Saul Villeda is an assistant professor and holds an endowed chair in biomedical science at the University of California, San Francisco. He received his Ph.D. in neuroscience from Stanford University, advised by Tony Wyss-Coray, where he studied how systemic changes in aging blood contribute to age-related impairments in neural stem cell function and cognitive processes. Immediately after graduate school, Villeda started his independent career at UCSF as a Sandler faculty fellow in the department of anatomy and at the Eli and Edythe Broad Center for Regeneration Medicine and Stem Cell Research. In starting his own laboratory, Villeda began investigating the cellular and molecular mechanisms underlying the rejuvenation of the aging brain. Villeda discovered that the aging process in the brain can be reversed by altering levels of circulating factors in blood. This work challenges traditional views that the aged brain lacks the inherent ability to combat the effects of aging, resulting in permanent functional impairments. Villeda is best known for his use of innovative heterochronic parabiosis and blood plasma administration approaches to investigate the influence of exposure to young blood in promoting molecular and cellular changes underlying cognitive rejuvenation. His work has garnered accolades including a National Institutes of Health Director’s Early Independence Award, a W.M. Keck Foundation medical research grant, and the Glenn Award for Research in Biological Mechanisms of Aging.