Post-trauma accumulation of Ly6G-positive granulocytes and monocytes. (A) Histological sections were divided into fields for the precise quantification of leukocytes in relation to the necrotic tissue in the contusion. In the figures in (B), the necrotic area is separated from the intact penumbra by the white line. The graphs illustrate the number of Ly6G-positive cells in each field at the indicated times following trauma. Leukocytes appeared in the brain only after neuronal cell death had occurred.