Figure 4.

GT1b and CSF-1 do not induce mechanical hypersensitivity in female mice. (a) The mechanical threshold was measured for 1 week following intrathecal injection of GT1b (25 µg/5 µl) or CSF-1 (100 ng/5 µl) in female mice (n = 6 for vehicle, n = 8 for GT1b, n = 10 for CSF-1) and (b) the areas under the threshold line were calculated. Female L5 spinal cord tissues were isolated 3 days after intrathecal injection of GT1b (25 µg/5 µl) or CSF-1 (100 ng/5 µl). (c) Coronal section of L5 spinal cord was immunostained with Iba-1 antibody and representative images are shown (n = 3 for each group; scale bar, 200 µm). (d) The fluorescent intensity of Iba-1 was measured and (e) Iba-1+/DAPI+ cells were counted. (f) The transcript levels of IL-1β, TNF-α, Nox2, CSF-1R, Ctss, and IRF5 were measured. Data are presented as mean ± SEM (one-way ANOVA, *** p < 0.0001, ** p < 0.001, p < 0.005 vs. vehicle at each time point). (g) The fold induction levels of each transcript in GT1b-injected male and female mice were compared. Data are presented as mean ± SEM (Student’s t-test, ***p < 0.001, **p < 0.01, p < 0.05).