Neurotransmitters: Exciting and Inhibiting. Gamma-Amino-Butyric-Acid, or GABA, is the chief inhibitory neurotransmitter in the human brain. Along with serotonin, dopamine, glutamate, glycine, histamine, and norepinephrine, among dozens of other neurotransmitters, GABA regulates brain function.eurotransmitters: Exciting and Inhibiting. Gamma-Amino-Butyric-Acid, or GABA, is the chief inhibitory neurotransmitter in the human brain. Along with serotonin, dopamine, glutamate, glycine, histamine, and norepinephrine, among dozens of other neurotransmitters, GABA regulates brain function.