Injuries to the nerves can blind or paralyze because adult nerve cells don’t regenerate their connections. Now, a team of UConn School of Medicine researchers report in Development that at least a small population of nerve cells exist in everyone that could be coaxed to regrow, potentially restoring sight and movement.
Glaucoma. Optic neuritis. Trauma or stroke of the optic nerve. All of these conditions can irreversibly damage the optic nerve, leading to blindness.
Some animals can regrow axons, but mammals such as mice and humans cannot. It was assumed that mammals lack the immature nerve cells that would be needed. But a team of researchers in UConn School of Medicine neuroscientist Ephraim Trakhtenberg’s lab has found otherwise: in an April 24 paper in Development they report the existence of neurons that behave similarly to embryonic nerve cells. They express a similar subset of genes, and can be experimentally stimulated to regrow long-distance axons that, under the right circumstances, could lead to healing some vision problems caused by nerve damage. The researchers also found two genes that were particularly active in these neurons during experimental axon regeneration, and found that activating them in injured neurons also promoted axon regeneration. They could be targets for future therapies. Trakhtenberg believes that similar immature nerve cells exist in regions of the brain outside the visual system too, and might also heal some features of paralysis under the right circumstances.
In a second Development paper, the researchers suggest that a multi-pronged approach would be needed to fully regenerate injured axons. The new insights into how axons grow could someday create a path for truly effective therapies for blindness, paralysis and other disorders caused by nerve damage.