Digital indirect fluorescent photomicrographs of murine sciatic nerve endoneurial microvessels within 3 hours (Day 0) and 7 days (Day 7) after crush injury in GDNF WT and GDNF CKO mice are shown, with Sham indicating uninjured sciatic nerves. CD31 (green, endothelial cell marker, A, E, I, M and Q) and nuclear marker DAPI (blue, C, G, K, O and S) were performed to identify endoneurial microvessels. Punctuate membrane CLDN4 expression is lost in both GDNF WT and CKO mice immediately after injury, with partial recovery seen in GDNF WT mice only on Day 7. N=2, Scale bar = 2.5 μm.