Uchiyama M, Iwasaki S, Murakami T
Department of Oral Physiology, School of Dentistry, Nippon Dental University, Niigata, Japan.
J Morphol. 1991 Feb;207(2):157-64. doi: 10.1002/jmor.1052070206.
Neuromast structure in Rana cancrivora larvae was observed by scanning and transmission electron microscopy. Neuromast units, each being composed of two or three neuromasts, are arranged in several well-defined lines in the head, body, and tail regions. The structure of neuromasts in these three regions is basically identical. The neuromast is composed of sensory, sustentacular, and mantle cells. The top of each neuromast has a hillocklike appearance, and is surrounded by four to six epidermal cells with tight intercellular junctions. Long kinocilia and many stereocilia occur in the apex of the neuromasts and are surrounded by numerous microvilli. Numerous granules are present on the apical portions of the mantle and the sustentacular cells. Four or five trapeziform mantle cells are connected closely with each other to form the shell of the neuromast. Large intercellular spaces occur between the mantle cells and the cells of the inner epidermal layers, and between the cells of the inner epidermal layer. Thus, at the apical parts of the neuromast intercellular junctions are tight and the intercellular spaces are more dilated in more basal areas. Morphologically the neuromasts of R. cancrivora larvae resemble those of generalized pond anurans, based on the grouping of Lannoo (Journal of Morphology 191:115-129, 1987a), although larvae of this species inhabit brackish water.
通过扫描电子显微镜和透射电子显微镜观察了食蟹蛙幼体的神经丘结构。神经丘单元由两到三个神经丘组成，在头部、身体和尾部区域以几条明确的线排列。这三个区域的神经丘结构基本相同。神经丘由感觉细胞、支持细胞和套细胞组成。每个神经丘的顶部呈小丘状，被四到六个具有紧密细胞间连接的表皮细胞包围。长动纤毛和许多静纤毛出现在神经丘的顶端，并被许多微绒毛包围。在套细胞和支持细胞的顶端部分存在大量颗粒。四五个梯形套细胞彼此紧密相连，形成神经丘的外壳。套细胞与内表皮层细胞之间以及内表皮层细胞之间存在大的细胞间隙。因此，在神经丘的顶端部分细胞间连接紧密，而在更基部的区域细胞间隙更宽。尽管该物种的幼体栖息在半咸水中，但根据Lannoo（《形态学杂志》191:115 - 129，1987a）的分类，食蟹蛙幼体的神经丘在形态上类似于一般的池塘无尾目动物。
