Scientists Seek Secrets of Salamander Limb Regeneration

Salamanders such as axolotls can regrow lost limbs, rebuilding bone, nerves, blood vessels and muscle through a specialized structure called a blastema. The process is triggered by injury‑induced signals, with nerves playing a key role: sufficient nerve signals are required for blastema formation, and rerouting a nerve can even produce an extra limb. In contrast, human tissue repair relies on wound closure and scar formation, with limited regenerative capacity seen only in skin, blood cells, liver, and occasionally finger tips in children. Researchers are dissecting the cellular and genetic cues that allow regenerative animals to control cell proliferation, patterning and termination of growth, hoping to translate these lessons to improve human healing.