The neurotransmitter serotonin is an important molecule that controls or affects many vital body processes and systems. Sometimes called the "happiness hormone," the effects of serotonin spread much further than the brain, affecting the digestive system, circulatory system and respiratory system.
Chemistry
According to the University of Bristol, serotonin is synthesized from L-tryptophan, an essential amino acid, by a process that converts tryptophan into 5-hydroxytryptophan and then into serotonin. Its chemical name is 5-hydoxytryptamine, or 5-HTP. In an article on eNotalone, Joseph M. Carver, Ph.D. explains that the molecule was first isolated in 1933 and subsequently found to affect multiple systems throughout the body.
Biology
Produced in the pineal gland of the brain, some serotonin remains in the central nervous system while some travels through the blood stream to affect other organs. According to the University of Bristol, the human body contains about 5 to 10 mg of serotonin at any given time. In the brain, it functions as a neurotransmitter, conducting nerve impulses from one neuron to another. Inside the brain, neuronal clusters called raphe nuclei hold serotonin until it is needed.
Effects
One major job of serotonin in the body is the regulation of the sleep cycle. Breathing, heart rate and digestion are all affected by serotonin. In fact, the majority of serotonin produced by the body migrates to the gastrointestinal tract where it assists in peristalsis, the movement of food through the stomach and intestines during digestion. Serotonin also has a strong effect on mood. High levels make an individual happier while low levels have been implicated in depression, anxiety, obsessive-compulsive disorder, anorexia and bulimia. It also helps regulate body temperature and libido. Low levels have been linked to an increase in sudden infant death syndrome, also known as SIDS, in infants.
Warning
The disorder serotonin syndrome results from an excess of accumulated serotonin in the body. Caused by taking too much of certain medications, illegal drugs or herbal supplements, this syndrome can be potentially fatal. Symptoms include restlessness, rapid heart rate, headache, shivering, unconsciousness and seizures. Stopping use of the offending medication or substance generally prevents serotonin syndrome from progressing. If severe symptoms are in progress, emergency medical assistance may be required.
Affecting Substances
Sometimes, serotonin receptors and production can be affected by outside sources. Some medications for acne and specific types of hormonal birth control have been linked to lowered levels of serotonin production. Antidepressants, herbs such as St. John’s Wort and supplemental 5-HTP may increase serotonin levels in the body. Other things that may boost serotonin in the body include exposure to sunlight and foods that contain tryptophan.
