Effects of dietary polyunsaturated fatty acids on neuronal function

Diets deficient in linoleic acid (18:2n-6), or that have unusual ratios of linoleic acid to alpha-linolenic acid (18:3n-3) induce changes in the polyunsaturated fatty acid (PUFA) composition of neuronal and glial membranes. Such changes have been linked to alterations in retina and brain function. These functional effects are presumed to follow from the biochemical consequences of modifying membrane PUFA content; known effects include modifications in membrane fluidity, in the activities of membrane-associated, functional proteins (transporters, receptors, enzymes), and in the production of important signaling molecules from oxygenated linoleic and alpha-linolenic acid derivatives. However, despite the demonstration that central nervous system function changes when dietary PUFA intake is altered, and that in general, membrane PUFA content influences membrane functions, little work has focused specifically on brain and retina to reveal the underlying biochemical bases for such effects. This review examines this issue, looking at known effects of dietary PUFA on neurons in both the central and peripheral nervous systems, and attempts to identify some approaches that might promote productive investigation into the underlying mechanisms relating changes in dietary PUFA intake to alterations in neuronal and overall nervous system functioning.