Post-Weaning Two Weeks’ Social Isolation Stress Causing Anxiety-Like Behavior, Locomotion, and Cognition Impairment in Rats

Document Type : Original article


Introduction: Social and psychological stressors are associated with cognitive impairment and anxiety. This study aimed to determine the effect of two weeks’ socially-isolated post-weaning rats on their learning, memory, locomotion, and anxiety-related behavior. Materials and Methods: Young male and female Wistar rats (21 days old), separated from different mothers (with no relationship), were divided into 4 groups: groups 1 and 2 comprised colonies of six male and six female rats in separate cages, lived for 2 weeks; groups 3 and 4 comprised stressed males and females housed individually in separated opaque cages (one rat lived alone in each cage for 2 weeks) in the same room. Then, we evaluated their passive avoidance and spatial memories, anxiety-like behaviors, and motor activity. The obtained data were analyzed by one-way ANOVA followed by Tukey’s post hoc test. P values less than 0.05 were considered significant between all the test groups.Results: Both avoidance and spatial memories were impaired in stressed (single lived) male and female rats significantly (P<0.01 and P<0.001, respectively) while they showed no motor dysfunction or change in swimming speed. Stressed male and female rats showed more severe anxiety-like behavior versus populated rats (P<0.01), while their locomotion behavior in open field tests was not different. Conclusion: These results show that social stress during subjects’ growth can negatively influence cognition, locomotion, and anxiety behaviors. It is suggested that infants and youths must keep away from psychological stressors during development to prevent behavioral impairment.