Astrocyte mitochondrial mechanisms of ischemic brain injury and neuroprotection

Research on ischemic brain injury has established a central role of mitochondria in neuron death (1-3). Astrocytes are also damaged by ischemia (4), although the participation of mitochondria in their injury is ill defined. As astrocytes are responsible for neuronal metabolic and trophic support, astrocyte dysfunction (5) will compromise postischemic neuronal survival. Ischemic alterations to astrocyte energy metabolism and the uptake and metabolism of the excitatory amino acid transmitter glutamate may be particularly important. Despite the significance of ischemic astrocyte injury, little is known of the mechanisms responsible for astrocyte death and dysfunction. This review focuses on differences between astrocyte and neuronal metabolism and mitochondrial function, and on neuronal-glial interactions. The potential for astrocyte mitochondria to serve as targets of neuroprotective interventions is also discussed.