1 Department of Pharmacology, School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina.
2 Department of Cell Biology & Physiology, School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina.
3 Richard D. Berlin Center for Cell Analysis and Modeling, University of Connecticut School of Medicine, Farmington, Connecticut.
4 Department of Neuroscience & Regenerative Medicine, Medical College of Georgia at Augusta University, Augusta, Georgia. Electronic address: evitriol@augusta.edu.