METAL HEADS

摘要

An ore prospector might think he was nearing the mother lode. For buried within the grey and white matter in your head, stashed safely inside nuggets of protein, is a surprising quantity of metal. In fact, the human brain contains about 6 milligrams of copper, enough to print a small circuit board. Zinc, iron and manganese are just as plentiful. While we've known about metals in the body and brain for decades, it's only recently that scientists have stopped viewing them as just "trace elements" and started to ask what on earth they're doing there.