Abstract
Arachidonic acid (20:4n-6, ARA), which is one of the n-6 essential fatty acids, has been accumulated about 10% of the total fatty acids in a rodent brain. We investigated the effects in the brain function after chronic supplementation of ARA. The chronic supplementation of ARA increased motor activity, and reduced the total time which is the time until taking the diet, in the radial maze test as the spatial cognitive function test, although ARA did not indicate severe toxicity. A decrease in brain function was also observed in the rota-rod test as the motor coordination test. In the fatty acid composition of brain, we detected the increase of the total n-6 fatty acids and the decrease of DHA as the n-3 fatty acid in the ARA supplementation group, but there were no differences in saturated and monounsaturated fatty acids. This change of the n-3 Def group was more remarkable than that of the n-3 Adq group. Therefore, the chronic supplementation of ARA should be careful because there is a risk of deterioration of brain function based on the enhancement in n-3 fatty acids deficiency.
