Correlating synaptic vesicle motion to cytoskeletal structure of the presynapse and axon.

Two neurons communicate via release of neurotransmitter from a presynapse of one neuron to a post-synapse of another. This neurotransmitter is carried from the inside of the presynapse to the membrane of the presynapse using a presynaptic vesicle. The transport mechanics of presynaptic vesicles thus influences presynaptic communication. Presynaptic vesicles undergo many types of motion, but it is still unclear how their motion corresponds to the overall structure of the synapse. High resolution fluorescence microscopy has recently been shown to be an effective tool to understand vesicle motion. We take advantage of recent three-dimensional microscopy experiments and develop a three-dimensional computational analysis method of single vesicle motion in live cells. We use the computational method to classify types of motion, then distinguish different types of motion relative to the known structure of the synapse observed. We show that this approach can distinguish types of vesicles motion relative to the synapse. This method also allows us to take a closer look at the vesicles when the motion is directed.