Figure 6. AAV β-arrestin2 knock-down (β-arrestin2-/-) and LID groups respectively followed by intraperitoneal injection of D1R antagonist (SCH23390) or saline. Rats were rated for AIMs on days 1, 3, 5, 7, 9, 11 and 13 after the injection of SCH23390 and L-dopa. Samples from the striatum of LID, LID plus β-arrestin2-/-, LID plus SCH23390, and LID plus β-arrestin2-/- plus SCH23390 were collected and different downstream markers of the D1R signal pathway were measured by WB. (A) Total AIM scores; (B) axial AIM score; (C) limb AIM score; (D) orolingual AIM score (n = 4 for each group, total 4*4=16); (E) The protein level of phosphor-ERK1/2, phosphor-DARPP32 and FosB by WB. Data are displayed as mean ± standard error; * P < 0.05 vs LID + βArr-/- + SCH23390 group (n = 4 for each group, Kruskal Wallis followed by Dunn’s test for multiple comparisons in AIM scores, ANOVA followed by LSD post-hoc comparisons in proteins detection).