WEST LAFAYETTE, Ind. -- Purdue University researchers have for the first time restored electrical nerve impulses in the severed spinal cord of a mammal.
The scientists conducted their experiments on isolated spinal cords removed from adult guinea pigs. Researchers fused the cut nerve fibers using a polymer called PEG. Electrical impulses were restored in all of the guinea pig cords used in the study. The repaired spinal cords transmitted between 5 percent and 58 percent of pre-cut impulses.
Significant numbers, but not all, of the nerve fibers within the cut spinal cords were reconnected. Researchers demonstrated this by passing special dyes through the repaired nerve fibers.
"If you have even 5 percent of the nerve fibers carrying nerve impulses, you'll get significantly more than 5 percent back in terms of restored behavior," says Richard B. Borgens, professor of developmental anatomy at Purdue. He and his colleague, assistant professor Dr. Riyi Shi, both of Purdue's Center for Paralysis Research in the School of Veterinary Medicine, will report their findings Thursday (11/12) in Long Beach, Calif., at the 18th annual meeting of the Society for Physical Regulation in Biology and Medicine. Borgens also has submitted a paper on the research to the Journal of Neurotrauma.
"This technique may be a revolutionary new way of dealing with injuries to the nervous system," Borgens says. "It's too soon to know whether it would help patients with old injuries, but it is likely to be useful in treating recent injuries."
Shi and Borgens now are testing the procedure in live animals. They plan to conduct clinical trials in natural cases of paraplegia in dogs early in 1999, but human clinical trials are at least two years away.
The isolated spinal cords remain viable for about 36 hours after removal. Borgens says the results of studies in live animals will shed more light on how permanent the new technique might be.