%0 Journal Article %J Proc Biol Sci %D 2018 %T Experiential contributions to social dominance in a rat model of fragile-X syndrome. %A Saxena, K %A Webster, J %A Hallas-Potts, A %A Mackenzie, R %A Spooner, P A %A Thomson, D %A Kind, P %A Chatterji, S %A Morris, R G M %X

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 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.

%B Proc Biol Sci %V 285 %8 2018 Jun 13 %G eng %N 1880 %R 10.1098/rspb.2018.0294