A monoamine is a neurotransmitter derived from amino acids containing one amine (-NH2) group. Monoamines play a crucial role in modulating various physiological functions, including mood, arousal, and attention, among others.
Origin: The term “monoamine” is derived from the presence of a single (mono-) amine group in the molecule.
Types: There are several key monoamines in the human body, including:
- Serotonin (5-HT): Derived from the amino acid tryptophan, serotonin is involved in mood regulation, appetite control, and sleep.
- Dopamine (DA): Originating from the amino acid tyrosine, dopamine plays roles in reward, motivation, and motor control.
- Norepinephrine (NE): Also derived from tyrosine, norepinephrine is involved in arousal and alertness.
- Epinephrine (Adrenaline): This monoamine, also stemming from tyrosine, is responsible for the body’s “fight or flight” response.
Role in Medicine: Several medications, including antidepressants like monoamine oxidase inhibitors (MAOIs) and selective serotonin reuptake inhibitors (SSRIs), target the monoaminergic system to treat conditions like depression and anxiety.
Notable Features:
- Monoamines are stored in vesicles within nerve cells (neurons) until they are released into the synaptic cleft.
- Once released, their action is terminated either by reuptake into the nerve cell or by enzymatic degradation.