Neurocentre Magendie



Tél : 33(0)5 57 57 37 22
Envoyer un email

1992-1994 : BTSA analyses biologiques et biotechnologiques (lycée agricole de Bordeaux-Blanquefort).
Depuis 2006 Assistant Ingénieur, Bordeaux Sciences Agro.

23 publication(s) depuis Février 2000:

Trier par

* equal contribution
Les IF indiqués ont été collectés par le Web of Sciences en

19/09/2017 | Proc Natl Acad Sci U S A   IF 9.7
Temporal binding function of dorsal CA1 is critical for declarative memory formation.
Sellami A, Al Abed AS, Brayda-Bruno L, Etchamendy N, Valerio S, Oule M, Pantaleon L, Lamothe V, Potier M, Bernard K, Jabourian M, Herry C, Mons N, Piazza PV, Eichenbaum H, Marighetto A

Temporal binding, the process that enables association between discontiguous stimuli in memory, and relational organization, a process that enables the flexibility of declarative memories, are both hippocampus-dependent and decline in aging. However, how these two processes are related in supporting declarative memory formation and how they are compromised in age-related memory loss remain hypothetical. We here identify a causal link between these two features of declarative memory: Temporal binding is a necessary condition for the relational organization of discontiguous events. We demonstrate that the formation of a relational memory is limited by the capability of temporal binding, which depends on dorsal (d)CA1 activity over time intervals and diminishes in aging. Conversely, relational representation is successful even in aged individuals when the demand on temporal binding is minimized, showing that relational/declarative memory per se is not impaired in aging. Thus, bridging temporal intervals by dCA1 activity is a critical foundation of relational representation, and a deterioration of this mechanism is responsible for the age-associated memory impairment.

09/2017 | anal bioanal chem   IF 3.4
Derivatization-free LC-MS/MS method for estrogen quantification in mouse brain highlights a local metabolic regulation after oral versus subcutaneous administration.
Lozan E, Shinkaruk S, Al Abed SA, Lamothe V, Potier M, Marighetto A, Schmitter JM, Bennetau-Pelissero C, Bure C

17beta-Estradiol (17beta-E2) is a steroid with pleiotropic actions. In addition to being a sexual hormone, it is also produced in the brain where it modulates the reproductive axis. It has been shown that 17beta-E2 also acts on synaptic plasticity and plays a role in neurological pathways and in neurodegenerative diseases. Assaying this steroid in the brain is thus interesting to improve our knowledge of 17beta-E2 effects in the brain. However, 17beta-E2 concentration in the central nervous system has been reported to be of a few nanograms per gram wet weight (nanomolar range concentration); therefore, its quantification requires both an efficient extraction process and a sensitive detection method. Herein is presented a derivatization-free procedure based on solid-phase extraction followed by LC-MS/MS analysis, targeted on 17beta-E2, its isomer17alpha-E2, and its metabolites estrone (E1) and estriol (E3). This extraction process allowed reaching 96% 17beta-E2 recovery from the mouse brain. Limit of detection (LOD) and limit of quantification (LOQ) values of 0.5 and 2.5 pmol mL(-1), respectively, were reached for both 17alpha-E2 and 17beta-E2. LOD values for E1 and E3 were 0.01 and 0.025 pmol mL(-1), respectively. The variation coefficients for intra- and inter-assays were 6 and 14%, respectively, for both estradiol forms. The method was applied to assess estrogen levels in the mouse brain and hippocampus after 17beta-E2 acute (subcutaneous injection) and chronic (drinking water) physiological administration. Total estrogen levels were determined after enzymatic deconjugation and compared to free estrogen levels. While 17alpha-E2 was not detected in biological samples, 17beta-E2 and metabolite measurements highlight a local biotransformation of estrogens after physiological administration via drinking water. Graphical abstract Method workflow: After oral or subcutaneous Estradiol administration, mouse brain or hippocampus was removed. Samples were homogenized and prepared according to a liquid-liquid extraction, followed by a solid-phase extraction. Then, LC-MS/MS was optimized to quantify 17ss-E2, its isomer17alpha-E2, its metabolites estrone (E1) and estriol (E3) and their conjugates.

01/11/2016 | Food Chem   IF 4.5
Removing isoflavones from modern soyfood: Why and how?
Fernandez-Lopez A, Lamothe V, Delample M, Denayrolles M, Bennetau-Pelissero C

Estrogenic isoflavones were found, in the 1940s, to disrupt ewe reproduction and were identified in soy-consumers' urine in 1982. This led to controversy about their safety, often supported by current Asian diet measurements, but not by historical data. Traditional Asian recipes of soy were tested while assaying soy glycosilated isoflavones. As these compounds are water-soluble, their concentration is reduced by soaking. Pre-cooking or simmering time-dependently reduces the isoflavone:protein ratio in Tofu. Cooking soy-juice for 15 or 60min decreases the isoflavone:protein ratios in Tofu from 6.90 to 3.57 and 1.80, respectively (p<0.001). Traditional Tempeh contains only 18.07% of the original soybean isoflavones (p<0.001). Soy-juice isoflavones were reduced by ultra-filtration (6.54 vs 1.24 isoflavone:protein; p<0.001). Soy-protein and isoflavones are dissociated by water rinsing and prolonged cooking, but these have no equivalent in modern processes. As regards human health, a precise definition of the safety level of isoflavone intake requires additional studies.

