Serotonin (5-HT) is a hormone and neurotransmitter that modulates neural activity as well as a wide range of other physiological processes including cardiovascular function, bowel motility, and platelet aggregation. 5-HT synthesis is catalyzed by tryptophan hydroxylase (TPH) which exists as two distinct isoforms; TPH1 and TPH2, which are responsible for peripheral and central 5-HT, respectively. […]