Brief Report: Altered Social Behavior in Isolation-Reared Fmr1 Knockout Mice

• Published in: Journal of autism and developmental disorders Vol. 43; no. 6; pp. 1452 - 1458
• Main Authors: Heitzer, Andrew M., Roth, Alexandra K., Nawrocki, Lauren, Wrenn, Craige C., Valdovinos, Maria G.
• Format: Journal Article
• Language: English
• Published: Boston Springer US 01.06.2013; Springer; Springer Nature B.V
• Subjects: Animal Behavior; Animals; Autism; Behavior; Behavior, Animal - physiology; Behavioral Science and Psychology; Biological and medical sciences; Brief Report; Child and School Psychology; Child clinical studies; Chromosome fragility (bloom syndrome, ataxia telangiectasia, fanconi anemia, x-linked mental retardation...); Cognitive Development; Disease Models, Animal; Fragile X Mental Retardation Protein - genetics; Fragile X Syndrome - genetics; Genetic Disorders; Intellectual disabilities; Laboratory animals; Medical genetics; Medical sciences; Mental Retardation; Mice; Mice, Inbred C57BL; Mice, Knockout; Mutation; Neurosciences; Novelty (Stimulus Dimension); Pediatrics; Proteins; Psychology; Psychology. Psychoanalysis. Psychiatry; Psychopathology. Psychiatry; Public Health; Reproducibility of Results; Social anxiety; Social Behavior; Social behavior disorders; Social Cognition; Social interaction; Social Isolation; Withdrawal (Psychology); United States > US; Illinois; Des Moines Iowa; knockout mouse; Social behavior; Fragile X syndrome; Chromosome fragility; Animal model; fmr1 knockout mouse; Rodentia; Experimental study; Vertebrata; Mammalia; Mouse; Social interaction; Social isolation; Animal; Knockout mouse; Social behavior disorder
• ISSN: 0162-3257; 1573-3432; 1573-3432
• DOI: 10.1007/s10803-012-1670-1

Social behavior abnormalities in Fragile X syndrome (FXS) are characterized by social withdrawal, anxiety, and deficits in social cognition. To assess these deficits, a model of FXS, the Fmr1 knockout mouse ( Fmr1 KO), has been utilized. This mouse model has a null mutation in the fragile X mental retardation 1 gene ( Fmr1 ) and displays physical and behavioral characteristics similar to humans with FXS. Several studies have investigated the social behavior of this model, but the results on the behavioral phenotype have not been consistent. In order to further characterize the social behavior in the knockout, isolation-reared Fmr1 KO were evaluated to determine if they differ in their social behavior compared to wild-type littermate controls. Differences by genotype were not observed in social approach behavior; however, the knockout mice showed a significantly reduced preference for social novelty and decreased sniff time in the sociability phase. These findings add to the growing body of knowledge on the subtle differences in social behavior shown by the Fmr1 knockout mice, and that differences occur when the subjects are isolation-reared. Validity of the model and possible changes to methodology are discussed.