What is Serotonin? It is classified as a monoamine neurotransmitter. Biochemically derived from tryptophan, serotonin is mostly located in the gastrointestinal tract, platelets, and in the central nervous system of humans and other animals.

How Serotonin works? It boosts feelings of well-being; consequently it is popularly known as the happiness hormone, even though it is not a hormone at all. It is known as 5-hydroxytryptamine (5-HT).

About 80% of the human body’s total serotonin is found in the enterochromaffin cells in the gut, where it is employed to control intestinal movements. The rest is synthesized in serotonergic neurons in the nervous system where it has several functions. These duties include the regulation of mood, appetite, sleep, as well as muscle contraction. 5-hydroxytryptamine also has a few cognitive functions, particularly in memory and learning. Modulation of 5-HT at synapses is considered to be a major action of several classes of pharmacological antidepressants.

Serotonin discharged from the enterochromaffin cells eventually finds its way out of tissues into the blood. There, it is actively absorbed by blood platelets, which store it. When the platelets attach to a clot, they disgorge 5-hydroxytryptamine, where it functions as a vasoconstrictor and helps to regulate hemostasis and blood clotting. 5-HT is also a growth factor for some types of cells, which may give it a part in wound healing.

In addition to animals, serotonin is also present in fungi and plants. This substance’s action in insect venoms and plant spines serves to cause pain, which is a side effect of serotonin injection. 5-HT is produced by pathogenic amoebas, and its effect on the gut provokes diarrhea. Its widespread presence in many seeds and fruits may serve to trigger the digestive tract into expelling the seeds.