An Amino Acid That Operates at Inhibitory Synapses in the Brain

Question

An amino acid that operates at inhibitory synapses in the brain is
A)acetylcholine.
B)epinephrine.
C)endorphin.
D)nitric oxide.
E)GABA.

Accepted Answer

GABA is an inhibitory neurotransmitter that operates at inhibitory synapses in the brain. Acetylcholine and epinephrine are excitatory neurotransmitters, while endorphin and nitric oxide are neuromodulators that do not directly operate at synaptic receptors.