Mitochondria, the Synapse, and Neurodegeneration

Abstract

Mitochondria have a remarkably sophisticated structure and essential function within neurons that ensure normal synaptic transmission and maintained synaptic plasticity and hence normal information processing that can occur within the brain. The importance of mitochondria for synaptic structural preservation and activity is exemplifi ed by a high mitochondrial density at synaptic sites, whereas synaptic mitochondrial dysfunction or loss of mitochondria from synapses leads to synaptic abnormalities. The increasing body of evidence for mitochondrial defects, early synaptic dysfunction, and/or decreased synaptic density in common neurodegenerative disorders places these organelles at centre stage and establishes synaptic mitochondria as good candidates for drug targeting. In this chapter, we describe synaptic mitochondrial functions and present the evidence for synaptic disturbances in common neurodegenerative and mitochondrial diseases. Finally, we discuss the proposed mechanisms of neuronal loss with a focus on early synaptic loss. Keywords Neurons and MitochondriaThe highly specialized neuronal morphology allows neurons to form networks that control and facilitate all the information processing that occurs within the brain. Information is conveyed from one neuron to another via synaptic transmission, a process that is highly dependent on mitochondrial function. Hence, mitochondrial