Effect of Environmental Factors on Depressive-like Behavior and Memory Function in Adolescent Rats

ABSTRACT

PURPOSE: The aim of this study was to identify the effects of environmental factors on depressive-like behavior and memory function during adolescence. We performed behavior tests in adolescent rats exposed to environmental enrichment, handling, and social deprivation for eight weeks. METHODS: Wistar rats were randomly assigned to control, environmental enrichment, handling, and social deprivation groups at the age of four weeks. RESULTS: In the forced swim test, the immobility time in the environmental enrichment group was decreased than that in the control group (p=.038), while the immobility time in the social deprivation group was increased than that in the control group (p=.035), the environmental enrichment group (p<.001), and the handling group (p=.001). In the Morris water maze test, the social deprivation group had an increased latency time than the control group (p=.013) and the environmental enrichment group (p=.001). In the passive avoidance test, the environmental enrichment group had an increased latency time than the control group (p=.005). However, the social deprivation group had reduced latency time than the socially housed groups (control: p=.030; environmental enrichment: p<.001; handling: p<.001). CONCLUSION: These findings suggest that environmental factors play an important role in emotion and memory function during adolescence.