In a lab in Switzerland, a little white rat is re-learning how to walk. In research dubbed Project Rewalk, Grégoire Courtine and his collaborators are figuring out how a spinal cord with a severe lesion might repair itself, to the point that voluntary locomotion could happen again -- not just reactive movement but brain-directed walking and running. The treatment involves a re-awakening cocktail of chemicals released onto the spinal cord, combined with electrical stimulation -- plus repeated exercise that rehearses the walking movement. As part of the experiment, Courtine's team developed a robot that gently supports the rat vertically but does not push it forward; the rat has to decide to move on its own. And eventually, it does. As Courtine explains, "the training forces the brain to recruit what is left of the neural system to get the job done."
 
Courtine holds the International Paraplegic Foundation chair in spinal cord repair at the Center for Neuroprosthetics at the Swiss Federal Institute of Technology in Lausanne.