GABA

GABA is a true neurotransmitter and is the major inhibitory neurotransmitter of the brain, occurring in 30-40% of all synapses. GABA is second only to glutamate, the brain’s major excitatory neurotransmitter. The GABA concentration in the brain is 200-1000 times greater than that of the monoamines or acetylcholine. The primary function of GABA is to prevent overstimulation. It does so by compensating for glutamate activity.; When GABA activates its receptor it causes negative ions to flow into the cell preventing depolarization. Glutamate can depolarize the cell and form an action potential by causing positive ions to flow into the cell when it activates its receptors. Overall, GABA regulates the activity of glutamate by preventing depolarization of the cell, therefore, preventing overstimulation.