THE SUBTHALAMIC NUCLEUS IS INVOLVED IN SOCIAL MEMORY IN MALE RATS

Human social behavior depends on complex socio-cognitive abilities, many of which are disrupted in neuropsychiatric disorders. We previously found that subthalamic nucleus (STN) lesions abolish familiarity-based modulation of social reward in rats, implicating the STN in social recognition. Here, we used pharmacological lesions, electrical deep brain stimulation (DBS), and optogenetic manipulations to dissect the STN’s role in social memory. STN lesions selectively impaired social discrimination memory without affecting social novelty discrimination or non-social memory. High-frequency optogenetic stimulation disrupted social discrimination memory only when applied during encoding, whereas STN optogenetic inhibition, and electrical DBS impaired social memory when applied during either encoding or retrieval. Notably, transient optogenetic inhibition abolished recognition of a cage-mate after short isolation, yet this ability was preserved after permanent lesions, suggesting compensatory adaptations. These results identify the STN as a key node for social memory and highlight the importance of considering its role in social cognition when implementing STN-targeted therapies.