PHILADELPHIA – For years, scientists have been trying to make injured spinal cords grow back, with limited success.
Lying awake in bed one night, University of Pennsylvania neurobiologist Douglas Smith came up with an offbeat alternative: Instead of trying to regrow the damaged nerves, how about taking nerve cells from elsewhere in the body and getting them to stretch? After all, he reasoned, a similar process must occur when whales and giraffes grow their spinal cords to tremendous lengths.
So far, it’s working. Smith and his University of Pennsylvania colleagues have taken clumps of non-essential nerve-cell bodies from rats, stretched them very slowly — a millimeter or two a day, in specially constructed stretching boxes — and successfully implanted them into other rats with injured spinal cords.
Still to come are tests to show whether the implanted nerves actually work. Any trials on humans are years away.
But the research is seen as promising, and is just one of several dramatic recent advances in science’s quest to reverse the irreversible.
Some scientists are using drugs to limit the harmful inflammation and other secondary damage that arises within hours of a spinal injury. Others, including Drexel University’s prominent spinal-cord group, have restored some muscular function in lab animals by using neural stem cells.
Still others are using drugs to stimulate neural regrowth. A variety of clinical trials are under way or about to begin.
The breadth of activity reflects what some see as a coming of age of spinal-cord science. It has been boosted by a shift in federal spending priorities and an increase in private funds — attributed in part to the lobbying efforts of Dana Reeve, who died this month, and her late husband, actor Christopher Reeve.
Scientists caution against raising the hopes of those with spinal-cord injuries, of whom there are an estimated 250,000 in the United States, according to the University of Alabama-Birmingham. There are no immediate expectations that paralyzed people will walk again, and researchers say that right now, that isn’t even the primary goal.
By Tom Avril
KNIGHT RIDDER NEWS SERVICE