22 and 50 kHz rat ultrasonic vocalization playback reveals sex differences in behavior and cFos in brain regions associated with affective processing.

Adult rats communicate using ultrasonic vocalization (USV) frequencies indicating negative (22 kHz) or positive (50 kHz) affective states. Playback of USVs can serve as an ethologically translational method to study affective processing in response to socially communicated states. However, few studies have examined behavioral and neural effects of USV playback in both male and female rats.

Playback of rat 22-kHz ultrasonic vocalizations as a translational assay of negative affective states: An analysis of evoked behavior and brain activity.

The subjective nature of human emotions makes them uniquely challenging to investigate in preclinical models. While behavioral assays in rodents aim to evaluate affect (i.e.