Stem cells have the unique ability to induce plasticity and repair in the nervous system. On one hand, they can give rise into mature neuronal and glial cell types, and act as a source of cell replacement. On the other hand, stem cells have a natural ability to stimulate endogenous mechanisms that promote cell survival, regeneration, and homeostasis in the brain. Our research broadly focuses on understanding the scope and dynamics of such stem cell effects, which can restore and revitalize the neural environment. In particular we are interested in using the information gained from these studies to develop therapeutic approaches for age-related neurological diseases such as Parkinson's disease.