Figure 6.
Morphine-dependent increase in colocalization of GIRK2 and PSD95 requires activated CaMKII. Hippocampal neurons (20 DIV) were exposed to 100 μm morphine for ∼18 h and during the last 2 h were either treated with the selective CaMKII inhibitor KN-93 (10 μm) and morphine or with the inactive peptide KN-92 (10 μm) and morphine. A–C, Representative images show immunostaining for GIRK2 and PSD95. KN-93 but not KN-92 or the vehicle DMSO prevents the morphine-dependent increase in GIRK2 colocalization with PSD95. Scale bar, 10 μm. D, Bar graph shows the mean colocalization ratio (±SEM) with the numbers in the bars indicating the number of dendritic regions analyzed. *, p < 0.05, one-way ANOVA followed by Bonferroni post hoc test for significance.