MAPT and Cognitive impairment: Another study showed that Aβ, Tau fibrils and AD patient brain lysates injected into the gut of 3 × Tg AD mice, cause Aβ and tau pathology to spread from the colon into the brain through the vagus nerve, initiates an inflammatory response that activates C/EBPβ/δ-secretase, resulting in AD pathology with cognitive impairment [78].