Our results show that MSC-EVs treatment inhibits the deposition of Aβ protein and neuronal loss observed in the hippocampus of AD mice as well as ameliorates the deficits in neuronal structure and function typified by the calcium transients, morphology alterations, mitochondrial changes, excitability abnormalities, and associated cognitive repairments observed in Aβ-stimulated primary culture or APP / PS1 mice. This evidence concerns the gene APP and Alzheimer disease.