Electrical Zaps Woke Up Dormant Neurons to Help Paralyzed People Walk Again
Published in Brain Activity, Brain/Neurology, Circuits.
What was science fiction is now scientific reality: with a series of targeted electrical zaps to the spinal cord, nine paralyzed people immediately walked again with help from a robot. Five months later, half of the participants no longer needed those zaps to walk.
Does the sentence sound a bit familiar? By themselves, the results—while undeniably impressive and utterly life-changing—may seem like old news. Thanks to improvements in brain implant designs, the last decade saw astonishing progress in restoring mobility to people with paralysis. In 2018, a 29-year-old man walked the length of an entire football field thanks to a few zaps to his spinal cord, after years of paralysis from a snowmobile accident. Last year, spinal cord stimulation helped several people with complete paralysis to stroll around a busy downtown area with a walker and kayak in smooth waters.
There’s no doubt that spinal cord stimulation transformed a once-irreparable injury into one that now can be reversed. But a looming question remains: why does it work?
A new study in Nature just gave us some clues. Building a 3D molecular map of the spinal cord as it recovers from injury, the team found a mysterious group of neurons nestled on its outskirts. They’re peculiar. Normally, these neurons are not required for walking. But in cases of spinal cord injury, after a few electrical jolts they burst with activity, reorganizing into new neural highways that help restore movements.