Scientists teach paralysed rats to walk

Research at the Swiss Federal Institute for Technology in Lausanne.
Research at the Swiss Federal Institute for Technology in Lausanne. Photo:

Just take a look at this remarkable video. At first sight it's just a rat in a funny waistcoat walking up some steps. In fact, its a real scientific breakthrough. Because that rat has a severe spinal injury that meant it couldn't walk. But after a radical new treatment it walks again - and not only walk, it can climb steps and jumps obstacles. That's the breakthrough.

Most spinal injuries to humans (whether from car crashes or bomb blasts) don't cut through the spinal cord completely - there are some nerve connections left, though the injury means they don't work. But could they be coaxed back into action? This new research, by scientists at the Swiss Federal Institute for Technology in Lausanne, suggests that they could.

They cut the spinal cord of rats in two places, to make sure no nerve impulses could get from the brain to the rat's hind legs. They couldn't walk. But then they used a combination of treatments to the spinal cord below the cuts.

They injected a cocktail of drugs to energise the nerve cells. They electrically stimulated the nerves and they put the rats in a special waistcoat, which lifted them up but didn't help them walk. They then trained the rats by offering them rewards to walk along a walkway. In only days they could take a few steps. In a few weeks they could walk 20 metres in three seconds.

And they could climb steps - that's important because it shows that the nerve cells that were left after the injury made new connections to the brain - and the rat's brain commanded its legs to climb the steps or jump the obstacles.

In other words, this combination of drugs, electrical stimulation and training encouraged the rats spinal cord to re-wire itself and to connect to the brain.

Could it work for humans? Theoretically, yes. But rats are not humans. And real injuries to human spinal cords also involve the nerves being crushed. So researchers still need to do a lot of work to show that these techniques could benefit paraplegics. But make no mistake, this is ground-breaking research that offers hope for the future.