Blackwell Reference Online

Extract

The chemical serotonin, or 5-hydroxytryptamine (5-HT), acts as a neurotransmitter in the brain. However, only a small amount of the body's serotonin concentration is actually localized in the brain. Most serotonin concentrations are produced in the gastrointestinal tract and assist in the regulation of gastric secretions and peristalsis. Serotonin has also been found to be located in blood platelets where it acts as a vasoconstrictor. An imbalance of serotonin often is considered the primary culprit in psychiatric disorders such as depression and mania. In fact, serotonin and other neurotransmitters that act on the limbic system are part of a much larger neurochemical network that has a role in the maintenance of well-being. In part, brain functions are carried out by a network of nerves. Neurotransmitters, which are packets of biochemicals, are involved in the transmission of electrical impulses from one nerve to another. Electrical impulses generated by nerves are used to carry out communications within the neural network. Although there are many different neurotransmitters that are involved in a variety of brain functions, serotonin is one of three neurotransmitters, along with norepinepherine and dopamine, which are used by some of the nerves that regulate the limbic system. The limbic system is the part of the brain that controls emotions such as joy, fear, sadness, and anger. ... log in or subscribe to read full text