Abstract
Studies were made, using rabbits, on the relationship between the mineral metabolism in brain and some environmental factors. The environmental factors were noise and cold (-10±2°C), and the noise condition was the same as the previous report. The animals were exposed to noise for 3 hours or to cold for 90 minutes. The brain was separated into 7 parts; telencephalon, diencephalon, the upper parts of mesencephalon, the lower parts of mesencephalon, cerebellum, pons and myelencephalon. And then, Na, K, and Ca were determined by flame photometry.
The results were as follows:
1) In the control group, the concentration of K and Na in pons and telencephalon were higher than that in the other parts, and Ca in pons was higher than the other.
2) In the noise condition, the concentration of K decreased in pons, and increased in diencephalon and cerebellum. The concentration of Na decreased in the lower parts of mesencephalon and pons, and increased in myelencephalon. The concentration of Ca decreased in pons, diencephalon and the lower parts of mesencephalon. The value of Na:K ratio decreased in the lower parts of mesencephalon and cerebellum, and increased in pons. The value of Ca:K ratio decreased in the diencephalon, the lower parts of mesencephalon and cerebellum.
3) In the cold condition, the concentration of K showed the same tendency as that in the noise, and Na increased in diencephalon, the upper and lower parts of mesencephalon, and Ca decreased in pons. The value of Na:K ratio increased in diencephalon and pons, and decreased in cerebellum. The value of Ca:K ratio decreased in diencephalon, the upper parts of mesencephalon, lower parts of mesencephalon, cerebellum and myelencephalon.
