泥鳅尾部神经分泌系统的形态和显微结构观察

Morphology and Microstructure of Caudal Neurosecretory System of Misgurnus Anguillicaudatus

尾部神经分泌系统(Caudal Neurosecretory System,CNSS)是鱼类特有的一套神经内分泌调控系统,具有参与繁殖调控、渗透压调节、应激、免疫等功能。选取性腺发育不同时期的泥鳅成体系统比较CNSS的形态和组织结构,结果表明泥鳅CNSS由起分泌功能的Dahlgren细胞、Dahlgren细胞向尾端发出的富含神经末梢的轴突和尾垂体3部分组成。Dahlgren细胞主要集中分布在最后2节脊椎骨对应的脊髓里,尾垂体即最后1节脊椎骨中的脊髓向腹面突起部分,有2种形态,一种葡萄状,一种半椭圆形,平均大小长为0.88±0.13 mm,宽为0.39±9.00×10^(-2)mm,高为0.22±7.00×10^(-2)mm。显微结构结果显示,性腺发育为Ⅱ到Ⅳ期时,Dahlgren细胞染色没有明显差异;性腺发育为Ⅴ期时,Dahlgren细胞染色较深,细胞充盈;卵排空到Ⅵ期后,Dahlgren细胞明显空泡化,这表明泥鳅分泌细胞内分泌物释放排空。以上结果为泥鳅CNSS参与繁殖调控提供了一些组织学证明。

Caudal neurosecretory system(CNSS)is a special neuroendocrine regulatory system in fish,which can participate in the regulation of reproduction,osmotic pressure,stress and immunity.The morphology and histological structure of CNSS were compared in the adult system of Misgurnus anguillicaudatus at different stages of gonadal development.The CNSS of Misgurnus anguillicaudatus consists of three parts:the secretory Dahlgren cells,the axons rich in nerve endings emitted from Dahlgren cells and the caudal pituitary.Dahlgren cells were mainly distributed in the corresponding spinal cord of the last 2 vertebrae.The caudal pituitary was a prominent protrusion of the spinal cord toward the ventral surface of the last vertebra.It contains two forms:a grape shape and a semi-oval shape.The average length was 0.88±0.13 mm,the width was 0.39±0.09 mm and the height was 0.22±0.07 mm.The microstructural results showed that there was no significant difference in the staining of Dahlgren cells from stage II to stage IV,but the staining of Dahlgren cells was deeper in stage V,the cells were filled,and the cells became vacuolated obviously after ovulation to stage VI,and the results indicated that the secretion of the secretion cells of Misgurnus anguillicaudatus was released and emptied.The whole results provided histological evidence for the involvement of CNSS in the regulation of reproduction.