Researchers provide evidence that LPS is a potent inducer for neuroinflammation by activation of astrocyte, microglia-cells, and TLR4, α7 nAChR, LRP-1 receptors, Aβ accumulation, and tau phosphorylation, which leads to neuronal loss, synaptic dysfunction, memory loss, decline in cognitive behaviors results in PD and Alzheimer’s disease. This evidence concerns the gene TLR4 and Alzheimer disease.