Characterizing Expression of a Neuron Specific Protein in the Regenerating Tails of Axolotls

NeuN is a highly conserved protein that has been considered a reliable marker of post-mitotic neurons for decades. However, recent studies have shown that injury, including disease and axotomy, can decrease NeuN expression. The absence of NeuN expression leads to the misidentification of neuronal death, although cells are alive or have regenerated. This is especially problematic for studies attempting to assess neuronal damage following injury and the success of subsequent therapies in the case of, for example, stroke victims. In my study, axolotls, which are fully capable of regenerating the spinal cord and all related tissues, were used to model neuronal death and recovery. Here, the tip of the tail was amputated, allowed to regrow, and amputated a second time in order to facilitate injury of the spinal cord its effects on the protein. In addition, four age groups were used to assess differences in NeuN expression, ranging from juvenile to adult axolotls. Unlike humans and many other vertebrates, axolotls are neotenous and retain juvenile characteristics into adulthood, although some regenerative capabilities may be more robust earlier in life. Therefore, this study will help us to better understand the nature of the NeuN protein, specifically how it reacts to neuronal injury and may change as axolotls mature.