Study may help treat spinal cord injuries

CHICAGO, Aug 15, 2005 (United Press International via COMTEX) -- Findings from a University of Chicago study might help physicians restore function to people with paralyzing spinal cord injuries.

Researchers say the same family of chemical signals that attracts developing sensory nerves up the spinal cord toward the brain serves to repel motor nerves, sending them down the cord and away from the brain.

Previously, researchers reported a gradient of biochemical signals known as the Wnt proteins acted as a guide for sensory nerves. These nerves have a receptor on the tips of their growth cones, known as Frizzled3, which responds to Wnts.

In the latest study, researchers show the nerves growing in the opposite direction are driven down the cord, away from the brain, under the guidance of a receptor, known as Ryk, which sees Wnts as repulsive signals.

"This is remarkable example of the efficiency of nature," said Yimin Zou, assistant professor of neurobiology, pharmacology and physiology. "The nervous system is using a similar set of chemical signals to regulate axon traffic in both directions along the length of the spinal cord."

The report appears in the September issue of Nature Neuroscience.