library_construction_protocol: Spinal cords were micro dissected and 5 mm segments around the lesion site (or the corresponding regions in uninjured spinal cords) were collected. Collected spinal cord was digested to single cell suspension using the Neural Tissue Dissociation Kit (Miltenyi) with papain digestion enzyme. Cell suspensions were collected in flow cytometry buffer, passed through a 70 µm filter, and myelin debris was reduced by centrifugation through a sucrose solution. Cells were resuspended in cytometry buffer and tdTomato expressing cells were sorted into cold DPBS (supplemented with 0.04% BSA) with an Influx cell sorter with a 100 µm nozzle. Sorted cells were processed for library preparation using the Chromium Single Cell 3' Reagent Kit v2, following the manufacturer's (10X Genomics) instructions. 