title: Photoreceptor regulation of spatial visual behavior.
abstract: OBJECTIVE
  To better understand how photoreceptors and their circuits support luminance-dependent spatial visual behavior.
  
  
  METHODS
  Grating thresholds for optokinetic tracking were measured under defined luminance conditions in mice with genetic alterations of photoreceptor activity.
  
  
  RESULTS
  The luminance conditions that enable cone- and rod-mediated behavior, and the luminance range over which rod and cone functions overlap, were characterized. The AII amacrine pathway was found to support low-resolution and high-contrast function, with the rod-cone pathway supporting high-resolution and low-contrast function. Rods alone were also shown to be capable of driving cone-like spatial visual function, but only when cones were genetically maintained in a physiological dark state.
  
  
  CONCLUSIONS
  The study defined how luminance signals drive rod- and cone-mediated spatial visual behavior and revealed new and unexpected contributions for rods that depend on an interaction between cone and rod systems.
authors: Department of Physiology and Biophysics, Weill Medical College of Cornell University, New York, New York, United States Burke Medical Research Institute, White Plains, New York, United States.
authors: Nazia M
authors: NM
authors: Alam
authors: Department of Biology, Johns Hopkins University, Baltimore, Maryland, United States.
authors: Cara M
authors: CM
authors: Altimus
authors: Department of Ophthalmology and Visual Sciences, University of British Columbia, Vancouver, British Columbia, Canada.
authors: Robert M
authors: RM
authors: Douglas
authors: Department of Biology, Johns Hopkins University, Baltimore, Maryland, United States Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States.
authors: Samer
authors: S
authors: Hattar
authors: Department of Physiology and Biophysics, Weill Medical College of Cornell University, New York, New York, United States Burke Medical Research Institute, White Plains, New York, United States.
authors: Glen T
authors: GT
authors: Prusky
mesh_terms: D000818:Animals; D005260:Female; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D010775:Photic Stimulation; D020419:Photoreceptor Cells, Vertebrate / Q000502:physiology*; D013037:Spatial Behavior / Q000502:physiology*; D065854:Spatial Navigation / Q000502:physiology*
keywords: cone; ipRGC; melanopsin; mesopic; optokinetic tracking; photopic; photoreceptors; rod; scotopic; spatial vision; visual behavior