Development of the human fetus cerebellum: a volumetric study of the cerebellar structures
Yamaguchi, K.; Goto, N.; Nara, T.
No to Hattatsu 20(1): 3-9
1988
ISSN/ISBN: 0029-0831 PMID: 3348919 Document Number: 321798
Volumetric analysis of the human fetus cerebellum was conducted after morphological observation of complete serial sections of the brain. Brains were from eight fetuses (16 .apprx. 40 weeks of gestation), an infant (2 months old), and an adult (63 years old). No apparent congenital anomalies nor injuries were observed at autopsy. During the fetal period, the cerebellum, especially the cerebellar cortex, increased markedly in volume, and the rate of increase (in volume) was relatively high compared with those of brainstem, ventricles, cerebellar medulla, and cerebellar nuclei. Before the 30th week of gestation, the volume of cerebellar medulla was larger than that of cerebellar cortex. The cortico-medullary volume ratio remarkably changed around this period. While the volume of the cerebellar nuclei increased slowly, their volume ratios to the whole cerebellum decreased slowly during the fetal period. In contrast, the volume ratios of individual nuclei to the whole cerebellar nuclei were almost constant after the 21st week of gestation. The volumetric analysis deduces that the human cerebellum has a critical period around the 30th week of gestation during fetal development.