蟾蜍松果体的细胞学观察及其冬眠期与非冬眠期形态学的比较研究

为了研究蟾蜍松果体的形态特征,并了解松果体在生物节律中所起的作用,运用常规的光镜样品制备技术,对松果体的细胞形态及其在冬眠期、非冬眠期的变化进行了观察.研究结果显示,松果体的额器及脑上体都具有与视网膜感光细胞相似的细胞,称之为类光感细胞,因而它们具有感受光的能力;同时,根据细胞结构的观察以及两者所处位置的不同,认为额器具有比脑上体更强的感光性能.通过冬眠期与非冬眠期的细胞形态学比较,可以看到额器及脑上体的类光感细胞外节均有较明显的变化.冬眠期可见额器的类光感细胞外节排列规则,但数量减少,而脑上体的类光感细胞外节排列明显不规则,内有很多小泡,呈退化状态.额器及脑上体支持细胞的细胞质和类光感细胞线粒体的形态在冬眠扨亦有一定的变化.实验结果表明,额器及脑上体感光性能在冬眠期与非冬眠期是有差异的,脑上体在冬眠斯进入退化状态。

THE MORPHOLOGY OF PINEAL GLAND AND ITS COMPARATIVE STUDIES DURING HIBERNATION AND NONHIBERNATION IN TOAD (BUFO BUFO GARGARIZANS)

This paper describes the morpholog y of the toad (Bufo bufo gargarizans) pineal gland, which consists of a frontal organ and anepiphysis, as well as its comparative cytology during hibernation and nonhibernation, with light and electron microscopes. Results show that both frontal organ and epiphysis have photoreceptive structures resembling those of the lateral eye's retina. But the frontal organ has a larger photoreceptive capacity than the epiphysis. The outer segments of photoreceptor-like cells in both frontal organ and epiphysis in nonhibermation are very different from those in hibernation. And the number of outer segments in the frontal organ decreases during hliberation. The epiphysis contains many disorganized outer segment membranes in hibernation, suggesting its degenerate pineal photosensory capacity. Besides,the supportive cells and the mithochonaria of pholoreceptor-like cells show morphological differences between hibernation and nonhibernation. It can be concluded that photoreceptive capacities of frontal organ and epiphysis in hibernation are different from those in nonhibernation and epiphysis's photoreceptive capaciry is degenerated during hibernation.