Abnormal social behaviors and dysfunction of autism-related genes associated with daily agonistic interactions in mice

Background The ability of people to communicate with each other is a necessary component of social behavior and the normal development of individuals who live in a community. An apparent decline in sociability may be the result of a negative social environment or the development of affective and neurological disorders, including autistic spectrum disorders. The behavior of these humans may be characterized by the deterioration of socialization, low communication, and repetitive and restricted behaviors. This study aimed to analyze changes in the social behaviors of male mice induced by daily agonistic interactions and investigate the involvement of genes, related with autistic spectrum disorders in the process of the impairment of social behaviors. Methods Abnormal social behavior is induced by repeated experiences of aggression accompanied by wins (winners) or chronic social defeats (losers) in daily agonistic interactions in male mice. The collected brain regions (the midbrain raphe nuclei, ventral tegmental area, striatum, hippocampus, and hypothalamus) were sequenced at JSC Genoanalytica (http://genoanalytica.ru/, Moscow, Russia). The Cufflinks program was used to estimate the gene expression levels. Bioinformatic methods were used for the analysis of differentially expressed genes in male mice. Results The losers exhibited an avoidance of social contacts toward unfamiliar conspecific, immobility and low communication on neutral territory. The winners demonstrated aggression and hyperactivity in this condition. The exploratory activity (rearing) and approaching behavior time towards the partner were decreased, and the number of episodes of repetitive self-grooming behavior was increased in both social groups. These symptoms were similar to the symptoms observed in animal models of autistic spectrum disorders. In an analysis of the RNA-Seq database of the whole transcriptome in the brain regions of the winners and losers, we identified changes in the expression of the following genes, which are associated with autism in humans: Tph2, Maoa, Slc6a4, Htr7,Gabrb3, Nrxn1, Nrxn2, Nlgn1, Nlgn2, Nlgn3, Shank2, Shank3, Fmr1, Ube3a, Pten, Cntn3, Foxp2, Oxtr, Reln, Cadps2, Pcdh10, Ctnnd2, En2, Arx, Auts2, Mecp2, and Ptchd1.Common and specific changes in the expression of these genes in different brain regions were identified in the winners and losers. Conclusions This research demonstrates for the first time that abnormalities in social behaviors that develop under a negative social environment in adults may be associated with alterations in expression of genes, related with autism in the brain.