Tony Wyss-Coray is a professor of Neurology and Neurological Sciences at Stanford University, the Co-Director of the Stanford Alzheimer’s Disease Research Center, and the Associate Director of the Center for Tissue Regeneration, Repair and Restoration at the Palo Alto VA. In this talk he talks about blood borne factors from young mice or humans are sufficient to slow aspects of brain aging and improve cognitive function in old mice, and vice versa, factors from old mice are detrimental for young mice and impair cognition.