The Effect of Early Malnutrition and Subsequent Rehabilitation on Brain Development

I. An Autoradiographic Study

Abstract

The brain of M_1-5, M_8-12, M_1-10, M_11-20, M_1-20 and control mice were removed at 20 and 60 days and weighed. At 10 and 14 days the proliferation kinetics of the cerebellar granular cells was investigated in M_1-10, M_1-20 and control mice with 3H-thymidine autoradiography (the labeled mitoses method). On midsagittal sections of 30-day-old mouse cerebelli, in which granule cell production had already been ceased, the area of the granular layer was measured and granule cell were counted in unit areas and multiplied by the total area. In M_1-20 the increase in brain weight was poor throughout the course. The generation time of the external granular cells was prolonged both at 10 and 14 days, and the ultimate number of the granule cells generated was significantly reduced (77%). In M_1-5 the brain weight in adulthood and the granule cell number were almost the same as in controls, although the increase in brain weight was temporarily stunted (79%). In M_1-10 the brain weight and the granule cell number were not completely restored, though the generation time of the external granular cells, which had been prolonged at 10 days, reverted to normal at 14 days. When the brain weight was compared between M_1-5 and M_8-12, and between M_1-10 and M_11-20 at 60 days, it was less in M_8-12 than in M_1-5, and likewise less in MM_11-20 than These data suggest that early malnutrition may result in deficiency in brain growth in spite of the plasticity of immature brain and that even in the suckling period the time as well as the duration of the malnutrition is important factor for the subsequent brain growth.