HISTOMORPHOGENESIS OF TELENCEPHALON DURING THE FIRST MONTH OF GESTATION IN GOATS

Prenatal developmenf of the telencephalon in goats was studied using 52 foetuses ranging from 9.4 cm CRL (24 days of gesfation) to 49.5 cm CRL (full term). By 24 days of age, the neural tube was completely fused and fhe telencephalon started to develop. Width of telencephalon was more than its height. Dorsal wall was thinner than the ventral wall and the lateral walls were the thickest. The lumen was not differentiated into the lateral ventricles. By 27 days of age (9.6 cm CRL), the lateral ventricles appeared and communicafed with fhe Third ventricle fhrough the paired inferventricular foramina of Monro. All the telencephalc parameters showed a significant positive correlation with the parameters of the other brain vesicles. Olfactory pits started to develop on either side of the telencephalon by 24 days of age. Histologically, the wall of the telencephalon by 24 days showed an inner ependymal, middle mantle and outer marginal layers bounded by the inner and outer limiting membranes. Inner ependymal layer was the thickest of all, composed of proliferating neuroepithelial cells. These cells differentiated into neuroblasts and spongioblasts that occupied the middle mantle layer. The outer non-cellular marginal layer was fhe thinnest, composed of growing processes of fhe neuroblast