Mitochondrial health maintenance in axons.

Neurons are post-mitotic cells that must function throughout the life of an organism. The high energetic requirements and Ca2+ spikes of synaptic transmission place a burden on neuronal mitochondria. The removal of older mitochondria and the replenishment of the functional mitochondrial pool in axons with freshly synthesized components are therefore important parts of neuronal maintenance. Although the mechanism of mitochondrial protein import and dynamics is studied in great detail, the length of neurons poses additional challenges to those processes. In this mini-review, I briefly cover the basics of mitochondrial biogenesis and proceed to explain the interdependence of mitochondrial transport and mitochondrial health. I then extrapolate recent findings in yeast and mammalian cultured cells to neurons, making a case for axonal translation as a contributor to mitochondrial biogenesis in neurons.