Fig. 5

Microglia may mediate the synergy between LPS, Aβ and TAU to induce neurodegeneration. Exposure of microglia to Aβ or LPS can prime microglia, such that subsequent exposure to LPS or Aβ results in a different quantity or quality of inflammation. These inflamed microglia may induce: i) hyperphosphorylation and aggregation of TAU in neurons, ii) phagocytosis of stressed synapses and neurons, and iii) neurotoxicity. All of these may promote TAU spreading to other brain regions