AMPK: keeping the (power)house in order?

Metabolically energetic organs, such as the brain, require a reliable source of ATP, the majority of which is provided by oxidative phosphorylation in the mitochondrial matrix. Maintaining mitochondrial integrity is therefore of paramount importance in highly specialized cells such as neurons. Beyond acting as cellular 'power stations' and initiators of apoptosis, neuronal mitochondria are highly mobile, transported to pre- and post-synaptic sites for rapid, localized ATP production, serve to buffer physiological and pathological calcium and contribute to dendritic arborization. Given such roles, it is perhaps unsurprising that recent studies implicate AMP-activated protein kinase (AMPK), a cellular energy-sensitive metabolic regulator, in triggering mitochondrial fission, potentially balancing mitochondrial dynamics, biogenesis and mitophagy.