Altered collagen IV immunostaining in the microvasculature of blast-exposed animals. Different magnifications of a focal lesion in the visual cortex from a rat that received 3 × 74.5 kPa blast exposures and was euthanized 10 months after the last blast exposure. Sections were immunostained for collagen IV without pepsin pretreatment (A, C). Nuclei were stained with DAPI (B, D). Asterisks indicate the site of the focal cortical lesion. Note the extensive collagen IV immunostaining extending from the lesion. Scale bar: 750 μm A-B; 400 μm C-D.