Rats with severed spinal cords partially recovered their ability to walk in new research that mirrors the results of earlier tests, but holds slightly better hope for humans.
Gene therapy was used to stimulate a regrowth of nerve cells in the severed spinal cords of the rats, researchers at the University of California San Diego School of Medicine reported.
In the new experiment, described in the July 15 issue of The Journal of Neuroscience, samples of normal skin cells taken through a biopsy were modified to produce a growth protein, neurotrophin-3, which encourages the survival and growth of nerve cells.
The skin cells were then grafted to the spine at the injured site of the animals. There, the modified cells continuously delivered the growth protein for several months, further enhancing the regeneration of damaged nerve cells.
In a previous study reported last summer, researchers at the Karolinska Institute in Sweden successfully removed a block of healthy nerve cells from lab rats and transplanted them to the injured sites, where they grew nerve connections across the gaps of severed spinal cords.
But that experiment, which also restored some motion and sensation to the paralyzed hind legs of the animals, proved only that regrowth was possible and did not necessarily indicate the best technique, scientists said at the time.
One scientist, Dr. Wise Young, a nerve system researcher at the New York University Medical Center in New York, said the bridge technique used in the Swedish study could probably never be used on humans.
Because of that, the new gene therapy technique could eventually prove more useful if it could be replicated in humans.