MAOI increases which neurotransmitters in the CNS?

• A. Dopamine and GABA
• B. Serotonin and Norepinephrine
• C. Acetylcholine and Dopamine
• D. Glutamate and GABA

Answer: (B)

Inhibition of monoamine oxidase raises monoamines in the brain. Monoamine oxidase is the enzyme that breaks down serotonin, norepinephrine, and dopamine. When MAO is blocked, these neurotransmitters are metabolized more slowly, so their levels increase in the CNS. Serotonin and norepinephrine are the ones most characteristically raised by MAO inhibition, which is why they are the correct pairing. Dopamine can also rise with some MAOIs, but GABA, glutamate, and acetylcholine are not primarily affected by MAO.