GABA (Gamma-amino butyric acid)
Although not strictly speaking an amino acid, GABA is often classified with the amino acids. It functions as the most widely distributed inhibitory neurotransmitter in the brain. The manufacture of GABA is regulated by vitamin B6. Benzodiazepine tranquillizer drugs (such as Valium), produce their anti-anxiety and muscle-relaxant effects by activating the neurons (nerve cells) and receptor sites which respond to GABA.
GABA is almost always deficient in clinical and experimental seizure disorders. It is involved in the regulation of mechanisms related to blood pressure, therefore stimulants of GABA receptors are considered useful in combating hypertension.
Availability: GABA is not readily available as a dietary supplement, but supplementation with the amino acid taurine increases the breakdown of glutamate to GABA.