Second harmonic imaging of axonal microtubules and examining the impact of their molecular conformation on mitochondrial transport

Mitochondria are often referred to as the power plants of the cell as they provide energy to ensure healthy cell functioning. These organelles are created in the soma and are transported to different cell compartments with high energy needs via the cell's cytoskeleton. Two of the major components of the cytoskeleton involved in mitochondrial transport are the microtubule and actin network. While most cell types have no spatial constriction for mitochondria to move around, nerve cells pose a specific risk for efficient transport as these cells can have processes that are up to 1 meter long. Generally a neuron has one single axon which sends out information towards other cells and a highly branched dendritic network, receiving information from other cells. Apart from the length of these projections, the axon is extremely narrow with an average diameter of 1 μm. As mitochondria are rather large organelles, the passage through this narrow shaft could easily get obstructed. Therefore we propose that tight regulation of mitochondrial fission events and the organisation of the cytoskeleton, specifically of the microtubule and actin network, is required to facilitate mitochondrial transport within this constricted space. Advanced imaging techniques will be used in combination with optogenetic tools to assess fission events and the organisation of the cytoskeleton during mitochondrial transport in axons.status: publishe