Spinal Cord Injury Treatment May Improve With New Findings On Nervous Sys...( Hyrc Ph.D. The research was performed...)

The researchers also reported that compounds that block glutamate's destructive action reduced stroke-related injury of oligodendrocytes in culture. And McDonald's most recent work has revealed that these compounds, called AMPA receptor antagonists, also protect white matter in the injured spinal cord. The compounds are being examined in clinical trials to evaluate safety, and it soon might be possible to test their effectiveness against central nervous system injury.

"Preserving the function of just a small fraction of the damaged long cables that go down the spinal cord could provide meaningful improvement in day-to-day function for people who sustain spinal cord injury," says McDonald, who also is director of the Spinal Cord Injury Unit at Barnes-Jewish Hospital. In the early 1980s, Washington University in St. Louis researchers discovered that glutamate, a chemical messenger that neurons squirt onto other neurons, turns into a killer when it floods onto neighboring cells from ruptured neurons. They named this phenomenon 'excitotoxicity' because glutamate can overexcite receptors on nearby neurons, opening channels that admit lethal amounts of calcium. These receptors are called NMDA receptors because they can be stimulated in the laboratory with a glutamate mimic called NMDA.

Subsequent experiments convinced the neuroscience community that oligodendrocytes are invulnerable to glutamate damage. First, scientists found that oligodendrocytes do not express NMDA receptors - they have a different type of glutamate receptor, the AMPA receptor, which is not so permeable to calcium. Second, they observed that even high levels of glutamate or AMPA fail to kill oligodendrocytes in culture.

Goldberg and McDonald were culturing different types
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Contact: Linda Sage
sage@medicine.wustl.edu
314-286-0119
Washington University in St. Louis
10-Apr-1998