His transmitter is mostly located in diffuse neuronal systems in the CNS, with cell bodies particularly in the raphe nuclei. It appears to play a major role in the expression of mood states, and many antidepressant drugs are thought to increase its functional activity.

a) Acetylcholine

b) acctone

c) acid

d) base

Answer: The correct answer is a) Acetylcholine.

Explanation:

The acetylcholine is a very important neurotransmitter involved in the mediation of synaptic activity between neurons. Among its most important functions we find: expression of mood states, vasodilation, gastrointestinal motility, bronchoconstriction, circular iris muscle contraction and sweat gland secretion.

Therefore the correct answer is a) Acetylcholine.