Serotonin is the baby boomer of neurotransmitters: It was identified in the late 1940s, its adolescence was troubled and turbulent, it made the drug scene in the 1960s, and it nearly died of an overdose in the early 1970s. At one point, the remark was made that serotonin doesn't do anything. On reaching its middle years, serotonin has matured and become an important topic of study, a household name, and more complicated than ever. Serotonin has been associated with, among other things, anxiety, depression, schizophrenia, drug abuse, sleep, dreaming, hallucinogenic activity, headache, cardiovascular disorders, and appetite control, and it is now dabbling in acupuncture and transcendental meditation.
Serotonin was independently identified in the late 1940s by two groups of investigators: In the United States, it was called serotonin, whereas in Italy, it was
called enteramine. Its total synthesis in the early 1950s confirmed that both substances were 5-hydroxytryptamine (5-HT ). Serotonin (5-HT ) was detected in
numerous plant and animal species and, in the mid-1950s, was identified in the central nervous system (CNS) of animals. A neurotransmitter role was
subsequently proposed for this substance. Later, 5-HT was implicated in a variety of central and peripheral physiologic actions. It seemed to be involved in
vasoconstriction and vasodilation, regulation of body temperature, sleep, and hormonal regulation, and evidence suggested that it might be involved in
depression. The structural similarity between 5-HT and the then recently discovered hallucinogenic agent (+)-lysergic acid diethylamide (LSD) intrigued
investigators. This observation led to speculation that 5-HT might be involved in the mechanism of action of psychoactive substances and that it might play a
seminal role in various mental disorders.
