title: The touchscreen operant platform for assessing cognitive functions in a rat model of depression.
abstract: In the present study we assessed alterations in cognitive functions in a chronic mild stress (CMS) rat model of depression. Cognitive functions were assessed in two different tasks applying the translational operant platform touchscreen technology; the visual discrimination/acquisition task was used to assess the ability to perceive and distinguish visual stimuli and to assess associative stimulus-reward learning. The visual discrimination/reversal learning task was used to assess functional brain plasticity or reprogramming of previously acquired stimulus-reward associations. These tasks permit the dissociation of multiple cognitive domains. The CMS model is a validated depression model with the useful feature that rats upon stress exposure show a graduated, individual stress response allowing the segregation of rats into different phenotypes including stress-resilient and anhedonic-like subgroups. Anhedonic-like rats are less likely to acquire the pairwise discrimination task, and they have a slower acquisition rate than controls. In the reversal learning task, resilient rats performed significantly better than anhedonic-like rats over time and 50% passed criterion as opposed to 25% for controls and only 14% for anhedonic-like rats. This indicates that resilient rats have higher cognitive flexibility than anhedonic-like rats. Thus they perform better in learning a novel task, which at the same time potentially implies an increased ability to inhibit previously rewarded behavior.
authors.affiliation: Translational Neuropsychiatry Unit, Department of Clinical Medicine, Aarhus University, Denmark.
authors.forename: Thao Phuong
authors.initials: TP
authors.lastname: Tran
authors.affiliation: Translational Neuropsychiatry Unit, Department of Clinical Medicine, Aarhus University, Denmark; Center for Functional and Integrative Neuroscience, Department of Clinical Medicine, Aarhus University, Denmark.
authors.forename: Helle Lyng
authors.initials: HL
authors.lastname: Christensen
authors.affiliation: Center for Functional and Integrative Neuroscience, Department of Clinical Medicine, Aarhus University, Denmark; Department of Nuclear Medicine and PET-Centre, Aarhus University Hospital, Aarhus, Denmark.
authors.forename: Freja Cecilia Brandt
authors.initials: FCB
authors.lastname: Bertelsen
authors.affiliation: Translational Neuropsychiatry Unit, Department of Clinical Medicine, Aarhus University, Denmark.
authors.forename: Elena
authors.initials: E
authors.lastname: Bouzinova
authors.affiliation: Center for Functional and Integrative Neuroscience, Department of Clinical Medicine, Aarhus University, Denmark; Department of Nuclear Medicine and PET-Centre, Aarhus University Hospital, Aarhus, Denmark.
authors.forename: Arne
authors.initials: A
authors.lastname: Møller
authors.affiliation: Translational Neuropsychiatry Unit, Department of Clinical Medicine, Aarhus University, Denmark. Electronic address: ove.wiborg@clin.au.dk.
authors.forename: Ove
authors.initials: O
authors.lastname: Wiborg
mesh_terms: D000818:Animals; D003072:Cognition Disorders / Q000175:diagnosis* / Q000209:etiology*; D003216:Conditioning, Operant / Q000502:physiology*; D003863:Depression / Q000150:complications*; D004195:Disease Models, Animal; D005518:Food Preferences / Q000502:physiology; D007398:Interpersonal Relations; D008297:Male; D010775:Photic Stimulation; D051381:Rats; D017208:Rats, Wistar; D012193:Reversal Learning; D018709:Statistics, Nonparametric; D013395:Sucrose / Q000008:administration & dosage; D014110:Touch
chemical_list: D013395:Sucrose
keywords: Behavior; Cognition; Depression; Learning; Stress; Touchscreen