Study Finds How Nerve Cells Regenerate After Injury

It is well-known that the peripheral nerves that connect our limbs and organs to the central nervous system have an astonishing ability to regenerate themselves after injury, unlike nerves of the spinal cord. Researchers have now revealed how this healing process works.
"We know a lot about how various cell types differentiate during development, but after a serious injury like an amputation, nerves must re-grow. They need a new mechanism to do that because the developmental signals aren't there," said Allison Lloyd of University College London. 
That kind of regrowth isn't easy to pull off. Peripheral nerves are long cells; their nucleus is in the spinal cord and the axons that extend from them and relay nerve messages can reach all the way down a leg. 
"When a nerve gets cut, all the axons downstream degenerate," said Lloyd. 
Regrowth requires that the two ends somehow find their way back to each other through damaged tissue. 
Scientists knew that Schwann cells were important to that process. Those cells are found wrapped around axons, where under normal circumstances they are rather "quiet" cells. 
All of that changes when an injury occurs-those Schwann cells de-differentiate back to a stem-cell-like state and play an important role in bridging the gap to repair damaged neurons. 
"Schwann cells could sit on a nerve for years and then, at any point, switch states. They are quite unusual cells," said Lloyd.

Source:MedIndia