Representative images of superficial vessels in following administration of anti-CD18 antibodies or control IgG. (A,B) Rolling and particularly adhering leukocytes and aggregates in cerebral venules 14 h after controlled cortical impact. The animals received either control IgG (A) or anti-CD18 antibodies (B). (C,D) Cerebral microcirculation at lower magnification (note the difference in scale bases compared with A and B). The animals received either control IgG (C) or anti-CD18 antibodies (D). After administration of anti-CD18 antibodies the adherence of both leukocytes and aggregates to the venular endothelium was significantly reduced (B,D).