Mitochondria, calcium and cell death: A deadly triad in neurodegeneration

Mitochondrial Ca²⁺ accumulation is a tightly controlled process, in turn regulating functions as diverse as aerobic metabolism and induction of cell death. The link between Ca²⁺ (dys)regulation, mitochondria and cellular derangement is particularly evident in neurodegenerative disorders, in which genetic models and environmental factors allowed to identify common traits in the pathogenic routes. We will here summarize: i) the current view of mechanisms and functions of mitochondrial Ca²⁺ homeostasis, ii) the basic principles of organelle Ca²⁺ transport, iii) the role of Ca²⁺ in neuronal cell death, and iv) the new information on the pathogenesis of Alzheimer's, Huntington's and Parkinson's diseases, highlighting the role of Ca²⁺ and mitochondria.