ALZHEIMER'S Brain cell removal offers hope

Mouse study is successful in clearing plaque that might cause the disease.
ST. LOUIS (AP) -- Brain cells in mice recovered rapidly after brain plaques characteristic of Alzheimer's disease were removed, offering hope that plaque-clearing treatments could benefit patients with the disease, Washington University researchers said Thursday.
Results of the study will appear in the Feb. 5 issue of the Journal of Clinical Investigation.
No one knows for sure if the sticky plaque -- amyloid beta peptide -- is the true cause of Alzheimer's, a brain degeneration disease that eventually robs victims of memory and the ability to communicate and care for themselves. About 4.5 million Americans have the disease.
But the plaque is a prime suspect, and several companies are developing drugs to target the buildup.
Researchers at Washington University injected mice with an antibody that cleared plaque in parts of the brain. Where the plaque was cleared, swelling on nerve cell branches disappeared quickly, the researchers said. They cautioned that while encouraging, more studies are needed to determine if similar effects might occur in people.
'Rapid recovery'
Removing the plaque "often led to rapid recovery of normal structure over a few days," said Dave Holtzman, senior author of the study and head of the Department of Neurology at Washington University.
He said that confirmed benefits of plaque-clearing treatments and "also gets us rethinking our theories on how plaques cause nerve cell damage."
Holtzman was among scientists who previously regarded plaque damage to nerve cells as something that happened once and was irreversible. Instead, the results suggest that plaques might not just cause damage but actively maintain it, he said.
Researcher Robert Brendza said he had expected the progression of cell damage to stop once the plaque was cleared. "But what we saw was much more striking: In just three days, there were 20 to 25 percent reductions in the number or size of the existing swellings," he said.
The rapid ability of the nerve cells to regain their normal structure could indicate that the cells are constantly trying to restore their normal structure, the researchers said.
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