Experiential contributions to social dominance in a rat model of fragile-X syndrome. Issue 1880 (13th June 2018)

• Record Type: Journal Article
• Authors: Saxena, K.; Webster, J.; Hallas-Potts, A.; Mackenzie, R.; Spooner, P. A.; Thomson, D.; Kind, P.; Chatterji, S.; Morris, R. G. M.
• Is Part Of: Proceedings. Volume 285:Issue 1880(2018)
• Publication Date: 2018-06-13
• Subjects: fragile-X -- social dominance -- hierarchy -- Fmr1 -- autism-spectrum disorders -- gene–environment interactions; Biology -- Periodicals; 570.5
• DOI: 10.1098/rspb.2018.0294
• Languages: English
• ISSNs: 0962-8452

Abstract

Abstract : Social withdrawal is one phenotypic feature of the monogenic neurodevelopmental disorder fragile-X. Using a 'knockout' rat model of fragile-X, we examined whether deletion of the Fmr1 gene that causes this condition would affect the ability to form and express a social hierarchy as measured in a tube test. Male fragile-X 'knockout' rats living together could successfully form a social dominance hierarchy, but were significantly subordinate to wild-type animals in mixed group cages. Over 10 days of repeated testing, the fragile-X mutant rats gradually showed greater variance and instability of rank during their tube-test encounters. This affected the outcome of future encounters with stranger animals from other cages, with the initial phenotype of wild-type dominance lost to a more complex picture that reflected, regardless of genotype, the prior experience of winning or losing. Our findings offer a novel insight into the complex dynamics of social interactions between laboratory living groups of fragile-X and wild-type rats. Even though this is a monogenic condition, experience has an impact upon future interactions with other animals. Gene/environment interactions should therefore be considered in the development of therapeutics.