Social Isolation Selectively Increases Anxiety in Mice without Affecting Depression-like Behavior.
10.4196/kjpp.2009.13.5.357
- Author:
Chuljung KWAK
1
;
Sue Hyun LEE
;
Bong Kiun KAANG
Author Information
1. National Creative Research Initiative Center for Memory, Department of Biological Sciences, College of Natural Sciences, Seoul National University, Seoul 151-747, Korea. kaang@snu.ac.kr
- Publication Type:Original Article
- Keywords:
Anxiety level;
Social isolation;
Housing environment;
Experimental animals;
Open field test;
Tail suspension test;
Forced swim test
- MeSH:
Animals;
Anxiety;
Bias (Epidemiology);
Hand;
Housing;
Mice;
Social Isolation
- From:The Korean Journal of Physiology and Pharmacology
2009;13(5):357-360
- CountryRepublic of Korea
- Language:English
-
Abstract:
It is hypothesized that a number of environmental factors affect animals' behavior. Without controlling these variables, it is very hard for researchers to get not only reliable, but replicable data from various behavioral experiments testing animals' cognitive as well as emotional functions. For example, laboratory mice which had restricted environment showed different synaptic potentiation properties with wild mice (Zhao MG et al., 2009). While performing behavioral experiments, however, it is sometimes inevitable that the researcher changes the animals' environments, as by switching the cages in which experimental animals are housed and separating animals raised together into small experimental groups. In this study, we investigated the effect of environmental changes on mice's emotional behaviors by socially isolating them or reducing the size of their cage. We found that social isolation selectively increases the animals' levels of anxiety, while leaving depression-like behaviors unchanged. On the other hand, alteration of the housing dimensions affected neither their anxiety levels nor their depression-like behaviors. These results suggest that environmental variables may have a prominent impact on experimental animals' emotional behaviors and possibly their psychological states, leading to bias in the behavioral data produced from experiments.
