Manganese uptake into rat brain during development and aging.

Manganese (Mn) is an essential metal and plays an important role in the brain. To evaluate Mn uptake into the brain during development and aging, 54Mn concentrations in the brain of rats aged from 5 days to 95 weeks were measured after injection of 54MnCl2. 54Mn concentration in the brain of 5-day-old rats was the highest of all age groups tested. The liver and blood of 5-day-old rats also showed the highest 54Mn concentrations among the age groups. These results suggest that Mn is required in a high amount during infancy and that a sufficient Mn supply is critical for normal brain development. The high uptake of Mn into the brain of neonatal rats may be due to high levels of Mn in the blood, which may be supplied from the liver. In the 5-day-old brain, 54Mn was relatively concentrated in the hippocampal CA3 and dentate gyrus and the pons. In the aging brain, 54Mn was relatively concentrated in the inferior colliculi, olivary nuclei and red nuclei.