Aversive conditioning to an odour from playback of ultrasonic vocalization alarm calls

Rats display behaviours in response to aversive stimuli that communicate danger. Both male and female rats display freezing and ultrasonic vocalisation alarm calls, which are proposed to have a communicative function. This study assessed dominance in both male and female rats using a resource competition assay, and recorded alarm vocalisations produced by dominant rats in response to aversive pavlovian conditioning. To assess the ability of alarm calls to support subsequent learning in a conspecific, the calls were played back to the submissive rats in presence of a neutral odour. Both sexes responded by freezing to the playback of alarm calls. Importantly, after pairing the alarm calls with the odour, the response could be elicited by the odour alone the following day. These findings demonstrate alarm calls can support olfactory conditioning in rats and highlight a role for ultrasonic vocalisation in transmission of affective state.