According to the Mayo Clinic, serotonin is a chemical manufactured by the human body, used for the proper functioning of various nerves throughout the body and the brain. References to serotonin and its links to mental illness, such as depression, permeate pharmaceutical commercials on television, radio and other media. The discovery of this chemical resulted in an important understanding of the causes of mental illness.
Significance
Dr. Particia Mack Whitaker-Azmitia writes, in an issue of Neuropsychopharmacolgy in 2002, that serotonin began "as an annoying artifact" viewed as getting in the way of understanding the cause of hypertension, but "ended as one of the most important discoveries of neuroscience." Serotonin's importance to neuroscience is characterized by helping to launch the field itself, thus leading to a greater understanding of the causes and treatment of mental illness.
History
While studying the cells found in the skins and intestines of various species in the 1930s, Dr. Vittorio Erspamer discovered an unknown substance. He named it enteramine. Research continued on this new substance through 1952, when scientists came to the realization that enteramine was the same chemical as serotonin, studied by other researchers. The name that stuck was serotonin, likely due to decisions made by Upjohn Pharmaceutical, the first company to synthesize it in 1951.
Function
The ability to synthesize serotonin opened new possibilities in the research of the chemical. However, the question of its overall purpose remained. Dr. Betty Mack Twarog discovered through research on mussels, found that serotonin functions as a muscle relaxer in the sea creature. Further examination by Twarog led to the discovery that serotonin exists in the mammalian brain as well, helping to shape the direction of the field of neuroscience. Other examples of serotonin function in humans is its role in brain development and the maintenance of a normal mood, as a shortage or excess of serotonin in the brain is theorized to contribute to depression.
Serotonin and the Brain
Serotonin's believed role in mental illness was proposed by Dr. D. W. Woolley, a blind researcher who determined that LSD was an antimetabolite of serotonin. Antimetabolites are structurally similar to naturally-occurring chemicals and work to inhibit or stop the effects of these chemicals. Dr. Woolley used LSD as a means to learn what role serotonin played in mental illness. He accomplished this by introducing LSD into an organism, thereby blocking the effects of serotonin and watching what happened. His research worked to establish that serotonin plays a definitive role in mental illness.
Treatment for Depression
The discovery of serotonin in the 1930s paved the way for the development of new treatments for depression in the late 20th century. Selective Serotonin Reuptake Inhibitors (SSRIs) are a class of antidepressant medication that target serotonin in the brain. According to the Mayo Clinic, fouxetine, better known as Prozac, was the first SSRI introduced to the U.S. market in 1987. How SSRIs relieve depression remains unclear, however, it seems that they assist in allowing more serotonin in the brain by blocking reabsorption of it by brain cells called neurons. Increased levels of serotonin facilitate transmission of nerve impulses, thereby improving mood.
