Chair: Hanna Trebesova (Nencki Institute of Experimental Biology, PAS, Warsaw, Poland)
Symposium 10: Unraveling the Social Brain: how hierarchies and partners, exogenous substances and hormones shape rodents behavior
The symposium will explore the neural and molecular dynamics underlying social interactions in rodents. Hanna Hörnberg will open by examining molecular mechanisms behind social variability, emphasizing how interactions between freely-moving mice reveal social heterogeneity. Hanna Trebesova will then address the central amygdala’s role in sustaining social behavior, differentiating between circuits for initiating versus maintaining social contact. Jonathan P. Fadok will discuss how female dominance hierarchies impact stress resilience, showcasing rank-based neurobiological responses to social stressors. Finally, Alan Kania will reveal oxytocin’s role in promoting social behavior through medial prefrontal cortex interneurons, linking hormonal action to reward and anxiety networks. Together, these talks provide an in-depth look at the interplay of hierarchy, social partners, and hormonal modulation in shaping complex social behaviors.
Hanna Hörnberg, Max-Delbrück-Centrum für Molekulare Medizin (MDC), Berlin, Germany
Molecular mechanisms of social heterogeneity
Sociability exists on a spectrum, and stable individual differences in sociability have been found in many animal species, including genetically similar laboratory mice. However, individual differences in social behavior will depend not only on the individual being tested but also on the partner’s behavior and the specific relationship between the two. I will discuss our work using deep social phenotyping to examine how the behavior of all interaction partners influences social encounters in freely-moving mice. We use this method in combination with mass spectrometry to better understand the molecular mechanisms underlying social heterogeneity.
Hanna Trebesova, Nencki Institute of Experimental Biology, PAS Warsaw, Poland
The Maintenance of the social behavior: the role of central amygdala
The motivation behind social interaction can be attributed to a number of factors, including the pursuit of food or the formation of relationships with other individuals. Accordingly, this social interaction may be maintained, and the mechanism in question requires the involvement of different brain regions. The present study focuses on the central amygdala (CeA) and aims to elucidate whether the neural circuits involved in the initiation of social contact and in the maintenance of social interaction are identical or distinct. By employing optogenetic stimulation in association with a range of social stimuli, it is possible to observe changes in social interaction maintenance.
Marzena Stefaniuk, PhD, Laboratory of Neurobiology, the Nencki Institute of Experimental Biology BRAINCITY, Polish Academy of Science, Warsaw, Poland
Sociability and Addiction-like Traits in Mice
Alcohol dependence has a strong social component. Social factors like peer influence, societal norms, and stressors impact susceptibility to alcohol use. We use an automated rodent homecage that allows for continuous monitoring of mice living in a social environment. Our observations indicate that mice develop social bonds-like behavior. We observed a distinction between individuals in terms of their interactions as measured by Social Score. These moreover change over time. We measured alcohol consumption, motivation to alcohol, persistence in alcohol seeking and set an Addiction Score for each mouse. Our observations indicate a possible correlation between a Social Score and an Addiction Score.
Alan Kania, Central Institute of Mental Health, Mannheim, Germany
Oxytocin facilitates social behavior through interneurons in the rat prefrontal cortex
Oxytocin (OT) is widely studied for its profound pro-social effects, yet the mechanisms behind its diverse actions remain unclear1,2. Our project explores OT’s role in the medial prefrontal cortex (mPFC). We demonstrated direct axonal projections from the hypothalamus to the mPFC and identified two types of oxytocin receptor (OTR) neurons activated during social interactions. Activating OTR+ axo-axonic interneurons in the mPFC enhances social behavior and shifts preferences, likely through selective modulation of principal neurons projecting to subcortical regions involved in social, reward, and anxiety-related processes, which may underlie the prosocial action of OT via the mPFC.
References:
1. Froemke RC, et al. Oxytocin, neural plasticity, and social behavior. Annual Review of Neuroscience, 2021. doi: 10.1146/annurev-neuro-102320-102847
2. Leng G, et al. Oxytocin—a social peptide? Deconstructing the evidence. Philos Trans R Soc Lond B Biol Sci., 2022. doi: 10.1098/rstb.2021.0055