Table 1.

Schedule of Drug Treatment

Experimental Day	Day 1	Days 2–7	Days 8–12	Day 13	Day 14	Days 15–37	Day 37	Day 39
Sal Group (N = 9)	Saline	Saline	Washout	5.0 mg/kg MDMA	Amph	Washout	Saline	Amph/MPD
2.5 Group (N = 9)	Saline	2.5 mg/kg MDMA	Washout	2.5 mg/kg MDMA	Amph	Washout	Saline	Amph/MPD
5.0 Group (N = 9)	Saline	5.0 mg/kg MDMA	Washout	5.0 mg/kg MDMA	Amph	Washout	Saline	Amph/MPD
10.0 Group (N = 9)	Saline	10.0 mg/kg MDMA	Washout	10.0 mg/kg MDMA	Amph	Washout	Saline	Amph/MPD

shows the schedule of drug treatment for the four experimental groups. Locomotor activity was recorded on experimental Days 1–7, 12–14, 37–39. The numbers in the first column (2.5, 5.0, and 10.0) refer to MDMA doses (i.p.). Amph = 0.6 mg/kg amphetamine. Amph/MPD: On experimental Day 39, animals in each group were given either 2.5 mg/kg methylphenidate (N = 3/group) or 0.6 mg/kg amphetamine (N = 6/group).