[Morphofunctional features of the development of the hypothalamo-hypophyseal neurosecretory system and adenohypophysis in the round goby Gobius melanostomas Pallas during early ontogenesis].

The formation of the hypothalamo-hypophysial neurosecretory system (HHNS) and adenohypophysis in the round goby takes place during the embryogenesis. The HHNS functional differentiation begins earlier than the anatomical one. The Homori-positive neurosecretory material was found in the neurohypophysis of one day old larvae. The first, within 7-10 days after the hatching, to be differentiated are the acidophilic cells of mesoadenohypophysis, then, on the 10-15th day, the acidophilic cells of proadenohypophysis and on the 20-25th day the basophilic cells of mesoadenohypophysis which perform the thyrotropic function and the cells of metadenohypophysis. The early development of the morpho-functional interrelations between HHNS and adenohypophysis is noted which ensures the realization of specific adaptations at the early stages of ontogenesis. The role of homoriphilic neurosecretory substance in the differentiation of glandular cells and the regulation of adenohypohysial functions is discussed.