Sydney: Scientists have decoded the secrets of the zebra fish`s amazing ability to heal its spinal cord after injury. The findings could eventually pave the way to stimulate spinal cord regeneration in humans, especially for those who are partly or completely paralysed.
A protein called fgf plays a major role in the remarkable self-healing ability of the fish, said Yona Goldshmit and Peter Currie, professor, who led the research team at the Monash University`s Australian Regenerative Medicine Institute (ARMI).
When the spinal cord is severed in humans and other mammals, the immune system kicks in, activating specialized cells called glia to prevent bleeding into it, Currie was quoted as saying in The Journal of Neuroscience.
"Glia are the workmen of nervous system. The glia proliferate, forming bigger cells that span the wound site in order to prevent bleeding into it. They come in and try to sort out problems. A glial scar forms," Currie said.
However, the scar prevents axons, thread-like structures of nerve cells that carry signals to the brain, of neighbouring nerve cells from penetrating the wound. The result is paralysis, said a university statement.
"The axons upstream and downstream of the lesion (injury) sites are never able to penetrate the glial scar to reform. This is a major barrier in mammalian spinal cord regeneration," Currie said.
Conversely, the zebra fish glia form a bridge that spans the injury site but allow the penetration of axons into it.
Fgf or fibroblast growth factor, controlled the shape of the glia, and accounted for the difference in the response to spinal cord injury between humans and zebra fish.
The fish can fully regenerate its spinal cord within two months of injury. "You can`t tell there`s been any wound at all," Currie said.
The scientists showed fgf could be manipulated in the zebra fish to speed up tissue repair even more.