TANGLED proteins that strangle brain cells from within seem to be what allows Alzheimer's disease to spread through the brain.
Alzheimer's damages the brain via a tangled version of the tau protein. Now Michel Goedert of the Laboratory of Molecular Biology in Cambridge, UK, and his colleagues have shown that tangles spread the disease from site to site. When they injected the brains of ordinary mice with brain material from mice that didn't have Alzheimer's, but were engineered to produce tangles, the tangles spread beyond the injection sites (Nature Cell Biology, DOI: 10.1038/ncb1901).
Next the researchers hope to identify and block the agent that allows the tangles to spread.