Active and Nonlinear Models for Cochlear Mechanics

描述(申请人提供)：在耳蜗中，声学、机械和电现象以一种仔细协调的方式相互作用，以过滤传入的声能并将其转化为神经输入。我们试图开发一个机械-电-声学(MEA)数学模型的层次结构，以预测健康耳蜗中的活动和非线性。MEA模型包括耳蜗电通路与外毛细胞的耦合(通过耳蜗叶和Corti环器)和耳蜗流体力学模型。在这项赠款申请中，这些模型的发展依赖于以下三个关于耳蜗活动的循环活动过程的假设的测试：假设1仅基于体细胞OHC运动；假设2仅基于OHC毛束(立体纤毛)运动，假设3基于OHC体细胞和毛束运动的组合。这些假说的新颖测试将使用电学和声学相结合的方式来确定它们的有效性。我们将与俄勒冈健康与科学大学俄勒冈听力研究中心和密歇根大学Kresge听力研究所的两个实验小组合作，将预测与生理实验结果联系起来，并测试耳蜗活动的假设。预测耳蜗对电和机械(声)输入的反应的能力将有助于开发非侵入性工具来评估听力健康。这些模型还将通过确定损伤机制来深入了解听力保护，并为未来假体设备的开发提供指导。

DESCRIPTION (provided by applicant): 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 processes for 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 an insight into hearing protection by determining mechanisms of damage, and provide guidance in the development of future prosthetic devices.