title: Ultrasonic vocalizations as indices of affective states in rats.
abstract: Adult rats spontaneously vocalize in ultrasonic frequencies. Although these ultrasonic vocalizations (USVs) have been described as by-products of locomotor activity or social signals, accumulating evidence suggests that they may also index anticipatory affective states. Converging ethological, pharmacological, and brain stimulation research indicates that whereas long low-frequency (> 0.3-s, approximately 22-kHz) USVs occur during anticipation of punishment or avoidance behavior, short, high-frequency (< 0.3-s, approximately 50-kHz) USVs typically occur during anticipation of reward or approach behavior. Thus, long 22-kHz USVs may index a state of negative activation, whereas short, 50-kHz USVs may instead index a state of positive activation. This hypothesis has theoretical implications for understanding the brain circuitry underlying mammalian affective states and clinical applicability for modeling hedonic properties of different psychotropic compounds.
authors.affiliation: Department of Psychology, Stanford University, California 94305, USA. knutson@psych.stanford.edu
authors.forename: Brian
authors.initials: B
authors.lastname: Knutson
authors.forename: Jeffrey
authors.initials: J
authors.lastname: Burgdorf
authors.forename: Jaak
authors.initials: J
authors.lastname: Panksepp
mesh_terms: D000339:Affect; D000818:Animals; D051381:Rats; D014465:Ultrasonics; D014828:Vocalization, Animal