By assessing the temporal dynamics of the BBB breakdown at 1, 3, 6, 12 and 24 hours after a permanent middle cerebral artery occlusion stroke model, we observe that already within the first hour pericytes exhibit two distinct behaviors: some undergo apoptosis, consistent with prior research,17 while others become activated expressing NG2 and RGS5, and evading apoptotic processes. This evidence concerns the gene RGS5 and Stroke.