Fig. 2.
Systemic blockade of D1 and D2 receptors during the incremental exercise test and open field. (a) Mean running time during the incremental test after systemic (i.p.) injection of the D1 antagonist SCH23390 (0.1 and 0.2 mg/kg). Data: SCH23390: 0 mg/kg: 36.75 ± 2.52 min (n = 14, blue bar), 0.1 mg/kg: 16.67 ± 3.74 min (n = 11, red bar), and 0.2 mg/kg: 5.23 ± 0.23 min, (n = 5, red bar). *p < 0.0001 vs 0 mg/kg, Tukey post hoc test after significant one-way ANOVA, F2,27 = 23.2, p < 0.0001. (b) Mean running time during the incremental test after systemic (i.p.) injection of the D2 antagonist raclopride (0.5 and 1 mg/kg). Data: 0 mg/kg: 36.75 ± 2.52 min (n = 14, blue bar), 0.5 mg/kg: 17.19 ± 3.99 min (n = 12, white bar), and 1 mg/kg: 8.78 ± 0.78 min (n = 5, white bar). *p < 0.001 vs 0 mg/kg, Tukey post hoc test after significant one-way ANOVA, F2,28 = 17, p < 0.0001. (c) Mean running time during the incremental test after systemic (i.p.) injection of SCH23390 (0.1 mg/kg) plus raclopride (0.5 mg/kg). Data: 0 mg/kg: 36.75 ± 2.52 min (n = 14, blue bar) and SCH23390 + raclopride: 5 ± 0 min (n = 8, red bar). t20 = 9.4, *p < 0.0001, unpaired t test. (d) Locomotor activity during an open field test, comparing the effects of systemic (i.p.) injections of vehicle (blue bar), SCH23390 (0.1 mg/kg, light red bar), raclopride (0.5 mg/kg, white bar), and SCH23390 (0.1 mg/kg) plus raclopride (0.5 mg/kg, dark red bar). Data: vehicle: 313 ± 23.86 (n = 6), SCH23390: 67.67 ± 31.85 (n = 6), and raclopride: 130 ± 21.25 (n = 6), SCH23390 + raclopride: 7.14 ± 1.95 (n = 7). *p < 0.0001 vs vehicle, #p = 0.0027 vs raclopride, Tukey post hoc test after significant one-way ANOVA, F3,21 = 37.6, p < 0.0001. Diamonds represent individual values