A mechanism by which beta-amyloid buildup kills brain cells is proposed over at EurekAlert!: "attacks on the mitochondrial protein Drp1 by the free radical nitric oxide - which causes a chemical reaction called S-nitrosylation - mediates neurodegeneration associated with Alzheimer's disease. Prior to this study, the mechanism by which beta-amyloid protein caused synaptic damage to neurons in Alzheimer's disease was unknown. These findings suggest that preventing S-nitrosylation of Drp1 may reduce or even prevent neurodegeneration in Alzheimer's patients. ... found that beta-amyloid can generate nitric oxide that reacts with Drp1. By identifying Drp1 as the protein responsible for synaptic injury, we now have a new target for developing drugs that may slow or stop the progression of Alzheimer's." Mitochondria are the power plants of cells; all sorts of things start to go wrong when they are systematically damaged. While its true that we've seen mice packed to the gills with beta-amyloid and suffering no harm due to it, indicating that there might be something to blocking the way in which beta-amyloid damages cells, I'd prefer to see clearance or identification and removal of the root cause of the build-up of aggregates rather than a strategy of dealing with them after the fact.