Investigating Behavioral Features and Ultrasonic Communication in Dyadic Female Mouse Interactions

Abstract

Acoustic communication is an essential facet of animals’ behavioral repertoires and is vital for survival. Insights from research on Drosophila melanogaster courtship song have revealed that the patterning of acoustic communication is flexible and dependent on the dynamic kinematic parameters of social interaction. In mice, the question of how behavior shapes acoustic communication strategies remains open. Laboratory mice emit ultrasonic vocalizations (USVs), which have been predominantly studied in the courtship context with a focus on male behavior and communication. Previous studies have indicated that vocalization patterns of both male and female mice are shaped by social and behavioral context, internal state, and notable sex differences. Female mice vocalize during both opposite-sex and same-sex interactions, and prior research has suggested a number of functions for USV usage in female-female interactions, including social recognition, social and sexual motivation, and establishment of dominance relationships. However, female vocalization behavior and the impacts of behavioral dynamics on USV emission remains relatively unexplored and thus poorly understood, especially in same-sex interactions. In this study, we sought to investigate the effects of select social, biological, and behavioral variables on modulating vocalization behavior and acoustic communication in female-female dyadic social interactions. We report on the use of an acute social isolation paradigm that permitted, for the first time, investigation of female-female vocalization behavior within an existing group social dominance hierarchy structure. We observed robust vocalization behavior in dyadic social interactions between female mice, with high vocalization counts and low latency to first vocalization. Importantly, we found that very low social distance between two female mice is associated with vocalization rates that are significantly higher than chance, and intermediate social distance is associated with vocalization rates that are significantly lower than chance. Finally, we present evidence suggesting that dominance hierarchy positions and estrous state may play a role in shaping vocalization behavior in dyadic female mouse interactions.