Type-1 (Nestin-GFP–/NG2-DsRed+) pericytes accumulate after spinal cord injury in vivo . (A) Spinal cord injury by dorsal funiculus incision in Nestin-GFP/NG2-DsRed mice. Spinal cord transverse and longitudinal sections were analyzed 2 weeks after injury. (B) Mouse spinal cord transverse-sectioned at the level of lumbar segment 5 (L5) (modified with permission from ALLEN Spinal Cord Atlas), illustrating the area where the injury was performed (gray). (C) Quantification of Nestin-GFP–/NG2-DsRed+ and Nestin-GFP+/NG2-DsRed+ cells before and 14 days after injury (n = 3 mice, 10 spinal cord sections from each). (D) Photomicrographs of transverse section at L5, 14 days after injury, illustrating the distribution of Nestin-GFP+ and NG2-DsRed+ cells. Second column shows the images in the first column at higher magnification. GFP and DsRed fluorescence images are illustrated. Top panels, brightfield images; bottom panels, merged images. Note that type-1 pericytes accumulated in the tissue formed after injury, but almost no Nestin-GFP+/NG2-DsRed+ cells were detected in this area. Nestin-GFP+/NG2-DsRed– cells, or ependymal cells, line the central canal in the spinal cord. (E) Photomicrographs of a longitudinal section of a spinal cord 14 days after injury. Nestin-GFP, NG2-DsRed, and their corresponding brightfield, merged fluorescence, and merged fluorescence and brightfield images are shown. Note the higher number of Nestin-GFP–/NG2-DsRed+ cells in the injured area. Scale bars = 100 μm.