said that gamma secretase is present throughout the body and, despite its role in the development of amyloid plaques
, plays a significant role in numerous important functions.
Florbetaben and florbetapir are both [.sup.18]F imaging compounds that bind to amyloid plaque
in the human brain.
"But this new study would suggest we might be able to intervene even before the amyloid plaques
begin to form.
Morgan of the University of South Florida in Tampa each described immunizing genetically engineered mice that normally develop amyloid plaques
and lose memory and learning skills.
The new method uses the drug florbetaben as a tracer during a PET scan of the brain to visualize amyloid plaques
If amyloid plaques
do cause Alzheimer's, then blocking beta-secretase may slow progression of the disease.
After the study, it was discovered that 25 percent of the participants had evidence of amyloid plaques
, which can appear years before the symptoms of Alzheimer's disease begin.
Taken aback by their findings, the investigators then gave a similar series of injections to 11-month-old mice that had already developed amyloid plaques
. The shots prevented additional amyloid deposits and even triggered clearance of some existing plaques, the scientists found.
Since people with memory problems who do not have amyloid plaques
are unlikely to have AD, the news raises hopes that scientists may at last have found a method of determining whether a living person has or is developing AD.
Beta-amyloid proteins are fragments that do not get eliminated by the brain, but instead accumulate and form sticky masses, or amyloid plaques
, which are associated with the destruction of neurons and the gradual loss of brain tissue.
Yet the new lesions are distinct from the amyloid plaques
, rarely overlapping in the brain, the investigators report.
Definitive conclusion came only after the death of the individual, when the brain samples containing high levels of beta amyloid plaques
, the growths that characterise AD, were found.