Formation of rock-hard protein in the brains of Alzheimer's disease victims may result from the loss of a key chemical that promotes signals between brain cells, researchers say.
Dr. Richard J. Wurtman, head of a lab at the Massachusetts Institute of Technology, where the study was done, said the finding directly links for the first time two characteristics of Alzheimer's and suggests a new way of treating or preventing the disease with drugs.
Researchers had established that patients with Alzheimer's disease have an abnormal buildup of a protein called amyloid, a substance that Wurtman calls "insoluble brick." Studies also have found that Alzheimer's patients have a shortage of a brain chemical called acetylcholine.
"Our finding is that these two are related," Wurtman said in an interview.
In a study with researchers from Massachusetts General Hospital, Wurtman said his group showed that the lack of acetylcholine causes nerve cells in the brain to metabolize protein in a way that leads to an accumulation of amyloid.
"This is a novel and bold new stroke in Alzheimer's research and should stimulate many new efforts to understand the formation of this toxic substance (amyloid) in the brain of Alzheimer's patients," said Dr. Thomas N. Chase, an Alzheimer's disease researcher at the National Institutes of Health.
"What Wurtman and his group have done is find one controlling factor in the formation of amyloid," he said. "It's a surprising one."
Chase said that if the work can be confirmed in other labs "it opens new doors" in Alzheimer's drug research.
The MIT-Massachusetts General study is to be published today in the journal Science.
Wurtman said the basic finding is that a chemical important in the thinking process also plays a role in the metabolism of protein in the brain.
Co-authors with Wurtman in the study were Roger M. Nitsch and John H. Growdon of Massachusetts General and Barbara E. Slack of MIT.