Mouse model of closed head injury (rCHI) was assessed for the effect of single hit vs. repetitive hits (3 hits) on the behavioral, biochemical and neuroproteomics changes at the acute (3 days) and sub chronic (7 days) time points in the cortex and hippocampus brain regions. This study will assess the mechanisms of repetitive hits in mild TBI on developing CTE like phenotype including tau aggregation and other pathological outcomes.