PSEN1 and Alzheimer disease: The study on an 8‐month‐old APP/PS1 transgenic mice model for AD revealed that astaxanthin (Ast), as a carotenoid with potent antioxidant and neuroprotective properties, can activate the mTOR pathway and can ameliorate cognitive impairment, and suggests that the Ast may be beneficial for the treatment of cognitive impairments in AD.