The urge to defend one’s territory is an evolutionarily conserved instinct aimed at securing optimal access to food, mates, and shelter. Conflict arises when territories become unstable due to seasonal changes in resource availability, or when population density increases. Under such conditions, individuals must carefully balance social aggression and avoidance to maximize their control of territorial resources while avoiding subordination at the hands of their neighbors. What is the neural basis of such dynamic territorial behaviors? We have found that an evolutionarily conserved medial hypothalamic brain structure serves as a switch between social aggression and avoidance. In this proposal we ask where and how is territory encoded in the brain and how could it control this hypothalamic switch? A clue emerges from recent work in which we discovered that neural activity in this structure encodes a map of social space much like the mammalian hippocampus encodes a map of navigational space. However, unlike hippocampal place cells that arise spontaneously as animals explore, hypothalamic territory cells require social experience to form. We will develop a semi-natural laboratory testing environment where we can monitor the dynamic acquisition of territories in mice over time and apply in vivo neural recording, activity perturbation, and computational modelling to extract precise synaptic integration and plasticity mechanisms that underlie territory-based decision-making in the mammalian brain. Uncovering the neural basis of territorial behaviors is an essential step toward a biological understanding of human aggression and fear and could provide insight into interventions for maladaptive responses to threats to personal space, resources, and beliefs.
