Microglia determine ß-amyloid plaque burden but are non-essential for downstream pathology

Evidence points to a role for microglia in Alzheimer’s disease (AD) risk, although their position in the pathological cascade is incompletely understood, prompting us to generate a model of ß-amyloidopathy lacking microglia. We find evidence that microglia promote plaque formation and creation of an Aß fibril-rich zone surrounding the plaque core. However, plaque-proximal reactive astrogliosis, synapse loss, and neurite dystrophy are still observed in the absence of microglia.