Januschka M M, Burkhardt D A, Erlandsen S L, Purple R L
Department of Physiology, University of Minnesota, Minneapolis 55455.
Vision Res. 1987;27(3):327-41. doi: 10.1016/0042-6989(87)90082-4.
The ultrastructure of single and twin cone photoreceptors in the retina of the walleye was analyzed by scanning and transmission electronmicroscopy. The outer segment disks resemble those of other vertebrates. An accessory outer segment arises from the inner segment, makes frequent contacts with the outer segment proper, and may thus provide a bridge for signal transmission from outer to inner segment. A palisade of some 30 calycal processes surrounds and may provide structural support for the outer segment. The region of apposition between the inner segments of twin cones consists of a space of some 28 nm with no indication of gap junctions. The proximal quarter of the inner segment displays a profusion of some 50 lateral fins which increase the inner segment surface by 3-4 X and do not contact fins of neighboring cones. The fins surround a profusion of Müller cell microvilli and probably promote metabolic exchange between cones and Müller cells. Apart from differences in size and the presence of apposed inner segments, twin and single cones appear to be morphologically similar.
通过扫描电子显微镜和透射电子显微镜分析了大眼梭鲈视网膜中单锥体和双锥体光感受器的超微结构。其外段盘状物与其他脊椎动物的相似。一个附属外段从内段产生，与正常外段频繁接触，因此可能为信号从外段向内段传递提供桥梁。约30个杯状突起形成栅栏围绕外段，并可能为其提供结构支撑。双锥体的内段之间的贴合区域由约28纳米的间隙组成，没有间隙连接的迹象。内段近端四分之一处有大量约50个侧向鳍，使内段表面积增加3 - 4倍，且不与相邻锥体的鳍接触。这些鳍围绕着大量米勒细胞微绒毛，可能促进锥体与米勒细胞之间的代谢交换。除了大小差异和并置内段的存在外，双锥体和单锥体在形态上似乎相似。
