title: Sociability and brain development in BALB/cJ and C57BL/6J mice.
abstract: Sociability--the tendency to seek social interaction--propels the development of social cognition and social skills, but is disrupted in autism spectrum disorders (ASD). BALB/cJ and C57BL/6J inbred mouse strains are useful models of low and high levels of juvenile sociability, respectively, but the neurobiological and developmental factors that account for the strains' contrasting sociability levels are largely unknown. We hypothesized that BALB/cJ mice would show increasing sociability with age but that C57BL/6J mice would show high sociability throughout development. We also hypothesized that littermates would resemble one another in sociability more than non-littermates. Finally, we hypothesized that low sociability would be associated with low corpus callosum size and increased brain size in BALB/cJ mice. Separate cohorts of C57BL/6J and BALB/cJ mice were tested for sociability at 19-, 23-, 31-, 42-, or 70-days-of-age, and brain weights and mid-sagittal corpus callosum area were measured. BALB/cJ sociability increased with age, and a strain by age interaction in sociability between 31 and 42 days of age suggested strong effects of puberty on sociability development. Sociability scores clustered according to litter membership in both strains, and perinatal litter size and sex ratio were identified as factors that contributed to this clustering in C57BL/6J, but not BALB/cJ, litters. There was no association between corpus callosum size and sociability, but smaller brains were associated with lower sociability in BALB/cJ mice. The associations reported here will provide directions for future mechanistic studies of sociability development.
authors.affiliation: Center for Neurobiology and Behavior, Department of Psychiatry, University of Pennsylvania School of Medicine, Translational Research Laboratory, 125 South 31st Street, Philadelphia, PA 19104-3403, USA.
authors.forename: Andrew H
authors.initials: AH
authors.lastname: Fairless
authors.forename: Holly C
authors.initials: HC
authors.lastname: Dow
authors.forename: Arati Sadalge
authors.initials: AS
authors.lastname: Kreibich
authors.forename: Matthew
authors.initials: M
authors.lastname: Torre
authors.forename: Mariyam
authors.initials: M
authors.lastname: Kuruvilla
authors.forename: Elliot
authors.initials: E
authors.lastname: Gordon
authors.forename: Elizabeth A
authors.initials: EA
authors.lastname: Morton
authors.forename: Junhao
authors.initials: J
authors.lastname: Tan
authors.forename: Wade H
authors.initials: WH
authors.lastname: Berrettini
authors.forename: Hongzhe
authors.initials: H
authors.lastname: Li
authors.forename: Ted
authors.initials: T
authors.lastname: Abel
authors.forename: Edward S
authors.initials: ES
authors.lastname: Brodkin
mesh_terms: D000367:Age Factors; D000704:Analysis of Variance; D000818:Animals; D000831:Animals, Newborn; D001921:Brain / Q000254:growth & development*; D003337:Corpus Callosum / Q000254:growth & development; D005260:Female; D008098:Litter Size / Q000235:genetics; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C / Q000033:anatomy & histology / Q000254:growth & development / Q000523:psychology; D008810:Mice, Inbred C57BL / Q000033:anatomy & histology / Q000254:growth & development / Q000523:psychology; D009929:Organ Size; D012737:Sex Factors; D012919:Social Behavior; D013045:Species Specificity