5 research outputs found
Dietary LongâChain nâ3 Polyunsaturated Fatty Acid Supplementation Alters Electrophysiological Properties in the Nucleus Accumbens and Emotional Behavior in NaĂŻve and Chronically Stressed Mice
Longâchain (LC) nâ3 polyunsaturated fatty acids (PUFAs) have drawn attention in the field of neuropsychiatric disorders, in particular depression. However, whether dietary supplementation with LC nâ3 PUFA protects from the development of mood disorders is still a matter of de-bate. In the present study, we studied the effect of a twoâmonth exposure to isocaloric diets containing nâ3 PUFAs in the form of relatively shortâchain (SC) (6% of rapeseed oil, enriched in αâlinolenic acid (ALA)) or LC (6% of tuna oil, enriched in eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA)) PUFAs on behavior and synaptic plasticity of mice submitted or not to a chronic social defeat stress (CSDS), previously reported to alter emotional and social behavior, as well as synaptic plasticity in the nucleus accumbens (NAc). First, fatty acid content and lipid metabolism gene expression were measured in the NAc of mice fed a SC (control) or LC nâ3 (supplemented) PUFA diet. Our results indicate that LC nâ3 supplementation significantly increased some nâ3 PUFAs, while decreasing some nâ6 PUFAs. Then, in another cohort, control and nâ3 PUFAâsupplemented mice were subjected to CSDS, and social and emotional behaviors were assessed, together with longâterm depression plasticity in accumbal medium spiny neurons. Overall, mice fed with nâ3 PUFA supple-mentation displayed an emotional behavior profile and electrophysiological properties of medium spiny neurons which was distinct from the ones displayed by mice fed with the control diet, and this, independently of CSDS. Using the social interaction index to discriminate resilient and suscep-tible mice in the CSDS groups, nâ3 supplementation promoted resiliency. Altogether, our results pinpoint that exposure to a diet rich in LC nâ3 PUFA, as compared to a diet rich in SC nâ3 PUFA, influences the NAc fatty acid profile. In addition, electrophysiological properties and emotional behavior were altered in LC nâ3 PUFA mice, independently of CSDS. Our results bring new insights about the effect of LC nâ3 PUFA on emotional behavior and synaptic plasticity. © 2022 by the authors. Licensee MDPI, Basel, Switzerland
Essential omega-3 fatty acids tune microglial phagocytosis of synaptic elements in the mouse developing brain
AbstractOmega-3 fatty acids (n-3 PUFAs) are essential for the functional maturation of the brain. Westernization of dietary habits in both developed and developing countries is accompanied by a progressive reduction in dietary intake of n-3 PUFAs. Low maternal intake of n-3 PUFAs has been linked to neurodevelopmental diseases in Humans. However, the n-3 PUFAs deficiency-mediated mechanisms affecting the development of the central nervous system are poorly understood. Active microglial engulfment of synapses regulates brain development. Impaired synaptic pruning is associated with several neurodevelopmental disorders. Here, we identify a molecular mechanism for detrimental effects of low maternal n-3 PUFA intake on hippocampal development in mice. Our results show that maternal dietary n-3 PUFA deficiency increases microglia-mediated phagocytosis of synaptic elements in the rodent developing hippocampus, partly through the activation of 12/15-lipoxygenase (LOX)/12-HETE signaling, altering neuronal morphology and affecting cognitive performance of the offspring. These findings provide a mechanistic insight into neurodevelopmental defects caused by maternal n-3 PUFAs dietary deficiency.Infrastructure de Recherche Translationnelle pour les BiothĂ©rapies en NeurosciencesProgram Initiative dâExcellenc
