WASHINGTON, D.C.− Neuroscientists have long believed that the only way to repair a spinal cord injury was to grow new neural connections, but researchers at Georgetown University Medical Center recently found that, especially in young rats, powerful cells near the injury site also work overtime to restrict nerve damage and restore movement and sensation.
The same process does not work as efficiently in adult rats and thus recovery time is much longer, the researchers also discovered. But they say that now that they know such a mechanism exists, it may be possible one day to "switch" these cells on therapeutically − and possibly help humans function better following serious spinal cord injuries.
"No one knew cells in the spinal cord acted to protect nerves in this way, so it gives us some hope that in the future we could stimulate this process in the clinic to enhance recovery and ensure the best outcome possible for patients," said the senior author, Jean R. Wrathall, Ph.D., professor in the Department of Neuroscience.
"This is an animal study, however, and there is much work to do to understand more about this process and how it might be altered," Wrathall said. The study, whose first author is graduate student Philberta Y. Leung, is published in the November 2006 issue of the journal Experimental Neurology.
At the least, Wrathall said, the study reveals surprising new information about nerve cell recovery that neuroscientists can now explore.
In vertebrates, the nervous system uses a two-way transmission system to communicate the electrical impulses that lead to muscle movement and the perception of sensation. In humans, hundreds of thousands of nerve fibers (axons), which can be several feet in length, run through the spinal cord like a two-lane road. Half of these axons connect the brain to distant muscles, and the other half links the body to the brain.