Commercial site, but (long) good article about glutamate, etc.

http://smart-drugs.net/ias-excitotoxins.htm

Bottom of the article may also interest any paleo presents who arrived here
via the low-carb route re: l-glutamine supplementation touted by many ardent
lc'ers (and advocated in the popular book _The Diet Cure_.)  From my
experience really, really nasty stuff, unless of course you want to have a
panic attack.  Glutamate is a precursor to glutamine, which can convert back
to glutamate.

Theola