Concomitant docosahexaenoic acid administration ameliorates stress-induced cognitive impairment in rats

- DHA administration prevented deleterious effects of chronic stress on memory.
- DHA facilitates functional recovery after stress with the strength of fluoxetine.
- Fluoxetine did not show the impact on working memory impairment after chronic stress.

Long chain n-3 fatty acids, especially eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) may slow cognitive decline. DHA plays an important role in neural function and decreased plasma DHA are associated with cognitive decline in healthy elderly adults and in patients with Alzheimer's disease. In this study we tested a hypothesis that DHA protects cognitive functions of male Wistar rats against negative impact of prolonged restraint stress. Specifically, we attempted to characterize the preventive action of prolonged treatment with DHA enriched preparation (daily dose of DHA: 300 mg/kg, p.o. for 21 days) in comparison with positive control (fluoxetine: 10 mg/kg daily, p.o. for 21 days) against an impairment caused by chronic restraint stress (2 h daily for 21 days) on recognition memory tested in a object recognition task and on the spatial working memory tested in Morris water maze. We found that administration of DHA enriched preparation prevented deleterious effects of chronic restraint stress both on recognition (p < 0.01) and on the working spatial memory (p < 0.001).