The effect of playback of 22-kHz and 50-kHz ultrasonic vocalizations on rat behaviors assessed with a modified open-field test

Increased Vocalization of Rats in Response to Ultrasonic Playback as a Sign of Hypervigilance Following Fear Conditioning

“…Please note that there was still a decrease in locomotor activity following 22-kHz playback [39]. Another reason for the discrepancy could be the difference in playback duration, which was only 10 s in our case, while others have investigated up to 10-15 min (e.g., [41,42]).…”

“…We also observed behavioral changes in animals when faced with different playbacks, which included approaching the speaker. It was shown before that playback of 50-kHz calls causes approach behavior in rats, however 22-kHz presentation was repeatedly reported to elicit behavioral inhibition and no-social-approach [33][34][35][36][37][38][39][40] and hiding [41], while we observed speaker-side preference following 22-kHz playback (Figure 1, Table S2). The preference could again be a result of the low-stress, home-cage-like experimental conditions.…”

Aversive (22 kHz) ultrasonic vocalization playback as translational assay of anxiety in rats: Evidence from both neural and behavioral studies

“…These results begin to suggest the possibility of inducing negative affect with 22 kHz USV playback. Another more recent study with male F344 Fischer rats using a modified OFT found that 15 minutes of 22 kHz USV playback from a male of the same strain led to decreased time in the center of the OFT (Inagaki & Ushida, 2021). When a hiding box was introduced, animals spent more time concealed in the box and less time with the head out of the box during playback as compared to a 1000 Hz long sine-wave tones (Inagaki & Ushida, 2021).…”

“…Another more recent study with male F344 Fischer rats using a modified OFT found that 15 minutes of 22 kHz USV playback from a male of the same strain led to decreased time in the center of the OFT (Inagaki & Ushida, 2021). When a hiding box was introduced, animals spent more time concealed in the box and less time with the head out of the box during playback as compared to a 1000 Hz long sine-wave tones (Inagaki & Ushida, 2021). In another emergence test with only 3 minutes of playback during which a rat was able to leave a small, enclosed box, 22 kHz USV playback increased latency to emerge from the box and decreased time spent outside of the box compared to 50 kHz USV playback or background noise (Burman et al, 2007).…”

“…However, age of the animal producing USVs effects ASR (Inagaki & Ushida, 2017), and unique effects of playback have been seen based on the individual animal that USVs were recorded from (Burman et al, 2007). It is also possible that the sex of the animal emitting USVs leads to different behavior as has been shown with increased exploration of male rats during female 50 kHz USV playback (Inagaki & Ushida, 2021), but this question has not been examined thoroughly with 22 kHz USVs. Second, playback parameters differ greatly between research groups.…”