Quantification of leukocyte-endothelium interaction (LEI) at various depths. (A-C) Number of rolling and adherent leukocytes (left) and aggregates (right) at the indicated depths 8 to 10 h after controlled cortical impact (CCI). At each depth, LEI was measured in four standardized regions of interest (ROI). In ROI 4 at 0 to 50 μm and in ROI 3 at 100 to 150 μm, we observed significantly more rolling leukocytes than in sham-operated animals (A and B left, indicated with an asterisk). In all other ROIs at all three depths, we observed no significant differences in LEI between CCI and sham-operated animals.