23 January 2025 – Adolescent mice with naturally lower levels of neurogenesis prior to the formation of a new group are more likely to become dominant and display higher anxiety scores compared with subordinate mice. A research group in Lausanne investigated the relationship between social hierarchy, adolescent and adult hippocampal neurogenesis, and anxiety in mice. They explored interindividual differences in inbred mice and their data reveal that the level of adolescent neurogenesis predicts not only the level of adult neurogenesis but also social status and anxiety levels.
The authors further experimentally reduced neurogenesis prior to the stabilization of social hierarchy in single or group-housed adolescent males and showed that in both cases this increased the probability of the males to become dominant in subsequent behavioral tests. In group-housed mice reducing neurogenesis also increased anxiety. These results were published today in EMBO Reports.
This study highlights a novel role for adult hippocampal neurogenesis, beyond stress resilience and memory. While the underlying causes for the natural variations in hippocampal neurogenesis of mice that are genetically identical are unclear, the authors of this study speculate on its possible consequences. “Differences in social hierarchy may help to diversify the strategies of male offspring for new colony formation later in life and thus increase their survival,” says Nicolas Toni, lead author of this study. The study also provides a framework to investigate the mechanisms underlying social hierarchy and the dysregulation of dominance behaviour in psychiatric diseases related to anxiety.
EMBO Reports
Natural variations of adolescent neurogenesis and anxiety predict the hierarchical status of adult inbred mice
Fabio Grieco, Atik Balla, Thomas Larrieu, Nicolas Toni
