Figure 3.

The transport and function of synaptic mitochondria. Movement of mitochondria along the axonal cytoskeleton is mediated by kinesin and dynein microtubule motors that are complexed with Milton/TRAK proteins and Miro, a protein localized to the outer membrane of mitochondria. Kinesin traffics mitochondria from soma to axon terminals (anterogradely) and dynein back to the soma (retrogradely). As neurons develop, the rate of mitochondrial trafficking to synapses decreases, hence, synapses are dense in mitochondria and accommodate high energy demands at presynaptic terminals. Synaptic mitochondria exhibit unique properties including higher levels of ROS, fission, and lower ATP production.