Figure 8.

G9a and BDNF are involved in pain facilitation of CPP. A, Time course of CFA-induced changes in pain threshold in mice with CeA infusion of lenti-sh-MeCP2 followed by vehicle or the G9a inhibitors (n = 5–6 mice per group); *p < 0.05 and #p < 0.05. B, CPP behaviors in mice conditioned with the subthreshold dose of morphine after CeA infusion of vehicle or the G9a inhibitors (n = 5–6 mice per group). C, Schematic drawing showing representative positions of cannula tips within the CeA for infusions of the G9a inhibitors. D, Changes in baseline pain threshold in mice (n = 10 per group) after CeA infusion of saline or BDNF. E, CPP behaviors in mice conditioned with a subthreshold dose (0.1 mg/kg) or an effective dose (0.3 mg/kg) of morphine without or with knockdown of CeA MeCP2 after CeA infusion of saline or BDNF (n = 5–6 mice per group). F, Changes in pain threshold 3 d after CFA injection in mice with CeA infusion of vehicle or the BDNF inhibitor TrkB-IgG (n = 8 per group). G, CPP behaviors in WT mice conditioned with an effective morphine dose, in WT mice with pain and conditioned with a subthreshold morphine dose, and in MeCP2-overexpressing mice conditioned with the subthreshold morphine dose after CeA infusion of vehicle or TrkB-IgG (n = 5–10 per group). H, Schematic drawing showing representative positions of cannula tips within the CeA for infusions of BDNF and TrkB-IgG. I, Total distance traveled in the open field test in mice before (preinjection) and after injection (post injection) with saline or CFA (n = 6 each group). Scale bars: C, 0.5 mm; H, 0.5 mm.