3,4-Methylenedioxymethamphetamine (MDMA) does not induce robust psychomotor activation and 50-kHz ultrasonic vocalisations in tryptophan hydroxylase 2 (Tph2)-deficient rats lacking serotonin in the central nervous system.
British journal of pharmacology November 23, 2025 Tianhua Wang, Rainer K W Schwarting, Markus Wöhr 1 citation
MDMA (ecstasy) stimulates arousal and euphoria by releasing dopamine, noradrenaline, and serotonin in the brain, but which chemical drives these effects has been unclear. In rats genetically modified to lack central serotonin, MDMA failed to increase psychomotor activity (a marker of arousal) and 50-kHz ultrasonic vocalizations (a marker of euphoria). Rats with reduced serotonin showed no euphoric response and only partial arousal. The findings indicate that central serotonin is necessary for MDMA's arousal- and euphoria-inducing effects, suggesting dopamine and noradrenaline are not sufficient to produce these responses.