Environmental Enrichment Improves Novel Object Recognition and Enhances Agonistic Behavior in Male Mice

• Published in: Aggressive behavior Vol. 39; no. 4; pp. 269 - 279
• Main Authors: Mesa-Gresa, Patricia, Pérez-Martinez, Asunción, Redolat, Rosa
• Format: Journal Article
• Language: English
• Published: United States Blackwell Publishing Ltd 01-07-2013; Wiley Subscription Services, Inc
• Subjects: agonistic behavior; Agonistic Behavior - physiology; Animals; Behavior, Animal - physiology; environmental enrichment; Exploratory Behavior - physiology; Form Perception - physiology; Housing, Animal; Learning; Male; male mice; Mice; Mice, Nude; object recognition test; Recognition (Psychology) - physiology; Sociability; Social Behavior; Social Dominance; Social interaction; Species Specificity; Stimulation
• ISSN: 0096-140X; 1098-2337
• DOI: 10.1002/ab.21481

Environmental enrichment (EE) is an experimental paradigm in which rodents are housed in complex environments containing objects that provide stimulation, the effects of which are expected to improve the welfare of these subjects. EE has been shown to considerably improve learning and memory in rodents. However, knowledge about the effects of EE on social interaction is generally limited and rather controversial. Thus, our aim was to evaluate both novel object recognition and agonistic behavior in NMRI mice receiving EE, hypothesizing enhanced cognition and slightly enhanced agonistic interaction upon EE rearing. During a 4‐week period half the mice (n = 16) were exposed to EE and the other half (n = 16) remained in a standard environment (SE). On PND 56–57, animals performed the object recognition test, in which recognition memory was measured using a discrimination index. The social interaction test consisted of an encounter between an experimental animal and a standard opponent. Results indicated that EE mice explored the new object for longer periods than SE animals (P < .05). During social encounters, EE mice devoted more time to sociability and agonistic behavior (P < .05) than their non‐EE counterparts. In conclusion, EE has been shown to improve object recognition and increase agonistic behavior in adolescent/early adulthood mice. In the future we intend to extend this study on a longitudinal basis in order to assess in more depth the effect of EE and the consistency of the above‐mentioned observations in NMRI mice. Aggr. Behav. 39:269–279, 2013. © 2013 Wiley Periodicals, Inc.