The impact of partner interaction on brief social buffering in adolescent female rats as analyzed by deep learning-based object detection algorithms

Abstract

Social buffering is a phenomenon whereby the stress response of anyone exposed to a distressing stimulus is alleviated by the presence of conspecific(s). In this study, we aimed to determine whether brief buffering (only 3 min) with conspecific immediately after fear conditioning can produce social buffering in adolescent Sprague-Dawley rats (4–5 weeks, male and female) and whether close partner interaction can impact brief social buffering in adolescent female rats. The rats received an electric shock in the black room of shuttle box, followed by a 3 min buffering period. After two learning sessions, the rats performed passive avoidance test individually, both immediately and 24 hr later. To reduce human bias and analyze variables not accessible to humans, data were analyzed using YOLOv8 and BoT-SORT, deep learning-based algorithm. As a result, Toy group, tested with an object resembling a rat, showed a significant increase in fear-related behavior for both sexes. Pair group, tested with a partner, showed a significant decrease in fear-related behavior in both sexes during the learning check, but only females maintained this decrease in the retention. In Pair female group, the longer the rat and its partner spent in the same room and the longer they stayed close, the higher the black room preference; this was a significant correlation. Therefore, we demonstrated that immediate brief social contact is sufficient to induce social buffering especially in female rats. In addition, social contact appears to be a key factor increasing the efficiency of social buffering.