Monoamine oxidase (cerebral form refers to presence in the brain) (MAO)

Monoamine oxidases are a family of flavin-containing mitochondrial enzymes (MAO-A and MAO-B) that catalyze the oxidative deamination of monoamines, including key neurotransmitters such as dopamine, serotonin, norepinephrine, and epinephrine. Both isozymes are present in the brain but have different tissue distributions and substrate specificities: MAO-A preferentially deaminates serotonin and norepinephrine, whereas MAO-B preferentially acts on phenylethylamine and is important for dopamine metabolism in specific brain regions. The enzymes are critical regulators of neurotransmitter signaling and homeostasis and have been extensively validated as drug targets in neuropsychiatric and neurodegenerative disorders. Inhibition of cerebral monoamine oxidase activity is a well-established mechanism in the treatment of depression, Parkinson's disease, and other neurological conditions, but carries specific dietary and pharmacological risks due to their central role in amine metabolism.

Other names

MAO (general family)MAO-A (isozyme A)MAO-B (isozyme B)Monoamine oxidase enzymesFlavin-containing amine oxidoreductases

Drugs that inhibit monoamine oxidase (MAOIs) increase levels of monoamine neurotransmitters in the brain by preventing their breakdown, thereby enhancing signaling in neuronal circuits involved in mood, movement, and autonomic functions. Selective inhibition (MAO-A or MAO-B) is used to target specific monoamine pathways; nonselective inhibition affects both.