Worms tip off on human brain repair

Washington: Scientists have revealed how worms regenerate their neurons after an injury, a finding they claim suggests that a similar restoration method could be applied to humans to promote repair in the nervous system.

In humans, regeneration of the peripheral nervous system after injury remains a hit-or-miss affair, while brain and spinal cord damage results in lifelong disabilities. But by studying nerve injury in roundworms, an international team, has found a different modality by which regeneration occurs.

"Though damaged nerves reconnect in a number of different ways, the underlying mechanisms remain poorly understood," said Dr Brent Neumann of the Queensland Brain Institute, who led the team.

The research, published in the `Developmental Dynamics`, examines a process called axonal fusion, which has been observed in crayfish, earthworms, leeches and now in the roundworm Caenorhabditis elegans.

It offers a fundamentally different mechanism for regeneration of axons (long structures that look like cables and conduct electrical impulses between neurons) than those traditionally proposed.

Using fluorescent imaging, the scientists showed that axonal fusion is a highly effective way to restore neuronal connections with the target tissue.

Dr Neumann said transected (severed) axons can restore their trajectories by bridging just the damage site instead of regrowing their entire length beyond an injury site.

Added team member Dr Massimo Hilliard: "In the worm, this process happens automatically a certain percentage of the time. As C Elegans are highly accessible for genetic analyses- future research will focus on the cellular and molecular mechanisms regulating the process, and how to make it happen when it doesn`t do so naturally.

"We do not know yet if something similar occurs in humans, but if it is not in place it doesn`t mean we can`t make it happen.