Fig. 15

Late chronic ultrastructural alterations in the motor cortex of a blast-exposed rat. a, Arteriolar spasm with partially occluded lumen next to a tear. Endothelial cell with an enlarged nucleus and irregular electron density within the ECM (asterisk) indicative of vascular remodeling and cellular detachment [74], (arrow). Note the degenerating neuropil next to the tear. b-f, Arteriole with irregular discontinuous ECM (arrow in b), attached swollen astrocytic feet (asterisks in c) and apoptotic microglia (arrow in c). Boxed region (c) shown at higher magnification in (d). d, Apoptotic microglia enmeshed in disrupted cytoplasm immediately adjacent to affected vasculature. Note swollen mitochondria along bottom left. d-f, Lack of nuclear membrane in the apoptotic microglia with folded chromatin fibers present in the cytoplasm (arrows d-f). g-i, Enlarged paravascular space, perivascular astrocytic degeneration and empty spaces in the neuropil. Boxed regions are shown at higher magnification (h, i). Arrows in g and h denote membrane damage in a postsynaptic spine and in a presynaptic axonal terminal. Asterisks in i indicate empty spaces within the neuropil. Note intact multisynaptic bouton in perivascular region immediately adjacent to a blast damaged vessel. Scale, 2 µm in a, b, d, g; 4 µm in c; 1.2 µm in e; 600 nm in f and 1 µm in h and i