Poster présenté par Benjamin Buaud, Responsable projets Nutrition Métabolisme & Santé à l’ITERG, lors des Journées Chevreul : Lipids and Brain III, 16-18 mars 2015
A. Létondor 1,2,3, D. Beracochéa 4,5, A. Krazem 4,5, C. Herrouin 3, B. Buaud 3, C. Vaysse 3, V. Pallet 1,2, S. Alfos1,2
1 Univ. Bordeaux, Nutrition et neurobiologie intégrée, UMR 1286, Bordeaux
2 INRA, Nutrition et neurobiologie intégrée, UMR 1286, Bordeaux
3 ITERG, Institut des Corps Gras, Pessac
4 CNRS, INCIA, UMR 5287, Talence
5 Univ. Bordeaux, INCIA, UMR 5287, Bordeaux.
Brain aging is associated with multiple morphological and biochemical changes leading to cognitive decline. Fatty acids are the main components of the brain membranes and among them docosahexaenoic acid (DHA) is the major n-3 polyunsaturated fatty acid (n-3 PUFA). Several studies suggested that n-3 PUFAs and most particularly DHA are critical for the maintenance of cognitive functions during aging. Other studies have shown that the unesterified DHA pool (active form) in plasma decreases with age in rodents and that brain DHA levels are altered during aging.
DHA may modulate brain functions by several mechanisms including the regulation of gene transcription. Indeed, DHA is the endogenous ligand of nuclear receptors such as the peroxisome proliferator-activated receptor (PPAR) and the retinoid X receptor (RXR) which are transcription factors that modulate, in the brain, the expression of genes involved in synaptic plasticity. RXR is a master regulator that forms heterodimers with numerous nuclear receptors such as PPAR or the retinoic acid receptor (RAR). Recent data suggest that unesterified DHA is involved in working memory in mice via RXRγ activation.
The objective of the present study was to evaluate in aged mice the effects of intraperitoneal (ip) administration of unesterified DHA on memory performances and on the mRNA expression of synaptic plasticity markers and nuclear receptors in the hippocampus.