Effect of NaHS pretreatment on AC protein expression in the brain regions of morphine-treated mice. (A) striatum; (B) prefrontal cortex; (C) hippocampus. Mean±S.E.M, n=3–4. *p<0.05, ***p<0.001, versus Con; #p<0.05, versus Mor. Con, control; Mor, morphine; S, NaHS; AC, adenylate cyclase.