SOCIAL-TERRITORIAL CONTEXT AS A DRIVER OF CA1 ACTIVITY

Territoriality entails behaviors in which an individual claims and defends a spatially confined area from conspecifics. Our goal was to explore its neural foundations. We hypothesized that territoriality is supported by neural circuits linking memory and spatial representation, with the hippocampus playing a central role. To investigate this, we conducted calcium imaging of dCA1 in the hippocampus during a resident-intruder paradigm. In this setup, a male ICR mouse expressing calcium indicators in the CA1 was housed with a sterile female for 21 days to establish territoriality. Starting on day 21, the resident mouse was exposed to an intruder for 10-minute sessions over several days. We observed that social encounters with an intruder were associated with changes in CA1 population activity and spatial representations, reflected in altered spatial tuning and reorganization of activity patterns across sessions. Our findings indicate that hippocampal population codes are dynamically modulated during territorial interactions, supporting a role for the hippocampus in linking space, experience, and social context during behaviorally relevant challenges.