Figure 2

Cross-sensitization by repeated administration of SCH58261 or DPCPX in habituated C57BL/6 mice. SCH58261 (2 mg/kg/day, i.p.), DPCPX (3 mg/kg/day, i.p.) or DMSO was administered for 14 days. Three days after the last injection of SCH58261, DPCPX or DMSO, mice were challenged with caffeine (10 mg/kg, i.p.) The horizontal locomotor activity was measured for 30 min. a The time course of locomotor activity measured over 10-min intervals. Data represent means ± SEM (n = 3). P < 0.001 versus DMSO-treated group (by two-way ANOVA). b Total locomotor activity counts during the 30-min period following acute administration of caffeine. Data represent means ± SEM. P < 0.01 versus DMSO-treated group (by Student's test). c The time course of locomotor activity measured over 10-min intervals. Data represent means ± SEM (n = 4). Data showed no significant difference between DPCPX-treated and DMSO-treated group.