Figure 3.

Chronic microvascular pathology following blast exposure. In (A) a section of the hippocampal dentate gyrus is shown from a rat sacrificed 6 months after receiving three 74.5 kPa blast exposures. Sections were immunostained for collagen IV without pepsin pretreatment and counterstained with DAPI as in Figure 2. Note the prominent vascular staining despite the lack of pepsin treatment. Arrows indicate strictures in the vessels. In (B) an electron micrograph is shown taken from the frontal cortex of a rat that received three 74.5 kPa blast exposures and was sacrificed 6 months after the last exposure. Note the amorphous material in the lumen creating a near complete occlusion (asterisk). The vessel also becomes narrowed (arrow). The brain parenchyma surrounding the vessel appears normal. Electron microscopy was performed as described in Gama Sosa et al. (57). Scale bar: 25 μm (A); 2 μm (B).