title: Retinas of the diurnal rodent Arvicanthis ansorgei are highly resistant to experimentally induced stress and degeneration.
abstract: OBJECTIVE
  Environmentally induced stress plays a significant role in retinal degeneration and blindness both in animals and in humans. Among such sources of stress, phototoxicity is well studied and has been shown to lead to photoreceptor-specific loss in a number of species. However, the vast majority of studies have been conducted in nocturnal, albino rod-dominant rat and mouse strains, and the pertinence of such findings to human pathology and cone loss is debatable. The authors examined retinal vulnerability to damage in the diurnal murid rodent Arvicanthis ansorgei, a pigmented species with a large number of cones.
  
  
  METHODS
  The authors used established protocols for exposing animals to a wide range of lighting conditions (variable intensity, duration, spectrum, previous light history, and time of exposure) and injecting N-methyl-N-nitrosourea (MNU); each procedure is reported to produce rapid and complete photoreceptor-specific damage. Animals then underwent electroretinography to record rod and cone function and were subsequently euthanized and used for immunohistochemical analysis of retinal structure and quantification of free fatty acids.
  
  
  RESULTS
  These standard regimens produced no detectable detrimental effects on A. ansorgei retinal phenotype, function, or structure. Partial retinal damage in A. ansorgei was induced by very intense blue light or elevated doses of MNU. This resistance was not attributable to differences in lipid composition (specifically, docosahexaenoic acid) between A. ansorgei and susceptible strains of mice and rats.
  
  
  CONCLUSIONS
  The retina of this species exhibits exceptionally high resistance to damage from light and toxins such as MNU.
authors.affiliation: Département de Neurobiologie des Rythmes, Université de Strasbourg, Institut des Neurosciences Cellulaires et Intégratives, Strasbourg, France.
authors.forename: Domitille L
authors.initials: DL
authors.lastname: Boudard
authors.forename: Niyazi
authors.initials: N
authors.lastname: Acar
authors.forename: Lionel
authors.initials: L
authors.lastname: Bretillon
authors.forename: David
authors.initials: D
authors.lastname: Hicks
mesh_terms: D000477:Alkylating Agents / Q000633:toxicity; D000818:Animals; D002940:Circadian Rhythm / Q000502:physiology; D004195:Disease Models, Animal; D004596:Electroretinography; D005230:Fatty Acids, Nonesterified / Q000378:metabolism; D008027:Light / Q000009:adverse effects; D008297:Male; D008770:Methylnitrosourea / Q000633:toxicity; D051379:Mice; D008810:Mice, Inbred C57BL; D009115:Muridae; D051381:Rats; D017949:Retinal Cone Photoreceptor Cells / Q000473:pathology / Q000528:radiation effects; D012162:Retinal Degeneration / Q000209:etiology / Q000473:pathology* / Q000503:physiopathology*; D013045:Species Specificity; D013312:Stress, Physiological / Q000187:drug effects / Q000502:physiology* / Q000528:radiation effects
chemical_list: D000477:Alkylating Agents; D005230:Fatty Acids, Nonesterified; D008770:Methylnitrosourea