An endangered salamander may hold the key to helping paralysed people walk again, scientists believe.

The axolotl, or Mexican salamander has the astonishing ability to regenerate limbs and even spinal cord if it has been injured.

But now a new study by the University of Minnesota in the US has discovered how the animals achieve the feat, and how humans may be able to replicate the same process.

When an axolotl suffers a spinal cord injury, nearby cells called glial cells begin proliferating rapidly, repositioning themselves to rebuild the connections between nerves and reconnect the injured spinal cord.

By contrast, when a human suffers a spinal cord injury, the glial cells form scar tissue, which blocks nerves from ever reconnecting with each other.

The US team discovered that a particular protein called c-Fos - which is carried by both salamanders and humans - is crucial for the regeneration process. However in humans the protein is prevented from working by another family of proteins known as Juns, which trigger scar tissue formation.