Figure 3.

CREST knockdown in the NAc core using morpholino impairs cocaine CPP. A, Quantified Western blot data showing CREST protein levels following intra-NAc core morpholino infusion. Morpholino against CREST in the NAc core results in a significant knockdown of CREST protein 2 and 6 d postinfusion. B, Cocaine-CPP expression indicated by mean PS (CS+ − CS−) ± SEM. At 5 mg/kg cocaine-HCl training dose, anti-CREST morpholino mice (depicted as Anti-CREST in figure) show significantly attenuated PS compared with Scrambled morpholino control (depicted as Control in figure). C, At 5 mg/kg cocaine-HCl training dose, anti-CREST animals showed similar locomotion compared with Controls. D, Left, Representative image of CREST (red) expression in the 5 mg/kg cocaine-HCl CPP mice that had received intra-NAc infusion of Control or anti-CREST. Nuclei (blue) were counterstained with DAPI. Right, Mean intensity of CREST immunofluorescence from NAc core. There was a significant knock down in CREST in anti-CREST animals compared with Control. E, Left, Representative Western blots showing reduced levels of CREST protein (55 kDa) with GAPDH as a loading/transfer control in the same animals. Right, Quantification of anti-CREST Western blot data. CREST protein was significantly knocked down in anti-CREST animals compared with Control. F, At 10 mg/kg cocaine-HCl training dose, no differences in PS were seen between groups. G, At 10 mg/kg cocaine-HCl training dose, anti-CREST animals showed similar locomotion compared with Controls. For time course experiment, n = 6 per hemisphere per day. For 5 mg/kg cocaine CPP experiment, n = 12 for Control and n = 11 for anti-CREST. For 10 mg/kg cocaine CPP experiment, n = 11 for Control and n = 10 for anti-CREST. *p < 0.05, **p < 0.01.