21/03/2016 | Psychoneuroendocrinology   IF 4.8
Estradiol enhances retention but not organization of hippocampus-dependent memory in intact male mice.
Al Abed AS, Sellami A, Brayda-Bruno L, Lamothe V, Nogues X, Potier M, Bennetau-Pelissero C, Marighetto A

Because estrogens have mostly been studied in gonadectomized females, effects of chronic exposure to environmental estrogens in the general population are underestimated. Estrogens can enhance hippocampus-dependent memory through the modulation of information storage. However, declarative memory, the hippocampus-dependent memory of facts and events, demands more than abilities to retain information. Specifically, memory of repetitive events of everyday life such as 'where I parked' requires abilities to organize/update memories to prevent proactive interference from similar memories of previous 'parking events'. Whether such organizational processes are estrogen-sensitive is unknown. We here studied, in intact young and aged adult mice, drinking-water (1muM) estradiol effects on both retention and organizational components of hippocampus-dependent memory, using a radial-maze task of everyday-like memory. Demand on retention vs organization was manipulated by varying the time-interval separating repetitions of similar events. Estradiol increased performance in young and aged mice under minimized organizational demand, but failed to improve the age-associated memory impairment and diminished performance in young mice under high organizational demand. In fact, estradiol prolonged mnemonic retention of successive events without improving organization abilities, hence resulted in more proactive interference from irrelevant memories. c-Fos imaging of testing-induced brain activations showed that the deterioration of young memory was associated with dentate gyrus dysconnectivity, reminiscent of that seen in aged mice. Our findings support the view that estradiol is promnesic but also reveal that such property can paradoxically impair memory. These findings have important outcomes regarding health issues relative to the impact of environmental estrogens in the general population.

31/07/2015 | Biol Psychiatry   IF 11.4
Temporal Memory and Its Enhancement by Estradiol Requires Surface Dynamics of Hippocampal CA1 N-Methyl-D-Aspartate Receptors.
Potier M, Georges F, Brayda-Bruno L, Ladepeche L, Lamothe V, Al Abed AS, Groc L, Marighetto A

BACKGROUND: Identifying the underlying cellular mechanisms of episodic memory is an important challenge, since this memory, based on temporal and contextual associations among events, undergoes preferential degradation in aging and various neuropsychiatric disorders. Memory storage of temporal and contextual associations is known to rely on hippocampal N-methyl-D-aspartate receptor (NMDAR)-dependent synaptic plasticity, which depends ex vivo on dynamic organization of surface NMDARs. Whether NMDAR surface trafficking sustains the formation of associative memory, however, remains unknown. METHODS: We tested this hypothesis, using single nanoparticle imaging, electrophysiology, and behavioral approaches, in hippocampal networks challenged with a potent modulator of NMDAR-dependent synaptic plasticity and memory, 17beta-estradiol (E2). RESULTS: We demonstrate that E2 modulates NMDAR surface trafficking, a necessary condition for E2-induced potentiation at hippocampal cornu ammonis 1 synapses. Strikingly, cornu ammonis 1 NMDAR surface trafficking controls basal and E2-enhanced mnemonic retention of temporal, but not contextual, associations. CONCLUSIONS: NMDAR surface trafficking and its modulation by the sex hormone E2 is a cellular mechanism critical for a major component of episodic memory, opening a new and noncanonical research avenue in the physiopathology of cognition.

02/2014 | Talanta   IF 4.2
Design and validation of a novel immunological test for enterolactone.
Shinkaruk S, Pinot E, Lamothe V, Schmitter JM, Baguenard L, Bennetau B, Bennetau-Pelissero C

Enterolactone (ENL) is produced by the gut microflora from lignans found in edible plants. ENL is estrogenic with no effect on the E-screen test and is a natural Selected Estrogen Receptor Modulator (SERM) with health interests that have to be checked in clinical studies with bioavailability assessment. Two haptens of ENL were synthesized, with a spacer arm at the C5 position having either 2 or 4 carbon atoms (ENLDelta2 and ENLDelta4, respectively). Hapten coupling to bovine serum albumin (BSA) was characterized by MALDI mass spectrometry. Polyclonal antibodies were obtained against the BSA conjugates. Additional conjugates were generated by coupling to swine thyroglobulin (Thyr). Homologous and heterologous competitive ELISAs were developed with Thyr or BSA conjugates as coating. The best assays were validated on biological samples from mice. Both antibodies exhibited the same IC50 at 1.5 ng mL(-1) with a detection limit below 0.5 ng mL(-1). Most cross-reactions with structurally related lignans were lower than 0.03%. This new assay type is faster, more specific and more reliable than existing ones.

