1 Department of Medicine, Washington University School of Medicine, St. Louis, MO, USA.
2 Washington University Center for Cellular Imaging, St. Louis, MO, USA.
3 Washington University Center for Cellular Imaging, St. Louis, MO, USA; Departments of Cell Biology & Physiology and Neuroscience, Washington University School of Medicine, St. Louis, MO, USA; Department of Biomedical Engineering, Washington University in Saint Louis, St. Louis, MO, USA.
4 Department of Medicine, Washington University School of Medicine, St. Louis, MO, USA. Electronic address: nod@wustl.edu.