title: Missing optomotor head-turning reflex in the DBA/2J mouse.
abstract: OBJECTIVE
  The optomotor reflex of DBA/2J (D2), DBA/2J-Gpnmb+ (D2-Gpnmb+), and C57BL/6J (B6) mouse strains was assayed, and the retinal ganglion cell (RGC) firing patterns, direction selectivity, vestibulomotor function and central vision was compared between the D2 and B6 mouse lines.
  
  
  METHODS
  Intraocular pressure (IOP) measurements, real-time PCR, and immunohistochemical analysis were used to assess the time course of glaucomatous changes in D2 retinas. Behavioral analyses of optomotor head-turning reflex, visible platform Morris water maze and Rotarod measurements were conducted to test vision and vestibulomotor function. Electroretinogram (ERG) measurements were used to assay outer retinal function. The multielectrode array (MEA) technique was used to characterize RGC spiking and direction selectivity in D2 and B6 retinas.
  
  
  RESULTS
  Progressive increase in IOP and loss of Brn3a signals in D2 animals were consistent with glaucoma progression starting after 6 months of age. D2 mice showed no response to visual stimulation that evoked robust optomotor responses in B6 mice at any age after eye opening. Spatial frequency threshold was also not measurable in the D2-Gpnmb+ strain control. ERG a- and b-waves, central vision, vestibulomotor function, the spiking properties of ON, OFF, ON-OFF, and direction-selective RGCs were normal in young D2 mice.
  
  
  CONCLUSIONS
  The D2 strain is characterized by a lack of optomotor reflex before IOP elevation and RGC degeneration are observed. This behavioral deficit is D2 strain-specific, but is independent of retinal function and glaucoma. Caution is advised when using the optomotor reflex to follow glaucoma progression in D2 mice.
authors.affiliation: Department of Ophthalmology and Visual Sciences, John Moran Eye Center, University of Utah School of Medicine, Salt Lake City, UT 84132, USA. sirmook12@gmail.com
authors.forename: Peter
authors.initials: P
authors.lastname: Barabas
authors.forename: Wei
authors.initials: W
authors.lastname: Huang
authors.forename: Hui
authors.initials: H
authors.lastname: Chen
authors.forename: Christopher L
authors.initials: CL
authors.lastname: Koehler
authors.forename: Gareth
authors.initials: G
authors.lastname: Howell
authors.forename: Simon W M
authors.initials: SW
authors.lastname: John
authors.forename: Ning
authors.initials: N
authors.lastname: Tian
authors.forename: René C
authors.initials: RC
authors.lastname: Rentería
authors.forename: David
authors.initials: D
authors.lastname: Krizaj
mesh_terms: D000818:Animals; D001522:Behavior, Animal; D004195:Disease Models, Animal; D004596:Electroretinography; D015870:Gene Expression; D005901:Glaucoma / Q000235:genetics / Q000378:metabolism / Q000503:physiopathology*; D019416:Head Movements / Q000502:physiology*; D007150:Immunohistochemistry; D007429:Intraocular Pressure; D051379:Mice; D008810:Mice, Inbred C57BL; D008811:Mice, Inbred DBA; D010775:Photic Stimulation; D016133:Polymerase Chain Reaction; D012313:RNA / Q000235:genetics; D012018:Reflex / Q000502:physiology*; D012165:Retinal Ganglion Cells / Q000502:physiology*; D050819:Transcription Factor Brn-3A / Q000096:biosynthesis / Q000235:genetics
chemical_list: C494189:Pou4f1 protein, mouse; D050819:Transcription Factor Brn-3A; D012313:RNA