Polyunsaturated fatty acids in the central nervous system: evolution of concepts and nutritional implications throughout lifeJean-Marc Alessandria, Philippe Guesneta, Sylvie Vancassela, Pierre Astorgb, Isabelle Denisa, Bénédicte Langeliera, Sabah Aïda, Carine Poumès-Ballihauta, Gaëlle Champeil-Potokara and Monique Laviallea
a Neurobiologie des Lipides, Laboratoire de Nutrition et Sécurité Alimentaire, INRA, 78352 Jouy-en-Josas, France
b UMR 557 Inserm/Inra/Cnam Épidémiologie Nutritionnelle, Institut scientifique et technique de la Nutrition et de l'alimentation, Cnam, 5 rue du Vertbois, 75003 Paris, France
(Received 18 June 2004; accepted 10 September 2004)
Abstract - Docosahexaenoic acid (DHA, 22:6n-3) and arachidonic acid (AA, 20:4n-6) are the major polyunsaturated fatty acids in the membranes of brain and retinal cells. Animals specifically deficient in dietary n-3 fatty acids have low DHA content in their membranes, reduced visual acuity and impaired learning ability. Studies on bottle-fed human infants have shown that adding DHA and AA to milk replacer-formulas can bring their concentrations in the infant blood lipids to values as high as those produced by breast-feeding and significantly improves mental development and maturation of visual function. In older subjects, diverse neuropsychiatric and neurodegenerative diseases have been associated to decreased blood levels of n-3 PUFA. Low intakes of fish or of n-3 PUFA in populations have been associated with increased risks of depression and Alzheimer disease, and n-3 PUFA, especially eicosapentaenoic acid (EPA, 20:5n-3), have shown efficacy as adjunctive treatment - and in some cases as the only treatment - in several psychiatric disorders. The mechanisms by which polyunsaturated fatty acids have an impact on neuronal functions will be reviewed: the modulation of membrane biophysical properties, regulation of neurotransmitter release, synthesis of biologically active oxygenated derivatives, and nuclear receptor-mediated transcription of genes responsive to fatty acids or to their derivatives.
Key words: docosahexaenoic acid / arachidonic acid / retina / brain / milk feeding / eicosanoids / synaptic terminals / phototransduction / neuroprotection / nuclear receptors / neuropsychiatric diseases / neurodegenerative diseases
Corresponding author: Jean-Marc Alessandri Jean-Marc.Alessandri@jouy.inra.fr
© INRA, EDP Sciences 2005