Supplementary Figure 4: AC activity in the spinal cord was similar between WT and V1b-/- mice after repeated morphine administration.

Morphine (10 mg/kg/day, s.c.) was administered daily for 5 days. On the 6th day, lumbar spinal cord was obtained for cAMP measurements. By two-way ANOVA, forskolin (F3,56 = 73.888, P < 0.0001), but not mouse genotype (F1,56 = 1.299, P = 0.259), had significant influence on cAMP levels. Graphs represent the mean ± S.E.M.