Contribution of complex stapes motion to cochlea activation
Contribution of complex stapes motion to cochlea activation
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DOI：
10.1016/j.heares.2011.11.008
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发表时间：
2012-02-01
期刊：
影响因子：
2.8
通讯作者：
Sim, Jae Hoon
中科院分区：
文献类型：
--
作者：
Eiber, Albrecht;Huber, Alexander M.;Sim, Jae Hoon
经典的听觉理论只认为镫骨运动的平移成分（活塞样成分）是耳蜗激活的有效刺激，从而产生听觉感觉。我们之前的研究（Huber et al., 2008）定性地表明，围绕脚底板长轴和短轴的旋转部件（类似摇晃的部件）也会导致耳蜗激活。在这项研究中，通过活体豚鼠的测量和相关的数学描述，定量研究了镫骨运动的活塞状和摇晃状成分对耳蜗激活的贡献。用三轴压电致动器刺激麻醉豚鼠离体镫骨，同时测量镫骨的三维运动和耳蜗的复合动作电位（CAP）。测量值被用来拟合一个假设的CAP作为一个线性组合的活塞和岩石类组件的对数。当它们超过一定的阈值时，类似活塞和类似摇摆的部件都会激活耳蜗反应。对于活塞式和摇臂式构件，这些阈值以及CAP与运动构件强度的关系有所不同。与柱塞式组件相比，类摇臂组件的阈值更高，灵敏度更低。在镫骨以活塞为主导运动的情况下，类摇分量的影响是次要的，尽管在类活塞分量的低振幅情况下可能变得显著。(C) 2011 Elsevier B.V.版权所有
Classic theories of hearing have considered only a translational component (piston-like component) of the stapes motion as being the effective stimulus for cochlear activation and thus the sensation of hearing. Our previous study (Huber et al., 2008) qualitatively showed that rotational components around the long and short axes of the footplate (rocking-like components) lead to cochlear activation as well. In this study, the contribution of the piston-like and rocking-like components of the stapes motion to cochlea activation was quantitatively investigated with measurements in live guinea pigs and a related mathematical description. The isolated stapes in anesthetized guinea pigs was stimulated by a three-axis piezoelectric actuator, and 3-D motions of the stapes and compound action potential (CAP) of the cochlea were measured simultaneously. The measured values were used to fit a hypothesis of the CAP as a linear combination of the logarithms of the piston-like and rocking-like components. Both the piston-like and rocking-like components activate cochlear responses when they exceed certain thresholds. These thresholds as well as the relation between CAP and intensity of the motion component were different for piston-like and rocking-like components. The threshold was found to be higher and the sensitivity lower for the rocking-like component than the corresponding values for the piston-like component. The influence of the rocking-like component was secondary in cases of piston-dominant motions of the stapes although it may become significant for low amplitudes of the piston-like component. (C) 2011 Elsevier B.V. All rights reserved.