Representative images of leukocyte migration into the brain 24 h post-controlled cortical impact (CCI). (A) No leukocytes migrated into the contralateral hemisphere. (B,C) Following CCI, leukocytes accumulated in the ipsilateral hemisphere. These leukocytes migrated predominantly into the contusion core (C), whereas they were nearly absent from the pericontusional penumbra (B). The leukocytes in the penumbra are indicated by the red arrows. Leukocytes were labeled using an anti-CD45 antibody.