Effects of repeated treatment with MDMA on working memory and behavioural flexibility in mice
Addiction Biology January 19, 2012 Xavier Viñals, Rafaël Maldonado, Patricia Robledo 32 citations
Repeated high doses of MDMA (30 mg/kg) given to mice impaired working memory and cognitive flexibility, with deficits in recalling learned alternation behavior persisting five days after the last dose. The high dose also increased perseveration errors in an attentional set-shifting task, indicating reduced cognitive flexibility. These behavioral effects were not due to anhedonia, as saccharin preference remained unchanged. Although baseline dopamine levels in the striatum were unaffected, an acute MDMA challenge failed to increase dopamine outflow in mice that had received the high dose, suggesting reduced dopamine transporter function. Dopamine outflow recovered seven days later. The findings suggest that neurotoxic MDMA doses cause lasting impairments in recall and cognitive flexibility in mice.