1. Department of Cell Biology and Physiology, Washington University School of Medicine, Saint Louis, MO 63110, USA.
2. Center for the Investigation of Membrane Excitability Diseases, Washington University School of Medicine, Saint Louis, MO 63110, USA.
3. Department of Anesthesiology, Washington University School of Medicine, Saint Louis, MO 63110, USA.
4. Center for the Study of Itch and Sensory Disorders, Washington University School of Medicine, Saint Louis, MO 63110, USA.
5. Department of Pathology and Immunology, Washington University School of Medicine, Saint Louis, MO 63110, USA.
6. Washington University Center for Cellular Imaging, Washington University School of Medicine, Saint Louis, MO 63110, USA.
7. Department of Neuroscience, Washington University School of Medicine, Saint Louis, MO 63110, USA.
8. Department of Biomedical Engineering, Washington University in Saint Louis, Saint Louis, MO 63130, USA.