title: 3D video analysis of the novel object recognition test in rats.
abstract: The novel object recognition (NOR) test has been widely used to test memory function. We developed a 3D computerized video analysis system that estimates nose contact with an object in Long Evans rats to analyze object exploration during NOR tests. The results indicate that the 3D system reproducibly and accurately scores the NOR test. Furthermore, the 3D system captures a 3D trajectory of the nose during object exploration, enabling detailed analyses of spatiotemporal patterns of object exploration. The 3D trajectory analysis revealed a specific pattern of object exploration in the sample phase of the NOR test: normal rats first explored the lower parts of objects and then gradually explored the upper parts. A systematic injection of MK-801 suppressed changes in these exploration patterns. The results, along with those of previous studies, suggest that the changes in the exploration patterns reflect neophobia to a novel object and/or changes from spatial learning to object learning. These results demonstrate that the 3D tracking system is useful not only for detailed scoring of animal behaviors but also for investigation of characteristic spatiotemporal patterns of object exploration. The system has the potential to facilitate future investigation of neural mechanisms underlying object exploration that result from dynamic and complex brain activity.
authors.affiliation: System Emotional Science, University of Toyama, Toyama, Toyama, Japan.
authors.forename: Jumpei
authors.initials: J
authors.lastname: Matsumoto
authors.affiliation: Department of Neuropsychiatry, Kanazawa Medical University, Ucninada-cho, Kahoku, Ishikawa, Japan.
authors.forename: Takashi
authors.initials: T
authors.lastname: Uehara
authors.affiliation: System Emotional Science, University of Toyama, Toyama, Toyama, Japan.
authors.forename: Susumu
authors.initials: S
authors.lastname: Urakawa
authors.affiliation: System Emotional Science, University of Toyama, Toyama, Toyama, Japan.
authors.forename: Yusaku
authors.initials: Y
authors.lastname: Takamura
authors.affiliation: Department of Clinical Research Promotion, National Center Hospital, National Center of Neurology and Psychiatry, Kodaira, Tokyo, Japan.
authors.forename: Tomiki
authors.initials: T
authors.lastname: Sumiyoshi
authors.affiliation: Department of Neuropsychiatry, University of Toyama, Toyama, Toyama, Japan.
authors.forename: Michio
authors.initials: M
authors.lastname: Suzuki
authors.affiliation: System Emotional Science, University of Toyama, Toyama, Toyama, Japan.
authors.forename: Taketoshi
authors.initials: T
authors.lastname: Ono
authors.affiliation: System Emotional Science, University of Toyama, Toyama, Toyama, Japan. Electronic address: nishijo@med.u-toyama.ac.jp.
authors.forename: Hisao
authors.initials: H
authors.lastname: Nishijo
mesh_terms: D000818:Animals; D004192:Discrimination, Psychological / Q000187:drug effects; D016291:Dizocilpine Maleate / Q000494:pharmacology; D018691:Excitatory Amino Acid Antagonists / Q000494:pharmacology; D005106:Exploratory Behavior / Q000187:drug effects; D021621:Imaging, Three-Dimensional / Q000379:methods*; D008297:Male; D009483:Neuropsychological Tests; D020318:Rats, Long-Evans; D021641:Recognition, Psychology / Q000187:drug effects; D065853:Spatial Learning / Q000187:drug effects; D014741:Video Recording / Q000379:methods*
chemical_list: D018691:Excitatory Amino Acid Antagonists; D016291:Dizocilpine Maleate
keywords: 3D video tracking; Attention; Exploratory behavior dynamic; MK-801; Object recognition memory; Phenotyping behavior