Neuronal Mitochondria are Different: Relevance to Neurodegenerative Disease

There are many gaps in basic knowledge about mitochondria, though new research efforts are beginning to fill these gaps as described in this chapter. Notably, there is little understanding of how mitochondrial organelles differ between neurons and other cell types, or within a single cell type. It is also not clear how these dynamic organelles maintain quality control and how entire organelles or portions thereof are turned over or degraded through mitophagy and other mechanisms. Dysregulation of mitochondrial dynamics is linked to compromised quality control, and is increasingly implicated in many neurodegenerative diseases. Neurons have unique properties, including their postmitotic state, and the distribution of mitochondria in distal axons. These and other features of neurons may contribute to their slow rate of mitochondrial turnover under conditions that readily degrade mitochondria in proliferating cells. The chapter also discusses how BCL-xL regulates mitochondrial dynamics and mitochondrial energetics.