For the first time, a team of researchers has allowed mice with complete spinal cord injuries to walk again.
To accomplish this feat, they used gene therapy to coax nerves to regrow and reconnect to their natural target regions below the injuries.
The researchers’ goal was to find out if guiding specific nerves so they regenerated at their natural target regions of the body could restore meaningful function in the mice after complete spinal cord injuries. Although other studies have shown that nerves can be regenerated after a complete spinal cord injury, those studies also showed that if left unguided, the nerves don’t grow back correctly.
“Five years ago, we demonstrated that nerve fibers can be regenerated across anatomically complete spinal cord injuries,” Mark Anderson, a senior author of the study and director of Central Nervous System Regeneration at NeuroRestore, tells the Innovation News Network. “But we also realized this wasn’t enough to restore motor function, as the new fibers failed to connect to the right places on the other side of the lesion.”
This time, the scientists identified which type of neuron is involved when the spinal cord naturally repairs itself after a partial injury. Then they used chemical signals to attract and guide the regeneration of these nerves to their natural target region in the lumbar spinal cord. This resulted in mice with complete spinal cord injuries regaining the ability to walk with a more or less natural gate.
“Our study provides crucial insights into the intricacies of [nerve] regeneration and requirements for functional recovery after spinal cord injuries,” Michael Sofroniew, professor of neurobiology at the David Geffen School of Medicine at UCLA and a senior author of the new study, says in a statement.
The scientists say this new gene therapy — one of a recent series of breakthroughs in treating spinal cord injuries — should enhance electrical spinal cord stimulation as a treatment for spinal cord injuries. “We believe a complete solution for treating spinal cord injury will require both approaches – gene therapy to regrow relevant nerve fibers, and spinal stimulation to maximize the ability of both these fibers and the spinal cord below the injury to produce movement,” Grégoire Courtine, a senior author of the study, tells The Innovation News Network.
The authors acknowledged that there are still many obstacles to overcome before this sort of gene therapy can be used in humans. Still, they said the principles underlying their work “will unlock the framework to achieve meaningful repair of the injured spinal cord and may expedite repair after other forms of central nervous system injury and disease.” TwP
The study, ‘Recovery of walking after paralysis by regeneration characterized neurons to their natural target region,’ is published in the journal Science.
Source: Gene therapy developed to restore motor function across complete spinal cord injuries