ASSESSING THE NEURAL CIRCUITS UNDERLYING MOTIVATIONAL CONFLICT BETWEEN SOCIAL THREAT AND RESOURCE AVAILABILITY IN TERRITORIAL BEHAVIOUR

Territoriality is an evolutionarily conserved instinctive behaviour across multiple species, including mice. This complex behaviour is mainly driven by intraspecific aggression; however, its primary purpose is considered to be ensuring optimal resource allocation among individuals. Therefore, not only is the presence of a conspecific important in the formation of one individual’s territory, but also the availability of resources. How individuals balance such opposite stimuli remains a question. One hypothesis could implicate the Paraventricular Thalamus (PVT), known to have a role in motivational conflict, since its neural activity has been proven to encode the behavioural salience and valence of different stimuli.
Such a hypothesis has been initially targeted by setting up a motivational conflict-based behavioural task, optimised in order to have two opposite stimuli (aggressive conspecific and highly palatable food) in the same spatial context, to represent the motivational conflict in a laboratory setting. Different parameters have been measured to describe the behavioural response, showing that the presence of food was able to reduce the negative effect of the social defeat. Chemogenetics experiments have shown that, when inhibiting PVT neurons, mice took longer to perform a choice, specifically in a conflicting context, hinting that they were impaired in the resolution of the conflict. However, when specifically inhibiting Esr1-expressing PVT neurons, the behavioural outcome was more generalised, where the inhibition counterbalanced the effect of the social defeat independently of the context. These results point towards the hypothesis that different populations are encoding different stimuli, which are then integrated in the PVT.