الفهرس | Only 14 pages are availabe for public view |
Abstract The present study was achieved to explore the distribution of active young cells throughout the variable neurogenic periventricular areas in adult tilapia fish brain in order to clarify how newly born neural cells are produced and the sites of generation, migration and differentiation into the mature neurons. In this study, a total of 100 adult Nile Tilapia (Oreochromis Niloicus) of both sexes, about 200-250 gm weight per each fish. Samples were taken at different seasonal periods for light microscopy, electron microscopy and immunohistochemistry studies. All samples were obtained from fish farms in Manzala at Dakahlia governorate. The fishes were transported in water boxes to the Histology and Cytology Department, Faculty of Veterinary Medicine, Mansoura University. The results revealed the following: The overall presence of proliferating young cells in certain areas of tilapia brain. The mitotic cells were located at the dorsal and ventral telencephalon especially in the median zone. At the early stages of mitosis, the cells revealed a spherical nuclear profile while during migration the cells were elongated. They were additionally observed at the optic tectum where vast majority of cells were existed at the caudal aspect of internal layer and torus Longitudinalis. In the diencephalon, a considerable numbers of proliferating cells were distributed along the ventricular lining of hypothalamus. Within the cerebellum, the dividing cells were organized at the corpus portion. |