Male Dark Agouti rats and C57BL6/J mice were induced with standard EAE and motor scores were assessed thereafter across the timecourse shown. Panel A: For rats, (+)-NTX (18 mg/kg/day), FTY720 (1 mg/kg/day) or DMSO in SC osmotic minipump was initiated on Day 14 post-MOG, continuing through day 28 (see gray rectangle indicating span of drug delivery). (+)-NTX failed to reverse motor disturbances, whereas the clinically-effective MS drug and positive control FTY720 succeeded to reversed motor disturbances (main effect of drug: F(2,28)=9.66 p<0.0001). Panel B: For mice, XT-203 (30 mg/kg/day) or DMSO was initiated on day 14 post-MOG continuing until day 22 (see gray rectangle indicating span of drug delivery). Similar to the results with (+)-NTX for rats, XT-203 also failed to reverse motor disturbances in mice. N=5–9/group.