Paraplegic Rats Enabled To "Walk" Again

eldavojohn notes a paper released in Nature Neuroscience today describing work in which paraplegic rats were enabled to walk again as early as a week after injury and treatment. The process involves a serotonin-influencing drug and electrical stimulation of the spine, along with an incentive to the paralyzed back legs to move — namely, being placed on a treadmill. Soon a poorly understood spinal mechanism called the "central pattern generator" kicks in and the rats' legs move under the stimulus of a rhythmic signal from the spine (the brain is not involved). Eurekalert reports, "Daily treadmill training over several weeks eventually enabled the rats to regain full weight-bearing walking, including backwards, sideways and at running speed. However, the injury still interrupted the brain's connection to the spinal cord-based rhythmic walking circuitry, leaving the rats unable to walk of their own accord."

Comments

Spinal reflex

[izomiac]

Walking is apparently a spinal reflex. Back in the days before there were strict guidelines on animal research/cruelty some researchers verified this using an experiment. Basically, they had a cat on a treatmill and rigged a device (I'm picturing something from Saw) that severed its spinal cord without knocking it over. The cat kept walking! Since spinal reflexes are preserved if they're below the level of damage, this bodes well for this type of research. Balance would probably be an issue though, since the cerebellum is thought to play a pretty significant role in that. Given, it's unassisted walking, but I'm not convinced many paraplegics would stand for wearing large gyroscopes. Ah, that brings me to the other major hurdle with this technology: standing.

Interestingly enough, I'm wondering what'll happen if laser rifles ever became reality, or perhaps entered hard science fiction. How weird would it be for a patrolling guard to get shot in the head, but keep on walking...