Follow-up: Nazik Issa
A team of scientists has identified neurons that can be stimulated to help paralyzed people walk again, even after turning off the electrical stimulation.
Details of the study, published in the scientific journal Nature, show that a small device implanted near the spinal cord that uses electrical impulses by electrically stimulating the epidural, the space outside the spine, has a major role in helping patients regain some movement.
Promising progress has been made in stimulating the neurons that control leg movement. Over the past decade, many improvements to the technology have shown steadily improved results, helping previously paralyzed patients move their legs, stand, and even walk with assistive devices such as crutches and tires.
In a new clinical trial at a research center called NeuroRestore, nine patients regained their ability to walk, and their motor function continued to improve even after rehabilitation was completed. Crucially, they were able to walk even after the electrical stimulation device was turned off, a stage that previous experiments and studies had failed to achieve.
The team created a 3D “map” of the spinal cord, down to individual neurons, and monitored which neurons were activated by the electrical stimulation. Then they narrowed their supervision to a specific family of neurons that express a gene called Vsx2. Interestingly, these neurons, which are not normally necessary for walking from a health point of view, appear to be necessary for the reorganization of nerve fibers for the repair of motor function after injury.
To test this new idea, the researchers used a new version of the epidural implant to stimulate the spinal cord and specifically destroy Vsx2 neurons. When the experiment was done on mice, the mice with spinal injuries stopped walking immediately, but the healthy mice could still walk normally.