Fig. 12

Chronic proteolysis of collagen type IV in the brains of blast-exposed rats. Unmasking collagen type IV epitopes in the vasculature of normal mature adult rodent brain for immunohistochemical detection requires protease pretreatment [37]. Shown are micrographs of collagen type IV-immunostained sections of brains of control and blast-exposed rats at 13 months post-blast exposure without protease treatment. a, b, Vasculature in the somatosensory cortex of control a and blast-exposed b rats immunostained for collagen type IV (red). Note the absence of collagen IV staining in the section from the control rat a. c A small vessel immunostained for collagen type IV (red) showing MMP-9 vescicles (green, arrow). d–f Collagen type IV (red) and GFAP (green) immunoreactivity of the somatosensory cortical vasculature of blast-exposed rats in the absence of protease pretreatment. Note the tortuosity of the vessel shown in e and the neuronal expression of GFAP (arrows) in this region f. DAPI, blue. Scale bar, 140 µm for a, b; 20 µm for c–f