Of axons that struggle to make ends meet: Linking axonal bioenergetic failure to programmed axon degeneration.

Axons are the long, fragile, and energy-hungry projections of neurons that are challenging to sustain. Together with their associated glia, they form the bulk of the neuronal network. Pathological axon degeneration (pAxD) is a driver of irreversible neurological disability in a host of neurodegenerative conditions. Halting pAxD is therefore an attractive therapeutic strategy. Here we review recent work demonstrating that pAxD is regulated by an auto-destruction program that revolves around axonal bioenergetics. We then focus on the emerging concept that axonal and glial energy metabolism are intertwined. We anticipate that these discoveries will encourage the pursuit of new treatment strategies for neurodegeneration.