What are the effects of Serotonin on the Brain?

Question

Apart from feeling happy.

Answer 1

Serotonin is measured on a venipuncture specimen in cases of suspected carcinoid syndrome (where it will be elevated). The normal range is 101 to 283 ng/ml.

Serotonin syndrome
Extremely high levels of serotonin can have toxic and potentially fatal effects, causing a condition known as serotonin syndrome. In practice, such toxic levels are essentially impossible to reach through an overdose of a single anti-depressant drug, but require a combination of serotonergic agents, such as an SSRI with an MAOI.[10] The intensity of the symptoms of serotonin syndrome vary over a wide spectrum, and the milder forms are seen even at non-toxic levels.[11] For example, recreational doses of MDMA (ecstasy) will generally cause such symptoms but only rarely lead to true toxicity.

Abnormally low serotonin activity in the brain has been specifically linked to intermittent explosive disorder (DSM IV), violent suicide, panic, and unrestrained aggression (rage).

Answer 2

vasoconstrictor, liberated by blood platelets, that inhibits gastric secretion and stimulates smooth muscle; present in relatively high concentrations in some areas of the central nervous system (hypothalamus, basal ganglia), and occurring in many peripheral tissues and cells and in carcinoid tumors.