Abstract
Spinal cord injury (SCI) results in gliosis and limited cellular regeneration. Multipotent progenitor cells have significant potential for nervous system regeneration. However, little is known about adult neural stem and progenitor cells. In the present study, we focus on oligodendrocyte. For this purpose, we choose NG2 proteoglycan, which is a marker of oligodendrocyte progenitors.SD rats were divided into a SCI group (n=25) and a sham-operated group (n=5). In the injury group, laminectomy was performed at Th11-12 and contusive compression injury was created by applying a weight of 30 g for 10 min. Rats were sacrificed at 24 h, and 1, 4, 8 and 12 weeks post-injury. Frozen 20μm sections of tissue 5 mm rostral and caudal to the epicenter of injury were prepared. Immunoistochemistry was performed using antibodies against NG2, GFAP and 3CB2. At 4 weeks after injury, NG2-positive glial cells arose from below the pial surface as bipolar cells with processes extending throughout the entire white matter. NG2 expression peaked at 4 weeks after injury, showing a 7-fold increase compared to the 24 h after injury. The NG2-positive cells with processes which increased in the white matter of the spinal cord were GFAP-positive and also co-localized with 3CB2 antigen. These results suggest that NG2 positive cells which derived from subpial layer, may have some lineage to RG and astrocyte progenitor cells after SCI in adult rodents. [J Physiol Sci. 2007;57 Suppl:S141]
