Serotonin levels are abnormally elevated in the fetus of the monoamine oxidase-A-deficient transgenic mouse.

Developmental changes in levels of serotonin, L-tryptophan and 5-hydroxyindol acetic acid (5-HIAA) were measured by high pressure liquid chromatography (HPLC) in the forebrain, brainstem and cervical cord of fetal, neonatal and adult mice from the wild strain C3H and the transgenic strain Tg8, created from the C3H line by the disruption of the gene encoding monoamine oxidase A. The results indicated that the absence of monoamine oxidase A activity in Tg8 mice results in abnormally high 5-hydroxytryptamine (5-HT) levels in all the central nervous structures and at all the studied developmental ages. Since serotonin levels were 4-5 times larger in Tg8 than in C3H mice at gestational day 20, comparing the central network function at birth of C3H and Tg8 neonates should shed some light on the role of serotonin in prenatal network maturation

Using multifactorial analysis to evaluate the contribution of terroir components to the oenological potential of grapes at harvest.

5 pagesInternational audienc

Abnormal phrenic motoneuron activity and morphology in neonatal monoamine oxidase A-deficient transgenic mice: possible role of a serotonin excess.

In rodent neonates, the neurotransmitter serotonin (5-HT) modulates the activity of both the medullary respiratory rhythm generator and the cervical phrenic motoneurons. To determine whether 5-HT also contributes to the maturation of the respiratory network, experiments were conducted in vitro on the brainstem-spinal cord preparation of neonatal mice originating from the control strain (C3H) and the monoamine oxidase A-deficient strain, which has a brain perinatal 5-HT excess (Tg8). At birth, the Tg8 respiratory network is unable to generate a respiratory pattern as stable as that produced by the C3H network, and the modulation by 5-HT of the network activity present in C3H neonates is lacking in Tg8 neonates. In addition, the morphology of the phrenic motoneurons is altered in Tg8 neonates; the motoneuron dendritic tree loses the C3H bipolar aspect but exhibits an increased number of spines and varicosities. These abnormalities were prevented in Tg8 neonates by treating pregnant Tg8 dams with the 5-HT synthesis inhibitor p-chlorophenylalanine or a 5-HT(2A) receptor antagonist but were induced in wild-type neonates by treating C3H dams with a 5-HT(2A) receptor agonist. We conclude that 5-HT contributes, probably via 5-HT(2A) receptors, to the normal maturation of the respiratory network but alters it when present in excess. Disorders affecting 5-HT metabolism during gestation may therefore have deleterious effects on newborns

Development of an analytical strategy based on liquid chromatography–high resolution mass spectrometry for measuring perfluorinated compounds in human breast milk: Application to the generation of preliminary data regarding perinatal exposure in France

Perfluorinated compounds (PFCs) are man-made chemicals for which endocrine disrupting properties and related possible side effects on human health have been reported, particularly in the case of an exposure during the early stages of development, (notably the perinatal period). Existing analytical methods dedicated to PFCs monitoring in food and/or human fluids are currently based on liquid chromatography coupled to tandem mass spectrometry, and were recently demonstrated to present some limitations in terms of sensitivity and/or specificity. An alternative strategy dedicated to the analysis of fourteen PFCs in human breast milk was proposed, based on an effective sample preparation followed by a liquid chromatography coupled to high resolution mass spectrometry measurement (LC–HRMS). This methodology confirmed the high interest for HRMS after negative ionization for such halogenated substances, and finally permitted to reach detection limits around the pg/mL range with an outstanding signal specificity compared to LC–MS/MS. The proposed method was applied to a first set of 30 breast milk samples from French women. The main PFCs detected in all these samples were PFOS and PFOA with respective median values of 74 (range from 24 to 171) and 57 (range from 18 to 102) pg/mL, respectively. These exposure data appeared in the same range as other reported values for European countries

Ion mobility-mass spectrometry to extend analytical performance in the determination of ergot alkaloids in cereal samples

This work evaluates the potential of ion mobility spectrometry (IMS) to improve the analytical performance of current liquid chromatography-mass spectrometry (LC-MS) workflows applied to the determination of ergot alkaloids (EAs) in cereal samples. Collision cross section (CCS) values for EA epimers are reported for the first time to contribute to their unambiguous identification. Additionally, CCS values have been inter-laboratory cross-validated and compared with CCS values predicted by machine-learning models. Slight differences were observed in terms of CCS values for ergotamine, ergosine and ergocristine and their corresponding epimers (from 3.3 to 4%), being sufficient to achieve a satisfactory peak-to-peak resolution for their unequivocal identification. A LC-travelling wave ion mobility (TWIM)-MS method has been developed for the analysis of EAs in barley and wheat samples. Signal-to-noise ratio (S/N) was improved between 2.5 and 4-fold compared to the analog LC-TOF-MS method. The quality of the extracted ion chromatograms was also improved by using IMS