The aims of the MRC Mitochondrial Biology Unit are to study the biology of the mitochondria, the powerhouses of the cell. There is a growing realisation that the dysfunction of various aspects of mitochondrial biology are connected to major neurodegenerative diseases including Parkinson's and Alzheimer's, and that as the major source of reactive oxygen species, the mitochondrion is likely also to be involved in ageing. Therefore, the Unit is developing its interests in the cell biology of mitochondria and is linking its activities to clinical science.