a chemical messenger in the brain, spinal cord, heart, lungs, and kidneys, which sends messages telling the body to slow down. GABA is the primary inhibitory neurotransmitter in the brain.
Gamma-aminobutyric acid (usually abbreviated to GABA) is an inhibitory neurotransmitter found in the nervous systems of widely divergent species. It is the chief inhibitory neurotransmitter in the vertebrate central nervous system.