Radial Glia’s Changes in GFAP Expression in Axolotl Spinal Cord Regeneration

While regeneration in amphibians is a ubiquitous phenomenon, in mammals it is rare. Axolotls (Ambystoma mexicanum) have the extraordinary ability to regenerate limbs, tails, retinas, and jaws all throughout their lives. This exotic amphibian species originates in the murky canals of Lake Xochimilco in Mexico. An essential part of axolotl spinal cord regeneration begins with various glial cell (non-neuronal cells of the central nervous system, CNS) activities. We analyzed radial glial cell morphology because these cells potentially act as neural stem cells within the CNS in axolotls and other salamanders. We amputated the distal two centimeters of each tail, then waited for one to two weeks to amputate the regenerated tail portion. Both of these amputations underwent tissue processing, including immunohistochemistry to label glial fibrillary acidic protein (GFAP). GFAP is a marker for radial glia in the ependymal layer of the spinal cord, allowing us to find and analyze these cells. We analyzed changes in GFAP expression before and after the tail amputation. Our preliminary data suggests radial glia are expressing less GFAP once regeneration has begun in the secondary cut; however, further research is needed to make conclusions on this. In studying stem cells within axolotls, we can elucidate the regeneration processes that remain active in amphibians and explore how applicable they can be to humans