Figure 5. AAV-Mediated β-arrestin2 knock-down (β-arrestin2-/-) aggravates AIMs induced by L-dopa in 6-OHDA-lesioned rats. Rats were rated for AIMs on days 2, 4, 6 and 8 after the striatum-targeted injection of β-arrestin2-/- (total n=40 rats). (A) Total AIM scores measured after L-dopa or saline injection in all groups; (B) axial AIM score; (C) limb AIM score; (D) orolingual AIM score; (E) Forelimb functional test. @ P<0.0001, * p < 0.05 vs LID + sh.EGFP group; ** P<0.01 vs PD group (n = 8 for each group, Kruskal Wallis followed by Dunn’s test for multiple comparisons).