COLORcation: A new application to phenotype exploratory behavior models of anxiety in mice

Background: Behavioral analyses in rodents have successfully delineated the function of many genes and signaling pathways in the brain. Behavioral testing uses highly defined experimental conditions to identify abnormalities in a given mouse strain or genotype. The open field (OF) is widely used to assess both locomotion and anxiety in rodents. In this test, the more a mouse explores and spend time in the center of the arena, the less anxious it is considered to be. However, the simplistic distinction between center and border substantially reduces the information content of the analysis and may fail to detect biologically meaningful differences. New method: Here we describe COLORcation, a new application for improved analyses of mouse behavior in the OF. Results: The application analyses animal exploration patterns in detailed spatial resolution (e.g. 10 x 10 bins) to provide a color-encoded heat map of mouse activity. In addition, COLORcation provides new parameters to track activity and locomotion of the test animals. We demonstrate the use of COLORcation in different experimental paradigms, including pharmacological and restraint-based induction of stress and anxiety. Comparison with existing method(s): COLORcation is compatible with multiple acquisition systems, giving users the option to make the most of their raw data organized text files containing time and coordinates of animal locations as input. Conclusion: These analyses validate the utility of the software and establish its reliability and potential as a new tool to analyze OF data. (C) 2016 Elsevier B.V. All rights reserved.