Abstract
Docosahexaenoic acid (DHA) is the principal -3 polyunsaturated fatty acids (PUFAs) in the brain, and it is essential for proper brain development. -3 PUFAs are not synthesized de novo in mammals, and thus they must be obtained from diets. Revealing the role of DHA in brain development is scientifically and socially important because intake of fishes, which are abundant in -3 PUFAs, has recently been decreased in many countries, including Japan. Previous in vitro studies have revealed the role of DHA in neural stem cells (NSCs); DHA modulates proliferation and neuronal differentiation of NSCs. In evaluation of in vivo roles of DHA, the balance of -3/-6 PUFAs must be considered due to the competition between these two classes of PUFAs for their synthesis, metabolism, and transport. Recently, we have reported the impact of maternal consumption of an -3-poor/-6-rich diet, a widely spread nutrition style in the world, on offspring's brain development in mice. We found that epoxy metabolites of DHA and arachidonic acid (an -6 PUFA) regulated the neurogenic-to-gliogenic fate transition of NSCs, and consequently they affected brain development. In the present review, we summarize the roles of DHA and its metabolites in NSCs and in brain development.
