Dstorm Of Synaptic Proteins

Synapses are specialized cell-cell junctions of several hundred nanometers in size that serve as junctions/contact points through which nerve cells send signals to other nerve cells, to muscle cells, or to hormone-secreting cells. Efficient synaptic transmission relies on the precise and specific interaction of synaptic proteins and vesicle fusion and changes in protein dynamics and expression are thought to allow synaptic plasticity. Unfortunately, our understanding of the exact nanoscopic distribution of individual proteins, their absolute numbers and interactions, and changes occurring during learning and memory, and in neurodegenerative disorders is still in its infancy. This is due to difficulties to study sub-synaptic structures e.g. by fluorescence microscopy due to the small size of synapses, which is near the diffraction-limited resolution of light microscopy and the limitation to visualize single synaptic protein localization and dynamics in the synapse. We demonstrate how super-resolution fluorescence imaging by direct stochastic optical reconstruction microscopy (dSTORM) can be used advantageously to study the distribution of synaptic proteins with an optical resolution of 15-20 nm in the imaging plane using standard, commercially available fluorescent probes. We demonstrate the potential of dSTORM by resolving the distribution and clustering of presynaptic proteins as well as postsynaptic receptors and postsynaptic junctional folds.