Dysregulation of intracellular Ca2+ homeostasis has been proposed as a common proximal cause of neural dysfunction during aging and Alzheimer's disease (AD). In this context, aberrant Ca2+ signaling has been viewed as a neuronal phenomenon mostly related to the dysfunction of intracellular Ca2+ stores. However, recent data suggest that, in AD, Ca2+ dyshomeostasis is not restricted to neurons but represents a global phenomenon affecting virtually all cells in the brain.