Development And Maturation Of Sulci And Gyri Of Cerebral Cortex In Developing Human Foetuses.

Introduction: The surface of the developing fetal brain undergoes significant morphological changes during fetal growth. The most characteristic feature of the forebrain is its presence of gyri and sulci on its surface and it can easily be differentiated from midbrain and hindbrain. Different major functional areas of the forebrain are demarcated by gyri and sulci. Aims: To study the development and maturation of gyri and sulci of the cerebral in human foetuses. Objective: To delineate the development of gyri and sulci and maturation of cortical lobules up to term. Material and Methods: Formalin fixed 85 foetal brains (M- 40, F- 45 ) were dissected at Deptt. of Anatomy, RIMS, Imphal, after getting formal permission from Institutional Ethics Committee, RIMS, Imphal from the age group of 12 weeks to 40 weeks and. The results are categorized into five groups: Group I (12- <18weeks), Group II (19- <24weeks), Group III (24-<30weeks), Group IV (30- <36 weeks) and Group V (36- 40 weeks). Results: A few chronology of sulcul and gyri development during 12 weeks to 40 weeks were summarized. Before 12 weeks few sulci were present. Measurement of different growth rates linearly increased with GA but no sexual dimorphism or cerebral asymmetry were detected. Conclusion: In the youngest specimen of the present study i.e. 12th week of gestation, the external surfaces of cerebral hemispheres were observed smooth i.e Lissencephalic. Features of the right cerebral hemisphere are seen more developed than left.