Cognitive assessment. Results indicate that cognitive deficits associated with TBI were ameliorated after transplantation of hADSCs in both young and aged rats in reversal training relative to vehicle and sham control. One-way ANOVA revealed significant treatment effects in the young (F(3,28) = 3.95, p < 0.0185; Bonferroni's test, p < 0.05) and aged (F(3,28) = 3.149, p < 0.01; Bonferroni's test, *p < 0.05) rats. CM treatment decrease the cognitive-associated TBI impairments only in young rats relative to vehicle and sham controls (p < 0.05). A and C shows escape errors (mean ± SEM) of young and aged rats, respectively, to find the hidden platform in the RAWM for days 1–3 (4 blocks per day; a block is 2 trials) and for reversal testing on day 4 (trials 1–4). B and D show trial 4 from the reversal training for young and aged rats, respectively.