GABA

GABA is an inhibitory neurotransmitter substance derived from glutamic acid that performs important inhibitory functions in the brain. GABA helps to maintain a kind of balance in the nervous system by controlling excitatory information from other cells. GABA receptors on nerve cells are ligand-gated ion channels, that open to admit negatively-charged ions to the cell when GABA (the ligand) binds. This prevents nerve cells from producing an excitatory electrical signal. General anaesthetics are thought to function by increasing the function of GABA receptors. Benzodiazepine drugs enhance the action of GABA. In Parkinson’s disease there is a considerable reduction in the number of GABA binding sites in the Substantia nigra of the brain.