McNulty J A
J Neural Transm. 1978;43(1):47-71. doi: 10.1007/BF02029018.
The pineal of the facultative, cave-dwelling fish, Chologaster agassizi, was examined electron microscopically. Two cell types, photoreceptor and supportive cells, were identified in the pineal epithelium. The photoreceptor cells had well developed outer segments and contained Golgi bodies which were surrounded by both clear and dense-cored vesicles. Vesicle-crowned rods were frequently seen in various regions of the cell. The supportive cells also contained Golgi bodies from which both clear and dense-cored vesicles appeared to originate. In addition, these cells were characterized by peculiar arrangements of the smooth endoplasmic reticulum and the presence of pigment granules. Large quantities of glycogen were observed in both cell types. Small, unmyelinated nerve fibers were seen coursing throughout the pineal epithelium. Terminals filled with pleomorphic, clear vesicles and dense-cored vesicles were present in the vicinity of these nerve fibers. Similar vesicle-filled terminals were observed in close association with the supportive cells. The results of this study indicate that the pineal in this light-deprived species is a metabolically active organ capable of photoreception. Specializations of the organelles in the pineal cells were similar to those observed in other vertebrates living in environments of low light levels.
对兼性洞穴鱼类阿加西氏穴鱼的松果体进行了电子显微镜检查。在松果体上皮中鉴定出两种细胞类型，即光感受器细胞和支持细胞。光感受器细胞具有发育良好的外段，含有被透明和致密核心小泡包围的高尔基体。在细胞的各个区域经常可见泡冠杆。支持细胞也含有高尔基体，透明和致密核心小泡似乎都起源于此。此外，这些细胞的特征是滑面内质网的特殊排列和色素颗粒的存在。在两种细胞类型中都观察到大量糖原。可见小的无髓神经纤维贯穿整个松果体上皮。在这些神经纤维附近存在充满多形性透明小泡和致密核心小泡的终末。在与支持细胞紧密相连的地方也观察到类似的充满小泡的终末。这项研究的结果表明，这种避光物种的松果体是一个具有光感受能力的代谢活跃器官。松果体细胞中细胞器的特化与在生活在弱光环境中的其他脊椎动物中观察到的相似。
