Monoamines are neurotransmitters and neuromodulators that contain one amino group that is connected to an aromatic ring by a two-carbon chain (-CH₂-CH₂-). All monoamines are derived from the aromatic amino acids phenylalanine, tyrosine, histidine, and tryptophan.

Examples:

• Catecholamines:
  • Dopamine (DA)
  • Norepinephrine (NE) (noradrenaline, NA)
  • Epinephrine (Epi) (adrenaline)

• Serotonin (5-HT)
• Histamine
• Thyronamines, a new group of compounds derived from thyroid hormones

• Trace amines:
  • β-Phenylethylamine (PEA, β-PEA)
  • Tyramine
  • Tryptamine

Specific transporter proteins called monoamine transporters exist that transport monoamines in or out of a cell. These are the dopamine transporter (DAT), serotonin transporter (SERT), and the norepinephrine transporter (NET) in the outer cell membrane and the vesicular monoamine transporters 1 and 2 (VMAT-1 and VMAT-2) in the membrane of intracellular vesicles.

Monoamine oxidase is an enzyme that breaks down monoamine neurotransmitters after they have been released into the synapse.

See also

• Monoamine oxidase
• Monoamine transporter
• Neurotransmitter