Mitochondrial dysfunction, oxidative stress and neurodegeneration.

Mitochondria play a critical role in several metabolic processes and apoptotic pathways, regulating life cycle from the cradle to the grave. Despite the evidence of morphological, biochemical and molecular abnormalities in mitochondria in various tissues of patients with neurodegenerative disorders, the question "is mitochondrial dysfunction a necessary step in neurodegeneration?" is still unanswered. Moreover, a growing body of evidence seems to indicate that oxidative stress, which is increased in damaged mitochondria, is an earlier event associated with neurodegeneration. Here we examine the current evidences in this field, which indicate a key role of mitochondria and oxidative stress in contributing to the neurodegenerative processes.