Title:Cross-species identification of circuit-specific neuronal ensembles

Social behaviors are essential for organismal survival as organisms must be able to appropriately direct their behavior based on a social stimulus. While essential, social behaviors are dysregulated in neurodevelopmental disorders, including autism spectrum disorder (ASD) and schizophrenia. The lateral septum (LS) is a primarily GABAergic brain region that controls several aspects of social behaviors within humans and mice. Specifically, neurons projecting from the basolateral amygdala (BLA) to the LS are required for social recognition, a social behavior in which an animal must discern between a novel or familiar conspecific. Recently, we identified a neuronal ensemble, or a group of neurons whose activity is coordinated to control brain function, within the LS that is activated both by BLA stimulation and social interaction. However, the distinct gene expression signature and spatial topography of the BLA-activated LS neuronal ensemble has not been studied. Based on previous findings implicating the BLA-LS circuit and LS neuronal ensembles in regulating social behaviors, my central hypothesis is that activating LS-projecting BLA neurons recruits a transcriptionally and spatially distinct ensemble of LS neurons that is conserved in the human brain