Researchers have found compelling evidence that certain neurodegenerative diseases such as “mad cow” disease, Alzheimer’s, and Parkinson’s may be significantly caused by a simple physical change in a normal protein called prion that’s found in all mammals so far examined. The newfound ability to make synthetic varieties of the prion protein allowed experimenters to see that “misfolding” a certain part of the protein causes it to turn into the infectious variety of itself.
The Science Daily article does a good job of explaining this breakthrough research. It goes on to say that they believe this misfolding occurs in everyone, but normally the misshapen proteins are cleared away in the brain. Next question: why doesn’t the clearing happen in some brains?