Figure 1.

Experimental design and timeline for induction of repeated mTBI and readouts. (A) Diagram showing the location of the closed head injuries (green circle), pCASL imaging slice (orange rectangle), and region characterized by immunohistochemistry (blue rectangle) on a mouse skull diagram. (B) Repeated mTBI consisted of three closed head injuries (CHIs) delivered to the skull surface overlying S1FL. Impacts were delivered at 2 m/s, with a dwell time of 200 ms, to a depth of 1 mm, and using a 1.5 mm impactor tip. Each impact was separated by a 3-day inter-impact interval. Two weeks following the final CHI, mice underwent either electrophysiology or MRI followed by immunohistochemistry. Sham-treated mice underwent the same timeline and surgical procedures, but no impacts. T₂-weighted images of structural damage at two timepoints of the study are shown on the bottom from two mice with alterations that are representative of each timepoint. The left image was acquired 24 h after a single impact, whereas the right image was taken two weeks after the last impact. White arrows indicate the locations to which impacts were delivered.