Active and Nonlinear Models for Cochlear Mechanics

在耳蜗中，声学、机械和电学现象以仔细协调的方式相互作用， 过滤传入的声能并将其转换为神经输入。我们试图建立一个机械的层次结构- 电声（MEA）数学模型，其预测在健康人中看到的活动和非线性， 耳蜗MEA模型包括耳蜗电通路的耦合（通过阶和 Corti电路的器官）与外毛细胞（OHC）和耳蜗的流体力学模型。在 在这项拨款申请中，这些模型的开发与以下三个方面的测试有关 耳蜗活动的周期性主动过程假说：假说1仅基于躯体的 OHC运动性;假设2仅关于OHC毛束（静纤毛）运动性，假设3关于 OHC体细胞和毛束运动的组合。这些假设的新测试使用组合 电和声激励将用于确定其有效性。我们将预测与 耳蜗活动的生理实验结果和测试假设， 实验组，在俄勒冈州健康与科学大学的俄勒冈州听力研究中心， 在密歇根大学的克雷斯吉听力研究所。预测反应的能力 电和机械（声学）输入的耳蜗将有助于非侵入性的发展， 评估听力健康的工具。这些模型还将提供对听力保护的深入了解， 确定损伤机制，并为未来假体装置的开发提供指导。

In the cochlea, acoustical, mechanical and electrical phenomena interact in a carefully coordinated fashion to filter incoming acoustical energy and convert it to neural input. We seek to develop a hierarchy of mechano- electrical-acoustical (MEA) mathematical models that predict the activity and nonlinearity seen in the healthy cochlea. The MEA models include the coupling of the cochlear electric pathways (through the scalae and organ of Corti circuitry) with the outer hair cells (OHCs) and a hydromechanical model for the cochlea. In this grant application, the development of these models is tied to the testing of the following three hypotheses of cycle-by-cycle active processesfor cochlear activity: Hypothesis 1 is based solely on somatic OHC motility; Hypothesis 2 solely on OHC hair bundle (stereocilia) motility and Hypothesis 3 on a combination of OHC somatic and hair bundle motility. Novel tests of these hypotheses using combined electrical and acoustical excitation will be used to determine their validity. We will relate predictions to physiological experimental results and test hypotheses of cochlear activity in collaboration with two experimental groups, at the Oregon Hearing Research Center at Oregon Health and Science University and at the Kresge Hearing Research Institute at the University of Michigan. The ability to predict the response of the cochlea to electrical and mechanical (acoustical) inputs will assist in the development of noninvasive tools for assessing the health of hearing. Such models will also provide a insight into hearing protection by determining mechanisms of damage, and provide guidance in the development of future prosthetic devices.