1. Coleman Memorial Laboratory and W. M. Keck Center for Integrative Neuroscience, Department of Otolaryngology, University of California, San Francisco, California 94143-0342;
2. Departments of Neuroscience and Otolaryngology, University of Florida Brain Institute, Gainesville, Florida 32610-0244; and
3. Department of Bioengineering, University of Utah, Salt Lake City, Utah 84112-9458