Takami Shigeru, Hirosawa Kazushige
Department of Fine Morphology, The Institute of Medical Science, University of Tokyo, Minato-ku, Tokyo 108, Japan.
J Morphol. 1990 Jul;205(1):45-61. doi: 10.1002/jmor.1052050106.
The vomeronasal sensory epithelium of a crotaline snake, Trimeresurus flavoviridis, was shown to consist of a superficial supporting cell layer and an underlying sensory cell layer composed of columns of sensory cells. The supporting cell layer consists of both supporting cells and dendrites of the underlying sensory neurons. The apical regions of sensory cell dendrites contain numerous microtubules, many elongated mitochondria, centrioles, and electron-dense bodies. The dendrites terminate as dendritic knobs from which microvilli project into the vomeronasal lumen. Smooth vesicles are abundant in the dendritic terminals and their vicinity. Supporting cells also bear microvilli, and these cells contain large electron-opaque granules and dense vesicles near their free surfaces. Cytoplasmic extensions of the supporting cells form a meshwork which separates dendrxites from each other in the vicinity of the luminal surface. The meshwork becomes obliterated in the infranuclear region of each supporting cell. Bipolar-shaped sensory cells with lightly stained round nuclei contain the characteristic cell organelles of neurons and are thought to be sensory neurons. These cells are especially characterized by well-developed lamellae of rough endoplasmic reticulum and extensive arrays of smooth endoplasmic reticulum. The perikarya of cells located in the apical region of the cell columns tend to contain larger amounts of smooth endoplasmic reticulum and lipofuscin granules than the perikarya of cells located in lower regions. Undifferentiated cells are found in the basal region of the columns. Satellite cells form the framework of the columns and are also found among neuronal elements.
研究表明，竹叶青蛇（Trimeresurus flavoviridis）的犁鼻器感觉上皮由浅层支持细胞层和深层感觉细胞层组成，深层感觉细胞层由感觉细胞柱构成。支持细胞层包括支持细胞和深层感觉神经元的树突。感觉细胞树突的顶端区域含有大量微管、许多细长的线粒体、中心粒和电子致密体。树突末端为树突小结，微绒毛从树突小结伸向犁鼻器管腔。树突末端及其附近有丰富的光滑小泡。支持细胞也有微绒毛，这些细胞在其游离表面附近含有大的电子不透明颗粒和致密小泡。支持细胞的细胞质延伸形成一个网络，在管腔表面附近将树突彼此分开。在每个支持细胞的核下区域，该网络消失。具有淡染圆形细胞核的双极形感觉细胞含有神经元特有的细胞器，被认为是感觉神经元。这些细胞的特别之处在于有发达的粗面内质网片层和广泛的滑面内质网排列。位于细胞柱顶端区域的细胞的胞体往往比位于较低区域的细胞的胞体含有更多的滑面内质网和脂褐素颗粒。在细胞柱的基部区域发现未分化细胞。卫星细胞形成细胞柱的框架，也存在于神经元成分之间。
