The entactogen MDMA (3,4-methylenedioxymethamphetamine, "Ecstasy") disrupts helping behaviour while reinforcing electrophysiological indicators of potentially associated synaptic plasticity in male Sprague-Dawley rats.
Frontiers in pharmacology January 1, 2026 Patricio Sáez-briones, Amanda Silva-Rodríguez, Michelle Morales-Vidal et al.
MDMA (Ecstasy) suppressed helping behavior in adult male rats at doses of 5 mg/kg and 10 mg/kg, fully eliminating the behavior, while lower doses (1 mg/kg and 0.5 mg/kg) caused partial inhibition only after the rats switched roles. The lowest dose (0.25 mg/kg) had no effect. Electrophysiological recordings showed that MDMA reinforced long-term depression in the nucleus accumbens core and increased long-term potentiation in the anterior cingulate cortex, with the latter depending on serotonin and oxytocin. These neuroplastic effects align with mechanisms thought to promote prosocial behavior, yet the drug disrupted helping behavior, suggesting MDMA may impair neural processes essential for executing helping actions without reducing the willingness to help.