Scar-free healing and axon regeneration after spinal cord injury in neonatal mice is orchestrated by microglia

By utilizing single-cell analysis at different times after P2 injury(0, 3, and 5 dpi), we discovered that neonatal microglia undergo a transient activation and play at least two critical roles in scar-free healing. First, they transiently secrete fibronectin and its binding proteins, to form extracellular matrix bridges that ligate the severed ends. Second, neonatal, but not adult, microglia express a number of extracellular and intracellular peptidase inhibitors, along with other molecules involved in inflammatory resolution. Five 10X genomics chromium samples from neonatal mice microglia cells with 3 conditions (0, 3, and 5 dpi).