Increased Vocalization of Rats in Response to Ultrasonic Playback as a Sign of Hypervigilance Following Fear Conditioning. Olszyński et al.
Raw data showing rats' responses to ultrasonic playback. Rats underwent fear conditioning with 0, 1, 6 or 10 shocks (1 s, 1.0 mA each). Their basic level of vocalization, heart rate and freezing was evaluated before fear conditioning; freezing levels were tested after conditioning (context, context plus cue). Then the rats spent 10 min in silence and where exposed to 10-s-long playbacks of 50-kHz ultrasonic vocalizations (USV), 50-kHz artificial tones, 22-kHz USV, 22-kHz tones in randomized order. Data are organized in 10-s-long intervals. Included are: distance traveled [cm], time spent [%] in the half of the cage next to the speaker, heart rate [HR, bpm], and number of emitted USV in response. The initial 10 min was also analyzed in 2-min-long bins. Outliers are marked and described in the publication. Data show increase of vocalizations in response to the playbacks, especially 50-kHz ones, increase in HR following 50-kHz playbacks and decrease in HR after 22-kHz playbacks. Importantly, the shocked rats showed higher locomotor activity during 50-kHz playback and a more significant decrease in locomotor activity following 22-kHz playback; they vocalized more often, their USV were longer and at a higher frequency than in control animals.