Analysis of mitochondrial free radical generation in animal models of neuronal disease

Mitochondria, the power plant of all eukaryotic cells, produce cellular energy in the form of ATP via electron transport and oxidative phosphorylation. However, the mitochondria leak electrons that can act as major sources of oxidative stress, and their dysfunction, have been proposed as causative events underlying neurodegeneration in stroke and neurodegenerative diseases. We examined whether MitoTracker Red CM-H2XRos, a rosamine derivative used to detect mitochondrial free radicals in vitro, would be applied to analyze the mitochondrial free radicals in various models of neurological diseases in vivo. The injections of MitoTracker Red CM-H2XRos revealed generation of mitochondrial free radicals primarily in vulnerable neurons following focal cerebral ischemia as well as administration of Fe2+ or 3-nitropropionic acid. MitoTracker Red CM-H2XRos was retained after fixation, compatible with immunocytochemistry or nuclear staining, and can be applied to study roles of mitochondrial free radicals in the process of neurodegeneration in vivo.