Serotonin/5-hydroxytryptamine (5-HT) physiology

Serotonin has a pervasive presence within both the central and peripheral nervous systems. Peripherally, serotonin stimulates various functions such as vasoconstriction, uterine contraction, bronchoconstriction, and platelet aggregation. Centrally acting serotonin inhibits excitatory neurotransmission and modulates alertness, concentration, emotions and mood, sexual behaviour, appetite, nociception and aggression. In addition to its extensive physiological role in the body, it is also the cause of certain diseases and the target of several pharmacological therapies. This review summarises the physiology of serotonin in humans and the clinical applications that are of relevance within anaesthesia.