3,4-Methylenedioxymethamphetamine (Ecstasy)-Induced Learning and Memory Impairments Depend on the Age of Exposure during Early Development

MDMA exposure during a period equivalent to the late human third trimester causes lasting learning and memory impairments in rats, while exposure during the early third trimester has little effect. Rats given MDMA on days 11–20 after birth showed dose-related difficulties in sequential learning and spatial learning and memory, but not in swimming or cued learning. Body weight temporarily dropped but recovered to 90–95% of controls. Brain chemical changes were small and did not explain the learning deficits. These findings suggest MDMA may pose a previously unrecognized risk to the developing brain.

Study at a glance

Abstract

Use of 3,4-methylenedioxymethamphetamine (MDMA; ecstasy) has increased dramatically in recent years, yet little is known about its effects on the developing brain. Neonatal rats were administered MDMA on days 1–10 or 11–20 (analogous to early and late human third trimester brain development). MDMA exposure had no effect on survival but did affect body weight gain during treatment. After treatment, body weight largely recovered to 90–95% of controls. MDMA exposure on days 11–20 resulted in dose-related impairments of sequential learning and spatial learning and memory, whereas neonatal rats exposed on days 1–10 showed almost no effects. At neither stage of exposure did MDMA-treated offspring show effects on swimming ability or cued learning. Brain region-specific dopamine, serotonin, and norepinephrine changes were small and were not correlated to learning changes. These findings suggest that MDMA may pose a previously unrecognized risk to the developing brain by inducing long-term deleterious effects on learning and memory.