FIG. 7.

Acute increase in IL-1β immunostaining after mild injury is associated with microglia. Increase in IL-1β staining was largely associated with Iba-1⁺ microglia, although signal was also detected in astrocytes. (A) Bright field images taken of sections from mCCI (a and c) and mFPI (b and d) injured animals immunostained with anti-IL-1β Abs and detected using a biotinylated secondary and visualized with a peroxidase-conjugated tertiary Ab. Minimal IL-1β immunoreactivity was detected in sham animals (a and b), whereas there was a robust increase in staining at 3 h postinjury (c and d) that largely subsided by 24 h postinjury (not shown). Scale bar: 200 μm. (B) Confocal image taken of the cortex underlying the injury site 3 h post-mFPI. Section was triple-immunostained for microglial marker Iba-1 (red), astrocyte marker GFAP (blue), and IL-1β (green). Colabeling is indicated by yellow coloring in the merged panel. Arrowheads, Iba-1⁺/IL-1β⁺ microglia; arrow, Iba-1⁺/IL-1β⁻ microglia; asterisk, GFAP⁺/IL-1β⁺ astrocyte. IL, interleukin; Iba-1, ionized calcium binding adaptor molecule 1; mCCI, mild controlled cortical impact; mFPI, mild fluid percussion injury; Abs, antibodies; GFAP, glial fibrillary acidic protein. Color image is available online at www.liebertpub.com/neu