Ultrasonic Vocalizations by Infant Mice: An Ethological Expression of Separation Anxiety

The ultrasonic vocalization, or isolation calling, of infant rats and mice has been studied as a measure of anxious affective state and as an early communicative behavior between a pup and mother. The protocol described herein is the typical separation testing procedure. Also included are procedures used to modulate crying by providing contact with littermates and/or dam and increased isolation calling response by a prior brief maternal interaction. These procedures provide the basis for experimental research on the early development of emotion and communication in a critically important experimental model species – the mouse.