Mechanisms by which dietary oils affect behavioral patterns of rats

与喂食富含α-亚麻酸的紫苏油的大鼠相比，喂食两代补充富含亚油酸的红花油（n-6）但缺乏α-亚麻酸（n-3）的大鼠在α亮度辨别学习测试（操作型）中表现出显著较低的学习能力，DHA含量显著降低。在这项研究中，我们研究了断奶后补充DHA是否可以恢复红花油组中观察到的学习能力下降。断奶后补充DHA（Saf + DHA组），脑中DHA和22：5 n-6含量达到紫苏油组水平。然而，Saf+DHA组的学习能力（正确反应率）与红花油组相当，但显著低于紫苏油组。对正、负刺激的压杆反应也与红花油组相似。内容 ...更多信息 测定脑区单胺类物质（脱胺酚、5-羟色胺及其代谢产物）的Ts，发现三个饮食组之间无显著差异。Saf+DHA组额叶皮层和海马的乙酰胆碱含量有降低的趋势，但与学习成绩无关。另一方面，与紫苏油组相比，红花油组的海马中的NGF（神经生长因子）含量显著降低，但梨状皮质中的NGF含量显著升高。当EPA（20：5 n-3），脑组织中DHA含量达到紫苏油组水平，而NGF含量与红花油组相当。这些结果表明，红花油组的学习能力下降是由于怀孕和哺乳期间大脑中DHA减少的不可逆影响。而脑内20：4 n-6、22：4 n-6和22：5 n-3等脂肪酸含量未达到紫苏油组水平，可能与红花油组和Saf+DHA组学习成绩下降有关。少

Rats fed through two generations a diet supplemented with safflower oil enriched with linoleic acid (n-6) but deficient in ci-linolenic acid (n-3) exhibited significantly lower learning ability in alpha brightness-discrimination learning test (operant-type) and significantly decreased DHA content than those fed a diet supplemented with perilla oil enriched with alpha-linolenic acid. In this study, we examined whether or not the supplementation of DHA after weaning restores the decreased learning ability observed in the safflower oil group. When DHA was supplemented after weaning (Saf + DHA group), DHA and 22 : 5n-6 contents in brain reached the levels seen in the perilla oil group. However, the learning ability (correct response ratio) of the Saf+DHA group was comparable to that of the safflower oil group, and was significantly lower than in the perilla oil group. Lever pressing responses to the positive and negative stimuli were also similar to those of the safflower oil group. Conten … More ts of monoamines (depamine, serotonin and their metabolites) in brain regions were determined to find no significant difference among the three dietary groups. Acetylcholine content tended to be lower in the frontal cortex and hippocampus of the Saf+DHA group than in the other groups, but was not correlated with learning performance. On the other hand, NGF (nerve growth factor) content was significantly lower in hippocampus but was significantly higher in the piriform cortex of the safflower oil group than in the perilla oil group. When EPA (20 : 5n-3) was supplemented to the safflower oil group after weaning, brain DHA content reached the level of the perilla oil group, but NGF level was comparable to that of the safflower oil group. These results suggest that the decreased learning ability of the safflower oil group is due to irreversible effect of decreased DHA in brain during gestation and lactation. However, some fatty acids in brain such as 20 : 4n-6, 22 : 4n-6 and 22 : 5n-3 did not reach the levels seen in the perilla oil group, and could be involved in the inferior learning performance of the safflower oil group and Saf+DHA group. Less