The Levenson Lab investigates the role and regulation of adult stem cells in traumatic brain injury (TBI), with a particular interest in the all too common problem of TBI-associated depression. This work includes examination of the neural stem cell populations found in the adult hippocampus and subventricular zone, and extends to the use of adult human mesenchymal stem cells (hMSC) as a treatment for TBI. Using a well-established pre-clinical model and a full range of genomic, cellular, and behavioral approaches, we are showing that hMSC treatment and nutritional support (e.g., zinc and vitamin A) can prevent TBI-induced depression. We are also developing a comprehensive mechanistic model of how these interventions work at the level of gene expression and stem cell proliferation, survival, and neuronal differentiation.