1. A neurotransmitter or other compound containing a single amino group, especially one that regulates mood and behavior in the brain (such as serotonin, dopamine, or norepinephrine).
Usage: technical; biochemistry; neuroscience

Examples

• Serotonin is one of the most important monoamines in the human brain.
• Depression is often associated with low levels of monoamines.
• Antidepressant medications work by increasing monoamine levels in the brain.
• Dopamine and norepinephrine are monoamines that affect attention and motivation.
• The monoamine hypothesis suggests that mood disorders result from imbalances in these neurotransmitters.