FIG. 2.

Central infusion of 10 μg/day human insulin-like growth factor-1 (hIGF-1) over 7 days elevates brain levels of hIGF-1 and enhances Akt activation in the hippocampus after controlled cortical impact (CCI). (A) hIGF-1 was detected in the ipsilateral (ipsi) cortex (CTX), and ipsilateral and contralateral (contra) hippocampus (HP) in sham and CCI mice at 7 days post-injury (*p < 0.05, contra HP compared to ipsi CTX or HP). (B) Representative western blot images of phosphorylated Akt (pAkt) and actin, as a control protein, for vehicle (Veh) and IGF-1–treated sham and CCI mice at 7 days post-injury. (C) Infusion of IGF-1 in CCI-injured mice resulted in a significant increase in Akt phosphorylation within the hippocampus at 7 days post-injury, compared to vehicle infusion (*p < 0.005). Optical density (OD) for each pAkt band was normalized to its respective control protein actin band OD; the mean of the triplicate samples for each mouse was normalized to the mean OD value of the vehicle-treated sham group. The results are presented as mean + SEM (n = 5 sham-injured/treatment and n = 9 CCI-injured/treatment). Akt, protein kinase B; SEM, standard error of the mean.