Institution: | 1. Department of Integrative Physiology, University of Colorado, Boulder, Colorado, USA
Institute for Behavioral Genetics, University of Colorado, Boulder, Colorado, USA;2. Department of Integrative Physiology, University of Colorado, Boulder, Colorado, USA;3. Department of Integrative Physiology, Center for Neuroscience, and Center for Microbial Exploration, University of Colorado, Boulder, Colorado, USA
Departments of Psychiatry, Neurology, and Physical Medicine & Rehabilitation, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
Rocky Mountain Mental Illness Research Education and Clinical Center (MIRECC), Rocky Mountain Regional Veterans Affairs Medical Center (RMRVAMC), Aurora, Colorado, USA
Military and Veteran Microbiome: Consortium for Research and Education (MVM-CoRE), Denver, Colorado, USA
Senior Fellow, inVIVO Planetary Health, of the Worldwide Universities Network (WUN), West New York, New Jersey, USA |
Abstract: | High and Low Activity strains of mice (displaying low and high anxiety-like behavior, respectively) with 7.8–20 fold differences in open-field activity were selected and subsequently inbred to use as a genetic model for studying anxiety-like behavior in mice (DeFries et al., 1978, Behavior Genetics, 8:3-13). These strains exhibited differences in other anxiety-related behaviors as assessed using the light–dark box, elevated plus-maze, mirror chamber, and elevated square-maze tests (Henderson et al., 2004, Behavior Genetics, 34: 267-293). The purpose of these experiments was three-fold. First, we repeated a 6-day behavioral battery using updated equipment and software to confirm the extreme differences in anxiety-like behaviors. Second, we tested novel object exploration, a measure of anxiety-like behavior that does not rely heavily on locomotion. Third, we conducted a home cage wheel running experiment to determine whether these strains differ in locomotor activity in a familiar, home cage environment. Our behavioral test battery confirmed extreme differences in multiple measures of anxiety-like behaviors. Furthermore, the novel object test demonstrated that the High Activity mice exhibited decreased anxiety-like behaviors (increased nose pokes) compared to Low Activity mice. Finally, male Low Activity mice ran nearly twice as far each day on running wheels compared to High Activity mice, while female High and Low Activity mice did not differ in wheel running. These results support the idea that the behavioral differences between High and Low Activity mice are likely to be due to anxiety-related factors and not simply generalized differences in locomotor activity. |