Mercury in your brain from
amalgam fillings in your mouth
Despite the endless, false, greed-oriented propaganda campaign to the contrary by the dental industry, and its ongoing campaign of persecution and excommunication of dentists with the intrepidity to warn the public about this health hazard, mercury in silver-amalgam dental fillings does indeed migrate into human brains.
For more info on dental mercury and human health, see:
http://bioprobe.com/
http://hugnet.com/