Mahendrasingam S, Katori Y, Furness D N, Hackney C M
Department of Communication and Neuroscience, Keele University, Staffs, UK
Hear Res. 1997 Sep;111(1-2):85-92. doi: 10.1016/s0378-5955(97)00091-9.
The apices of the majority of cells of the organ of Corti are connected together by junctional complexes to form the reticular lamina, a barrier that prevents the mixing of endolymph and perilymph. These complexes include tight junctions, adherens junctions and desmosomes. Further information is required about the identity and distribution of the molecules involved in these connections if the function and organization of the reticular lamina are to be well understood. One major category of molecules occurring in adherens junctions and desmosomes, and involved in the maintenance of tissue integrity, is the cadherins. However, although cadherin has been identified in junctions between supporting cells in the adult mammalian organ of Corti at the light microscopic level, its ultrastructural distribution has not so far been described. A post-embedding immunogold labelling technique has therefore been used in conjunction with a monoclonal antibody to cadherin to investigate its ultrastructural distribution in the adult guinea-pig reticular lamina. Immunolabelling is observed in hair cell-supporting cell junctions and in supporting cell-supporting cell junctions. In addition, there is more labelling associated with inner hair cell-supporting cell junctions than with outer hair cell-supporting cell junctions. This may indicate that the junctions associated with the two types of hair cell have different functional properties.
柯蒂氏器大多数细胞的顶端通过连接复合体连接在一起，形成网状板，这是一种防止内淋巴和外淋巴混合的屏障。这些复合体包括紧密连接、黏着连接和桥粒。如果要充分理解网状板的功能和组织结构，就需要进一步了解参与这些连接的分子的特性和分布情况。黏着连接和桥粒中存在的、参与维持组织完整性的一大类分子是钙黏着蛋白。然而，尽管在成年哺乳动物柯蒂氏器支持细胞之间的连接中，在光学显微镜水平已鉴定出钙黏着蛋白，但其超微结构分布迄今尚未见报道。因此，已采用包埋后免疫金标记技术，结合抗钙黏着蛋白单克隆抗体，来研究其在成年豚鼠网状板中的超微结构分布。在毛细胞-支持细胞连接以及支持细胞-支持细胞连接中观察到免疫标记。此外，与内毛细胞-支持细胞连接相关的标记比与外毛细胞-支持细胞连接相关的标记更多。这可能表明与两种类型毛细胞相关的连接具有不同的功能特性。
