Dextran uptake by dystrophic endings demonstrates activity in vivo well after injury. A, B, Confocal images of dystrophic endings of axons (arrows) in spinal cord that were able to take up dextran-Texas Red 1 d after a lesion. C, D, Confocal images of dystrophic endings (arrows) of spinal cord axons that took up dextran-Texas Red 7 d after lesion. Some of these active endings contain large vacuoles (A, C). Scale bar, 10 μm.