title: Association between exploratory activity and social individuality in genetically identical mice living in the same enriched environment.
abstract: We previously reported that inbred, genetically identical mice living in one enriched environment develop individual behavioral trajectories, indicating increasingly different levels of spatial exploratory behavior as quantified by roaming entropy. Cumulative roaming entropy (cRE) correlated positively with adult hippocampal neurogenesis, a type of plasticity involved in the flexible integration of new information into existing contexts (Freund et al., 2013). The study on which we report here was done in parallel to that first experiment, but here we acquired detailed observational data on the behavior of individual mice. Roaming entropy (RE) was again assessed in real-time with an antenna-based system over the entire experimental period of 3months. Compared to the least active mice in the enclosure (low number of antenna contacts), the most active animals showed tendencies of increased socially interactive behavior in the final observation block whereas least active mice displayed more self-related behavior (non-social local exploration and play). When looking at roaming behavior, we discovered that RE correlated negatively with latent factors representing social exploratory and non-social exploratory and play behavior. Adult neurogenesis could not be studied in the present cohort but we do know that under identical conditions, cumulative RE correlated positively with adult hippocampal neurogenesis. We can thus hypothesize that the mice with more exploratory experience in terms of areal coverage (as quantified by RE) and related greater levels of adult hippocampal plasticity, might also be the ones that were less involved in interactions within the group and, hence, more individualistic. While this remains to be confirmed experimentally, the present data suggest that the described mechanism of individualization, which has previously been shown to be hippocampus-dependent, has a social component.
authors.affiliation: CRTD - DFG Research Center for Regenerative Therapies Dresden, Technische Universität Dresden, Germany.
authors.forename: J
authors.initials: J
authors.lastname: Freund
authors.affiliation: Center for Lifespan Psychology, Max Planck Institute for Human Development, Berlin, Germany.
authors.forename: A M
authors.initials: AM
authors.lastname: Brandmaier
authors.affiliation: Department of Behavioral Biology, Westfälische Wilhelms Universität Münster, Germany; Department of Behavioral Biology, Universität Osnabrück, Germany.
authors.forename: L
authors.initials: L
authors.lastname: Lewejohann
authors.affiliation: CRTD - DFG Research Center for Regenerative Therapies Dresden, Technische Universität Dresden, Germany.
authors.forename: I
authors.initials: I
authors.lastname: Kirste
authors.affiliation: Institute for Geoinformatics, Westfälische Wilhelms Universität Münster, Germany.
authors.forename: M
authors.initials: M
authors.lastname: Kritzler
authors.affiliation: Institute for Geoinformatics, Westfälische Wilhelms Universität Münster, Germany; German Research Center for Artificial Intelligence, Saarbrücken, Germany.
authors.forename: A
authors.initials: A
authors.lastname: Krüger
authors.affiliation: Department of Behavioral Biology, Westfälische Wilhelms Universität Münster, Germany.
authors.forename: N
authors.initials: N
authors.lastname: Sachser
authors.affiliation: Center for Lifespan Psychology, Max Planck Institute for Human Development, Berlin, Germany.
authors.forename: U
authors.initials: U
authors.lastname: Lindenberger
authors.affiliation: CRTD - DFG Research Center for Regenerative Therapies Dresden, Technische Universität Dresden, Germany; German Center for Neurodegenerative Disease (DZNE) Dresden, Germany. Electronic address: gerd.kempermann@dzne.de.
authors.forename: G
authors.initials: G
authors.lastname: Kempermann
mesh_terms: D056044:Actigraphy; D000818:Animals; D001835:Body Weight; D001921:Brain / Q000033:anatomy & histology; D004777:Environment; D005106:Exploratory Behavior; D005260:Female; D006624:Hippocampus; D006799:Housing, Animal; D007206:Individuality; D008810:Mice, Inbred C57BL / Q000235:genetics / Q000523:psychology*; D009043:Motor Activity / Q000235:genetics; D055495:Neurogenesis; D009929:Organ Size; D017440:Photoperiod; D010988:Play and Playthings; D011897:Random Allocation; D012919:Social Behavior; D012984:Software; D013239:Stereotyped Behavior; D013997:Time Factors
keywords: adult neurogenesis; dentate gyrus; experience; exploration; hippocampus; plasticity