G-CSF treatment accelerates extinction. A, Schematic for experiment 1. B, Acquisition of active responding for cocaine (0.8 mg/kg/infusion, FR1) for rats later assigned to PBS or G-CSF groups showed no group differences (F(1,11) = 0.79, p > 0.05). C, Pretreatment groups also did not differ on inactive lever presses (F(1,11) = 0.48, p > 0.05). D, During extinction injections of G-CSF reduced lever pressing on the previously active lever (F(1,11) = 5.37, p < 0.05) but did not affect rates of inactive lever pressing (E, F(1,11) = 0.10, p > 0.05). F, Locomotor data during extinction show no effect of G-CSF on general activity (F(1,11) = 0.32, p = 0.58). All data presented as means ± SEM, * p < 0.05, main treatment effect.