Brain Signals Reverse Paralysis In Monkeys

Device Used To Revive Paralyzed Muscles Called "An Important Step Forward"

(AP)  Monkeys taught to play a computer game were able to overcome wrist paralysis with an experimental device that might lead to new treatments for patients with stroke and spinal cord injury.

Remarkably, the monkeys regained use of paralyzed muscles by learning to control the activity of just a single brain cell.

The result is "an important step forward," said Dawn Taylor of Case Western Reserve University in Cleveland, who studies the concept of using brain signals to overcome paralysis. She wasn't involved in the new work.

The device monitored the activity of a brain cell and used that as a cue to stimulate wrist muscles electrically. Researchers found it could even use brain cells that normally had nothing to do with wrist movement, said study co-author Chet Moritz.

So a large untapped pool of brain cells may be available for letting paralyzed people do things like grasping a coffee cup or brushing teeth, Moritz said. But he stressed the approach is years, if not decades, away from use in people.

Moritz and colleagues at the University of Washington in Seattle report the results in a paper published online Wednesday by the journal Nature.

Taylor, who also works with the Cleveland VA Medical Center, said the results illustrate the potential of the approach and the flexibility of brain cells.

Lee Miller, a researcher at Northwestern University who has done similar work, said any demonstration of a device using brain signals to make paralyzed limbs move is "an important new development."

Miller used the pattern of activity in about 100 brain cells to predict the kind of wrist movement a monkey wanted to make. Moritz said focusing on the outputs of individual brain cells instead may turn out to work better for overcoming paralysis.

The research is an example of what scientists call functional electrical stimulation, or FES, which involves stimulating muscles by applying electrical current. Partially paralyzed people use FES devices now to let them stand, walk, use their arms and hands, and do other things. But they control those devices by flicking a switch, moving joints or tensing a muscle — even, say, the muscle that lets them wiggle an ear.

Taylor said using brain signals instead could be a particularly good strategy for people paralyzed from the neck down. That's because such people have so few available muscles to tell devices how they want their arms and hands to move.

In the new work, scientists worked with two pigtail macaques. Each animal's hand was placed on a flat surface and immobilized. The animals learned that by using their wrists to press their hands downward or upward, they could make a computer cursor reach a target on a screen. Then researchers temporarily paralyzed their wrists with an anesthetic.

Scientists put a probe into the animals' brains that monitored how often a single brain cell was firing electrical signals. That firing rate was converted into an electrical stimulation that went to the wrist muscles.

It was set up so that different firing rates would make the hand press downward or upward, or relax. The monkeys quickly learned to use the brain cells to control their wrist muscles and continue playing the computer game.

In people, more complex movements would require monitoring many brain cells at once to activate multiple muscles, Moritz said. Researchers would rely on the brain to learn how to coordinate all these signals to produce a useful motion, he said. After all, that's what the brain does when a person learns to swing a tennis racket effectively, he said.

"There's a long ways to go, and there's no way to say with confidence that it will work," Moritz said.

It's also possible that a single brain cell could stimulate a group of muscles, if its signals are relayed to particular sites in the spinal cord, researchers said.

Andrew Schwartz of the University of Pittsburgh, who has used brain signals to enable monkeys to control robot arms, said he considered the new work a modest advance, noting hurdles that remain.

[Dr_Vaquero]

Brain Plasticity; It is the ability of brain cells of making function and structure changes in order to get or restore activities. As the article said, we see this every day in the tennis player when he or she learns to swing. There are several studies witch show brain gets the shape regarding the owner´s activities. For example, a taxi driver in London who knows almost all the streets and routes would have an enormous memory area (hippocampus) yet it isn´t big in terms of size, since it has been told no more neurons can grow, but it is big using the surrounding brain cells, cells with different function within other people. What I want to say is that brain doesn´t obey our squared anatomy and physiology descriptions, each brain can adjust to new adversities.

Brain plasticity is slow and sometimes incomplete though; patients with important brain damage, caused during a brain stroke, can reach almost 100% of their ability such as understanding language, read, speak, move and feel in months or they can be condemned to have incapacity forever, nonetheless the last group of patients can improve some paralysis with help of the rehabilitation. Rehabilitation is to stimulate brain plasticity. I thinks this proposal is very interesting and useful because researchers want to increase brain plasticity stimulus many times fold using electronic special devices.

I hope, not too far in future, we can rehabilitate our patients with the classic exercises and electronic devices; both helping the brain to find out new tracts, to hire new neurons and, why not, to create new cells.

[babooph]

Those Peta whacos will not like testing monkeys just to help some paralized person-how did that bunch end up with any say at all.

[kenhamlett]

Finally some good research. It has been my belief that while prevention and restoration of damaged tissue would be preferable, retraining the brain or rerouting signals and processing is possible and desirable. While I support some research on how to live with damage, I far prefer cures. While retraining the brain is not exactly a cure in the traditional sense, It could lead to the equivalent of a cure if other parts of the brain can assume the tasks of damaged areas. This particular research may not directly lead to success, it demonstrates that it is not beyond practical implementation.
It can be done.