Why the caged mouse sings: Studies of the mouse ultrasonic song system and vocal behavior

Abstract

Laboratory rodents participate in a significant amount of communication using ultrasonic vocalizations (USVs), and two types of USVs have been studied extensively as measures of internal states: pup isolation calls; and adult USVs in aversive, rewarding or social conditions. Mouse (Mus musculus) USVs do not appear to signal affect but are used primarily during non-aggressive social encounters and may facilitate social interactions. The most well characterized adult mouse USVs are those produced by males when they detect the presence of a sexually mature female and after copulation. Although the general occurrence of these male mouse USVs has been known for decades, in depth analyses of their spectro-temporal and syntactic features and the supporting neural substrate have only recently begun. Nevertheless, the field of mouse ultrasonic vocal communication is advancing rapidly on multiple fronts: discoveries at the molecular level; initial descriptions of the neural systems for vocal production and control; characterization of mouse models of social communication disorders and neuropsychiatric dysfunction; and ethological perspectives on the social function of ultrasonic communication in mice. As the mechanisms of mouse USV production become better understood, it is becoming possible to employ mouse vocalizations for purposes of behavioral phenotyping in mouse models of various neurological disorders and investigating the basic mechanisms of neural control of social communication in mammals. This chapter will describe some of the recent findings related to mouse vocal communication, with an emphasis on adult ultrasounds, and discuss the current interpretations and potential opportunities for advances in the field.