The researchers used a combination therapy of fetal spinal tissue transplants and nerve growth factors, or neurotrophins. Earlier studies in animals have shown that fetal tissue transplants and neurotrophins can improve regrowth of injured neurons in the adult spinal cord, and that some injured neurons can regrow even after long periods of time. However, the new study is the first to show that spinal cord regeneration is actually improved when treatment is postponed until most of the initial injury-related changes in the rat spinal cord and the surrounding environment have stabilized, says Barbara S. Bregman, Ph.D., of Georgetown University Medical Center, who led the study. The work was supported in part by the National Institute of Neurological Disorders and Stroke (NINDS) and appears in the December 1, 2001, issue of The Journal of Neuroscience.*
"This is an exciting finding and gives us hope that similar therapies may ultimately be useful in humans with severe spinal cord trauma," says Audrey S. Penn, M.D., acting director of NINDS. "The surprising and important implication is that therapy may work better if it is delayed."
Dr. Bregman and colleagues studied four groups of adult rats with completely severed spinal cords. One group received no treatment and a second group received immediate treatment with fetal spinal tissue grafts. With the remaining two groups of rats, the wound was cleaned out and scar tissue was removed after intervals of either 2 or 4 weeks. The rats then received fetal spinal cord tissue grafts. All the rats receiving transplants also had infusions of either saline, neu
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NIH/National Institute of Neurological Disorders and Stroke