Guoxin Ying‡1, Jeanne M. Frederick‡ and Wolfgang Baehr‡,§,¶2 From the ‡Department of Ophthalmology, University of Utah Health Science Center, Salt Lake City, Utah 84132, the §Department of Neurobiology and Anatomy, University of Utah, Salt Lake City, Utah 84112, and the ¶Department of Biology, University of Utah, Salt Lake City, Utah 84132 ↵1 To whom correspondence may be addressed. E-mail: g.ying{at}utah.edu. ↵2 Recipient of an RPB Senior Investigator award and an RPB Nelson Trust award.