Nine people paralyzed by severe spinal cord injuries have been able to walk again thanks to a combination of electrical pulses to their lower spine and physical therapy, reports a study published in the Journal this month Nature.
The paper builds on work from 2018 that helped three people walk again. But this time, the researchers have identified the neurons that might be responsible. Their findings, which examined neurons in mice, could eventually help scientists develop more sophisticated treatments for humans, per health day‘s Amy Norton.
The research “is finally getting to the important factors that contribute to recovery,” says Sarah Mondello, a neuroscientist at the University of Washington who did not contribute to the findings Science‘s Claudia Lopez Lloreda.
Severe spinal cord injuries can disrupt the line of communication between the brain and the neurons in the lower spine that are responsible for walking. Researchers first used electrical stimulation of the lower spine, called epidural electrical stimulation (EES), to treat pain in people with spinal cord injuries, writes New scientist‘s Carissa Wong.
But over the last decade, EES has helped a small number of paralyzed people get up or walk, per Health day news. When combined with physical therapy, EES can also help people regain bladder and bowel function and engage in sexual activity Science.
“We mimic the way the spinal cord is normally activated by electrical signals from the brain when you walk by electrically stimulating the right part of the spinal cord at the right time to move the leg muscles,” says Jocelyne Bloch, a neuroscientist at the University of Lausanne in Switzerland and co-author of the paper New scientist.
In the new study, nine participants with similar spinal cord injuries received implants of the electrical devices. At the start, three participants could not feel or move their legs, and the others had some feeling but little to no movement.
But after five months of treatment, all nine people were able to walk, and four people were able to walk without EES, per Messages from nature‘ Dyani Lewis.
To determine exactly how the electrical stimulation worked, the team performed the same experiment on mice. According to the researchers, they paralyzed the rear legs of the mice New scientist. EES and physical therapy on a treadmill also allowed the mice to walk again. A computer program revealed a specific type of neuron in the spinal cord that appears to play a key role Science.
When the researchers then blocked the activity of these nerve cells in the injured mice, the mice did not learn to walk again. In healthy mice, however, this had no effect on their walking, leading the researchers to conclude that these neurons could help with recovery Science.
The same neurons likely play the same role in humans because humans and mice have similar spinal architectures, says Eiman Azim, a neuroscientist at the Salk Institute for Biological Studies who did not collaborate on the study Messages from nature. Azim co-authored an opinion piece in Nature accompanying the new sheet.
Grégoire Courtine, co-author of the new study and neuroscientist at the Swiss Federal Institute of Technology, tells Science that there are likely other types of neurons that may also play an important role in recovery.
The findings could also help researchers identify types of neurons that help restore other functions, Mondello says Science. Marc Ruitenberg, a neurologist at the University of Queensland in Australia who did not contribute to the research, says Messages from nature that it would be interesting to see if the technology could help with bladder, bowel and sexual function, which can improve quality of life more than walking.
Greg Nemunaitis, who did not contribute to the research and is director of spinal cord injury rehabilitation at the Cleveland Clinic, narrates health day that the restored function in the nine patients in the study is “amazing” and that the research in mice is “a first step in understanding and improving function in humans.”