Debora Masini (Stockholm): Beyond Aggression: Uncovering the Phenotypic Identity of Social Rank School of Psychology and Neuroscience Friday seminar series

The School of Psychology and Neuroscience seminar series presents a talk by Debora Masini (Stockholm) titled ‘Beyond Aggression: Uncovering the Phenotypic Identity of Social Rank in Male Mice”, which will be hosted by Dr Ilary Allodi in person in the Old Library and online through MS Teams.

Abstract:
Laboratory mice are central to the study of brain circuitry and behavior. For those interested on social behavior, aggression and dominance are defining features of how these animals interact. A common assumption is that these are phenotypically parallel traits, reflecting a shared advantage in resource acquisition, sometimes also presupposing joint neural substrates. This thinking often leads to conflation of the two concepts when interpreting the behavioral effects of circuit manipulations.

Here, we tested whether social rank predicts aggression in male mice. Contrary to expectation, dominant animals were significantly less likely to attack, regardless of the opponent's rank. When measuring how mice compete to access resources, we observed that dominant animals make regular concessions primarily to familiar lower-ranked individuals, effectively granting them “free wins”. This pattern of dyad interaction still guarantees a high win performance by dominants.

Next, we hypothesized that social rank represents a phenotypic identity which may persevere outside social interactions, effectively influencing behavior wherever an individual goes. To examine this possibility, we employed unsupervised machine learning (deep variational embeddings of animal motion) to deconstruct behavior into fundamental elements. We found that when exploring novel environments, mice exhibited a flexible representation of their own social rank, which was further modulated by environmental cues, revealing a surprising degree of specificity between exploratory behavior and social status. We provide further empirical support, by showing that exploratory pattern alone, is sufficient to predict one's social rank in multiple contextual scenarios. Together, these findings suggest strategies for social dominance which do not necessarily engage neural circuits that drive aggression. Finally, I will present one hypothalamic area as an example of this neural substrate dissociation.

Key Papers:
Battivelli, D., Fan, Z., Hu, H. et al. How can ethology inform the neuroscience of fear, aggression and dominance?. Nat. Rev. Neurosci. 25, 809–819 (2024). https://doi.org/10.1038/s41583-024-00858-2