5-HT receptors are receptors for the neurotransmitter and peripheral signal mediator 5-hydroxytryptamine (5-HT), also known as serotonin. 5-HT receptors are of great interest as they also mediate the effects of a broad range of pharmaceutical and hallucinogenic drugs. Like most other members of this family, the 5HT1A receptor (also referred to as 5HT receptor 1A or serotonin receptor 1A) is a G-protein coupled receptor. It acts by decreasing cellular levels of cAMP and causes neuronal inhibition. In mammals, 5HT1A receptor expression is strongest in CNS limbic pathways that control emotion, and 5HT1A receptor function is associated with a number of behavioural effects (sleep, feeding, thermoregulation, aggression and anxiety). Agonists for the 5HT1A receptor include LSD, buspirone, and psilocin.