SEROTONIN IN THE MEDIATION OF BEHAVIORAL EFFECTS OF OMEGA-3 FISH OIL SUPPLEMENTS: A STUDY IN RATS.

Abstract

Omega-3 polyunsaturated fatty acids (omg-3 PUFAs) are widely prescribed for improving therapeutic strategies in many diseases. There are reports that the use of these supplements can reduce disease-related depression and anxiety in patients taking these supplements. However, pre-clinical research shows mixed results. In view of the role of serotonin (5-hydroxytryptamine, 5-HT) in anxiety and depression, the present study concern effects of omg-3 on anxiety-like behavior and on serotonin metabolism in brain regions known to have a role in anxiety. It was found that administration of omg-3 for 20 days did not alter food intake and body weight. The treatment reduced locomotor activity in an open field arena and enhanced anxiety-like behavior in an elevated plus-maze test. 5-HT concentration increased in the hippocampus (HPC) and midbrain (MB) but decreased in the prefrontal cortex (PFC). Levels of 5-hydroxyindoleacetic acid (5-HIAA) were decreased in these regions. The tryptophan levels were not affected in the PFC but increased in the HPC and MB at a low dose; suggesting that decreases of 5-HT and 5-HIAA were not due to a decrease in the availability of tryptophan. The present study implied that unnecessary use of omg-3 supplements can reduce serotonin neurotransmission via the PFC to predispose to anxiety.