With the help of a robotic harness, some drugs and electrodes, rats with severed spinal cords are sprinting and climbing up stairs! Someday, a similar method of neurorehabilitation could help restore leg movement in paralyzed humans.
Nerve fibers that help move muscles in the body don’t regrow in adults. In spite of the nervous system’s amazing capacity to forge new connections around an injury, nerve damage to a severed spinal cord is generally considered too great for repair.
To challenge this view, a Swiss team led by Grégoire Courtine of Swiss Federal Institute of Technology (EPFL) studied rats with injuries similar to those causing lower-body paralysis in people.
"This is the world-cup of neurorehabilitation," Courtine says in a release. "Our rats have become athletes when just weeks before they were completely paralyzed. I am talking about 100% recuperation of voluntary movement."
The rehab remodeled the circuitry all the way from the spinal cord up through the brain. But the experiment with the treadmill-trained rats suggests that full recovery depends on making intentional movements, not just any movement, ScienceNOW explains.
The rats had to engaged, participating in their own rehabilitation. "In the beginning... the animal is struggling and it is really difficult," Courtine tells AFP. "Then the first time it happens, the animal is surprised. It looks at you like, 'Wow. I walked!'"
“Willpower-based training translated into a fourfold increase in nerve fibers throughout the brain and spine,” explains study researcher Janine Heutschi of EPFL. Courtine thinks this regrowth is like a duplication of an baby’s growth phase. The newly formed fibers bypassed the original spinal lesion and allowed signals from the brain to reach the electrochemically-awakened spine.
Human, phase II trials might begin in a couple years Switzerland. EPFL researchers are coordinating an $11.1 million project called NeuWalk, which aims to design a fully operative spinal neuroprosthetic system for implanting into humans.
The findings were published in Science yesterday.
This post was originally published on Smartplanet.com