Soons Joris A M, Ricci Anthony J, Steele Charles R, Puria Sunil
Department of Mechanical Engineering, Stanford University, 496 Lomita Mall, Durand Building, Stanford, CA, 94305, USA,
J Assoc Res Otolaryngol. 2015 Feb;16(1):47-66. doi: 10.1007/s10162-014-0497-1. Epub 2014 Oct 28.
The cells in the organ of Corti are highly organized, with a precise 3D microstructure hypothesized to be important for cochlear function. Here we provide quantitative data on the mouse organ of Corti cytoarchitecture, as determined using a new technique that combines the imaging capabilities of two-photon microscopy with the autofluorescent cell membranes of the genetically modified mTmG mouse. This combination allowed us to perform in situ imaging on freshly excised tissue, thus minimizing any physical distortions to the tissue that extraction from the cochlea and chemical fixation and staining might have caused. 3D image stacks of the organ of Corti were obtained from base to apex in the cochlear duct, from which 3D lengths and relative angles for inner and outer hair cells, Deiters' cells, phalangeal processes, and inner and outer pillars were measured. In addition, intercellular distances, diameters, and stereocilia shapes were obtained. An important feature of this study is the quantitative reporting of the longitudinal tilts of the outer hair cells towards the base of the cochlea, the tilt of phalangeal processes towards the apex, and Deiters' cells that collectively form a Y-shaped building block that is thought to give rise to the lattice-like organization of the organ of Corti. The variations of this Y-shaped element along the cochlear duct and between the rows of outer hair cells are shown with the third row morphologically different from the other rows, and their potential importance for the cochlear amplifier is discussed.
柯蒂氏器中的细胞高度有序，其精确的三维微观结构被认为对耳蜗功能至关重要。在此，我们提供了关于小鼠柯蒂氏器细胞结构的定量数据，这些数据是使用一种新技术测定的，该技术将双光子显微镜的成像能力与转基因mTmG小鼠的自发荧光细胞膜相结合。这种结合使我们能够对新鲜切除的组织进行原位成像，从而将从耳蜗提取、化学固定和染色可能对组织造成的任何物理变形降至最低。从耳蜗管的基部到顶部获取了柯蒂氏器的三维图像堆栈，并测量了内、外毛细胞、Dieters细胞、指状突以及内、外支柱的三维长度和相对角度。此外，还获得了细胞间距离、直径和静纤毛形状。本研究的一个重要特点是定量报告了外毛细胞向耳蜗基部的纵向倾斜、指状突向顶部的倾斜，以及共同形成一个Y形结构单元的Dieters细胞，该结构单元被认为产生了柯蒂氏器的晶格状组织。展示了这种Y形结构单元沿耳蜗管以及在外毛细胞排之间的变化，其中第三排在外貌上与其他排不同，并讨论了它们对耳蜗放大器的潜在重要性。
