Administration of these exosomes to the lateral ventricle in the streptozotocin (STZ) model of AD inhibits the hyperactivity of hippocampal microglia and astrocytes, downregulates the expression level of IL‐1β, IL‐6, TNF‐α, Aβ1‐42, p‐Tau and up‐regulate the expression of BDNF as an essential synapse‐related protein. This evidence concerns the gene MAPT and Alzheimer disease.