個體發育과 環境條件이 雄性쥐의 大腦發達과 半球別 偏在化에 마치는 效果

Abstract

The quantitative and qualitative changes of soluble proteins in the left and right cerebral hemispheres were studied, as a function of each development, environmental conditioning, and brain asymmetry during postnatal development of the male Donryu rats from a day (P0) to 1 year (P360) after birth. After three weeks of age they were divided into two groups. The one was reared in enriched condition (EC), and the other impoverished condition. During development from P0 to P360 in EC rats, brain and cerebrum weights and total protein in cerebrum were increased. Especially, protein per cerebrum weight developed at different rates and with different postnatal onset times of growth spurts, and growing period is divided into 4· periods, similar to human cognitive developmenal stages described by Piaget. Electrophoretic patterns from P0 to P80 in the left and right hemispheres are different in total 84 and 73 protein spots, respectively. As a result of differential experiences caused by environmental conditionings, EC than IC at P80 showed high values in cerebrum weight, total protein in cerebrum and protein per cerebrum weight. Compared electrophoretic patterns of the left and right cerebral hemispheres at P80 with ones at P0, 70 and 62 protein spots were newly synthesized in EC rats, but only 7 and 3 protein spots in IC ones, respectively. Electrophoretic patterns of cerebral proteins show that total 40 protein spots is specialized to left hemisphere and total 16 protein spots to right one during development from P0 to P80. It indicate that brain is asymmetry in its function and differentiation of function in left hemisphere is more stronger than in right one. These results include implications in science education in view of that memory and learning require proteins.