This is one of those stories you really can’t miss hearing about. Rats with spinal cord injuries get better, learn to sprint up steps after specialized rehab. It got picked up by all the major newspapers and science news sources. The images and videos are irresistible: the rat girl wears a black vest hooked up to a little crane device overhead; she’s on her hind legs, seeming to thrust herself forward, eyes intent on an unseen treat (we learn later it’s Swiss chocolate, and we also learn that this motivation is a critical part of the experiment); in videos, the rat is indeed dashing up a set of steps or over a hurdle.
I won’t break the whole thing down again here but in a nutshell, Grégoire Courtine and his team at the Ecole Polytechnique Fédérale de Lausanne (they call themselves the G-Lab; they are all young and good looking and have a Facebook
page) restored voluntary control of rat hind limbs – overground and not just on a treadmill.
Said the G-man: "After a couple of weeks of neurorehabilitation with a combination of a robotic harness and electrical-chemical stimulation, our rats are not only voluntarily initiating a walking gait, but they are soon sprinting, climbing up stairs and avoiding obstacles." Added Courtine, who holds the International Paraplegic Foundation (IRP) Chair in Spinal Cord Repair at EPFL,
"This is the world-cup of neurorehabilitation,” said Courtine. “Our rats have become athletes when just weeks before they were completely paralyzed. I am talking about 100 per cent recuperation of voluntary movement ... the brain develops a completely new way to orchestrate the movement [of the legs] and that is what is so amazing."
The paper is significant because the G-Lab showed that voluntary movement occurred only after brain connectivity was restored. They showed this plasticity with electrical measurements and also by chemically disconnecting the new brain input and thus interrupting the recovery.
There are obvious hints that this might work out in humans but there are a lot of things to work out. First, the G-Lab used an injury model that made two cuts in the spinal cord, paralyzing the animal but leaving some spinal cord intact. Human injuries almost always involve a contusion, or bruising of the cord. Would the training, the drugs and the stimulation work on this model?
Also, Courtine and his group used a cocktail of neurotransmitter drugs to sensitize the spinal cord so it would respond to training. No such drugs exist for human use.
Don’t miss the documentary
segments produced by the G-Team. If you love animals you will appreciate Rubia van den Brand, lead author of the paper, cajoling her little paralyzed friends to succeed, and later cuddling with one of the rat athletes.
Here are some of the better news reports:
Paralyzed Rats Walk, Even Sprint After Rehab
, featuring Moses Chao, a New York University neuroscientist and member of the Reeve Science Advisory Council:
Paralyzed Rats Walk Again in Swiss Lab Study
, Washington Post
With Willpower, and a Jolt of Electricity, Paralyzed Rats Learn to Walk Again
, Scientific American
, with comment from Reggie Edgerton, the UCLA scientist who led the effort last year to use epidural stimulation and training
to restore function in a human subject, Rob Summers. Edgerton, whose lab is a member of the Reeve International Research Consortium on Spinal Cord Injury, was Courtine’s boss when Grégoire was a post-doc at UCLA.
Here is the abstract for the paper, Restoring Voluntary Control of Locomotion after Paralyzing Spinal Cord Injury
, from the journal Science
. You can’t get the full version on line but very detailed supplemental materials have been made available, including charts and three short video segments.
Courtine’s unique neuroprosthesis and harness system was the subject of another paper the G-Lab published last week, Versatile Robotic Interface to Evaluate, Enable and Train Locomotion and Balance After Neuromotor Disorders
, this one in Nature Neuroscience
, and supported in part by the Reeve Foundation.