All of the following are excitatory neurotransmitters except: (A) Gamma-aminobutyric acid, (B) Acetylcholine, (C) Dopamine, (D) Serotomin
Answer is A. GABA is the major inhibitory mediator in the brain, including being responsible for presynaptic inhibition. GABA, which exists as b-aminobutyrate in the body fluidsReference: Ganong review of medical physiology 23rd edition Page no; 141