Morphogenesis of Cerebral Hemispheres in Goat Foetuses

Abstract

Morphogenesis of cerebrum in goats was studied using 52 foetuses ranging from 1.4cm CRL (24 days of gestation) to 41.5cm CRL (full term). The cerebral hemispheres arose as bilateral evaginations of lateral wall of telencephalon at 26 days of gestation. During second month, the surface of the cerebral hemispheres was smooth. Lateral wall was the thickest followed by dorsal, ventral and medial walls. Gyri and sulci started developing by 69 days of age. The rhinal sulcus was the first to appear followed by Sylvian sulcus, suprasylvian sulcus and hippocampal fissure. By 76 days, the coronal and marginal sulci appeared. At 83 days, the cruciate fissure also made its appearance. During the fourth month, ansate, endomarginal, callosal, diagonal, presylvian, ectosylvian and endogenual sulci
started appearing. At the beginning of the fifth month, the cerebral surface showed most of the gyri and sulci. The
ectomarginal sulcus was absent. By term, several secondary and tertiary sulci appeared dividing the cortical surface into numerous small gyri and the cerebral surface attained the adult pattern. Percentage contributions of cerebral hemispheres to the total brain weight showed a sharp and steady increase during gestation.