Oméga 3 et troubles de l'humeur : mécanismes d'actions neuroprotecteurs
The brain is rich in polyunsaturated fatty acids (PUFA) whose long chains, such as docosahexaenoic acid (DHA) and ecosapentaenoic acid (EPA) from omega 3 (n-3), accumulate during development. Their precursors are not synthesized de novo by mammals and must be provided by food. However, it has been shown that an unbalanced and deficient maternal dietary intake of n-3 PUFAs induces cognitive and electrophysiological alterations in infants and in mouse models of nutritional deficiency. We are interested in the impact of a nutritional intervention during development and how a diet unbalanced in n-3 PUFA alters neural networks and cognition, by studying the molecular mechanisms and taking into account the gender. To this end, different models are used: 1) mice are deficient in PUFAs during development and then exposed to a diet rich in n-3 PUFAs at weaning; 2) to develop a local deficiency model by viral injection blocking the expression of the elongase ELOVL2 (involved in the synthesis of long-chain PUFAs) in astrocytes to assess the impact on the properties of the surrounding neurons.Our results suggest that a change in nutritional status from deficiency to a diet rich in n-3 PUFA at weaning restores 1) long-term synaptic plasticity in the hippocampus in males and females, 2) cognition as well as fatty acid levels in the brain but in a differential manner between the two sexes.In the second part of the results, a local variation of PUFA synthesis in the astrocyte modifies the excitability of neurons without modifying the levels of fatty acids in the brain structure while modifying some criteria of emotional behavior.Le cerveau est riche en acides gras polyinsaturĂ©s (AGPI) dont les chaĂźnes longues, comme lâacide docosahexaĂ©noĂŻque (DHA) et lâacide ecosapentaĂ©noĂŻque (EPA) issus des omĂ©ga 3 (n-3), sâaccumulent au cours du dĂ©veloppement. Leurs prĂ©curseurs ne sont pas synthĂ©tisĂ©s de novo par les mammifĂšres et doivent ĂȘtre apportĂ© par la nourriture. Or, il a Ă©tĂ© dĂ©montrĂ© quâun apport nutritionnel maternel dĂ©sĂ©quilibrĂ© et carencĂ© en AGPI n-3 induit des altĂ©rations cognitives et Ă©lectrophysiologiques chez le nourrisson et dans des modĂšles murins de carence nutritionnelle. Nous nous intĂ©ressons Ă lâimpact dâune intervention nutritionnelle au cours du dĂ©veloppement et comment un rĂ©gime dĂ©sĂ©quilibrĂ© en AGPI n-3 altĂšre les rĂ©seaux neuronaux et la cognition, en Ă©tudiant les mĂ©canismes molĂ©culaires et en prenant en compte le sexe. Pour cela diffĂ©rents modĂšles sont utilisĂ©s 1) les souriceaux sont carencĂ©s en AGPI pendant le dĂ©veloppement puis exposĂ©s Ă une diĂšte riche en AGPI n-3 au sevrage ; 2) dĂ©velopper un modĂšle de carence locale par injection virale bloquant lâexpression de lâĂ©longase ELOVL2 (impliquĂ©e dans la synthĂšse des AGPI Ă longues chaĂźnes) dans les astrocytes pour Ă©valuer lâimpact sur les propriĂ©tĂ©s des neurones environnants. Nos rĂ©sultats suggĂšrent quâun changement de statut nutritionnel dâune carence vers un rĂ©gime riche en AGPI n-3 au sevrage restaure 1) la plasticitĂ© synaptique Ă long terme dans lâhippocampe chez les mĂąles et les femelles, 2) la cognition ainsi que les taux dâacides gras dans le cerveau mais de maniĂšre diffĂ©rentielle entre les deux sexes. Dans la seconde partie des rĂ©sultats, une variation locale de la synthĂšse des AGPI dans lâastrocyte modifie lâexcitabilitĂ© des neurones sans modifier les taux dâacides gras dans la structure cĂ©rĂ©brale tout en modifiant certains critĂšres de comportement Ă©motionnel
