Histogenesis of Human Fetal Cerebellum during the Second Trimester of Gestation

Background: The cerebellum is one of the structures in the brain that begins first to differentiate but last to mature, since its development is spread over a longer period and shows age-related changes. The cerebellar cortex is divided into the outer molecular layer, middle Purkinje cell layer, and inner granular layer. The external granular layer appears first on the surface of the cerebellum as a dense layer of cells at third embryonic month. The external granular layer is the precursor of the Purkinje layer, and internal granular cell layer. Aims and objective of the study is to observe histogenesis of cerebellum in second trimester of intrauterine life in our population. Material and Method: In the present study, 20 specimens were divided into four groups according to their gestational age, 12–28 weeks. Observation and Result: In Group A (12–16 weeks), an external granular layer was seen, Group B (16–20 weeks) small groove-like folia was observed. In Group C (20–24 weeks), Purkinje cells started appearing. In Group D (24–28 weeks), Purkinje cells were better differentiated. Conclusion: Knowledge of normal histogenesis of brain and its different parts will help us in avoiding Congenital malformation as any delineation from this can help us understand the pathological etiology.