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Alzheimer's disease strikes about a quarter of all people who reach their eighties and affects millions of patients and their families. Although the cause of the disease remains a mystery, it is known that the brains of Alzheimer's victims contain structures - senile plaques and neurofibrillary tangles - which are not present in normal brains.
A team of physicists at Boston University's Center for Polymer Studies, working with neurologists at Massachusetts General Hospital, has been able to gain a clearer picture of the structure of these plaques, as well as a better understanding of how they develop in the brain. The BU team, including Sergey Buldyrev, Luis Cruz, Shlomo Havlin, Brigita Urbanc and led by physics Professor H. Eugene Stanley worked from digitized images of extremely thin sections of plaques produced by the MGH team. Using a Silicon Graphics Onyx2 supercomputer, the BU team reconstructed the plaques in three dimensions and found, contrary to previous belief, the plaques are not solid, but have porous cores which become progressively less dense as you move toward the outer surface. The scientists then used a computer simulation which grew clusters similar to plaques, molecule by molecule to demonstrate that the porosity was caused by a simultaneous building up and wearing down of the amyliod protein (amyloid b) deposits that make up the plaque.
Another aspect of the research which involves mapping and comparing the topography of normal brains with those of people who have died of Alzheimer's has resulted in the discovery of a column-like structure of neurons between the layers of the brain which is less pronounced in Alzheimer's victims. Work is also underway to better understand how neurofibrillary tangles are formed and how they effect the neurons of the brain.
This research was funded in part by a five-year, $2.2 million National Institutes of Health grant and a more recent, one-year, $300,000 grant from an anonymous foundation.
The Center for Polymer Studies is also involved in a number of important projects that utilize advanced computational approaches to understand natural and social phenomena. These include the establishment of the Center for Complex Biomedical Signals, a joint project with Harvard University and MIT; applying statistical analyses to reveal new economic paradigms; studying the phenomenon of spontaneous self-stratification, which has enormous implications for understanding how avalanches occur; and understanding the complex and unusual nature of water - the most abundant substance on Earth. |
