Serotonin

Serotonin is a monoamine that could be found in plans, animals and human body. The homeostasis of serotonin is maintained by the series of interdependent processes that include synthesis, storage, transport and removal/degradation. In the human body serotonin is synthesized in two independent compartments that are separated by brain-blood barrier. The majority of serotonin is synthesized in enterochromaffin cells of the gastrointestinal tract, released in the blood stream and stored in blood platelets. About 5% of serotonin is synthesized in the brain within serotonergic neurons. As a neurotransmitter serotonin plays an important role in the regulation of physiological functions like body temperature, sleep, vomiting, sexuality, appetite, behaviour and cognitive functions such as learning and memory. The dysfunction of the serotonergic system has been implicated in the aetiology of a variety of psychiatric (depression, schizophrenia, alcoholism) and neurological (migraine, Alzheimer’s disease, epilepsy) disorders. Recent genetic association studies of the neuropsychiatric disorders have focused on functional polymorphisms i.e. DNA sequence variations that alter the expression and/or functioning of the gene product in the loci encoding different genes. Some of them are genes for tryptophan hydroxylase, serotonin transporter and serotonergic receptors