AUTOMATED ANALYSIS OF RODENT BEHAVIOR USING INTELLIPROFILLER: A POTENTIAL TOOL FOR STUDYING NEURODEVELOPMENTAL DISORDER-LIKE MODEL MICE

Abstract Autism spectrum disorder (ASD) is a prevalent neurodevelopmental disorder (NDD) characterized by deficits in social communication and repetitive behaviors. With an increased number of children diagnosed with ASD, the need to understand the mechanisms and symptoms of NDDs is growing to develop effective treatments and interventions. Animal models have been instrumental in studying NDDs, employing classical behavioral paradigms such as the open field test and the social interaction test. However, obtaining consistent results is still challenging due to the handling effects of experimenters. To address this issue, we have developed a novel system, IntelliProfiler, enabling automated analysis of rodent behavior. IntelliProfiller allows us to analyze the relative distances between individual mice and the travel distances of multiple mice, each embedded with a transponder, without image analysis. The system provides a unique opportunity to evaluate the relative social distance between individuals and groups, which could indicate affinity to others or anxiety in a social environment. Our preliminary analysis using IntelliProfiler revealed pronounced differences in social interaction between wild-type (WT) littermates and a mouse model of ASD (Pax6 heterozygous mutant; Pax6Sey/+). Notably, our previous study did not observe these differences in the three-chamber test (Yoshizaki et al., 2016). Additionally, Pax6Sey/+ female mice exhibited hyperactive behavior and sleep disturbance, suggesting potential comorbidity with attention deficit hyperactivity disorder (ADHD). Our previous research using Pax6rSey2/+ female rats also supports these findings, which exhibited reduced vocal communication and decreased brain volume (Umeda et al., 2010; Hiraoka et al., 2016). Our data suggest that Pax6Sey/+ female mice may serve as a valuable model for studying severe sex-biased ASD-like features, potentially with concomitant ADHD. The application of IntelliProfiller in studying neuropsychiatric behaviors in NDD model mice holds significant promise, offering several advantages over classical behavior analyses. These advantages include 1) the ability to conduct long-term studies of basal activity in a non-contact setting and 2) quantitative analyses of anxiety in social environments using multiple animals. References 1. Ochi S, Manabe S, Kikkawa T, Osumi N. Thirty Years' History since the Discovery of Pax6: From Central Nervous System Development to Neurodevelopmental Disorders. Int J Med Sci 30; 23(11):6115 (2022). 2. Kikkawa T, Casingal CR, Chun SH, Shinohara H, Hiraoka K, Osumi N. The role of Pax6 in brain development and its impact on pathogenesis of autism spectrum disorder. Brain Res 15;1705:95-103 (2019). 3. Hiraoka K, Sumiyoshi A, Nonaka H, Kikkawa T, Kawashima R, Osumi N. Regional Volume Decreases in the Brain of Pax6 Heterozygous Mutant Rats: MRI Deformation-Based Morphometry. PLoS One 29;11(6):e0158153 (2016). 4. Yoshizaki K, Furuse T, Kimura R, Tucci V, Kaneda H, Wakana S, Osumi N. Paternal Aging Affects Behavior in Pax6 Mutant Mice: A Gene/Environment Interaction in Understanding Neurodevelopmental Disorders. PLoS One 17;11(11):e0166665 (2016). 5. Umeda T, Takashima N, Nakagawa R, Maekawa M, Ikegami S, Yoshikawa T, Kobayashi K, Okanoya K, Inokuchi K, Osumi N. Evaluation of Pax6 mutant rat as a model for autism. PLoS One 21;5(12):e15500 (2010). 6. Osumi N, Shinohara H, Numayama-Tsuruta K, Maekawa M. Concise review: Pax6 transcription factor contributes to both embryonic and adult neurogenesis as a multifunctional regulator. Stem Cells. 26(7):1663-72 (2008).