Paralyzed rat walking (via EPFL)
Researchers at the Swiss Federal Institute of Technology have successfully restored an astonishing amount of voluntary movements to rats paralyzed by spinal cord injuries. Grégoire Courtine and his team used a mix of chemicals, electrical stimulation, and robot assisted rehabilitation to allow rats to walk on their hind legs and even up stairs to fetch a treat. The recent studies give people paralyzed by spinal cord injuries a hope that they may one day walk again.
Spinal injuries causing paralysis destroy the nerve fibers or axons in our spinal cord. In adults, these nerves do not re-grow causing the injuries to become a lifelong disability. Past attempts at treatments included using stem cells to promote re-growth and similar therapies, but a successful treatment has remained elusive.
Courtine's team decided to try an alternative method to restoring the rats lower body movements. Based on a critical observation that most spinal cord injuries to do not sever the spine completely, only the nerves, they decided to try and bypass the disconnected nerves by using the remaining connected tissue. For about 30 minutes a day the researchers began the rehab process by injecting the rats with chemicals that improve the function of neural circuits in the spine associated with leg movements. In addition, the area was stimulated with electrodes which send an ongoing signal to nerves which control leg movements. That rats were also fitted with a robotic harness with the sole purpose of keeping the rats up on their hind legs and preventing them from falling down. With a chocolate treat at the end of the path to motivate rats to move, the rats slowly began taking small steps toward the treat. After four to six weeks the little guys began to move on their own to fetch treats.
Courtine hopes to begin human treatment research with the next two years. However, the study will have limitations such as the spinal cord cannot be completely disconnected. The electrical and chemical treatment to the rats provides very encouraging evidence that we may one day have a method to restore paralyzed victims lower body movements.