Figure 2.
PKA-mediated phosphorylation of DARPP-32 and GluR1 is associated with LID. Sham- or 6-OHDA-lesioned mice were treated with saline, acute l-DOPA, or chronic l-DOPA. Phospho-Thr34–DARPP-32 (a, b) and phospho-Ser845–GluR1 (c, d) were determined by Western blotting (see Materials and Methods). a, c, 6-OHDA-lesioned mice were divided into low dyskinetic (L Dys) and highly dyskinetic (H Dys) according to their total AIM score (see Materials and Methods) using the median value of 28 as cutoff. Top row shows representative autoradiograms. Bottom row is a summary of data represented as means ± SEM (n = 9–13). ***p < 0.001 versus Sham treated with saline; †††p < 0.001 versus H Dys; one-way ANOVA (a, F(4,52) = 38.44; b, F(4,52) = 69.85), followed by Bonferroni–Dunn test. b, d, Simple regression analysis indicating a significant correlation between AIMs and levels of phospho-Thr34–DARPP-32 (b) (r = 0.921; p < 0.001) and phospho-Ser845–GluR1 (d) (r = 0.953; p < 0.001).