title: Hope for the best or prepare for the worst? Towards a spatial cognitive bias test for mice.
abstract: Cognitive bias, the altered information processing resulting from the background emotional state of an individual, has been suggested as a promising new indicator of animal emotion. Comparable to anxious or depressed humans, animals in a putatively negative emotional state are more likely to judge an ambiguous stimulus as if it predicts a negative event, than those in positive states. The present study aimed to establish a cognitive bias test for mice based on a spatial judgment task and to apply it in a pilot study to serotonin transporter (5-HTT) knockout mice, a well-established mouse model for the study of anxiety- and depression-related behavior. In a first step, we validated that our setup can assess different expectations about the outcome of an ambiguous stimulus: mice having learned to expect something positive within a maze differed significantly in their behavior towards an unfamiliar location than animals having learned to expect something negative. In a second step, the use of spatial location as a discriminatory stimulus was confirmed by showing that mice interpret an ambiguous stimulus depending on its spatial location, with a position exactly midway between a positive and a negative reference point provoking the highest level of ambiguity. Finally, the anxiety- and depression-like phenotype of the 5-HTT knockout mouse model manifested--comparable to human conditions--in a trend for a negatively distorted interpretation of ambiguous information, albeit this effect was not statistically significant. The results suggest that the present cognitive bias test provides a useful basis to study the emotional state in mice, which may not only increase the translational value of animal models in the study of human affective disorders, but which is also a central objective of animal welfare research.
authors.affiliation: Department of Behavioural Biology, University of Münster, Münster, Germany; Otto Creutzfeldt Center for Cognitive and Behavioral Neuroscience, University of Münster, Münster, Germany.
authors.forename: Vanessa
authors.initials: V
authors.lastname: Kloke
authors.affiliation: Department of Behavioural Biology, University of Münster, Münster, Germany; Otto Creutzfeldt Center for Cognitive and Behavioral Neuroscience, University of Münster, Münster, Germany.
authors.forename: Rebecca S
authors.initials: RS
authors.lastname: Schreiber
authors.affiliation: Department of Behavioural Biology, University of Münster, Münster, Germany.
authors.forename: Carina
authors.initials: C
authors.lastname: Bodden
authors.affiliation: Department of Behavioural Biology, University of Münster, Münster, Germany.
authors.forename: Julian
authors.initials: J
authors.lastname: Möllers
authors.affiliation: Department of Behavioural Biology, University of Münster, Münster, Germany.
authors.forename: Hanna
authors.initials: H
authors.lastname: Ruhmann
authors.affiliation: Department of Behavioural Biology, University of Münster, Münster, Germany; Otto Creutzfeldt Center for Cognitive and Behavioral Neuroscience, University of Münster, Münster, Germany.
authors.forename: Sylvia
authors.initials: S
authors.lastname: Kaiser
authors.affiliation: Division of Molecular Psychiatry, Laboratory of Translational Neuroscience, Department of Psychiatry, Psychosomatics and Psychotherapy, University of Würzburg, Würzburg, Germany.
authors.forename: Klaus-Peter
authors.initials: KP
authors.lastname: Lesch
authors.affiliation: Department of Behavioural Biology, University of Münster, Münster, Germany; Otto Creutzfeldt Center for Cognitive and Behavioral Neuroscience, University of Münster, Münster, Germany.
authors.forename: Norbert
authors.initials: N
authors.lastname: Sachser
authors.affiliation: Department of Behavioural Biology, University of Münster, Münster, Germany; Otto Creutzfeldt Center for Cognitive and Behavioral Neuroscience, University of Münster, Münster, Germany; Behavioral Biology, University of Osnabrück, Osnabrück, Germany.
authors.forename: Lars
authors.initials: L
authors.lastname: Lewejohann
mesh_terms: D000818:Animals; D001007:Anxiety / Q000378:metabolism / Q000503:physiopathology*; D001008:Anxiety Disorders / Q000378:metabolism / Q000503:physiopathology*; D001522:Behavior, Animal / Q000502:physiology; D015982:Bias; D003071:Cognition / Q000502:physiology*; D003863:Depression / Q000378:metabolism / Q000503:physiopathology*; D003866:Depressive Disorder / Q000378:metabolism / Q000503:physiopathology*; D004195:Disease Models, Animal; D005260:Female; D007600:Judgment / Q000502:physiology*; D007858:Learning / Q000502:physiology; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D010865:Pilot Projects; D050486:Serotonin Plasma Membrane Transport Proteins / Q000378:metabolism
chemical_list: D050486:Serotonin Plasma Membrane Transport Proteins; C493231:Slc6a4 protein, mouse