Interesting article which states you have 100 trillion brain cells and lists 50 ways you can kill them, from lead poisoning, (we had lead water pipes for my first 20 years of life), to inhaling many things like solvents which can cross the BBB.
http://www.fasting.ws/juice-fasting/...l-a-brain-cell
It recommends a fasting procedure to replace lost cells.
Ron