What is the evidence that cilantro actually chelates mercury from the brain?

Couldn't it be that it chelates from non-central nervous system tissues, and that if the mercury is not excreted tightly bound then passes into the brain? This would give similar symptoms, and the severity of the symptoms would depend on the concentration gradients of brain versus body mercury.

Does anybody now of any PubMed sources or reliable quotes from Cutler and the like that addresses this issue?