Alzheimer’s disease develops over decades. It begins with a fatal chain reaction in which masses of misfolded beta-amyloid proteins are produced that in the end literally flood the brain. Researchers including Mathias Jucker from the Hertie Institute for Clinical Brain Research (HIH) in Tübingen and the German Center for Neurodegenerative Diseases (DZNE) show in the journal Nature Neuroscience that this chain reaction starts much earlier in mice than commonly assumed. This means that in addition to the well-known early phase of the disease with protein deposits but without symptoms of dementia, there is an even earlier phase in which the chain reaction is triggered by invisible tiny seeds of aggregation. If this is confirmed to occur also in humans, a treatment addressing the causes of disease would have to prevent this process. The scientists have already identified an antibody that might accomplish this.