http://neurotalk.psychcentral.com/ar...p/t-62190.html
reverett123 posted on 11-29-2008 :
"GABA seems a strong possibility for the tool box. My wife (non-PD) has been taking it daily for six months or more for anxiety and it works wonders for her. Anything that counters anxiety is worth a look."

Rick: In this old thread you seemed to be puzzled by the fact that your wife benefited from taking Gaba supplement because Gaba is known to be not able to cross BBB.
At any rate, the following article discusses this topic and provide possible answer to your puzzle, as it suggests (as you and Ron had speculated) that under certain conditions Gaba crosses the BBB. Additionally it suggests that there a back door which enable GABA to enter the brain through the pituitary gland. Finally the article discusses Supplemental GABA Derivitives:
"Though nature may limit GABA from crossing the barrier, chemists have found a way to create GABA-like supplements or analogues that can cross the barrier and function like GABA in the brain. Phenibut, or beta-phenyl-gamma-aminobutyric acid Hcl, is a designer GABA analogue. Chemists added a 6-carbon ring to GABA that enables it to cross the barrier and act on GABA receptors. Another GABA analogue supplement is picamilon, or nicotinoyl-GABA. Picamilon is made by adding niacin to the GABA molecule. Once picamilion crosses the barrier, the niacin molecule is cleaved off, leaving pure GABA."
I checked that the supplement picamilion is sold on line in US.
I am hesitant to try picamilion. What do white rats of this forum think ?

http://www.livestrong.com/article/492571-gaba-supplements-that-pass-the-blood-brain-barrier/#ixzz2AY7fmc69