PLX5622 treatment did not change the temporal expression of mechanical OIH induced by either constant or escalating dosaging of morphine. Constant morphine dosaging (20mg/kg, i.p./day for 7 days) or escalating dosaging (from 20, 25, 30, 35, 40, 45, 50mg/kg/day) were used to induce OIH in C57BL/6 male mice. PLX5622 treatment started at 5 days before the first dose of morphine. (N=6 mice/group).