title: Social deficits in BTBR T+tf/J mice are unchanged by cross-fostering with C57BL/6J mothers.
abstract: Inbred strains of mice are useful model systems for studying the interactions of genetic and environmental contributions during neurodevelopmental stages. We recently reported an inbred strain, BTBR T+tf/J (BTBR), which, as compared to the commonly used C57BL/6J (B6) strain, displays lower social interactions as juveniles, lower social approach in adult ages, and higher levels of repetitive self-grooming throughout developmental stages. The present study investigated whether the early postnatal maternal environment contributes substantially to the unusually low expression of social behaviors and high self-grooming in BTBR as compared to B6. Within 24h of birth, entire litters of pups were cross-fostered to either a dam of the same strain or a dam of the opposite strain. Control litters were left with their own mothers. Offspring were tested for juvenile play at postnatal day 21+/-1, for sociability at 8 weeks of age in an automated three-chambered social approach test, and for self-grooming at 9-11 weeks of age. Results indicate that deficits in play behaviors in juvenile BTBR pups were not rescued by a B6 maternal environment. Similarly, a BTBR maternal environment did not induce play deficits in B6 pups. Cross-fostering had no effect on sociability scores in adults. The high self-grooming in BTBR and low self-grooming in B6 were not affected by maternal environment. These findings favor a genetic interpretation of the unusual social behaviors and self-grooming traits of BTBR, and support the use of the BTBR inbred strain as a mouse model to study genetic mechanism of autism.
authors.affiliation: Laboratory of Behavioral Neuroscience, Intramural Research Program, National Institute of Mental Health, Bethesda, MD 20892-1375, USA. yangmu@mail.nih.gov
authors.forename: Mu
authors.initials: M
authors.lastname: Yang
authors.forename: Vladimir
authors.initials: V
authors.lastname: Zhodzishsky
authors.forename: Jacqueline N
authors.initials: JN
authors.lastname: Crawley
mesh_terms: D000374:Aggression / Q000502:physiology*; D000818:Animals; D001321:Autistic Disorder / Q000235:genetics / Q000523:psychology; D004195:Disease Models, Animal; D005260:Female; D006120:Grooming / Q000502:physiology; D008098:Litter Size; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D008815:Mice, Inbred Strains; D016487:Parenting / Q000523:psychology*; D010988:Play and Playthings / Q000523:psychology; D012919:Social Behavior; D012930:Social Dominance; D012931:Social Environment; D013045:Species Specificity