Fig. 1
Effect of dose on initiating a syndrome. Occurrence of a syndrome was instrumentally detected with changes in 5-HT and Tcor under the normal environmental conditions. Arrows indicate the time of binge injection of 10 mg/kg × 3 (high-dose, HD; left panel) or 2 mg/kg × 3 at 2 h intervals (low-dose, LD; right panel). a Time course of 5-HT response to MDMA binge injection. X-axis represents time in hours, starting at 0 when given the first drug administration while y-axis represents fold increases in 5-HT above baseline. 5-HT data are expressed as means ± SEM (10 mg/kg × 3, N = 6 rats/group; 2 mg/kg × 3, N = 5–6 rats/group). *P < 0.05, **P < 0.01 and ***P < 0.001 vs. the SAL group at the same time point. **P < 0.01, indicating the first HD injection vs. the second or third HD injection. n.s., not significant, indicating the first LD injection vs. the second or third LD injection. #P < 0.05, indicating the animal group with 10 mg/kg × 3 vs. the group with 2 mg/kg × 3. b Time course of Tcor response to MDMA binge injection. X-axis represents time in hours, starting at 0 as given the first drug administration while y-axis represents changes in Tcor from baseline (38.54 ± 0.31 °C, N = 22). *P < 0.05, and ***P < 0.001 vs. the SAL group at the same time point. n.s., not significant, indicating the animal group with 10 mg/kg × 3 vs. the group with 2 mg/kg × 3