In addition, we assessed the impact of a low and of a high concentration of spermidine on AD-related neuropathology, autophagic activity, APP cluster clearance and microtubule acetylation, employing single molecule and correlative microscopy techniques in an in vitro and in vivo model of paraquat-induced neurotoxicity and a model of APP overexpression. The gene discussed is APP; the disease is Alzheimer disease.