Fig. 6.

Effect of selective D₂, D₃, or D₄ antagonists on amphetamine-stimulated rearing behavior. Rearing Behavior refers to the number of amphetamine-stimulated rearing episodes during the 30 min poststimulant observation period minus the number of rearing episodes during the 30 min prestimulant observation period (see Materials and Methods). For drug name abbreviations and dosages, see the legend to Figure 3. Statistically significant inhibition of rearing was observed only for 10 mg/kg of L-741,626, whereas U-99194A significantly increased rearing (*significantly different from VEH).