Researchers Find Switch to Restore Damaged Axons

Researchers have found the key to redirect cells in the peripheral nervous system to “repair” mode, which can restore damaged axons, a discovery that could help traumatic brain injury patients as well as various other patients such as diabetics and patients with spinal cord injuries.

Read More: Traumatic Brain Injury Attorney in Wisconsin

Researchers at the University of Wisconsin-Madison made the discovery, which redirects helper cells, according to an article in News Wise.

“Axons are long fibers on neurons that transmit nerve impulses. The peripheral nervous system, the signaling network outside the brain and spinal cord, has some ability to regenerate destroyed axons, but the repair is slow and often insufficient,” the article reads. “The new study suggests tactics that might trigger or accelerate this natural regrowth and assist recovery after physical injury, says John Svaren, a professor of comparative biosciences at the UW-Madison School of Veterinary Medicine. The finding may also apply to genetic abnormalities such as Charcot-Marie-Tooth disease or nerve damage from diabetes.”

Svaren is the senior author of a report that was recently published in The Journal of Neuroscience. He focused his study on how Schwann cells, which hug axons in the peripheral nervous system, transform themselves to play a much more active and “intelligent” role after injury.

Schwann cells, also called neurilemma cells, are cells in the peripheral nervous system that produce the myelin sheath around neuronal axons. Schwann cells are named after German physiologist Theodor Schwann, who discovered them in the 19th century.

“Svaren and his graduate student, Joseph Ma, compared the activation of genes in Schwann cells in mice with intact or cut axons,” the article reads. “We saw a set of latent genes becoming active, but only after injury … and these started a program that places the Schwann cells in a repair mode where they perform several jobs that the axon needs to regrow.”

In the repair mode, Schwann cells help to dissolve myelin, which is essential for proper functioning but ironically deters regeneration after injury.

“This cleanup must happen within days of the injury, says Svaren, who directs the cellular and molecular neuroscience core at the Waisman Center on the UW-Madison campus,” the article reads. “The Schwann cells also secrete signals that summon blood cells to aid the cleanup, and they map out a pathway for the axon to regrow. Finally, they return to the insulator role to grow a replacement myelin sheath on the regenerated axon.”

According to Svaren, nearly every other nervous-system injury response, especially in the brain, is thought to require stem cells to repopulate the cells.

“But there are no stem cells here,” Svaren says. “The Schwann cells are reprogramming themselves to set up the injury-repair program. We are starting to see them as active players with dual roles in protecting and regenerating the axon, and we are exploring which factors determine the initiation and efficacy of the injury program.”