Serotonin
Serotonin, also known as 5-hydroxytryptamine or 5-HT, is an organic monoamine neurotransmitter and hormone involved in a wide range of physiological processes. It is synthesized from the essential amino acid tryptophan by the enzymes tryptophan hydroxylase and aromatic L-amino acid decarboxylase. In humans, most 5-HT is produced outside the brain, in enterochromaffin cells of the gut, and stored in platelets; a smaller amount is produced in neurons of the raphe nuclei and functions as a neurotransmitter in the central nervous system. Because serotonin cannot cross the blood–brain barrier in meaningful amounts, peripheral and central serotonin operate largely in separate pools.
In the brain, serotonin modulates mood, emotion, sleep, appetite, cognition, and thermoregulation. In the periphery, it
Serotonin acts on a family of receptors designated 5-HT1 through 5-HT7, with at least several subtypes in
Disrupted serotonergic signaling is linked to mood and anxiety disorders. Pharmacological strategies include selective serotonin reuptake