ACTIVITY OF DISTINCT POPULATIONS OF CELLS IN THE CENTRAL AMYGDALA CODING VARIOUS SOCIAL STIMULI

The central amygdala (CeA) is a key structure in the brain’s motivational system and plays a crucial role in processing social behavior. However, the specific contributions of distinct neuronal populations within the CeA to social information processing remain poorly understood. A deeper understanding of how different cell types respond to social interactions is essential for identifying the neural circuits underlying social behavior. Such insights could provide valuable information for understanding social deficits associated with neuropsychiatric disorders and identifying potential therapeutic targets. In this study, we aimed to characterize how two well-defined inhibitory neuronal populations in the CeA - somatostatin-positive (SOM) and corticotropin-releasing factor–positive (CRF) neurons - contribute to the processing of social stimuli. Neuronal activation during social interaction was assessed by mapping cFOS-positive cells and their colocalization with AAV-DIO-mCherry in the CeA of transgenic SOM-Cre and CRF-Cre mouse models. To complement these anatomical analyses, we performed functional activity monitoring by injecting AAV-DIO-GCaMP8m into the CeA and recording neuronal activity using wireless photometry (Telefipho). This approach enabled us to measure neuronal responses to various social stimuli, including interactions with unfamiliar and familiar male partners with known social hierarchy, as well as with females. Our results reveal activity patterns in SOM and CRF neurons depending on the social context, highlighting their differential roles in encoding social information. These findings advance our understanding of how the CeA processes diverse social stimuli and provide a foundation for future studies linking functional activity with anatomical connectivity to identify key social behavior circuits.