GABA: The Brain’s Main Inhibitory Neurotransmitter | Mechanism, Receptors & Clinical Importance

GABA serves as the primary inhibitory neurotransmitter in the central nervous system, where it plays a critical role in balancing excitatory and inhibitory neuronal activity. Synthesized from glutamate via the enzyme glutamate decarboxylase, GABA relies on vitamin B6 as an essential cofactor for its production. Two primary receptor types, GABA-A and GABA-B, mediate its effects. GABA-A receptors act as ligand-gated ion channels, favoring fast inhibition through chloride ion influx, whereas GABA-B receptors function as metabotropic G-protein-coupled receptors. Drugs like barbiturates and benzodiazepines modulate these receptors to produce calming, sedative, or anticonvulsant effects. When GABAergic signaling is disrupted, the resulting imbalance in neuronal circuitry often contributes to neurological disorders such as epilepsy and autism spectrum conditions.