Brain tissues were homogenized with lysis buffer using a tightly fitting homogenizer. The homogenates were centrifuged at 12,000×g for 20 minutes, and the protein concentration of the supernatants was determined using the BioRad protein assay. IL-6 protein levels in the brain and serum were measured by enzyme-linked immunosorbent assay (ELISA), according to the manufacture’s instructions (Pierce, Rockford, IL).
