Fig. 4

Endotoxin may act at different steps to promote neurodegeneration. (1) Endotoxin may promote aggregates of Aβ, tau, α-synuclein and TDP-43 by inhibiting removal or by increasing production, spread or aggregation (in part by stimulating ROS production). (2) Endotoxin may prime microglia and stress neurons, making them more susceptible to disease-specific agents. (3) Endotoxin may activate microglia, already primed by disease to execute stressed synapses and neurons