These results indicated that lateral ventricle administration, but not caudal vein injection of BMSC-exos, can improve AD-like behaviors in STZ-injected mice, the mechanism of which might be involved with the regulation of glial activation and its associated neuroinflammation, together with BDNF-related neuropathological changes in the hippocampus. The gene discussed is BDNF; the disease is Alzheimer disease.