Abstract

Effect of forced swim stress on wistar albino rats in various behavioral parameters

Author(s):Ambareesha Kondam, Nilesh N Kate, Gaja Lakshmi, Suresh M and Chandrashekar M

Introduction: Stress is an important factor of depression that causes the changes in various body systems. The forced swim test is a commonly used stressor test where rats are forced to swim in specially constructed tanks for a particular period where there is behavioral activation characterized by vigorous swimming and diving to search for alternate routes of escape. Animal health including human has been shown to be affected by the stressful events of life inducing situation which alters cognition, learning memory and emotional responses, causing mental disorders like depression and anxiety and stress in rats. Methods: The experiment was carried out with 12 healthy albino Wistar female rats weighing about 150-180gms. The animals were randomly divided into two groups of six animals each. Group – I (control), Group – II (Stressed Group). Group –II rats are placed in plastic tanks for 45minutes for15 days. Temperature of water was maintained at 20ËÂ�?�??�?šC. During stress phase, the animals will be trained for forced swim test, behavioral changes observed by open field apparatus for emotions, and eight arm maze for memory & leaning, elevated plus maze for anxiety. Results: Forced swim stress causes to a significant change (p<0.05) on cognitive functions: motivation, learning and memory. Forced swim stress is the factor damaging the hippocampus causes repeated immobilization and produce atrophy of dendrites of pyramidal neurons and neuroendocrinological disturbances, controlled by the hypothalamo-pituitary-adrenal axis (HPA). Repeated stress in the form of forced swimming activates the free radical processes leading to an increase in lipid peroxidation in many tissues. Conclusion: This study reveals the effect of repeated forced swim stress causes wide range of adaptive changes in the central nervous system including the elevation of serotonin (5- HT) metabolism and an increased susceptibility to affective disorders. The earlier findings have reported that chronic and acute stress procedures weaken working memory functions in rats. There are very few studies on sub acute forced swim stress on working memory status of the animal. The study was undertaken to assess the various behavioral changes by applying sub acute forced swim.

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