Omega 3 and mood disorders : neuroprotective mecanisms
Le cerveau est riche en acides gras polyinsaturĂ©s (AGPI) dont les chaĂźnes longues, comme lâacide docosahexaĂ©noĂŻque (DHA) et lâacide ecosapentaĂ©noĂŻque (EPA) issus des omĂ©ga 3 (n-3), sâaccumulent au cours du dĂ©veloppement. Leurs prĂ©curseurs ne sont pas synthĂ©tisĂ©s de novo par les mammifĂšres et doivent ĂȘtre apportĂ© par la nourriture. Or, il a Ă©tĂ© dĂ©montrĂ© quâun apport nutritionnel maternel dĂ©sĂ©quilibrĂ© et carencĂ© en AGPI n-3 induit des altĂ©rations cognitives et Ă©lectrophysiologiques chez le nourrisson et dans des modĂšles murins de carence nutritionnelle. Nous nous intĂ©ressons Ă lâimpact dâune intervention nutritionnelle au cours du dĂ©veloppement et comment un rĂ©gime dĂ©sĂ©quilibrĂ© en AGPI n-3 altĂšre les rĂ©seaux neuronaux et la cognition, en Ă©tudiant les mĂ©canismes molĂ©culaires et en prenant en compte le sexe. Pour cela diffĂ©rents modĂšles sont utilisĂ©s 1) les souriceaux sont carencĂ©s en AGPI pendant le dĂ©veloppement puis exposĂ©s Ă une diĂšte riche en AGPI n-3 au sevrage ; 2) dĂ©velopper un modĂšle de carence locale par injection virale bloquant lâexpression de lâĂ©longase ELOVL2 (impliquĂ©e dans la synthĂšse des AGPI Ă longues chaĂźnes) dans les astrocytes pour Ă©valuer lâimpact sur les propriĂ©tĂ©s des neurones environnants. Nos rĂ©sultats suggĂšrent quâun changement de statut nutritionnel dâune carence vers un rĂ©gime riche en AGPI n-3 au sevrage restaure 1) la plasticitĂ© synaptique Ă long terme dans lâhippocampe chez les mĂąles et les femelles, 2) la cognition ainsi que les taux dâacides gras dans le cerveau mais de maniĂšre diffĂ©rentielle entre les deux sexes. Dans la seconde partie des rĂ©sultats, une variation locale de la synthĂšse des AGPI dans lâastrocyte modifie lâexcitabilitĂ© des neurones sans modifier les taux dâacides gras dans la structure cĂ©rĂ©brale tout en modifiant certains critĂšres de comportement Ă©motionnel.The brain is rich in polyunsaturated fatty acids (PUFA) whose long chains, such as docosahexaenoic acid (DHA) and ecosapentaenoic acid (EPA) from omega 3 (n-3), accumulate during development. Their precursors are not synthesized de novo by mammals and must be provided by food. However, it has been shown that an unbalanced and deficient maternal dietary intake of n-3 PUFAs induces cognitive and electrophysiological alterations in infants and in mouse models of nutritional deficiency. We are interested in the impact of a nutritional intervention during development and how a diet unbalanced in n-3 PUFA alters neural networks and cognition, by studying the molecular mechanisms and taking into account the gender. To this end, different models are used: 1) mice are deficient in PUFAs during development and then exposed to a diet rich in n-3 PUFAs at weaning; 2) to develop a local deficiency model by viral injection blocking the expression of the elongase ELOVL2 (involved in the synthesis of long-chain PUFAs) in astrocytes to assess the impact on the properties of the surrounding neurons.Our results suggest that a change in nutritional status from deficiency to a diet rich in n-3 PUFA at weaning restores 1) long-term synaptic plasticity in the hippocampus in males and females, 2) cognition as well as fatty acid levels in the brain but in a differential manner between the two sexes.In the second part of the results, a local variation of PUFA synthesis in the astrocyte modifies the excitability of neurons without modifying the levels of fatty acids in the brain structure while modifying some criteria of emotional behavior
