reserpine decreased the available serotonin, so that seemed to fit together nicely with the other discovery.
British Dictionary definitions for reserpine
an insoluble alkaloid, extracted from the roots of the plant Rauwolfia serpentina, used medicinally to lower blood pressure and as a sedative and tranquillizer. Its main adverse effect is mental depression. Formula: C33H40N2O9
C20: from German Reserpin, probably from the New Latin name of the plant
reserpine re·ser·pine (rĭ-sûr'pēn', -pĭn, rěs'ər-pĭn, -pēn', rěz'-) n. A white to yellowish powder isolated from the roots of certain species of Asian shrubs and used as a sedative and an antihypertensive.