Figure 6.

Regulation of cocaine CPP by NFκB signaling. A, Cocaine CPP (time in cocaine-paired chamber minus time in saline-paired chamber) was measured after intra-NAc injections of HSV-GFP, -IKKdn, or -IKKca in male C57BL/6 mice. Animals infected with HSV-IKKdn had decreased preference for 5 and 10 mg/kg cocaine (*p < 0.05, ANOVA, n = 8–16). B, Enhanced levels of CPP after a prior course of cocaine exposure, as seen in the GFP and IKKca groups (p < 0.05, Student's t test, n = 8–16). In contrast, expression of IKKdn, during chronic cocaine pretreatment, prevents this enhancement of cocaine CPP. Below each graph, in A and B, is the timeline for CPP and CPP sensitization paradigms. For baseline CPP, mice were injected with intra-NAc infusions of HSV-IKKca, -IKKdn, or -GFP and conditioned for cocaine CPP starting 3 d after HSV infusion (A). For CPP sensitization, mice were pretreated with cocaine (20 mg/kg, i.p. for 4 d) at the onset of HSV expression, and after 3 additional days without treatment, animals received CPP training with 5 mg/kg cocaine (B).