Autophagosomal activity in vacuolated RMO14+ axonal profiles. A–C) At 2 days after blast, many RMO14+ axonal profiles are also LC3b+ (arrows in the higher magnification views shown in panels B and C). Numerous RMO14+ axonal profiles that are not labeled for LC3b are also present (arrowheads in B). In A, the adjacent gray matter is visible at the bottom of the field of view. D–F) At 3 days after blast, vacuolated RMO14+/LC3b+ axonal profiles (arrows in F) are still common, and some are especially large. Arrowheads in E mark RMO-14+/LC3b-negative labeled profiles. Asterisks in A and D mark small RMO14+/LC3b-negative profiles that, based on their small size and simple morphology, may correspond to fragments of degenerating axons. Small arrows in D mark blood vessels at the midline of this ventral strip of spinal cord. G–I) A long segment of a vacuolated axon appears to be breaking up into separate fragments. Scale bar in G = 100 μm for A, D, and G; 50 μm for B, C, E, F, H and I.