Figure 2. RXRα expression levels in NAc are not regulated by acute cocaine but correlate with markers of striatal activity and plasticity.
(A) Experimental design, using male and female mice (n = 4-5/group).
(B) Rxra mRNA levels were not significantly regulated after acute cocaine exposure (LMM-ANOVA: main effect of Drug: F1,31 = 0.8185, p = 0.3726; interaction Drug:Time: F1,31 = 2.5762, p = 0.1186).
(C) RXRα protein levels in whole tissue lysates were not significantly regulated after acute cocaine exposure (LMM-ANOVA: main effect of Drug: F1,32 = 0.1004, p = 0.7534; interaction Drug:Time: F1,32 = 0.4864, p = 0.4906).
(D) RXRα protein levels in nuclear fractions were not significantly regulated after acute cocaine exposure (LMM-ANOVA: main effect of Drug: F1,32 = 0.4631, p = 0.2353; interaction Drug:Time: F1,32 = 0.0070, p = 0.9340).
(E) Summary heatmap showing that Rxra/RXRα levels correlated strongly with other genes/proteins implicated in striatal function – including several IEGs – across saline only, cocaine only or all samples (Pearson’s r, * p < 0.05, ** p < 0.01, *** p < 0.001, **** p < 0.0001).
(F) Representative example of Rxra mRNA levels correlation with the IEG Zif268 (across saline samples only: Pearson’s r = 0.83, p < 0.0001; across cocaine samples only: Pearson’s r = 0.73, p = 0.0002; across all samples: Pearson’s r = 0.73, p < 0.0001).
(G) Representative example of RXRα protein levels correlation with active transcription factor pCREB (across saline samples only: Pearson’s r = 0.73, p = 0.0003; across cocaine samples only: Pearson’s r = 0.40, p = 0.0844; across all samples: Pearson’s r = 0.51, p = 0.0007).
(H) Representative example of RXRα nuclear levels correlation with pCREB (across saline samples only: Pearson’s r = 0.29, p = 0.2148; across cocaine samples only: Pearson’s r = 0.54, p = 0.0130; across all samples: Pearson’s r = 0.43, p = 0.0061).
Representative Western Blot pictures for RXRα and control actin and TBP bands are attached to the corresponding quantifications. Bar graphs represent mean ± SEM after combining male and female data. Correlation graphs represent regression line with its 95% confidence interval.