Dark Agouti rats given a single dose of 12.5 mg/kg MDMA demonstrated more exploratory behaviors and fewer anxiety-related behaviors than vehicle-treated rats, but only roughly 2.5 months (73-80 days) after drug administration. MDMA-treated rats spent significantly longer time in the open arms of the elevated plus maze 80 days after MDMA administration than controls, but not 8 or 29 d post-administration. (Rats in both conditions were repeatedly tested at each point in time.) They also made more total and closed arm entries on Day 80, and there was a trend for more open arm entries. MDMA-treated rats reared more than controls in the plus maze on Day 80, but not Day 8 or Day 29, and MDMA-treated rats in the plus-maze made more head dips than controls. When tested in an open field under white illumination (stressful for rat), there was a trend for MDMA-treated rats to move more and to spend more time in the open field. Under red illumination (less aversive), this trend became significant on Day 73. On Day 73, MDMA-treated rats were more likely to rear and less likely to defecate in the open field, when compared with controls. The authors conclude that adaptive changes produced after MDMA neurotoxicity produced a reduction in anxiety or an increase in risk-taking or impulsivity. Neurochemical examination of the 5-HT system was not performed. These findings appear at odds with the results of Morley et al. 2002, who found that MDMA-treated albino Wistar rats expressed increased anxiety on several measures, including elevated plus maze, and with those of Fone et al. 2002, who found decreased social interaction after a confirmed non-neurotoxic dose of MDMA. Differences might by partially due to differences in rat strain.