Â鶹´«Ã½

Joshua R. Sanes, (314) 362-2507, [email protected]; or

Bill Loftus, (208) 885-7694, [email protected]

Molecules Guide Nerve Growth, a Finding Key to Future Medical Advances, UI Researcher Says

MOSCOW, Idaho -- The discovery of key molecules that affect nerve growth both expand basic understanding of the topic and may lead to medical treatments for illnesses ranging from muscular dystrophy to nerve and spinal injury, a University of Idaho scientist believes.

Those molecules, ephrins, determine how muscle and spinal muscles connect. Beyond helping neurobiologists learn how genetic conditions may disrupt that connection, ephrins may someday help reconnect damaged nerves or the spinal cord, said Michael Laskowski of the University of Idaho at Moscow.

For now, the study expands understanding of how organisms map the links between nerves and muscles.

Laskowski was a member of a team of scientists from Washington University Medical School at St. Louis, Harvard Medical School at Cambridge, Mass., and the Medical Nobel Institute at Stockholm probing the role of ephrins. The team's work appears in the latest issue of Neuron, a widely respected international journal.

The paper's authors include Guoping Feng, who with Laskowski was credited with contributing equally to the work, David A. Feldheim of Harvard Medical School, Hongmin Wang of UI, Renate Lewis of Washington University Medical School, Jonas Frisen of the Medical Nobel Institute at the Stockholm-based Karolinska Institute, John G. Flanagan of Harvard and Joshua Sanes of Washington Univeristy.

Laskowski is the UI director for the Washington, Wyoming, Alaska, Montana and Idaho Medical Program.
A television commercial during January's Super Bowl showed actor Christopher Reeve walking to signify the possibility of future breakthroughs. It raised the hopes of those with spinal injuries that a cure had been found.

The latest research into how ephrins affect nerve growth and regeneration may help treat injuries but he wants to avoid wrongly inflating hopes. "I get letters asking if I can help people who are paraplegics or quadriplegics." Laskowski said he has a close friend who lost the use of his legs and must tell him, too, that prospects for a cure remain far off still.

"The things my lab is involved in look at the long run," Laskowski said. That said, he is confident the team's newly published study and other work lays the foundation for progress.

Scientists long have tried to trace the chemical mechanism that allows nerves to connect with developing muscles. The question was, Laskowski said, "What is it the growing nerve homes in on, sort of the lock-and-key fit that it works on."

Growing muscles and nerves must follow a sort of topographic mapping system, much as a cruise missile must sense its surroundings to find its intended target.

The discovery of a molecule important in the optic nerve helped focus attention on ephrins, Laskowski said. The latest study showed how important ephrins are.

"It is important in understanding how the visual system and the spinal cord system work," Laskowski said. "It is all based on genetics and understanding what the molecule is."

The study relied on specially cloned mice. One set, produced by Feng and Sanes, was genetically manipulated so that high levels of ephrin were produced in muscles that usually have low levels. In the other set of mice, produced by the Harvard and Stockholm labs genes for two ephrins were deleted so muscles had none of these ephrins.

As a result, the neurobiologists could study the animals' ability to successfully map proper nerve-muscle connections with the production of too little or too much ephrin. It turned out that the body requires precise amounts of ephrin for the system to function properly.

Laskowski conducted much of his share of the research while on sabbatical leave at Washington University. He and Joshua Sanes there have collaborated on research since the mid-1980s. The National Institutes of Health supported their research and work by Harvard's Flanagan.

--30--

BL-2/23/2000
WWAMI