IL-6 antibody (1:1,000 dilution, Abcam, Cambridge, MA) was used to recognize IL-6 (24 kDa). PSD-95 antibody (1:1,000, Cell Signaling, Danvers, MA) was used to detect PSD-95 (95 kDa). Antibody anti-β-Actin (1:10,000, Sigma, St. Louis, MO) was used to detect β-Actin (42 kDa). Western blot quantification was performed as described by Xie et al.32 (link) Briefly, signal intensity was analyzed using a Bio-Rad (Hercules, CA) image program (Quantity One). We quantified Western blots in two steps, first, we used β-Actin levels to normalize (e.g., determine the ratio of IL-6 to β-Actin amount) protein levels and control for loading differences in the total protein amount. Second, we presented protein level changes in mice in the CFA injection group as a percentage of those in the control group. One-hundred percent of protein level changes refer to control levels for the purpose of comparison of experimental conditions.