1. Department of Molecular and Integrative Physiology (H.-Y.L., S.Z., O.D.S.), University of Illinois at Urbana-Champaign, Urbana, Illinois 61801
2. Department of Cell Biology and Neuroscience, University of South Alabama College of Medicine (P.A.F.), Mobile, Alabama 36688
3. College of Medicine (O.D.S.), University of Illinois at Urbana-Champaign, Urbana, Illinois 61801