title: Contrast sensitivity, spatial and temporal tuning of the larval zebrafish optokinetic response.
abstract: OBJECTIVE
  To characterize the quantitative properties of the optokinetic response (OKR) in zebrafish larvae as a tool to test visual performance in genetically modified larvae.
  
  
  METHODS
  Horizontal OKR was triggered in 5-day-old zebrafish larvae by stimulation with projected computer-generated gratings of varying contrast, angular velocity, temporal and spatial frequency, and brightness. Eye movements were analyzed by a custom-made eye tracker based on image analysis.
  
  
  RESULTS
  The gain of the OKR slow phase was dependent on angular velocity, spatial frequency, and contrast of a moving grating, but largely independent on brightness. Eye velocity was a logarithmically linear function of grating contrast with a slope of approximately 0.8 per log unit contrast.
  
  
  CONCLUSIONS
  The OKR of the larval zebrafish is not scaled for stimulus contrast and spatial frequency. These properties make the OKR a valuable tool to quantify behavioral visual performance such as visual acuity, contrast sensitivity, and light adaptation. This behavioral paradigm will be useful for analyzing visual performance in mutant and gene-knockdown larval zebrafish.
authors.affiliation: Swiss Federal Institute of Technology, Department of Biology, and Brain Research Institute of the University Zurich, Zurich, Switzerland.
authors.forename: Oliver
authors.initials: O
authors.lastname: Rinner
authors.forename: Jens M
authors.initials: JM
authors.lastname: Rick
authors.forename: Stephan C F
authors.initials: SC
authors.lastname: Neuhauss
mesh_terms: D000818:Animals; D001522:Behavior, Animal / Q000502:physiology; D015350:Contrast Sensitivity / Q000502:physiology*; D007814:Larva / Q000502:physiology; D008027:Light; D017120:Nystagmus, Optokinetic / Q000502:physiology*; D013028:Space Perception / Q000502:physiology*; D015027:Zebrafish / Q000502:physiology*