Monday, July 24, 2006

Re-Growing Nerves After Spinal Cord Injury

In a recent study, researchers from Johns Hopkins in Baltimore and the University of Michigan in Ann Arbor have uncovered a treatment involving the use of the enzyme sialidase to help regain growth of the spinal cord nerves after an injury.

Researchers mirrored a human injury in rats that would occur if the arm were forcefully tugged from the body, causing nerves to be jerked from the spinal cord, the arm to lose muscle and feeling, and the body to become unable to support the arm, such as in childbirth or a motorcycle accident. This was mimicked by severing nerves between the rats shoulder and spinal cord.

Rats were then given one of three enzymes into a transplanted nerve, put in to rejoin damaged nerve ends. Four weeks later, dyes were injected into the nerves to observe the growth of nerve fibers.
Sialidase, one of the enzymes given, proved to be effective, revealing more than twice the amount of new nerve fibers created by the dummy treatment of saline.

"Molecules in the environment of the injured spinal cord are specifically instructing the nerve not to re-grow," according to Ronald Schnaar, Ph.D., professor of pharmacology and neuroscience at Johns Hopkins. However, he adds researchers "have established that the enzyme sialidase, which destroys one of the molecules that inhibits nerve regeneration, is sufficient to robustly improve nerve fiber outgrowth from the spinal cord."

Surgical procedures to help nerve fiber growth are sometimes helpful, but researchers believe the addition of this treatment could be beneficial.

Dr. Schnaar and his colleagues at Johns Hopkins are testing sialidase to see if it can assist in other types of spinal cord injuries.