Fig. 4

Relative gene expression in the ventrolateral periaqueductal gray (vlPAG). a represents a diagram of the ventrolateral periaqueductal gray region that was taken for RNA extraction, cDNA synthesis, and real-time PCR analysis. Males and females were treated with either water (n = 8 per sex) or minocycline (n = 8 per sex; 50 and 25 mg/kg 12 h later) then treated with morphine (4 mg/kg) or saline s.c. Tissue was collected 20 min post morphine administration. Data were analyzed using a 2 × 2 × 2 ANOVA with sex, morphine treatment, and minocycline treatment as variables. Main effects and interactions are depicted as indicated below. Graphs represent the mean ± SEM. b shows the graph of relative gene expression analysis using GFAP. Number sign represents a main effect of sex (p < 0.05). c depicts the gene analysis for CD11b, TLR4, and IL-β in the vlPAG. TLR4 shows a main effect of sex (^# p < 0.05) and an interaction between sex and minocycline treatment (*p < 0.05). d represents the relative gene expression analysis of fractalkine receptor CX3CR1 and its ligand CX3CL1. Both show a main effect of sex (^# p < 0.05)