AMP-activated protein kinase protects against anoxia in Drosophila melanogaster.

During anoxia, proper energy maintenance is essential in order to maintain neural operation. Starvation activates AMP-activated protein kinase (AMPK), an evolutionarily conserved indicator of cellular energy status, in a cascade which modulates ATP production and consumption. We investigated the role of energetic status on anoxia tolerance in Drosophila and discovered that starvation or AMPK activation increases the speed of locomotor recovery from an anoxic coma. Using temporal and spatial genetic targeting we found that AMPK in the fat body contributes to starvation-induced fast locomotor recovery, whereas, under fed conditions, disrupting AMPK in oenocytes prolongs recovery. By evaluating spreading depolarization in the fly brain during anoxia we show that AMPK activation reduces the severity of ionic disruption and prolongs recovery of electrical activity. Further genetic targeting indicates that glial, but not neuronal, AMPK affects locomotor recovery. Together, these findings support a model in which AMPK is neuroprotective in Drosophila.