Mice prenatally exposed to valproic acid do not show autism-related disorders when fed with polyunsaturated fatty acid-enriched diets

AbstractDietary supplementations with n-3 polyunsaturated fatty acid (PUFA) have been explored in autism spectrum disorder (ASD) but their efficiency and potential in ameliorating cardinal symptoms of the disease remain elusive. Here, we compared a n-3 long-chain (LC) PUFA dietary supplementation (n-3 supp) obtained from fatty fish with a n-3 PUFA precursor diet (n-3 bal) obtained from plant oils in the valproic acid (VPA, 450 mg/kg at E12.5) ASD mouse model starting from embryonic life, throughout lactation and until adulthood. Maternal and offspring behaviors were investigated as well as several VPA-induced ASD biological features: cerebellar Purkinje cell (PC) number, inflammatory markers, gut microbiota, and peripheral and brain PUFA composition. Developmental milestones were delayed in the n-3 supp group compared to the n-3 bal group in both sexes. Whatever the diet, VPA-exposed offspring did not show ASD characteristic alterations in social behavior, stereotypies, PC number, or gut microbiota dysbiosis while global activity, gait, peripheral and brain PUFA levels as well as cerebellar TNF-alpha levels were differentially altered by diet and treatment according to sex. The current study provides evidence of beneficial effects of n-3 PUFA based diets, including one without LCPUFAs, on preventing several behavioral and cellular symptoms related to ASD

Primitive layered gabbros from fast-spreading lower oceanic crust

Three-quarters of the oceanic crust formed at fast-spreading ridges is composed of plutonic rocks whose mineral assemblages, textures and compositions record the history of melt transport and crystallization between the mantle and the sea floor. Despite the importance of these rocks, sampling them in situ is extremely challenging owing to the overlying dykes and lavas. This means that models for understanding the formation of the lower crust are based largely on geophysical studies and ancient analogues (ophiolites) that did not form at typical mid-ocean ridges. Here we describe cored intervals of primitive, modally layered gabbroic rocks from the lower plutonic crust formed at a fast-spreading ridge, sampled by the Integrated Ocean Drilling Program at the Hess Deep rift. Centimetre-scale, modally layered rocks, some of which have a strong layering-parallel foliation, confirm a long-held belief that such rocks are a key constituent of the lower oceanic crust formed at fast-spreading ridges. Geochemical analysis of these primitive lower plutonic rocks-in combination with previous geochemical data for shallow-level plutonic rocks, sheeted dykes and lavas-provides the most completely constrained estimate of the bulk composition of fast-spreading oceanic crust so far. Simple crystallization models using this bulk crustal composition as the parental melt accurately predict the bulk composition of both the lavas and the plutonic rocks. However, the recovered plutonic rocks show early crystallization of orthopyroxene, which is not predicted by current models of melt extraction from the mantle and mid-ocean-ridge basalt differentiation. The simplest explanation of this observation is that compositionally diverse melts are extracted from the mantle and partly crystallize before mixing to produce the more homogeneous magmas that erupt

Contribution à l'analyse spectrale de la bathymétrie et de la gravimétrie en domaine océanique (apports à l'étude de la rhéologie de la lithosphère de l'atlantique nord-est)

BREST-BU Droit-Sciences-Sports (290192103) / SudocRENNES-Géosciences (352382209) / SudocSudocFranceF

Bathymetric Reconstruction Method: Application to the Central Atlantic Basin between 10°N and 40°N

It is well known that a general relationship exists between the age of the earth's crust at mid-ocean ridges and its depth (Menard, 1969; Sclater and Francheteau, 1970; Sclater et al., 1971). Depths increase from 2500 300 meters at a spreading center, to 5800 5300 meters in oceanic crust of Early Cretaceous to Late Jurassic age (Figure 1; Sclater et al., 1971). The 3 km deepening of the oceanic crust can be satisfactorily explained by simple models involving the thermal structure of the oceanic lithosphere during its spreading from the axis of ridges to the adjacent oceanic basins (Sclater and Francheteau, 1970; Davis and Lister, 1974). It has also been suggested that structural highs like aseismic ridges, which have not come about by accretion, nevertheless follow the subsidence law of normal oceanic crust since they ride "piggy-back" on top of the oceanic lithosphere immediately after their creation at or close to spreading centers (Detrick et al., 1977). [NOT CONTROLLED OCR