Figure 4.
The role of DA in fear memory consolidation is mediated by D5 receptors. Experimental design was as depicted in Figure 1A using intense shock (1 mA). A, B, Either saline (Sal) or a D1/5 antagonist (SCH, 30 μg/kg) was administered to wild-type (WT) and β receptor knock-out (KO) mice. For β2 mice, p = 0.016 for the main effect of treatment; p = 0.0044 for the main effect of genotype; and p = 0.0006 for the interaction of treatment and genotype (5/group). C, Sal was administered to WT and β1,2 double KO mice. No significant difference was observed (5/group). D, E, Either Sal or a β2 antagonist (ICI, 30 μg/kg) was administered to WT and DA receptor KO mice. For D5 mice, p = 0.004 for the main effect of treatment; p = 0.0006 for the main effect of genotype; and p = 0.029 for the interaction of treatment and genotype (5–8/group). #p < 0.001.