Paralysed rats have been helped to walk involuntarily over obstacles by electrically stimulating the severed part of their spinal cord in research at Switzerland's EPFL. Human trials inside an innovative gait platform at a nearby hospital could begin next year, offering hope to spinal cord injury sufferers currently unable to walk. Jim Drury reports.
STORY: This laboratory rat is paralysed - but, with electric stimulation applied to its severed spinal cord, can now walk again, albeit involuntarily. Scientists at Switzerland's EPFL technology institute say their research paves the way for human trials next year. Flexible electrodes were implanted into the rodent's' spinal cord and stimulated by electric current, while a combination of drugs modulated its neurotransmitters, says co-author Gregoire Courtine. SOUNDBITE (English) GRÉGOIRE COURTINE, EPFL NEUROSCIENTIST, SAYING: "We performed experiments with rats that received a complete transection of the spinal cord that completely interrupts the communication between the brain and the spinal cord. This leads to a complete paralysis. To enable locomotion we delivered two components - one a pharmalogical cocktail and secondly electrical stimulation in the dorsal aspect of the severed spinal cord." Researchers found a direct relationship between how high rats lifted their legs and the frequency of the electrical stimulation. They adapted this knowledge to control an individual rat's stride as it walked towards barriers. SOUNDBITE (English) GRÉGOIRE COURTINE, EPFL NEUROSCIENTIST, SAYING: "We developed all the technology to monitor the movement of the animal in real time and with this feedback we adjust the stimulation parameters very precisely in order to enable a completely paralysed rat not only to walk naturally but also to adjust its stride in order to climb a staircase." A 2012 study by Courtine's team saw paralysed rats walk after being injected with cell binding chemicals and similar electric stimulation. The difference this time is the ability to make rodents walk without any conscious effort. Human trials should begin next summer in this custom-made gait platform at the nearby University Hospital of Lausanne. Eventually Courtine and his team hope to decode signals directly from the brain to stimulate the spinal cord, helping the paralysed walk again.