Ultrasonic Vocalizations in Rodent Courtship Behavior

Each male was tested in its home cage in the presence of a female from one of the four treatment groups as previously described (Capela et al. 2018 (link), 2019 (link); Dombret et al. 2017 (link)). After the introduction of a female, vocalizations were recorded for 4 min with an UltraSoundGate microphone (Avisoft Bioacoustics), which was connected to an ultrasound recording interface plugged into a computer equipped with the Avisoft-SASLab Pro (version 5.2.09; Avisoft Bioacoustics) recording software. Vocalizations were analyzed using Avisoft-SASLab Pro (Avisoft Bioacoustics). Spectrograms were generated for each detected call (frequency resolution: FFT-length: 512; frame size: 100%; overlap: 50%). The parameters used for the automatic quantification of the vocalizations were: cutoff frequency of $30\text{\hspace{0.17em}kHz}$ , element separation based on an automatic single threshold with a hold time of $15\text{\hspace{0.17em}ms}$ . Syllables were identified and grouped into three main categories (simple, complex, frequency-jump). The total number and duration of USVs were analyzed, as well as the number and duration of each syllable.