The 7th Super-Resolution User Club Meeting was held in collaboration with Prof Pavel Hozák , at the Institute of Molecular Genetics of the ASCR in Prague. Keeping the event close to science is one of the founding principles of the event, allowing all participants to network, share and explore exciting new super-resolution and nanoscopy applications. Central to this are the scientific talks given during the meeting, with this cutting-edge microscopy technique as their central theme. A wide selection of topics were covered, prompting interesting discussions during the workshops.
The canonical atrial myocyte (AM) is characterized by sparse transverse tubule (TT) invaginations and slow intracellular Ca2+ propagation but exhibits rapid contractile activation that is susceptible to loss of function during hypertrophic remodeling. Here, we have identified a membrane structure and Ca2+-signaling complex that may enhance the speed of atrial contraction independently of phospholamban regulation. This axial couplon was observed in human and mouse atria and is composed of voluminous axial tubules (ATs) with extensive junctions to the sarcoplasmic reticulum (SR) that include ryanodine receptor 2 (RyR2) clusters. In mouse AM, AT structures triggered Ca2+ release from the SR approximately 2 times faster at the AM center than at the surface.