title: Development of home cage social behaviors in BALB/cJ vs. C57BL/6J mice.
abstract: BALB/cJ and C57BL/6J inbred mouse strains have been proposed as useful models of low and high levels of sociability (tendency to seek social interaction), respectively, based primarily on behaviors of ∼30-day-old mice in the Social Approach Test (SAT). In the SAT, approach and sniffing behaviors of a test mouse toward an unfamiliar stimulus mouse are measured in a novel environment. However, it is unclear whether such results generalize to a familiar environment with a familiar social partner, such as with a littermate in a home cage environment. We hypothesized that C57BL/6J mice would show higher levels of social behaviors than BALB/cJ mice in the home cage environment, particularly at 30 days-of-age. We measured active and passive social behaviors in home cages by pairs of BALB/cJ or C57BL/6J littermates at ages 30, 41, and 69 days. The strains did not differ robustly in their active social behaviors. C57BL/6J mice were more passively social than BALB/cJ mice at 30 days, and C57BL/6J levels of passive social behaviors declined to BALB/cJ levels by 69 days. The differences in passive social behaviors at 30 days-of-age were primarily attributable to differences in huddling. These results indicate that different test conditions (SAT conditions vs. home cage conditions) elicit strain differences in distinct types of behaviors (approach/sniffing vs. huddling behaviors, respectively). Assessment of the more naturalistic social interactions in the familiar home cage environment with a familiar littermate will provide a useful component of a comprehensive assessment of social behaviors in mouse models relevant to autism.
authors.affiliation: Center for Neurobiology and Behavior, Department of Psychiatry, Perelman School of Medicine at University of Pennsylvania, Translational Research Laboratory, 125 South 31st Street, Room 2220, Philadelphia, PA 19104-3403, USA.
authors.forename: Andrew H
authors.initials: AH
authors.lastname: Fairless
authors.forename: Julia M
authors.initials: JM
authors.lastname: Katz
authors.forename: Neha
authors.initials: N
authors.lastname: Vijayvargiya
authors.forename: Holly C
authors.initials: HC
authors.lastname: Dow
authors.forename: Arati Sadalge
authors.initials: AS
authors.lastname: Kreibich
authors.forename: Wade H
authors.initials: WH
authors.lastname: Berrettini
authors.forename: Ted
authors.initials: T
authors.lastname: Abel
authors.forename: Edward S
authors.initials: ES
authors.lastname: Brodkin
mesh_terms: D000367:Age Factors; D000818:Animals; D000831:Animals, Newborn; D001835:Body Weight; D001921:Brain / Q000502:physiology; D005260:Female; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D009929:Organ Size; D012919:Social Behavior; D012931:Social Environment; D013045:Species Specificity; D013223:Statistics as Topic