title: Loss of outer retinal neurons and circuitry alterations in the DBA/2J mouse.
abstract: OBJECTIVE
  The DBA/2J mouse line develops essential iris atrophy, pigment dispersion, and glaucomatous age-related changes, including an increase of IOP, optic nerve atrophy, and retinal ganglion cell (RGC) death. The aim of this study was to evaluate possible morphological changes in the outer retina of the DBA/2J mouse concomitant with disease progression and aging, based on the reduction of both the a- and b-waves and photopic flicker ERGs in this mouse line.
  
  
  METHODS
  Vertically sectioned DBA/2J mice retinas were evaluated at 3, 8, and 16 months of age using photoreceptor, horizontal, and bipolar cell markers. Sixteen-month-old C57BL/6 mice retinas were used as controls.
  
  
  RESULTS
  The DBA/2J mice had outer retinal degeneration at all ages, with the most severe degeneration in the oldest retinas. At 3 months of age, the number of photoreceptor cells and the thickness of the OPL were reduced. In addition, there was a loss of horizontal and ON-bipolar cell processes. At 8 months of age, RGC degeneration occurred in patches, and in the outer retina overlying these patches, cone morphology was impaired with a reduction in size as well as loss of outer segments and growth of horizontal and bipolar cell processes into the outer nuclear layer. At 16 months of age, connectivity between photoreceptors and horizontal and bipolar cell processes overlying these patches was lost.
  
  
  CONCLUSIONS
  Retinal degeneration in DBA/2J mice includes photoreceptor death, loss of bipolar and horizontal cell processes, and loss of synaptic contacts in an aging-dependent manner.
authors.affiliation: Department of Physiology, Genetics, and Microbiology, University of Alicante, San Vicente del Raspeig, Spain.
authors.forename: Laura
authors.initials: L
authors.lastname: Fernández-Sánchez
authors.affiliation: Department of Neurobiology, David Geffen School of Medicine, University of California at Los Angeles, Los Angeles, California, United States.
authors.forename: Luis Pérez
authors.initials: LP
authors.lastname: de Sevilla Müller
authors.affiliation: Department of Neurobiology, David Geffen School of Medicine, University of California at Los Angeles, Los Angeles, California, United States.
authors.forename: Nicholas C
authors.initials: NC
authors.lastname: Brecha
authors.affiliation: Department of Physiology, Genetics, and Microbiology, University of Alicante, San Vicente del Raspeig, Spain.
authors.forename: Nicolás
authors.initials: N
authors.lastname: Cuenca
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000502:physiology; D004195:Disease Models, Animal; D004596:Electroretinography; D005260:Female; D005901:Glaucoma / Q000473:pathology* / Q000503:physiopathology; D007429:Intraocular Pressure; D007498:Iris / Q000473:pathology; D008027:Light; D051379:Mice; D008810:Mice, Inbred C57BL; D008811:Mice, Inbred DBA; D008817:Mice, Mutant Strains; D020419:Photoreceptor Cells, Vertebrate / Q000473:pathology / Q000502:physiology; D012160:Retina / Q000473:pathology* / Q000502:physiology; D051245:Retinal Bipolar Cells / Q000473:pathology / Q000502:physiology; D012162:Retinal Degeneration / Q000473:pathology* / Q000503:physiopathology; D012165:Retinal Ganglion Cells / Q000473:pathology* / Q000502:physiology; D051248:Retinal Horizontal Cells / Q000473:pathology / Q000502:physiology
keywords: bipolar cell; glaucoma; horizontal cell; photoreceptor; retinal degeneration; synaptic triad