Chronic ω-3 fatty acids supplementation promotes beneficial effects on anxiety, cognitive and depressive-like behaviors in rats subjected to a restraint stress; protocol

Recent evidence has demonstrated dietary influence on the manifestation of different types of behaviors induced by stressor tasks. The present study examined the impact of omega-3 polyunsaturated fatty acids (PUFAs) supplementation in an early phase of the brain development with the goal of preventing or even attenuating the occurrence of stress-related behaviors such as depressive-like behaviors, anxiety and cognitive dysfunctions in male rats subjected to restraint stress. Our results indicated that the supplementation regimen successfully counteracted the anxiogenic effects of stress as evidenced by the rats' increased exploration time in the aversive arms of the elevated plus maze. The forced swimming test indicated that immobility and swimming were more deeply influenced by PUFAs supplementation, thereby demonstrating an antidepressant effect. Furthermore, cognitive function was shown to be intensely affected by restraint stress, but the effects were surprisingly counteracted by the PUFAs supplementation. Lastly, plasmatic corticosterone levels were demonstrated to be drastically increased by the restraint stress; however, PUFAs supplementation promoted a reduction of this stress-related hormone to levels that were comparable to those observed in the control group. Our results suggested that the mechanisms underlying these effects are possibly associated with the reduction of corticosterone levels promoted by the PUFAs supplementation in the stress-induced animals. Further studies to examine the participation of PUFAs in mediating different behaviors in rats subjected to restraint stress are warranted. (C) 2010 Elsevier B.V. All rights reserved.