Scientists Have Made Paralyzed Monkeys Walk

In what could someday prove to be a major step forward for people with spinal cord injuries, scientists out of Switzerland are reporting in the journal Nature that they've gotten paralyzed monkeys to walk again. NPR describes the surgery on the rhesus macaques thusly: A neurosurgeon "placed electrodes in the part of the monkey's brain that controls leg movement, and docked a wireless transmitter on the outside of his skull. Then, she put another set of electrodes along the spinal cord, below the injury." The idea is that the brain device beams instructions to the spine, which tells the legs to move. Using this "brain-spine interface," they used electrical activity they recorded in the monkeys' spinal cords prior to the injuries and "played it back" to restore movement. "That’s an approach that wouldn’t be practical after an actual spinal-cord injury," says the lead researcher.

"The whole team was screaming in the room as we watched," the lead researcher, who travels between Switzerland and China (where regulations are more lenient on experimenting with primates) tells Nature News. Experts around the world have seen many failed experiments to restore walking over the years, and while the rhythm of the leg movement wasn't totally natural, the monkeys were able to support their weight enough to walk on a treadmill without dragging their feet. A small clinical trial is already underway in Switzerland for two people with spinal cord injuries to further test the interface. "It will take at least another decade in order to achieve the full translation in humans, with no guarantee whatsoever that it will be a successful endeavor," says the lead researcher. (Meanwhile, a monkey's head has been successfully transplanted.)