Serotonin
Say it: ser-uh-TOH-nin
Serotonin is a chemical messenger made from tryptophan that acts as a neurotransmitter in the brain and as a signal in the gut and blood.
Also: 5-HT, 5-hydroxytryptamine
Definition
What is serotonin?
Serotonin, also called 5-hydroxytryptamine or 5-HT, is a biogenic amine made from the essential amino acid tryptophan. Although it is best known as a brain neurotransmitter, most of the body's serotonin is found in the digestive tract, and blood platelets carry large amounts as well.
In the brain, serotonin neurons influence mood, sleep, appetite and many other functions, and its wide range of effects comes from a large family of serotonin (5-HT) receptors. After release, a transporter pumps serotonin back into the presynaptic neuron. Blocking this reuptake step is how the selective serotonin reuptake inhibitors (SSRIs), a widely used group of antidepressants, raise serotonin levels at synapses. In the gut, serotonin helps regulate the movement of the intestine, and at a wound, platelets release it to help keep injured blood vessels constricted while a clot forms.
Students meet serotonin often in pharmacology. Taking two or more drugs that boost serotonin, such as an SSRI together with a triptan migraine medicine, can cause serotonin syndrome, a potentially life-threatening reaction to excess serotonin activity.
Word parts
Where does the word “serotonin” come from?
- sero-
- serum, the fluid left when blood clotsLatin serum (whey)
- -tonin
- tone or tension, since it was found to tighten blood vesselsGreek tonos
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Related
Terms that go with it
- NeurotransmitterA neurotransmitter is a chemical messenger that a neuron releases at a synapse to excite or inhibit a target neuron, muscle cell or gland cell.
- SynapseA synapse is the junction where a neuron passes a signal to another cell, usually by releasing a neurotransmitter across a narrow gap.
- PlateletA platelet is a small cell fragment in the blood that helps stop bleeding by plugging damaged vessels and helping a blood clot form.
- ReceptorA receptor is a protein, on a cell's surface or inside it, that binds a specific signaling molecule and triggers a response in the cell.
- DopamineDopamine is a catecholamine neurotransmitter made from tyrosine that helps control movement, motivation and learning from reward.
- Amino acidAn amino acid is a small organic molecule with an amino group, a carboxyl group and a side chain; amino acids link together to form proteins.
Sources
Checked against
Written for biofideX in plain words, after checking these references:
- NCI Dictionary of Cancer Terms: serotonin
- NCBI MeSH: Serotonin
- OpenStax Anatomy and Physiology 2e, 12.5 Communication Between Neurons
- MedlinePlus Medical Encyclopedia: Serotonin syndrome
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