Radial Glia and Cell Heterogeneity Across The Lizard Central Nervous System: Distal Spinal Cord Rupture Does Not Induce a System‐Wide Response

Radial glia are resident neural stem/progenitor cells of the central nervous system of many non‐mammalian species. Radial glia are capable of spontaneously generating new neurons, and are considered to be crucial for both brain development and injury‐mediated regeneration. Recently, radial glia have also been identified in the tail spinal cord of the lizard Eublepharis macularius (the leopard gecko), a species capable of tail spinal cord regeneration. Here, we investigated whether similar populations of radial glia were present within the body spinal cord (bSC) and brain. Using a bromodeoxyuridine pulse‐chase strategy, we determined that label‐retaining cells were found throughout the bSC and the forebrain following a 20‐week chase. Next, we established that populations of cells lining the central canal (of the bSC) and ventricular system (of the brain) express a panel of radial glia markers, including the transcription factor SOX2 and the intermediate filaments GFAP and Vimentin. However, Vimentin expression was conspicuously absent from the diencephalon (except for the hypothalamic eminence), as well as the midbrain and hindbrain. Further, cell populations lining the central canal of the bSC include both radial glia and cells with a neuronal phenotype (as evidenced by expression of the neuronal marker HuCD). An identical diversity of cell types is also reported for in the regeneration‐competent tail spinal cord. Finally, we determined that constitutive proliferation by cells lining the central canal (of the bSC) and the ventricular system (of the forebrain) are essentially unaltered in response to distal central nervous system injury (tail spinal cord rupture as a result of tail loss). Combined, our data demonstrates that radial glia are present throughout the central nervous system of the gecko, that the bSC is essentially identical to that of the tail, and that the bSC and forebrain are resilient to distal spinal cord injuries. Support or Funding Information Natural Sciences and Engineering Research Council Discovery Grant 400358 (MKV), Canadian Foundation for Innovation Leaders Opportunity Fund 25371(MKV) This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal .