arkfreepdom is correct. My mother has a GABA-related neurological condition and has been assured by all her specialists that eating GABA doesn't result in more GABA in your brain. The stuff is widely available as a supplement, apparently (per PoisedWoman's post) because it has other effects, though the supplement sellers would probably not bother disabusing any prospective customers of the notion that it might increase brain levels of GABA.
"My mother has a GABA-related neurological condition and has been assured by all her specialists that eating GABA doesn't result in more GABA in your brain. " ---- Did she try it? I would check to make sure it doesn't cause harm or interfere with other things, but "if it can't hurt, but may help" well, who knows.
As walkingman mentioned in post 4, that while ordinary GABA doesn't cross the blood-brain barrier, but you can get some with some transporter which does. "The "Good" GABA is linked to a lipid soluable 'transporter' (usually hydropyridine)"
This may or may not be worth it to people in general, but if your Mother's condition is specifically related to lack of GABA, I personally would consider trying it.