Fridberger Anders, Boutet de Monvel Jacques, Ulfendahl Mats
Department of Clinical Neuroscience and Center for Hearing and Communication Research, Karolinska Institutet, SE-171 76 Stockholm, Sweden.
J Neurosci. 2002 Nov 15;22(22):9850-7. doi: 10.1523/JNEUROSCI.22-22-09850.2002.
The vibration of the hearing organ that occurs during sound stimulation is based on mechanical interactions between different cellular structures inside the organ of Corti. The exact nature of these interactions is unclear and subject to debate. In this study, dynamic structural changes were produced by stepwise alterations of scala tympani pressure in an in vitro preparation of the guinea pig temporal bone. Confocal images were acquired at each level of pressure. In this way, the motion of several structures could be observed simultaneously with high resolution in a nearly intact system. Images were analyzed using a novel wavelet-based optical flow estimation algorithm. Under these conditions, the reticular lamina moved as a stiff plate with a center of rotation in the region of the inner hair cells. Despite being enclosed in several types of supporting cells, the inner hair cells, together with the adjacent inner pillar cells, moved in a manner signifying high compliance. The outer hair cells displayed radial motion indicative of cellular bending. Together, these results show that shearing motion occurs between several parts of the organ, and that structural relationships within the organ change dynamically during displacement of the basilar membrane.
在声音刺激过程中，听觉器官产生的振动是基于柯蒂氏器内不同细胞结构之间的机械相互作用。这些相互作用的确切性质尚不清楚，存在争议。在本研究中，通过逐步改变豚鼠颞骨体外标本中的鼓阶压力，产生了动态结构变化。在每个压力水平采集共聚焦图像。通过这种方式，可以在一个几乎完整的系统中以高分辨率同时观察多个结构的运动。使用一种基于小波的新型光流估计算法对图像进行分析。在这些条件下，网状板作为一个刚性板移动，其旋转中心在内毛细胞区域。尽管内毛细胞被几种类型的支持细胞包围，但内毛细胞与相邻的内柱细胞一起以高顺应性的方式移动。外毛细胞表现出指示细胞弯曲的径向运动。这些结果共同表明，在听觉器官的几个部分之间发生了剪切运动，并且在基底膜位移期间，器官内的结构关系会动态变化。
