Severed Spines

Dateline: 12/03/98
Updated: 12/02/99

Just imagine: paralyzed individuals walk again; damaged nerves regenerate; and severed spines are repaired. Is this the stuff of science fiction? Perhaps, but researchers at Purdue University in Indiana came a step closer to making these dreams a reality. For the first time, nerve impulses in mammals were restored to guinea pigs whose spinal cords had been severed.

In the study, the researchers removed and then severed the spinal cords of guinea pigs. By gently pressing the cords together and applying a polymer called PEG (polyethylene glycol) for approximately two minutes, the researchers re-fused the severed cords. The polymer allowed the membranes of many of the cells to fuse together again and the nerve impulses to traverse the previous cut. Between 5 and 60 percent of the precut impulse level was restored.

Scientists are now attempting the technique in live specimens. If successful, they speculate that human trials might be two to three years down the road.

Nerve cells in the brain and spinal cord do not regenerate. Other nerve cells may regenerate depending on the level of damage. By applying such a technique, the scientists could allow the nonregenerating cells in the brain and spinal cord to be repaired.

The researchers have dubbed the technique fusion technology and are looking at a variety of enhancements to the procedure. Ultimately, they hope to develop a feasible technique for repairing damaged nerves, including severed spines.

What do you think? Might we one day be able to help paralyzed individuals to walk again? Do you think there are limits to what might be achieved using these techniques? Come on over to the Biology Forum and share your thoughts, opinions, and feelings.

For additional information see:

• Researchers Splice Severed Spinal Cords
  
• News release concerning the study from Science Daily.
• Walking Again
  
• Will a new device enable paralyzed individuals to walk again?
• The Signal Amplifier
  
• Animal implant testing may one day allow paraplegics to walk.