度和频率调整。这 解释将通过将行为度量相关联测试 听力损失的各个阶段的绝对阈值和频率分辨率 耳蜗，听觉神经和耳蜗核的结构变化。 假设行为评估的感知缺陷的开始 将与周围神经的超微结构变化相关 在总体耳蜗变性之前，导致明显的毛细胞损失。这些 发现可能会更好地理解早期临床的重要性 治疗深度SNHL的干预措施。橄榄石传出纤维 从听觉脑干到耳蜗的该项目终止于外部 毛细胞；因此，SNHL的最常见模式都破坏了两者 听觉外围的传入和传统过程。第二个特定 AIM将隔离受损的传出的离散功能后果 反馈系统通过测量Alpha-9敲除小鼠的听力阈值 安静且在连续的背景噪音中。最近的生理研究已经 表明这些突变小鼠表现出正常的传入反应，但没有明显 人工耳蜗传出活动，因为胆碱能橄榄石投影无法 在没有α-9乙酰基胆碱受体的情况下的功能。基于 在其他物种中先前的橄榄石病变实验的结果，它是 假设遗传性去效力的小鼠对 噪声掩盖效果比正常对照。这些研究可以解释为什么 当前的助听器设计在存在的情况下无法有效地发挥作用 环境噪音。