Mitochondria and ischemic reperfusion damage in the adult and in the developing brain.

The developing and the adult brain respond in similar ways to ischemia, but also display clear differences. For example, the relative contributions of necrosis and apoptosis to neuronal death may be different, such that apoptotic mechanisms would be more prevalent in the developing brain. During normal development, more than half of the neurons in some brain regions are removed through apoptosis, and effectors like caspase-3 are highly upregulated in the immature brain. Mitochondria are pivotal regulators of cell death through their role in energy production and calcium homeostasis, their capacity to release apoptogenic proteins and to produce reactive oxygen species. This review will summarize some of the current studies dealing with mitochondria-related mechanisms of ischemic brain damage, with special reference to developmental aspects.