南方鲇尾部神经分泌系统的形态、结构及繁殖前后的变化

Changes on the Morphology and Structure and Pre-reproduction and Postreproduction of Caudal Neurosecretory System of Silurus meridionalis Chen

以重要经济大型鱼类南方鲇为实验材料,采用解剖学、组织学方法和透射电镜技术对其尾部神经分泌系统(caudal neurosecretory system,CNSS)的形态结构和繁殖前后的结构变化作了比较研究.结果显示:南方鲇CNSS主要由尾垂体、轴突和Dahlgren细胞3部分组成;尾垂体体积较大,属于单个连续型,有倒三角锥形和近似蝌蚪形两种形态;轴突主要是无髓神经纤维;Dahlgren细胞主要分布在尾部最后3段脊髓中,可分为Ⅰ型和Ⅱ型细胞,两种细胞大小形态存在显著差异,在繁殖前后形态结构也存在显著变化.繁殖前,Dahlgren细胞突起及末梢内充满电子密度高和低两种类型的分泌颗粒,细胞器丰富;繁殖后,细胞内分泌颗粒及核糖体急剧减少,线粒体空泡化,RER管腔膨大.

The changes on the morphology and structure and pre-reproduction and post-reproduction of caudal neurosecretory system （CNSS） from Silurus meridionalis were comparative studied by using the technology of anatomy, histology and transmission electron microscope （TEM） . The results showed： The CNSS of Silurus meridionalis is mainly composed by urophysis, axon and Dahlgren cell. The urophysis is large, single style and continuousness, and it has two forms, semi-heart-shaped and hammer-shaped. The axon is usually amyelinated nerve fibers. The Dahlgren cell mainly distributes in the last size and morphology three caudal spinal cord, and have two type, type I and type 11. There are significant different in and the changes of reproduction, the processes and endings pre-reproduction and post-reproduction between the two type cell. In pre- of Dahlgren cell are full of two types of secretory granules which are electron dense-density and low-density. It contained abundant organelles in soma. In post-reproduction, secretory granules and ribosome declined sharply, mitochondrial vacuolization and RER lumen enlarge.