title: Affective communication in rodents: ultrasonic vocalizations as a tool for research on emotion and motivation.
abstract: Mice and rats emit and perceive calls in the ultrasonic range, i.e., above the human hearing threshold of about 20 kHz: so-called ultrasonic vocalizations (USV). Juvenile and adult rats emit 22-kHz USV in aversive situations, such as predator exposure and fighting or during drug withdrawal, whereas 50-kHz USV occur in appetitive situations, such as rough-and-tumble play and mating or in response to drugs of abuse, e.g., amphetamine. Aversive 22-kHz USV and appetitive 50-kHz USV serve distinct communicative functions. Whereas 22-kHz USV induce freezing behavior in the receiver, 50-kHz USV lead to social approach behavior. These opposite behavioral responses are paralleled by distinct patterns of brain activation. Freezing behavior in response to 22-kHz USV is paralleled by increased neuronal activity in brain areas regulating fear and anxiety, such as the amygdala and periaqueductal gray, whereas social approach behavior elicited by 50-kHz USV is accompanied by reduced activity levels in the amygdala but enhanced activity in the nucleus accumbens, a brain area implicated in reward processing. These opposing behavioral responses, together with distinct patterns of brain activation, particularly the bidirectional tonic activation or deactivation of the amygdala elicited by 22-kHz and 50-kHz USV, respectively, concur with a wealth of behavioral and neuroimaging studies in humans involving emotionally salient stimuli, such as fearful and happy facial expressions. Affective ultrasonic communication therefore offers a translational tool for studying the neurobiology underlying socio-affective communication. This is particularly relevant for rodent models of neurodevelopmental disorders characterized by social and communication deficits, such as autism and schizophrenia.
authors.affiliation: Behavioral Neuroscience, Experimental and Physiological Psychology, Philipps University of Marburg, Gutenbergstrasse 18, 35032, Marburg, Germany, markus.woehr@staff.uni-marburg.de.
authors.forename: Markus
authors.initials: M
authors.lastname: Wöhr
authors.forename: Rainer K W
authors.initials: RK
authors.lastname: Schwarting
mesh_terms: D000819:Animal Communication; D000818:Animals; D001522:Behavior, Animal / Q000502:physiology*; D004644:Emotions / Q000502:physiology*; D006801:Humans; D051379:Mice; D009042:Motivation / Q000502:physiology*; D051381:Rats; D012377:Rodentia