(A) CFA assay timeline enabling behavioral testing of immediate and prolonged behavioral effects of YM155. D0 through D11 = day 0 through day 11. PD-D1 through PD-D9 = post-drug (YM155 or saline) day 1 through post-drug day 9. (B) Beam break locomotor assay in female mice (naïve; no CFA), assessed at intervals 10 to 60 min after treatment with either saline or YM155 (5 mg/kg); n = 5 to 6 animals per group. Differences not statistically significant by two-way ANOVA with Sidak’s m.c. tests. (C and D) Thermal and mechanical sensitivity thresholds in female mice before hindpaw CFA injection (Pre-CFA), 2 days after CFA [D2 Post-CFA(-drug)], and either 3 days (for thermal) or 4 days (for mechanical) after CFA and 30–60 min after administration of either saline or YM155 (5 mg/kg i.p. daily), referring to the timeline in (A). Data are mean ± SEM from n = 6 animals per group in both panels. *P < 0.05 and ****P < 0.0001 by two-way ANOVA Sidak’s m.c., see also table S2. (E and F) Effect of YM155 (5 mg/kg) on thermal and mechanical sensitivity thresholds in female mice described in (C and D), at later time points, referring to the timeline in (A). BL = baseline, at “D2” (no drug). n = 6 animals per group in both panels. *P < 0.05, **P < 0.01, ***P < 0.001 by two-way ANOVA Sidak’s m.c., see also table S2. (G) Weight of CFA-injected female mice over the course of administration of saline or YM155 (5 mg/kg), referring to the timeline in (A). (H) Effect of hindpaw injection of IFN-β (300U in 25 μL) on contralateral versus ipsilateral mechanical hypersensitivity in male mice at the post-injection times indicated (hr. = hours). Data are mean ± SEM from n = 5 animals per group. **P < 0.01, ***P < 0.001 by two-way ANOVA Sidak’s m.c., see also table S2. (I) Effect of YM155 treatment (5 mg/kg i.p.), initiated at the time of IFN-β injection and continued through day 3 (D3), on mechanical hypersensitivity induced by hindpaw injection with IFN-β (300U in 25 μL) in female mice. BL = prior to IFN-β and YM155 administration. Data are expressed as mean ± SEM from n = 7 to 8 animals per group. ****P < 0.0001 by two-way ANOVA Sidak’s m.c., see also table S2. (J) Effect of two daily administrations of YM155 (2.5 mg/kg i.p.) initiated after Day 1 of IFN-β injection on mechanical hypersensitivity in male mice three days after hindpaw injection of IFN-β (300U in 25 μL). Data are mean ± SEM from n = 7 animals per group. ****P < 0.0001 by two-way ANOVA Sidak’s m.c., see also table S2. (K) Effect of pre-treatment with YM155 (5 mg/kg i.p. once-daily for seven days after BL, before PT-BL measurements) on mechanical hypersensitivity in female mice after paw incision. BL = pre-treatment baseline; PT-BL = thresholds after YM155 administration, pre-paw incision; D1 to D7 = days after paw incision. Data are expressed as mean ± SEM from n = 6 animals per group. *P < 0.05 for two-way ANOVA Sidak’s m.c., see also table S2. (L) Locomotion observed over the course of an hour on the day after paw incision in mice pretreated with YM155 (blue) or saline (black). Data are from n = 6 animals per group.