Effect of AJN on D
R by immunohistochemical staining and autoradiography. A: Representative staining pictures and effect of AJN on D2R by immunohistochemical staining. B: Representative autoradiograms and effect of AJN on D2R by autoradiography with [125I]-IBZM. Morphine administration reduces D2R expression by about 20%. AJN pre-treatment completely inhibits the morphine-induced D2R decrease. And AJN post-treatment alleviate the decrease in D2R expression in a dose-dependent manner. NS: control group; Mor: morphine group. Data are expressed as the means ± SD (*p < 0.05, **p < 0.01, vs. morphine group; n = 5; Student’s t-test).