Polyphenol-rich extract from grape and blueberry attenuates cognitive decline and improves neuronal function in aged mice

Ageing is characterised by memory deficits, associated with brain plasticity impairment. Polyphenols from berries, such as flavan-3-ols, anthocyanins, and resveratrol, have been suggested to modulate synaptic plasticity and cognitive processes. In the present study we assessed the preventive effect of a polyphenol-rich extract from grape and blueberry (PEGB), with high concentrations of flavonoids, on age-related cognitive decline in mice. Adult and aged (6 weeks and 16 months) mice were fed a PEGB-enriched diet for 14 weeks. Learning and memory were assessed using the novel object recognition and Morris water maze tasks. Brain polyphenol content was evaluated with ultra-high-performance LC-MS/MS. Hippocampal neurotrophin expression was measured using quantitative real-time PCR. Finally, the effect of PEGB on adult hippocampal neurogenesis was assessed by immunochemistry, counting the number of cells expressing doublecortin and the proportion of cells with dendritic prolongations. The combination of grape and blueberry polyphenols prevented age-induced learning and memory deficits. Moreover, it increased hippocampal nerve growth factor (Ngf) mRNA expression. Aged supplemented mice displayed a greater proportion of newly generated neurons with prolongations than control age-matched mice. Some of the polyphenols included in the extract were detected in the brain in the native form or as metabolites. Aged supplemented mice also displayed a better survival rate. These data suggest that PEGB may prevent age-induced cognitive decline. Possible mechanisms of action include a modulation of brain plasticity. Post-treatment detection of phenolic compounds in the brain suggests that polyphenols may act directly at the central level, while they can make an impact on mouse survival through a potential systemic effect

Dietary polyphenol supplementation prevents alterations of spatial navigation in middle-aged mice

Spatial learning and memory deficits associated with hippocampal synaptic plasticity impairments are commonly observed during aging. Besides, the beneficial role of dietary polyphenols has been suggested as potential functional food candidates to prevent this memory decline. Indeed, polyphenols could potentiate the signaling pathways of synaptic plasticity underlying learning and memory. In this study, spatial learning deficits of middle-aged mice were first highlighted and characterized according to their navigation patterns in the Morris water maze task. An eight-week polyphenol-enriched diet, containing a polyphenol-rich extract from grape and blueberry (PEGB; from the Neurophenols Consortium) with high contents of flavonoids, stilbenes and phenolic acids, was then successful in reversing these age-induced effects. The use of spatial strategies was indeed delayed with aging whereas a polyphenol supplementation could promote the occurrence of spatial strategies. These behavioral results were associated with neurobiological changes: while the expression of hippocampal calmodulin kinase II (CaMKII) mRNA levels was reduced in middle-aged animals, the polyphenol-enriched diet could rescue them. Besides, an increased expression of nerve growth neurotrophic factor (NGF) mRNA levels was also observed in supplemented adult and middle-aged mice. Thus these data suggest that supplementation with polyphenols could be an efficient nutritional way to prevent age-induced cognitive decline

Approche de la vulnérabilité du territoire D’Orly Rungis et Seine Amont (94) aux risques d’inondations, et orientations d’aménagement

L’approche de la vulnérabilité du territoire Orly Rungis et Seine Amont aux risques d’inondations vise à apprécier la vulnérabilité d’un territoire étendu, fortement inondable, sur lequel sont projetés de grands aménagements dans le cadre d’une Opération d’Intérêt National. Fondée sur une approche systémique et développée à partir des données accessibles, cette approche conduit à appréhender le territoire comme un système d’éléments (biens, activités et espaces physiques…) liés entre eux par différentes relations. L’analyse, dont certains extraits sont présentés dans cet article, s’appuie sur celle d’enjeux liés à l’occupation du sol (statiques) et celle d’enjeux majeurs, essentiels pour le fonctionnement du territoire (notion de dépendance et de transmission de vulnérabilité à l’ensemble d’un territoire). Au-delà d’une appréciation de la vulnérabilité du territoire à une inondation type 1910 ou d’occurrence plus fréquente, cette démarche amène à questionner ou renforcer les orientations à mettre en oeuvre dans les projets d’aménagement engagés, voire de proposer de nouveaux aménagements, pour porter une politique de maîtrise et de réduction de la vulnérabilité, y compris de l’existant, à de multiples échelles et partagée entre les différents acteurs