Stem cells repair nerves in mice

Further hope seen for spinal injuries

September 20, 2005|Associated Press

WASHINGTON -- Injections of human stem cells seem to directly repair some of the damage caused by spinal cord injury, according to research that helped partly paralyzed mice walk again.

The experiment, reported yesterday, isn't the first to show that stem cells offer tantalizing hope for spinal cord injury; other scientists have helped mice recover, too.

But the new work went an extra step, suggesting the connections that the stem cells form to help bridge the damaged spinal cord are key to recovery.

Surprisingly, they didn't just form new nerve cells. They also formed cells that create myelin, the biological insulation that nerve fibers need to communicate.

''The actual cells that we transplanted, the human cells, are the ones that are making myelin," said lead researcher Aileen Anderson of the University of California, Irvine. ''We're extremely excited about these cells."

The research is reported in yesterday's issue of Proceedings of the National Academy of Sciences.

The researchers injured the spinal cords of mice and nine days later injected some with the human neural stem cells. Four months later, the treated mice could again step normally with their hind paws. Mice given no treatment or an unrelated cell showed no improvement.

When the human cells were killed, the improvements in walking disappeared, suggesting that the cells themselves were responsible for the recovery.