Regenerative potential of zebrafish and mouse central nervous system. Top , representation of the outcomes of brain injury in zebrafish, neonatal and adult mice. In zebrafish, injury is followed by proliferation of radial-glial cells (RGCs), differentiation, neurogenesis, and migration of newly formed neurons to the lesion site. Adult mammals are incapable of this regenerative response and undergo glial and fibrotic scarring at the injury site. Some regeneration is possible in neonatal mice. Bottom , spinal cord injury in zebrafish is also followed by extensive neurogenesis from ependymo radial-glial progenitors (ERGs) around the central canal, glial bridging, and axon regeneration, ultimately resulting in functional recovery. By contrast, in adult mammals, SCI leads to the formation of glial and fibrotic scarring that impedes regeneration and axonal growth across the lesion site, despite some compensatory axonal sprouting. Similar to zebrafish, neonatal mice are capable of axon regeneration after SCI. Figure generated using Biorender
