MAPT and Cognitive impairment: As an example, the novel drugs ANAVEX® 3–71 and ANAVEX® 2–73, which possess dual agonist properties on both M1 and σ1R muscarinic receptors, have demonstrated efficacy in alleviating cognitive deficits, synaptic impairment, amyloid and tau pathologies, and neuroinflammation in murine models of AD [66,67,68,69].