Article Figures & Data
Figures
- Fig 1.
Longitudinal changes in FA after CHI. A, Automatically segmented ROIs deep to the site of impact on 3 consecutive slices show the cortex (green), white matter (red), and subcortical tissue (blue). Longitudinal follow-up during the first 50 days shows the evolution of mean FA values across time, which differ between white matter (B) and gray matter (C–E) structures, as well as important differences between single and double injury. Data are means; ‡ indicates P < .05 versus the sham; asterisk, P < .05 versus baseline (day 0 [D0]).
- Fig 2.
No focal hemorrhage or contusion on conventional MR imaging after experimental CHI. T2-weighted imaging and susceptibility-weighted imaging with in-plane resolution of 78 μm obtained at 7T on day 1 and day 50 after single (A) and double (B) CHI show no contusion, edema, or microhemorrhage. One representative animal from each group for the longitudinal study is shown here.
- Fig 3.
Cortical loss after experimental CHI. There is a clear decrease in cortical volume as measured on T2-weighted images 50 days postinjury compared with baseline (A), with a greater percentage volume change after double injury (n = 12) compared with sham surgery (n = 9) and single injury (n = 12). Reduction of cortical volume is associated with the number of impacts. Data are means. ‡ indicates P < .05 versus the sham; #, P < .05 versus the single CHI; SMCx, sensorimotor cortex.
- Fig 4.
Behavioral deficits after CHI. mNSS (A) and beam-walking duration (B) after single and double CHI compared with sham surgery. In single-injury rodents, the mNSS score and beam-walking duration follow a similar time course compared with animals in the sham group; whereas in double-injury rodents, the mNSS score and beam-walking duration both increase significantly after CHI by day 7 and do not resolve by day 50. Locomotive activity as measured by movement duration (C) and travel distance (D) in the open-field trial after single and double CHI is impaired and persisted at day 50 after double injury. Data are means. ‡ indicates P < .05 versus the sham; asterisk, P < .05 versus baseline (day 0 [D0]); #, P < .05 versus the single CHI.
- Fig 5.
Astroglial and microglial expression in the cortex and hippocampus underlying the impact region after CHI. A, GFAP-positive staining and quantification of GFAP expression in the cortex (B) and hippocampus (C) after CHI. D, CD 68–positive staining and quantification of CD 68 expression in the cortex (E) and hippocampus (F) after CHI. As early as 24 hours after both single and double CHI, elevated GFAP is observed in both the cortex and hippocampus deep to the impact site. CD 68 expression indicating neuroinflammation is also observed at 24 hours postinjury and sustained to day 50 in the cortex after double CHI. Scale bar, 40 μm.
