Abstract
This study was undertaken to investigate the effects of early undernutrition on brain develop-ment using autoradiographic technique.
Newborn mice were divided into the under-nourished group and the control group. The dams, provided with an unresticted ration and water, nursed the litter until weaning. Thereafter the weanlings from both groups were provided with an unlimited balanced ration until the 60th day.
At 20th day, the undernourished revealed a 50 % reduction in body weight and a 18% in brain weight compared with the control. Despite of nutritional rehabilitation until 60 days after birth, the undernourished was not completely recovered in both body and brain weights.
Entire size of the cerebellum of the undernourished was smaller than that of the control and the external granular layer (EGL) was disappea-red later. Labeling index counted at the external matrix layer in the EGL of 5- and 10-day-old mice did not show the significant difference between the undernourished and the control.
However after 15 days of age, the labeling in-dex of the undernourished showed significantly higher value than that of the control. Generation time obtained on the external matrix cell at the EGL of 10-day-old mouse was about 2.5 hours longer in the undernourished. Hence it may be concluded that the undernutrition during early postnatal life may cause reduction of the granule cell number in the cerebellum subsequent to the prolongation in the generation time of the exter-nal matrix cell in the EGL.
