Social behavior assay in mouse model of autism spectrum disorder

Abstract

Autism spectrum disorder (ASD) is very heterogeneous disease that symptoms widely vary as its name suggests and exact etiology is not yet found. Clinical diagnosing criteria of ASD are defined thoroughly by behavioral phenotype (American Psychiatric Association, 2013) because ASD has no specific biomarker or imaging-marker (Buxbaum and Hof, 2012). Therefore, investigating ASD with animal models also has to rely largely on behavioral assays. Researchers have been developing mouse models of psychiatric diseases, including ASD, to provide testing ground for investigating molecular mechanism of the disease and to find curing drugs. However, developing appropriate behavioral test method is another challenge since many laboratories find it hard to reproduce the same behavioral results even though they use the same mouse line and behavioral test scheme (Crabbe et al., 1999

Wahlsten et al., 2003). Reliable behavioral experimental method is especially important for ASD study because with no biomarker, behavioral phenotype would work as final gate for confirming applied treatments, drugs etc. In this study, we utilized three-chamber apparatus and pup retrieval test scheme to assess C57BL/6 mice first and then assess established ASD mouse models, CD38 knockout (CD38KO) mice and Shank2 knockout (Shank2KO) mice. C57BL/6 mouse line shows high level of social characteristics and widely used as a genetic background for many mutant mouse lines, which make them as a good comparison group. Both CD38KO and Shank2KO mice have genetic background of C57BL/6 and their autism-like behavior are reported in previous studies (Jin et al., 2007

Won et al., 2012). CD38KO mice exhibited social behavior deficit in three-chamber test compared to their wild type (WT) littermates and to C57BL/6. Shank2KO mice showed tendency of impairment in pup retrieval test compared to their WT littermates and to C57BL/6 mice.