Effect of a high linoleate and a high alpha-linolenate diet on general behavior and drug sensitivity in mice

Semi-purified diets supplemented with either a high linoleate (n-6) (safflower) oil or a high alpha-linolenate (n-3) (perilla) oil were fed to mouse mothers and their offspring through 6 weeks of age. The proportions of n-3 and n-6 highly unsaturated fatty acids in brain phospholipids reflected the n-3/n-6 balance of the diets while no difference was found in phospholipid compositions or cholesterol/phospholipid ratios. In the elevated plus maze task, the total number of entries into the open- and enclosed-arms was smaller and the time spent in the dark enclosed arms tended to be longer in the perilla group than the safflower group. The time required to reach a safe platform in Morris's water maze test was less in the perilla group, but no significant difference was observed in the entries into the arms darkened with a movable cover in Y-maze dark-preference task. The safflower group was more sensitive to pentobarbital; the anesthesia onset time was less and the anesthetic time was longer than in the perilla group. Increased locomotion induced by scopolamine injection was less in the safflower group as compared with the perilla group. These results indicate that in mice the dietary alpha-linolenate/linoleate balance affects the n-3/n-6 ratio of brain phospholipid acyl chains and that this is accompanied by general behavioral changes as well as changes in sensitivities to drugs known to affect behavior.