Alzheimer's may originate via infection

Alzheimer's may originate in a form similar to that of infectious prion diseases such as bovine spongiform encephalopathy (mad cow), U.S. researchers say. Claudio Soto, professor of neurology at The University of Texas Medical School at Houston, and colleagues injected the brain tissue of a confirmed Alzheimer's patient into mice and compared the results to those from injected tissue of a control without the disease. None of the mice injected with the control showed signs of Alzheimer's, whereas all of those injected with Alzheimer's brain extracts developed plaques and other brain alterations typical of the disease. "Our findings open the possibility that some of the sporadic Alzheimer's cases may arise from an infectious process, which occurs with other neurological diseases such as mad cow and its human form, Creutzfeldt-Jakob disease," Soto said in a statement. "The underlying mechanism of Alzheimer's disease is very similar to the prion diseases. It involves a normal protein that becomes misshapen and is able to spread by transforming good proteins to bad ones. The bad proteins accumulate in the brain, forming plaque deposits that are believed to kill neuron cells in Alzheimer's." The study was published in the online issue of Molecular Psychiatry.