“…More recently, we proposed that 50-kHz ultrasonic vocalizations (USV), which are related to positive affect, could be an additional readout for manic-like states (Pereira et al, 2014;Wendler et al, 2016Wendler et al, , 2019Engelhardt et al, 2017). In this line, lisdexamfetamine (LDX), a pro-drug of amphetamine, induces increased locomotor activity and 50-kHz USV that are prevented by lithium or valproate administration (Macêdo et al, 2013;de Souza et al, 2015;Wendler et al, 2016;Bristot et al, 2019). According to their spectrogram shapes, 50-kHz USV can be classified into different subtypes (Costa et al, 2020;Mulvihill and Brudzynski, 2020;Wright et al, 2010) and we have applied a rather common classification into four subtypes: trill, step, mixed and flat (e.g.…”