“Ecstasy” [3,4-methylenedioxymetamphetamine (MDMA)] is of considerable interest in light of its prosocial properties and risks associated with widespread recreational use. Recently, it was found to bind trace amine-1 receptors (TA 1 Rs), which modulate dopaminergic transmission. Accordingly, using mice genetically deprived of TA 1 R ( TA 1 -KO ), we explored their significance to the actions of...