The possibility of humans regrowing lost limbs or damaged or non-functioning organs may be a possibility in the future, after a team of scientists studying how Salamanders regrow lost back legs discovered how the process happens.

The salamanders seem to possess cells that remember, in part, how to make bone, muscle or nerve tissue the team have found. The actual process of how this happens is still unknown though at the present time however.

The main obstacle to overcome in discovering how nature gives the amphibians legs again is to discover why the salamander has this quality and mammals do not. However, the fact that the scientists have observed the cells regenerating can give some element of hope to amputees for the future.

Salamanders blood vessels contract very quickly to limit bleeding when a limb is cut. Their skin cells quickly cover the wound and form a group which is called a ‘blastema’. Initially the team presumed these cells must be stem cells, which are found in early human embryos and which are able to start growing into any kind of cell in the body. In healthy human embryos they change quickly into different cell types in the womb (such as skin, nerve, muscle), usually within a matter of days.

The blastema are not actually stem cells however. Each cell within it does not have the same power to differentiate into anything as stem cells do but instead seem to be pre-programmed to grow the necessary parts of the legs in the event that the limb is lost. At the place where the limb has been severed, the remaining cells have the ability to regress into embryonic programs of tissue formation and produce the leg.

It may be possible to produce and replicate blastemas in other animals and eventually people someday, according to the scientists working on the study. Every animal can regenerate to some degree. In mammals the liver is the only organ which regenerates itself and can regenerate to full health with only a third of the organ remaining in some cases. In humans, a fingertip which has been lost can sometimes grow back and scratches and cuts too, often heal without scars.

The possibility of human regeneration lies in finding out exactly how these blastema cells are able to recreate an entire leg after it has been severed from the body, something which is unique in nature to salamanders, as far as we are currently aware.