Bipolar Disorder  & Serotonin

Serotonin is a monoamine neurotransmitter synthesized in serotonergic neurons in the central nervous system and enterochromaffin cells in the gastrointestinal tract of animals including humans. Serotonin is also found in many mushrooms and plants, including fruits and vegetables.

In the central nervous system, serotonin is believed to play an important role in the regulation of anger, aggression, body temperature, mood, sleep, vomiting, sexuality, and appetite. Low levels of serotonin have been associated with several disorders, namely increase in aggressive and angry behaviors, clinical depression, Obsessive-compulsive disorder,migraine, irritable bowel syndrome, tinnitus, fibromyalgia, bipolar disorder, and anxiety disorders. If neurons of the brainstem that make serotoninmdashserotonergic neuronsmdashare abnormal, there is a risk of sudden infant death syndrome .

Isolated and named in 1948 by Maurice M. Rapport, Arda Green, and Irvine Page, the name serotonin is something of a misnomer and reflects the circumstances of the compounds discovery. It was initially identified as a vasoconstrictor substance in blood serum ndash hence serotonin, a serum agent affecting vascular tone. This agent was later chemically identified as 5-hydroxytryptamine by Rapport, and, as the broad range of physiological roles were elucidated, 5-HT became the preferred name in the pharmacological field.

Serotonin is synthesized extensively in the human gastrointestinal tract,and the major storage place is platelets in the blood stream.

In the body, serotonin is synthesized from the amino acid tryptophan by a short metabolic pathway consisting of two enzymes ndash tryptophan hydroxylase and amino acid decarboxylase.The TPH mediated reaction is the rate limiting step in the pathway. TPH has been shown to exist in two forms TPH1, found in several tissues and TPH2, which is a brain specific isoform. There is evidence that genetic polymorphisms in both these subtypes influence susceptib