A team at the the École Polytechnique Fédérale in Switzerland has restored movements to entirely paralysed rats, allowing them to walk fluidly on their hind legs while their upper bodies are supported by a tiny harness. The technique involves zapping the rat’s spinal cord with electrical pulses to replace the commands that are normally sent out by the brain, but are obscured when the spine is severely injured.

The Swiss scientists worked with six paralysed rats and placed flexible electrodes in the lower parts of their severed spinal cords. A drug called serotonin agonist was administered, which improves the communication between the spinal cord and the legs, and then the rats were placed in a little harness and onto a treadmill.

Receiving electrical pulses directly to their spinal cords, the rats were able to make over 1,000 steps, and could even walk up rat-sized stairs. “This is the first closed-loop control system that can really adjust leg movements in real time, despite paralysis,” one of the team, neuroscientist Gregoire Courtine, told Courtney Humphries at MIT’s Technology Review .

Publishing their results in the journal Science Translational Medicine, the team hopes to trial the technique on human subjects to see if they can replicate this amazing result.

A separate study by researchers from the University of Louisville and the University of California, Los Angeles (UCLA) in the US has seen four paralysed men have movement restored to their hips, legs and feet this year thanks to a similar technique known as epidural stimulation. "Though the movements achieved were modest- and fall short of allowing the men to walk on their own- the technology let them exercise their legs, which seemed to restore some movement,” Courtine told Humphries at Technology Review.

The US technique is far from perfect - not only are the movements restricted and not very coordinated, but the electrical stimulators need to be manually operated. Which is where the Swiss team’s technology can make a significant improvement, because it’s more automated and remotely operated, plus the software has been built to constantly adjust the electrical pulses itself to ensure synchronised, rhythmic stepping movements. This gives the rat a steady, more balanced walk.

“The better it is, the better it will free up the individual that is being stimulated so that person does not have to make constant decisions,” said UCLA physiologist, V. ReggieEdgerton, from the US team to Technology Review.

The Swiss team hopes to test their technology on a human volunteer next year, and if successful, they will move on to larger trials. They’re also looking into extending the capabilities of this technology to one day allow the patients to control the spine-stimulating electrical pulses using their thoughts alone.

http://pda.sciencealert.com.au/news/20142609-26237.html

Rat

Naija which way?