Fig. 2

IL-6 from CSF mediated widespread pain. A Heatmap showed the alteration of all tested 34 cytokines in CCI-ION’s CSF compared with the sham’s CSF. n = 4/group. B The KEGG analysis for the altered cytokines in the CSF of CCI-ION group. C The ELISA analyzed the concentration of IL-6 in the CSF samples from CCI-ION group and sham group. t test, *p < 0.05, n = 6–10/group. D qRT-PCR revealed a significant increase in mRNA expression level of IL-6 in MDH after CCI-ION. t test, **p < 0.01, n = 8–9/group. E qRT-PCR revealed a significant increase in mRNA expression level of IL-6 in TG after CCI-ION. t test, ****p < 0.0001, n = 8/group. F The workflow for i.c. injection of CCI-ION CSF pre-treated by IL-6 antibody or isotype IgG and relative behavioral test for recipient rats. G The time course of mechanical escape threshold of vibrissal pad for recipient naïve rats receiving CCI-ION CSF pre-incubated by IL-6 antibody or isotype IgG. Two-way ANOVA, **p < 0.01, ***p < 0.001, ****p < 0.0001, n = 7/group. H The thermal withdrawal latency of hind paw for recipient naïve rats receiving CCI-ION CSF pre-incubated by IL-6 antibody or isotype IgG. Two-way ANOVA, **p < 0.01; ****p < 0.0001, n = 7/group. I The mechanical threshold of hind paw for recipient naïve rats receiving CCI-ION CSF pre-incubated by IL-6 antibody or isotype IgG. Two-way ANOVA, **p < 0.01, ****p < 0.0001, n = 7/group. J The workflow for application of different concentrations of IL-6 antibody or isotype IgG for CCI-ION rats. K The escape threshold of vibrissal pad in CCI-ION rats receiving different concentrations of IL-6 antibody or isotype IgG. Two-way ANOVA, **p < 0.01, ***p < 0.001, ****p < 0.0001, vs. IgG, n = 6/group. L, M The thermal withdrawal latency and mechanical threshold of hind paw in CCI-ION rats receiving IL-6 antibody or isotype IgG. Two-way ANOVA, **p < 0.01, ***p < 0.001, ****p < 0.0001, vs. IgG, n = 6/group