1. Department of Biological Structure, University of Washington, Seattle, WA 98195, USA
2. Neurobiology and Behavior Program, University of Washington, Seattle, WA 98195, USA
3. Molecular and Cellular Biology Program, University of Washington, Seattle, WA 98195, USA
4. Department of Physiology and Biophysics, University of Washington, Seattle, WA 98195, USA
5. Department of Ophthalmology and Visual Sciences, John A. Moran Eye Center, University of Utah, Salt Lake City, UT 84132, USA