The role of mitochondria in epilepsy: implications for neurodegenerative diseases.

The epileptic seizures observed in a broad variety of diseases involving mitochondrial DNA (mtDNA) and central nervous system pathology strongly suggest the possible role of mitochondria in the pathomechanism of various forms of epilepsy. The mtDNA mutations in these diseases affect the functions of complexes of oxidative phosphorylation that have mitochondria-encoded subunits. Similar deficiencies of oxidative phosphorylation, in particular of Complexes I and IV, have been detected in the epileptogenic brain regions of therapy-resistant focal epilepsies, such as the hippocampal subfield CA3 in temporal lobe epilepsy with Ammon's horn sclerosis. This suggests that impaired mitochondrial function can affect the viability and excitability of hippocampal neurons because of (1) decreased production of adenosine 5'-triphosphate; (2) increased generation of reactive oxygen species; and (3) alteration of calcium homeostasis.