Omega 3 and mood disorders : neuroprotective mecanisms
Le cerveau est riche en acides gras polyinsaturĂ©s (AGPI) dont les chaĂźnes longues, comme lâacide docosahexaĂ©noĂŻque (DHA) et lâacide ecosapentaĂ©noĂŻque (EPA) issus des omĂ©ga 3 (n-3), sâaccumulent au cours du dĂ©veloppement. Leurs prĂ©curseurs ne sont pas synthĂ©tisĂ©s de novo par les mammifĂšres et doivent ĂȘtre apportĂ© par la nourriture. Or, il a Ă©tĂ© dĂ©montrĂ© quâun apport nutritionnel maternel dĂ©sĂ©quilibrĂ© et carencĂ© en AGPI n-3 induit des altĂ©rations cognitives et Ă©lectrophysiologiques chez le nourrisson et dans des modĂšles murins de carence nutritionnelle. Nous nous intĂ©ressons Ă lâimpact dâune intervention nutritionnelle au cours du dĂ©veloppement et comment un rĂ©gime dĂ©sĂ©quilibrĂ© en AGPI n-3 altĂšre les rĂ©seaux neuronaux et la cognition, en Ă©tudiant les mĂ©canismes molĂ©culaires et en prenant en compte le sexe. Pour cela diffĂ©rents modĂšles sont utilisĂ©s 1) les souriceaux sont carencĂ©s en AGPI pendant le dĂ©veloppement puis exposĂ©s Ă une diĂšte riche en AGPI n-3 au sevrage ; 2) dĂ©velopper un modĂšle de carence locale par injection virale bloquant lâexpression de lâĂ©longase ELOVL2 (impliquĂ©e dans la synthĂšse des AGPI Ă longues chaĂźnes) dans les astrocytes pour Ă©valuer lâimpact sur les propriĂ©tĂ©s des neurones environnants. Nos rĂ©sultats suggĂšrent quâun changement de statut nutritionnel dâune carence vers un rĂ©gime riche en AGPI n-3 au sevrage restaure 1) la plasticitĂ© synaptique Ă long terme dans lâhippocampe chez les mĂąles et les femelles, 2) la cognition ainsi que les taux dâacides gras dans le cerveau mais de maniĂšre diffĂ©rentielle entre les deux sexes. Dans la seconde partie des rĂ©sultats, une variation locale de la synthĂšse des AGPI dans lâastrocyte modifie lâexcitabilitĂ© des neurones sans modifier les taux dâacides gras dans la structure cĂ©rĂ©brale tout en modifiant certains critĂšres de comportement Ă©motionnel.The brain is rich in polyunsaturated fatty acids (PUFA) whose long chains, such as docosahexaenoic acid (DHA) and ecosapentaenoic acid (EPA) from omega 3 (n-3), accumulate during development. Their precursors are not synthesized de novo by mammals and must be provided by food. However, it has been shown that an unbalanced and deficient maternal dietary intake of n-3 PUFAs induces cognitive and electrophysiological alterations in infants and in mouse models of nutritional deficiency. We are interested in the impact of a nutritional intervention during development and how a diet unbalanced in n-3 PUFA alters neural networks and cognition, by studying the molecular mechanisms and taking into account the gender. To this end, different models are used: 1) mice are deficient in PUFAs during development and then exposed to a diet rich in n-3 PUFAs at weaning; 2) to develop a local deficiency model by viral injection blocking the expression of the elongase ELOVL2 (involved in the synthesis of long-chain PUFAs) in astrocytes to assess the impact on the properties of the surrounding neurons.Our results suggest that a change in nutritional status from deficiency to a diet rich in n-3 PUFA at weaning restores 1) long-term synaptic plasticity in the hippocampus in males and females, 2) cognition as well as fatty acid levels in the brain but in a differential manner between the two sexes.In the second part of the results, a local variation of PUFA synthesis in the astrocyte modifies the excitability of neurons without modifying the levels of fatty acids in the brain structure while modifying some criteria of emotional behavior