Scaling Axonal Injury and Unconsciousness Thresholds from Infant to Toddler to Pre- Adolescent Children

tightness by affecting tight junction protein stability. Results using primary human brain microvascular endothelial cells and a novel vector based assay for the evaluation of occludin and claudin-5 protein stability showed a significant increase in the half-life of these proteins when GSK3b was inactivated. Of the inhibitors tested, GSK3b inhibitor SB216763 (5lM) and LiCl (5 mM) showed the best efficacy by preventing occludin and claudin-5 degradation by approximately 32% and 43% respectively. The effect on the tight junction proteins was further validated using transendothelial electrical resistance (TEER). Inhibition of GSK3b produced a gradual and sustained increase in TEER (as high as 22% over baseline). This phenomenon was attributed to the effect on turn-over and not as result of transcriptional regulation since mRNA levels of occludin, claudin-5 were unchanged. These analyses led us to test whether GSK3b inhibitors identified to stabilized tight junction proteins (such as SB216763) would offer protection of the BBB in our experimental CCI-TBI model. The results of BBB permeability by fibrinogen leakage, showed an approximately 70% decrease in barrier permeability at 24hrs when the selected inhibitor was present following moderate CCI-TBI.