Oxidative stress in neurodegeneration: cause or consequence?

Oxidative stress has long been linked to the neuronal cell death that is associated with certain neurodegenerative conditions. Whether it is a primary cause or merely a downstream consequence of the neurodegenerative process is still an open question, however. The advent of a growing number of in vitro and in vivo models that emulate human disease pathology is aiding scientists in deciphering just where oxidative stress intersects with other cellular events in the emerging roadmap leading to neurodegeneration. Here I review the evidence for oxidative stress in neurodegeneration and how this relates to other cellular events.