This could be exciting news for persons who have paralyzed body parts due to spinal cord injury (SCI). Researchers are getting closer to developing a method of artificially connecting brain cells to nerves and muscles. Unfortunately, it could be years or even decades before the science becomes a commercially available reality.

Electrical Stimulation
Many persons with SCI are already familiar with functional electrical stimulation (FES). FES uses low levels of electrical current to activate the nerves and muscles that have been paralyzed. This results in some functional usage for partially paralyzed persons. But, what if the electrical stimulation came directly from the individual's own brain cells?

Research done by three neuroscientists at the University of Washington (first published in September 2008) describes results that come one step closer to creating an artificial connection between brain cells and muscles.

Brain Cell Experiment
The subjects of the study, two Macaca nemestrina monkeys, had electrodes placed in the part of the brain that controls voluntary body movement (the motor cortex), specifically in the area controlling wrist and hand movement. External circuitry was then used to connect the brain cells to a computer. The cursor of the computer was controlled by the cell activity in the monkeys' brains.

Both monkeys, through a system of biofeedback reinforced by an applesauce reward, learned to control the cursor to hit targets on the screen—using brain cell activity alone. Although this part of the experiment itself seems amazing, it is not new. In previous experiments, computer cursors as well as robotic arms have been controlled in this manner.

Now comes the new and exciting part of the experiment. When the monkeys became proficient at controlling the cursor through firing of nerve cells in the brain, their wrist muscles were temporarily paralyzed by injecting anesthetic to create nerve blocks. They were unable to move their wrists and hands. Their brain cell activity was then converted to proportional electrical stimulation delivered to the temporarily paralyzed muscles.

This time the monkeys had to learn to control the cursor with wrist movements. The monkeys' brain cell activity produced enough stimuli, delivered through an artificial connection, to work the paralyzed wrist muscles. Additionally, any nerve cell in the motor cortex seemed to work (i.e., it didn't have to be ones that were ordinarily associated with wrist and hand movements).

The authors stated, "Further development of such direct-control strategies may lead to implantable devices that could help restore volitional movements to individuals living with paralysis."

For further information, refer to: "Direct control of paralysed muscles by cortical neurons," Moritz, C PhD; Perlmutter, S PhD; Fetz, E PhD; Nature, October 15, 2008; epublication by the Department of Physiology & Biophysics and Washington National Primate Research Center, University of Washington, Seattle, Washington 98195, USA.

See Related Articles
For more information about recovering with a SCI, see Spinal Cord Injury Recovery Helped with Treadmill Training.

See SCI Patients Reduce Spasticity Through Horseback Riding to learn more about horse therapy and how it helps SCI patients.