This immune tolerance is abolished by early low-level stimulation of microglia with TLR4 agonists such as LPS or monophosphoryl lipid A (MPL), which were shown to restore long-term potentiation that was impaired by Aβ and improve spatial and working memory in an AD rat model (Pourbadie et al., 2018). This evidence concerns the gene TLR4 and Alzheimer disease.