Autistic behavioral differences between female mouse strains BTBR T+tf/J and C57BL/6 mutant

Abstract

Autism is a neurodevelopmental disorder that is characterized by aberrant social interaction and communication deficits, and repetitive behavior (American Psychiatric Association, 2013). As increasing number of children has been diagnosed with autism, the awareness on autism and importance of researches are also growing. In most mouse behavioral studies, male mice are frequently used while behavioral studies with female mice are rare. As result, there is only insufficient information on female mouse behavioral 4 phenotypes, and more information is needed. In this research, we used female autistic spectrum disorder model mice (BTBR T+tf/J and Shank2 Δe6-7 knockout and wild type and naïve female C57BL/6 mice to find out autistic behavioral phenotypes of female mice. Analysis from open field test shows that both autism model mouse groups have significantly more hyperactivity than their control groups, but anxiety level was not statistically meaningful between experimental and control groups. Increased mobility in autism models agrees with previous researches on male autism model mice. In ultrasonic vocalization test, BTBR T+tf/J tended to emit smaller amount of vocalizations than its comparison group. This observation reflects a typical behavioral phenotype of main autism symptoms. Both autism model groups showed impairment in retrieving pups. It is interesting to note that both BTBR T+tf/J and Shank2 Δe6-7 knockout(KO) mice showed decrease repetitive behavior than their controls in marble burying test, and this result contrasts previous reports on male mice with autism like behaviors (Spencer et al., 2011

Amodeo et al., 2012). This observation may imply less sustained behavioral pattern, however we suggest it may reflect a lack of motivation, which is one of important autism symptoms. From water based Y-maze test, we found out BTBR T+tf/J, Shank2 Δe6-7 wild type (WT) and C57BL/6 mice have normal learning abilities while Shank2 Δe6-7 KO exhibited a severe impairment in learning.