Behavioral Deficits Associated with Dietary Induction of Decreased Brain Docosahexaenoic Acid Concentration

Abstract

Docosahexaenoic acid (DHA), an n‐3 fatty acid, is rapidlydeposited during the period of rapid brain development. The influence of n‐3fatty acid deficiency on learning performance in adult rats over twogenerations was investigated. Rats were fed either an n‐3 fatty acid‐adequate(n‐3 Adq) or ‐deficient (n‐3 Def) diet for three generations (F1‐F3). Levelsof total brain n‐3 fatty acids were reduced in the n‐3 Def group by 83 and 87%in the F2 and F3 generations, respectively. In the Morris water maze, the n‐3Def group showed a longer escape latency and delayed acquisition of this taskcompared with the n‐3 Adq group in both generations. The acquisition andmemory levels of the n‐3 Def group in the F3 generation seemed to be lowerthan that of the F2 generation. The 22:5n‐6/22:6n‐3 ratio in the frontalcortex and dams' milk was markedly increased in the n‐3 Def group, and thisratio was significantly higher in the F3 generation compared with the F2generation. These results suggest that learning and cognitive behavior arerelated to brain DHA status, which, in turn, is related to the levels of themilk/dietary n‐3 fatty acids.