Page Scott, Ghaffari Roozbeh, Freeman Dennis M
Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, MA, USA.
Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, MA, USA.
Hear Res. 2025 Aug;464:109311. doi: 10.1016/j.heares.2025.109311. Epub 2025 May 17.
Despite enormous progress in understanding the electro-mechanical properties of outer hair cells and the molecular basis of these properties, less is known about the relative motion of the organ of Corti and accessory structures that shape cochlear responses to acoustic stimulation. Here, we characterize absolute and relative motions of apical regions of the excised gerbil cochleae using a custom Doppler optical coherence microscopy (DOCM) system. Responses to sinusoidal stimuli show nanometer-scale motions of the tectorial membrane (TM), organ of Corti structures (e.g. outer hair cells, pillar cells), and basilar membrane in the apical turn of the cochlea. Motion-magnified analysis reveals rotations about the inner pillar cells at nearly constant phase, whereas TM motion lags that of the underlying cells by as much as 0.1 radians. Our DOCM results demonstrate a new technique capable of concurrent high resolution anatomical imaging and nanometer-scale motion analysis of cellular and acellular structures in response to stapes stimulation, enabling investigations of relative cochlear motions and feedback mechanisms.
尽管在理解外毛细胞的机电特性及其分子基础方面取得了巨大进展，但对于构成耳蜗对声刺激反应的柯蒂氏器和附属结构的相对运动，我们了解得还较少。在这里，我们使用定制的多普勒光学相干显微镜（DOCM）系统来表征切除的沙鼠耳蜗顶端区域的绝对运动和相对运动。对正弦刺激的反应显示，耳蜗顶端转弯处的盖膜（TM）、柯蒂氏器结构（如外毛细胞、柱细胞）和基底膜存在纳米级的运动。运动放大分析揭示了围绕内柱细胞的近乎恒定相位的旋转，而盖膜运动比其下方细胞的运动滞后多达0.1弧度。我们的DOCM结果展示了一种新技术，该技术能够同时对细胞和无细胞结构进行高分辨率解剖成像以及纳米级运动分析，以响应镫骨刺激，从而能够研究耳蜗的相对运动和反馈机制。
