We are interested in molecular mechanisms underlying neural development, neuro-degeneration, and bone homeostasis. Although neural development, neurodegeneration, and bone homeostasis are three distinct events/processes, there are potential links among these processes. For examples, patients with neurodegenerative disorders, including Alzheimer’s disease (AD) and Parkinson’s disease (PD), frequently have non-cognitive/non-motor related defects. These non-typical symptoms occur earlier in AD/PD patients’ life, thus, they not only impact patients’ quality of life, but also could be predictor for disease progression. We have found that one of these non-typical defects is bone-degenerative-like phenotype. We therefore have invested significant efforts in understanding why and how the non-typical deficits (e.g., bone deficits) are associated with AD/PD. Technically, we have used a combination of biochemical (in vitro), cell biological (in culture), and genetic mutant animal models to address this issue.