Serotonin, also known as 5-hydroxytryptamine is a hormone in the pineal gland, the digestive tract, the central nervous system, and blood platelets. It is a neurotransmitter - this is a chemical substance that transmits nerve impulses across the space between nerve cells or neurons. We call these spaces synapses.
Serotonin plays an important part in the regulation of learning, mood, sleep and vasoconstriction (constriction of blood vessels). Experts say serotonin also might have a role in anxiety, migraine, vomiting and appetite.
Alterations in serotonin levels in the brain may affect mood. Some antidepressant medications affect the action of serotonin, i.e. they are used to treat depression.
