GABA – gamma-aminobutyric acid

GABA is the main inhibitory neurotransmitter found in the brain.^[1] GABA is synthesised predominantly from glutamate, by the enzyme glutamic acid decarboxylase that is found almost exclusively in GABAergic neurones.^[1] The ionotropic GABA receptors are usually inhibitory, because when activated they allow the flow of negative chlorine ions across the membrane – reducing the potential for neuronal signalling.^[1]

Chemicals that function as GABA agonists have been used to treat various conditions, and include anticonvulsants, anxiolytics, benzodiazepines, and hypnotics.^[2]

References:
[1] Purves D, Augustine GJ, Fitzpatrick D, et al. (eds). Neuroscience. 4th edition. Sinauer Associates ,2008.

[2] Stahl SM. Stahl’s Essential Psychopharmacology. Neuroscientific Basis and Practical Applications. 4th edition. © Cambridge University Press, 2013.