Explorer Analysis of individual mouse activity in group housed animals of different inbred strains using a novel automated home cage analysis system

9 Central nervous system disorders such as autism as well as the range of neurodegenerative 10 diseases such as Huntington’s disease are commonly investigated using genetically altered 11 mouse models. The current system for characterizing these mice usually involves removing 12 the animals from their home-cage environment and placing them into novel environments 13 where they undergo a battery of tests measuring a range of behavioral and physical 14 phenotypes. These tests are often only conducted for short periods of times in social isolation. 15 However, human manifestations of such disorders are often characterized by multiple 16 phenotypes, presented over long periods of time and leading to significant social impacts. 17 Here, we have developed a system which will allow the automated monitoring of individual 18 mice housed socially in the cage they are reared and housed in, within established social 19 groups and over long periods of time. We demonstrate that the system accurately reports 20 individual locomotor behavior within the group and that the measurements taken can provide 21 unique insights into the effects of genetic background on individual and group behavior not 22 previously recognized. 23 24