1Department of Veterinary Anatomy and Histology, College of Veterinary and Animal Sciences, Mannuthy-680 651, Kerala, India.
2College of Veterinary and Animal Sciences, Pookot-673 576, India.
*Part of Ph.D. thesis submitted by first author to Kerala Agricultural University.
Prenatal development of the neurons in the brain of goats was studied using 52 foetuses ranging from 1.4cm CRL (24 days of gestation) to 41.5cm CRL (full term). By 24 days, the middle mantle layer of the neural tube showed two types of cells, viz., the larger neuroblasts and the smaller spongioblasts. Primitive neurons could be clearly distinguished from spongioblasts at 40 days. Aggregation of neuroblasts, the nuclei, first appeared in the seventh week in the thalamus, mesencephalic tegmentum, pons and medulla oblongata. Neurofibrils appeared in the cytoplasm of neurons towards the middle of gestation. But the Nissl granules appeared in the middle of fourth month. Most of the neurons of the brain differentiated during fourth month. Nuclei of most of the neurons were vesicular, centrally placed with dark staining nucleoli. In the granular layer of cerebellum, the nuclei were chromatic and non-vesicular. Towards term, neurons in all parts of the brain were well developed.
