3D video analysis of the novel object recognition test in rats

Behav Brain Res. 2014 Oct 1;272:16-24. doi: 10.1016/j.bbr.2014.06.047. Epub 2014 Jun 30.

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.

Keywords: 3D video tracking; Attention; Exploratory behavior dynamic; MK-801; Object recognition memory; Phenotyping behavior.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Discrimination, Psychological / drug effects
  • Dizocilpine Maleate / pharmacology
  • Excitatory Amino Acid Antagonists / pharmacology
  • Exploratory Behavior* / drug effects
  • Imaging, Three-Dimensional / methods*
  • Male
  • Neuropsychological Tests
  • Rats, Long-Evans
  • Recognition, Psychology* / drug effects
  • Spatial Learning / drug effects
  • Video Recording / methods*

Substances

  • Excitatory Amino Acid Antagonists
  • Dizocilpine Maleate