Researchers investigate the ability of lower animals like the salamander to regenerate limbs and organs with the hopes that some of these mechanisms also exist in humans, just turned off at some point in our evolutionary history. Even if this is not the case, it may be that a greater understanding of the mechanisms of salamander regeneration will lead to ways to improve human regenerative capacity.
Salamanders' immune systems are key to their remarkable ability to regrow limbs, and could also underpin their ability to regenerate spinal cords, brain tissue and even parts of their hearts. [Researchers] found that when immune cells known as macrophages were systemically removed, salamanders lost their ability to regenerate a limb and instead formed scar tissue. "Now, we need to find out exactly how these macrophages are contributing to regeneration. Down the road, this could lead to therapies that tweak the human immune system down a more regenerative pathway."
Salamanders deal with injury in a remarkable way. The end result is the complete functional restoration of any tissue, on any part of the body including organs. The regenerated tissue is scar free and almost perfectly replicates the injury site before damage occurred. There are indications that there is the capacity for regeneration in a range of animal species, but it has, in most cases been turned off by evolution. "Some of these regenerative pathways may still be open to us. We may be able to turn up the volume on some of these processes. We need to know exactly what salamanders do and how they do it well, so we can reverse-engineer that into human therapies."