[The aging of central nervous system in methylmercury intoxication in Niigata, Japan--quantitative investigation of neurofibrillary tangles and senile plaques].

In order to elucidate the progression of aging process in the brains of methylmercury intoxication in humans, neurofibrillary tangles (NFT) and senile plaques (SP) were examined quantitatively in the temporal lobe and calcarine cortex of 16 patients with methylmercury intoxication and 12 control subjects by using tau and beta-peptide immunostained preparations. The numbers of NFT and SP in the patients of methylmercury intoxication were almost equal to those in control subjects, and statistically there is no significant difference. The findings indicate that the methylmercury intoxication in humans does not induce or exacerbate the NFT or SP forming disease process at least in these regions in the brain.