FIG. 2.

Silver staining at 7 days after a second sham insult or mild traumatic brain injury (mTBI). Post-natal day 18 rats were divided into three groups and subjected to (1) two sham insults (S-S), (2) one mTBI, one sham insult (mTBI-S), or (3) two mTBIs (mTBI-mTBI) 24 h apart. (A) Representative views of coronal sections (scale bar = 100 μm) at approximately −3.0 to 4.5 mm bregma. Insets include higher magnification (scale bar = 10 μm) image of axonal silver staining indicated by arrows. (B) Red (cortex), blue (external capsule), and black (corpus callosum) boxes indicate areas of interest, shown in higher magnification in panels A. (C) Proportional area of positive silver staining in rat brains (n = 3/group). Mean ± standard error of the mean, *p < 0.05 vs. S-S, ^§p = 0.09 vs. mTBI-S. Color image is available online at www.liebertpub.com/neu