Figure 4.

Histology. (a) T₂ maps of a brain slice of a rat from the SD group at post-SAH days 1 (top) and 3 (bottom). A subcortical lesion was present at post-SAH day 1, before SD induction, and a cortical lesion became apparent at post-SAH day 3, i.e. two days after SD induction. Regions of interest in early injured tissue (region 2), delayed injured tissue (region 4), and unaffected contralesional counterparts (regions 1 and 3, respectively) are displayed in the post-SAH day 3 image. (b) Nissl staining of four regions of interest (20X magnification) as displayed in Figure 3(a). Contralesional regions (1 and 3) show unaffected healthy tissue. Tissue with early injury after SAH (i.e. before SD induction) shows clear signs of blood extravasation into the parenchyma (reddish brown areas), neuronal damage and/or death, as shown by the majority of shrunken, pyknotic nuclei (region 4). The extent of tissue injury is milder in the region with delayed lesion manifestation (i.e. after SD induction) (region 2), with only a few dark, shrunken nuclei interspersed in the parenchyma. Scale bars: 300 µm.