[Cerebral fatty acids. Synthesis in situ and food intake].

The nervous tissue is extremely rich in lipids, including fatty acids. These lipids are the basis of all biological membranes. Each individual membrane in the brain is constituted with particular fatty acids, the nature of the fatty acids could be parallelled with a specific biological function. Brain is able to synthesise saturated and monounsaturated fatty acids of any chain length. Localisation, biochemical mechanisms and nature and site of regulations have been determined at the cellular and subcellular levels. However all non-essential fatty acids are not synthetized in the brain, but have nutritional origin (the blood and eventually the diet). The dietary origin of polyunsaturated fatty acids is essential, brain need important amount of w3 and w6 of fatty acids. The relative quantities of these fatty acids in the diet must be precisely defined by in vivo studies and cell culture.