Active and Nonlinear Models for Cochlear Mechanics

描述（由申请人提供）：在耳蜗中，声学、机械和电现象以一种精心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。我们寻求发展一个层次的机械-电-声（MEA）数学模型来预测健康耳蜗的活动和非线性。MEA模型包括耳蜗电通路（通过Corti电路的鳞片和器官）与外毛细胞（ohc）的耦合以及耳蜗的流体力学模型。在这项拨款申请中，这些模型的发展与以下三个关于耳蜗活动周期活跃过程的假设的测试有关：假设1仅基于体细胞OHC运动；假设2仅与热碳毛束（立体纤毛）运动性有关，假设3与热碳体细胞和毛束运动性的结合有关。将使用电和声联合激励对这些假设进行新的测试，以确定其有效性。我们将与俄勒冈健康与科学大学的俄勒冈听力研究中心和密歇根大学的克雷斯格听力研究所的两个实验组合作，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（声学）输入的反应的能力将有助于开发用于评估听力健康的非侵入性工具。这些模型还将通过确定损伤机制来深入了解听力保护，并为未来假肢装置的开发提供指导。

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.