Researchers Restore Movement in Paralyzed Rats, Look to Human Trials
Swiss researchers have restored paralyzed rats' ability to walk with a combination of electrical and chemical stimulation, rehabilitation, and intensive training. According to scientists, the techniques used in this successful study hold the promise of treating a wide variety of spinal cord injuries in people.
This study, published in the scientific research journal, Science, explains that the rats in the research underwent spinal cord injuries that left their hind legs completely paralyzed. Researchers then promoted recovery by using electrical stimulation in the brain and spinal injury site, as well as with chemical stimulation with drugs that promote nerve growth.
The rats underwent a daily treatment regimen to promote healing and restored movement. The New York Times explains that after being equipped with small vests “held upright on their back legs but left to bear their full weight, the rats tried to move toward a piece of cheese that beckoned nearby.”
The scientists began seeing results after two to three weeks of 30-minute daily rehabilitation sessions. After six weeks of the rehabilitative treatment and stimulation, nerve growth was obvious and all 10 rats were able to walk on their own again.
In fact, some rats were even able to run or climb stairs after this period of training. However, a control group of rats with the same severed nerve connection to the hind legs did not receive the same intensity of rehabilitation and failed to show comparable levels of progress.
This control group “trained more passively on a treadmill” and the New York Times explains that researchers soon discovered that voluntary motion, or “hard work combined with sustained stimulation” was necessary for the brain to restore control over the limbs. The study supports the theory that this “training forces the brain to recruit what is left of the neural system to get the job done,” lead researcher Dr. Grégoire Courtine explained.
The Times explains that the nervous system remaps its connections with such training and stimulation, sprouting neurons like “seedlings on a Chia Pet when they are seeking new connections.” In fact, neuron growth of over 300 percent was witnessed by the scientists around the injury and in the brain stem of those rats that underwent the active therapy and stimulation.
The article explains that Dr. Courtine and his team have now replicated this recovery in about 100 rats and are developing the technology to be used in a human trial. They hope to begin these trials with people who suffered similar injuries in the next couple of years.