Development of behavioral patterns in young C57BL/6J mice: a home cage-based study

Katharina Schönhoff,Heidrun Potschka,Ines Koska,Lara Von Schumann,Claudia Pace,Rupert Palme,Maria Reiber

doi:10.1038/s41598-022-06395-1

Abstract

Evidence exists that behavioral patterns only stabilize once mice reach adulthood. Detailed information about the course of behavioral patterns is of particular relevance for neuroscientific research and for the assessment of cumulative severity in genetically modified mice. The analysis considered five age groups focusing on behavioral assessments in the animals’ familiar home cage environment during the adolescence phase. We confirmed age- and sex-specific differences for several of the behavioral parameters and fecal corticosterone metabolites. Interestingly, an age-dependent decline in saccharin preference was detected in female mice. Regardless of sex, relevant levels of burrowing activity were only observed during later developmental phases. The development of nest complexity following the offer of new material was affected by age in female mice. In female and male mice, an age-dependency was evident for wheel running reaching a peak at P 50. A progressive increase with age was also observed for Open field activity. The data sets provide guidance for behavioral studies and for development of composite measure schemes for evidence-based severity assessment in young mice. Except for the burrowing test, the different behavioral tests can be applied in different age groups during post-weaning development. However, age- and sex-specific characteristics need to be considered.

Highlights

Evidence exists that behavioral patterns only stabilize once mice reach adulthood
All animal groups displayed a preference for sweetened saccharin solution (Fig. 1a)
The analysis of saccharin preference at different time points during the post-weaning phase revealed an age-dependency with young female animals exhibiting a stronger prefer

Summary

Introduction

Evidence exists that behavioral patterns only stabilize once mice reach adulthood. Detailed information about the course of behavioral patterns is of particular relevance for neuroscientific research and for the assessment of cumulative severity in genetically modified mice. The data sets provide guidance for behavioral studies and for development of composite measure schemes for evidence-based severity assessment in young mice. Various genetic mouse lines modeling neurodevelopmental and neuropsychiatric disorders display behavioral alterations during distinct developmental phases These animal models can be characterized by peaks of distress during the ‘adolescence’ p hase[4]. We generated reference data in female and male C57BL/6JRj wildtype mice, one of the most commonly used background strains for genetically modified mice and the most widely used inbred mouse strain[11], in order to assess the generalizability and robustness of selected parameters as a basis for candidate composite measure schemes in young mice. Once validated in genetically altered strains, age-specific composite measure schemes provide a basis for evidence-based refinement recommendations in the sense of a reliable and comprehensive severity classification of genetic mouse models

Objectives

Methods

Results

Conclusion