Sex differences in vocalizations to familiar or unfamiliar females in mice.

Eri Sasaki,Yuiri Tomita,Kouta Kanno

doi:10.1098/rsos.201529

Abstract

Mice, both wild and laboratory strains, emit ultrasound to communicate. The sex differences between male to female (male–female) and female to female (female–female) ultrasonic vocalizations (USVs) have been discussed for decades. In the present study, we compared the number of USVs emitted to familiar and unfamiliar females by both males (male–female USVs) and females (female–female USVs). We found that females vocalized more to unfamiliar than to familiar females. By contrast, males exhibited more USVs to familiar partners. This sexually dimorphic behaviour suggests that mice change their vocal behaviour in response to the social context, and their perception of the context is based on social cognition and memory. In addition, because males vocalized more to familiar females, USVs appear to be not only a response to novel objects or individuals, but also a social response.

Highlights

Social animals use signals of specific modalities to communicate with other individuals
Under the 30 min isolation condition, the number of ultrasonic vocalizations (USVs) emitted from subject females to unfamiliar females was significantly higher than that from familiar partners
Under the 30 min isolation condition, no significant differences were detected between the number of USVs emitted from males to unfamiliar and familiar partners

Summary

Introduction

Social animals use signals of specific modalities to communicate with other individuals. Among such signals, vocal communication is widely observed in animals and is superior in several aspects [1]. Ultrasonic vocalizations (USVs) are used for communication, and they can be widely observed in both wild and laboratory strains [2]. There are two types of USVs commonly known in mice: pupUSVs and courtship vocalizations [3]. Adult male mice emit ultrasounds in the presence of adult females or their urine [5]; these are known as courtship vocalizations or courtship songs [6].

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Discussion

Conclusion