Serotonin

Article By:

Wurtman, Richard J. Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts.

Last reviewed:March 2020

DOI:https://doi.org/10.1036/1097-8542.616100

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• Serotonin, published June 2014:Download PDF Get Adobe Acrobat Reader

A monoamine compound derived from tryptophan that plays a role in neurotransmission, functions as a local vasoconstrictor, and has pharmacologic properties. Serotonin is a biological compound derived from tryptophan (an essential amino acid) [see illustration]. It has the chemical formula C₁₀H₁₂N₂O and also is known as 5-hydroxytryptamine (5-HT). In mammals, including humans, serotonin is found in brain and nerve tissue, blood platelets, and the gastrointestinal tract. As such, serotonin plays a dynamic role in neurotransmission, affecting many physiological and behavioral functions. It also acts as a local vasoconstrictor and has been used pharmaceutically to restrict blood flow. Moreover, in the pineal gland of the brain, serotonin is an intermediate in the synthesis of the hormone melatonin, which helps to maintain daily (circadian or biological clock) rhythms and is an important factor in initiating and sustaining sleep. See also: Biological clock; Brain; Melatonin; Nervous system (vertebrate); Neurobiology; Pineal gland; Sleep and dreaming; Sleep disorders

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