鲫鱼尾部神经分泌系统显微和亚显微结构的季节性变化

鲫鱼尾部神经分泌系统的神经分泌细胞和它的轴突中可观察到各种不同电子密度的颗粒。在性腺各个不同的发育阶段,该系统的分泌物具有累积、充满、释放和恢复这样一种周期性变化,由此说明鲫鱼的尾部神经分泌系统和它的生殖有关。

OBSERVATIONS ON THE SUBMICROSCOPIC SEASONAL CHANGES IN THE CAUDAL NEUROSECRETORY SYSTEM OF THE CRUCIAN CARP (CARASSIUS AURATUS L.)

The general monthly histology of the caudal neurosecretory system and its seasonal ultrastru-ctural changes in relation to the development of gonad of Carassius auratus were studied. The neurosecretory cells (Dahlgren cells) and their axons contain four major types of granules or vesicles, namely, synaptic vesicles, large electron-lucent granules, electron-dense and less electron-dense neurosecretory granules. At the pre-spawnmg period, the secretory material is accumulated in the cytoplasm and Herring bodies of the Dahlgren cells. There are many ueurosecretory granules in the urophysis. During the spawning season, the content is discharged from Herring bodies into the dense blood capillaries. The electron-dense neurosecrctory granules and electron-lucent granules both increase in number. At the post-spawning period, the neurosecretory granules decrease in number. As to the seasonal changes observed in the caudal neurosecretory system, it may be divided into four stages, namely, accumulation, filling and release of the secretory granules and restoration of the caudal neurosecretory system. A correlation between the caudal neurosecretory system and the reproductive processes was discussed.