DAF treatment reduces interaction of C3a-C3aR in the rat brain tissue after blast exposure. Representative photomicrographs of C3a-C3aR interaction in frontal grey matter ( a ) and hippocampus (DG) ( b ) of frozen sections stained with anti-C3a (red) and anti-C3aR (green) antibodies. Original magnification of × 200 (grey matter) and × 400 (DG). Scale bars, 200 μm (grey matter) and 100 μm (DG). n = 8 for control, 3 and 24 h experimental groups. n = 5 for 48 h experimental groups.