Researchers at Germany’s Ruhr University Bochum have reached a goal sought for centuries by medical science: how to make legs paralyzed by a massive spinal cord injury walk again.
The spine’s nerve fibers, once damaged or cut, are unable to regenerate themselves. As a result, communication is lost between the mind and the body below the damaged point of the spinal cord.
Scientists have had some luck restoring lost function by transplanting nose nerve cells, which can regenerate, into the spinal cords of paralyzed dogs.
But the German team bypassed the spine entirely and went directly to the brain.
They genetically altered a naturally occurring protein that fosters communication among cells so that the protein would spark nerve cell regeneration. Then they injected the protein directly into the motor-control portion of the brains in mice whose spinal cords had been crushed, completely paralyzing their rear legs.
After two to three weeks, the mice were walking normally on all fours again.
The brain not only began producing the designer protein but also passed instructions to make it down through the body’s neural network. The instructions reached the spinal cord and its branch nerves and caused the network to repair or replace the spinal cord’s damaged nerves.
The German scientists now are testing how long after the injury the treatment will work.
While Bochum’s researchers were publishing their findings, a group at the University of California at Los Angeles was showing another way to help spinal cords knit themselves back together.
The California bioscientists injected the spinal cord injury site in mice with a microscopic scaffold made of hyaluronic acid, which occurs naturally throughout the body and retains moisture in tissues.
The researchers loaded pores in the scaffold with genes that foster the creation of “brain-derived neurotrophic factor (BDNF),” a protein that makes new nerve cells.
Eight weeks after the injection, the scientists found that the damaged spinal cords had made notable progress in repairing themselves compared to mice that had received the scaffold but no genes to make BDNF.
TRENDPOST: The new work hints at ways in which humans who’ve lost control over their legs might regain it, as well as new approaches to treating neural degenerative diseases, designing prosthetic devices, and even brain-machine interfaces.
By mid-century, paraplegia – loss of the use of legs – is likely to be a reversible condition.
Photo credit: Ruhr University Bochum
