NG2 expression in the dorsal column of wild type animals following lysolecthin injection. Compared to sham-operated animals (A), an increased number of dapi (blue) positive nuclei, as well as increased NG2 expression (red), are observed within the injury site at 1 week (B and D-J) and 6 weeks (C) after lysolecithin injection. Panels D-G depict labeling in the same tissue section with multiple markers. More intense expression of pan-neurofilament (NF, cyan) is seen in axons in the inflammatory region (D-G). NG2 (red) positive cells are seen (1) closely apposed to vessel-like structures (arrowheads), (2) in close proximity to completely or partially demyelinated axons (arrow), as judged by NF (cyan) and MBP (green) staining (F and G), and (3) in association with MBP labeling (asterisk, yellow, F). Each of these patterns of NG2 expression is magnified in the inset panels in F. Double labeling for NG2 along with PDGFR alpha (arrow, Pα, H), CD11b (asterisk, I), or PDGFR beta (arrowhead, Pβ, J) reveals NG2 co-expression by oligodendrocyte progenitors (H), macrophages/microglial cells (I), or pericytes/mesenchymal stem cells (J). Scale bar = 100 μm (A-C), 50 μm (D-G), and 30 μm (H-J).