50-kHz calls in rats: Effects of MDMA and the 5-HT1A receptor agonist 8-OH-DPAT

► Behavioral activity and ultrasonic vocalization were tested in rats. ► The amphetamine derivative MDMA and the 5-HT1A agonist 8-OH-DPAT were tested. ► Both drugs led to dose-dependent behavioral activation. ► Unlike the prototypical d-amphetamine, MDMA did not lead to 50-kHz calls. ► The 5-HT1A agonist led to 50-kHz calls only at an intermediate dose (0.5 mg/kg).