Mercury level and histochemical distribution in a human brain with Minamata disease following a long-term clinical course of twenty-six years.

Details are given of the mercury level and deposition in a human brain with Minamata disease following a twenty-six year clinical course after the first severe attack in 1956. This is the first report of a case in which the methylmercury level within the brain has returned to normal limits in a severely affected victim. However, the total mercury remained high in the brain, and mercury was clearly demonstrated histochemically in microglial cells or macrophages over wide areas of the brain and in neurons of specific brain areas. Bergmann's glial cells also contained mercury deposits, whereas Purkinje's cells had relatively little or no deposition. Mild deposition of the metal was demonstrable in the epithelial cells of the choroid plexus.