The Temporal and Spatial Distribution Patterns of Necrotic and Apoptotic Cells in and Around the Spinal Cord Injury Site †

Background: Acute spinal cord trauma management necessitates understanding the primary and secondary injury mechanisms at different timepoints. Objectives: To characterize the cell death process by examining the temporal and spatial distributions of necrosis and apoptosis in an experimental spinal cord injury model. Methods: Wistar male rats were divided into trauma (n = 30) and sham (n = 6) groups, and a 50 g/cm weight drop contusion design was used. The rats were sacrificed 1, 6, 24, 48, 72, and 168 h after the injury. Every 0.5 cm spinal cord segment was examined cranially and caudally up to a total of 2.5 cm for neuronal and glial damage via the apoptotic count and DNA damage index via morphology and immunohistochemistry using an anti-ssDNA antibody. The results were mapped to visualize the damage extent, intensity, and distribution. Results: The central zone underwent hemorrhage and necrosis one hour after the injury. The apoptotic cells and DNA damage index increased with time (p < 0.001), and specific spatial alterations were observed among the segments (p < 0.001). Mapping the apoptotic cells and DNA damage clearly reflected the injury’s severity and extent. Conclusion: The DNA damage and the apoptotic cell count increase over time were well correlated with the morphology and could easily be elucidated using ssDNA immunostaining.