01/12/2012 | Food Chem   IF 4.5
Bioavailability of glycitein relatively to other soy isoflavones in healthy young Caucasian men.
Shinkaruk S, Durand M, Lamothe V, Carpaye A, Martinet A, Chantre P, Vergne S, Nogues X, Moore N, Bennetau-Pelissero C

Glycitein is a Selective Estradiol Receptor Modulator (SERM) from soy. The study reports plasma bioavailability and urine excretion of glycitein compared to other soy isoflavones after a unique intake of food supplement based on soy germ containing 55.24mg isoflavones. Eighteen plasma and urinary sampling profiles collected over 48h from healthy young Caucasian men were analysed using specific ELISAs. Eight profiles contained equol. Glycitein T(max), C(max), AUC(0-->24h) and T((1/2)) in plasma were calculated. Urine T(max), % of excretion at 24h and clearance were assessed. Glycitein is one of the best absorbed flavonoids. Plasma steady-state level can be achieved by several intakes a day. Glycitein bioavailability is similar to that of daidzein and its urinary excretion is significantly higher than that of genistein. Equol does not affect glycitein bioavailability. Knowing glycitein bioavailability in man is essential for the development of soy-germ-based food supplements for health applications.

15/01/2010 | Food Chem   IF 4.5
Development and validation of two new sensitive ELISAs for Hesperetin and Naringenin in biological fluids
Shinkaruk S, Lamothe V, Schmitter J-M, Manach C, Morand C, Berard A, Bennetau B, Bennetau C

Carboxylic acid haptens were synthesised, for Hesperetin (Hesp) and Naringenin (Nar). They had a spacer arm (4 or 6 carbons long) on the C7 position. Haptens were coupled to bovine serum albumin. Polyclonal antibodies were generated. Enzyme-linked immunosorbent assays (ELISAs) were developed. Owing to sensitivity, one antibody for each flavanone was retained, namely anti-h4-Hesp and anti-h4-Nar. For Hesp and Nar, IC50 of the standard curves were 1.29 pmol/well and 0.72 pmol/well, respectively. Intra-assay and inter-assay variations were 10.24% and 10.53%, respectively for Hesp and 10.03% and 10.79%, respectively for Nar. Anti-h4-Hesp was highly specific when anti-h4-Nar showed cross-reactions with liquiritigenin and eriodictyol, which were significantly reduced in heterologous assay conditions. Assays were validated by comparisons with HPLC Coularray. Measurements were done on diet, plasma and urine samples from mice fed on diets enriched with Hesp or Nar and on a range of diluted mice urine samples.

12/12/2009 | Br J Nutr   IF 3.7
Influence of ethnic origin (Asian v. Caucasian) and background diet on the bioavailability of dietary isoflavones.
Vergne S, Sauvant P, Lamothe V, Chantre P, Asselineau J, Perez P, Durand M, Moore N, Bennetau C

Soya isoflavones: genistein and daidzein are increasingly consumed in Western countries. Their beneficial effects are discussed considering nutrition and health in Asia. The present study aimed to check whether chronic ingestions, ethnic origin and dietary context can influence soya phyto-oestrogen bioavailability. Two prospective trials were carried out to blindly assess the pharmacokinetics after acute and chronic intake of soya-based cheese (45.97 (sd1.57) mg isoflavones) taken once a day for 10 d. Twelve healthy young Asians immersed for 2 months in France were randomised in a cross-over design to compare the influence of a Western v. Asian dietary context. The second trial partly nested in the first one, compared Asians under the Western diet to twelve healthy young male Caucasians under the same diet. All volunteers were non-equol producers. After an acute intake of soya in Western diet, Asians exhibited higher maximum concentration measured in plasma (Cmax) and area under the plasma concentration-time curve (AUC) for genistein and daidzein than Caucasians (P = 0.005, 0.006, 0.032 and 0.008, respectively). In Caucasians under Western diet, AUC and Cmax values significantly increased after chronic intake. This was not the case for daidzein in Asians whatever the dietary context. For the first time, it is evidenced that on acute intake of soya cheese, Asians absorb soya phyto-oestrogens better than Caucasians, regardless of whether the background diet is Western or Asian. On chronic ingestions, AUC and Cmax values were increased for daidzein and genistein in Caucasians but not in Asians. There are ethnic differences in isoflavone pharmacokinetic and bioavailability. This may influence health outcomes.

2009 | Acta Horticulturae   IF 0.2
Preliminary Characterisation of an antibody raised against a prenylflavanone for further use in an immunoassay for isoxanthohumol
Shinkaruk S, Bennetau B, Lamothe V, Babin P, Schmitter JM, Pelissero-Bennetau C