Synapses underlie rapid and flexible neural communication in the brain and they hold the key to understanding higher brain functions in health and disease. Because they are very small and highly dynamic, it is very difficult to study them with traditional techniques. Fortunately, recent ground-breaking advances in optical microscopy (e.g. STED, PALM, STORM, SIM) have greatly improved our ability to image living synapses at the nanoscale, even down to the level of single molecules. The proposed volume brings together leading researchers to review these exciting new techniques and their application in neurobiological research. It will explain and discuss the basic principles behind the various superresolution modalities, how they are implemented, what their scope and limitations are, etc. In addition, several key research discoveries on synapses enabled by these novel approaches will be highlighted.