Krill-derived Phospholipids Rich in n-3 Fatty Acid Improve Spatial Memory in Adult Rats

We indicated previously that dietary supplementation of the ethyl ester form of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) improves spatial cognition through an increase in DHA levels in the hippocampus and cerebral cortex. In the present study, we investigated the effects of peroral administration of krill-derived phospholipids (KPL) on the spatial learning ability and the fatty acid composition of the plasma and brain tissues. Both parameters of the radial arm maze task, the reference- and working memory errors, significantly decreased after KPL administration. The plasma and brain levels of n-3 PUFAs significantly increased, and the levels of arachidonic acid were significantly decreased after KPL administration. Lipid peroxidation in the plasma and in brain tissues was depressed, and cell generation in the dentate gyrus was enhanced in KPL-administered rats. All these effects are similar to those induced by the ethyl ester forms of EPA and DHA.