Changes in innervation of lumbar motoneurons and organization of premotor network following training of transected adult rats

International audienceRats with complete spinal cord transection (SCT) can recover hindlimb locomotor function under strategies combining exercise training and 5-HT agonist treatment. This recovery is expected to result from structural and functional reorganization within the spinal cord below the lesion. To begin to understand the nature of this reorganization, we examined synaptic changes to identified gastrocnemius (GS) or tibialis anterior (TA) moto-neurons (MNs) in SCT rats after a schedule of early exercise training and delayed 5-HT agonist treatment. In addition, we analyzed changes in distribution and number of lumbar interneurons (INs) presynaptic to GS MNs using retrograde transneuronal transport of rabies virus. In SCT-untrained rats, we found few changes in the density and size of inhibitory and excitatory inputs impinging on cell bodies of TA and GS MNs compared to intact rats, whereas there was a marked trend for a reduction in the number of premotor INs connected to GS MNs. In contrast, after training of SCT rats, a significant increase of the density of GABAergic and glycinergic axon terminals was observed on both GS and TA motoneuronal cell bodies, as well as of presynaptic P-boutons on VGLUT1 afferents. Despite these changes in innervation the number of premotor INs connected to GS MNs was similar to control values although some new connections to MNs were observed. These results suggest that adaptation of gait patterns in SCT-trained rats was accompanied by changes in the innervation of lumbar MNs while the distribution of the spinal premotor circuitry was relatively preserved

Extracellular ATP acts on P2Y2 purinergic receptors to facilitate HIV-1 infection

Contact with HIV-1 envelope protein elicits release of ATP through pannexin-1 channels on target cells; by activating purinergic receptors and Pyk2 kinase in target cells, this extracellular ATP boosts HIV-1 infectivity

Current characterization methods for cellulose nanomaterials

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Towards a French National Biodiversity Virtual Research Environment

Research processes in biodiversity are evolving at a rapid pace, particularly regarding data-related steps from collection to analysis. This evolution, mainly due to technological advances, offers equipment that is more powerful and generalizes the digitalization of research data and associated products. It is now urgent to accelerate good practices in scientific data management and analysis in order to offer products and services corresponding to the new context, presenting more and more openness, requiring more and more FAIRness (Wilkinson et al. 2016). Using Information and Communication Technology (ICT) as international standards and software (Ecological Metadata Language and associated solutions for metadata management, Galaxy web platform for data analysis), we propose, through the national research e-infrastructure called "Pôle national de données de biodiversité" (or PNDB, formerly ECOSCOPE), to build a new type of Biodiversity Virtual Research Environment (VRE) for French communities. Although deployment of this kind of environment is challenging, it represents an opportunity to pave the way towards better research processes through enhanced collaboration, data management, analysis practices and resources optimization

The Myriapoda and Onychophora collection (MY) of the Muséum national d’Histoire naturelle (MNHN, Paris)

The Myriapoda and Onychophora collection dataset inventories the occurrence records of the collection of myriapods and onychophorans in the Muséum national d’Histoire naturelle, Paris. The dataset currently consists of 202 lots of onychophorans, representing all of those present, and almost ten thousand (9 795) lots of myriapods, representing 33 to 40% of the MNHN Myriapoda collection. This collection, which is of key historic importance, represents the results of two centuries of myriapod and onychophoran studies. The sources of the collection are worldwide, with a high representation for metropolitan France for the myriapods. None of the occurrences are yet georeferenced. Access to the dataset via the data portals of the MNHN and the GBIF has been made possible through the e-ReColNat project (ANR-11-INBS-0004). The Myriapoda and Onychophora collection of MNHN is actively expanding, hence both the collection and dataset are in continuous growth. The dataset can be accessed through the portals of GBIF at http://www.gbif.org/dataset/3287044c-8c48-4ad6-81d4-4908071bc8db and the MNHN at http://science.mnhn.fr/institution/mnhn/collection/my/item/search/form

Adsorption versus grafting of poly(N-Isopropylacrylamide) in aqueous conditions on the surface of cellulose nanocrystals

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Prenatal exposure to fenugreek impairs sensorimotor development and the operation of spinal cord networks in mice.

Fenugreek is a medicinal plant whose seeds are widely used in traditional medicine, mainly for its laxative, galactagogue and antidiabetic effects. However, consumption of fenugreek seeds during pregnancy has been associated with a range of congenital malformations, including hydrocephalus, anencephaly and spina bifida in humans. The present study was conducted to evaluate the effects of prenatal treatment of fenugreek seeds on the development of sensorimotor functions from birth to young adults. Pregnant mice were treated by gavage with 1 g/kg/day of lyophilized fenugreek seeds aqueous extract (FSAE) or distilled water during the gestational period. Behavioral tests revealed in prenatally treated mice a significant delay in righting, cliff avoidance, negative geotaxis responses and the swimming development. In addition, extracellular recording of motor output in spinal cord isolated from neonatal mice showed that the frequency of spontaneous activity and fictive locomotion was reduced in FSAE-exposed mice. On the other hand, the cross-correlation coefficient in control mice was significantly more negative than in treated animals indicating that alternating patterns are deteriorated in FSAE-treated animals. At advanced age, prenatally treated mice displayed altered locomotor coordination in the rotarod test and also changes in static and dynamic parameters assessed by the CatWalk automated gait analysis system. We conclude that FSAE impairs sensorimotor and coordination functions not only in neonates but also in adult mice. Moreover, spinal neuronal networks are less excitable in prenatally FSAE-exposed mice suggesting that modifications within the central nervous system are responsible, at least in part, for the motor impairments

Disturbed sensorimotor and electrophysiological patterns in lead intoxicated rats during development are restored by curcumin I

<div><p>Lead poisoning is one of the most significant health problem of environmental origin. It is known to cause different damages in the central and peripheral nervous system which could be represented by several neurophysiological and behavioral symptoms. In this study we firstly investigated the effect of lead prenatal exposure in rats to (3g/L), from neonatal to young age, on the motor/sensory performances, excitability of the spinal cord and gaits during development. Then we evaluated neuroprotective effects of curcumin I (Cur I) against lead neurotoxicity, by means of grasping and cliff avoidance tests to reveal the impairment of the sensorimotor functions in neonatal rats exposed prenatally to lead. In addition, extracellular recordings of motor output in spinal cord revealed an hyper-excitability of spinal networks in lead treated rats. The frequency of induced fictive locomotion was also increased in treated rats. At the young age, rats exhibited an impaired locomotor gait. All those abnormalities were attenuated by Cur I treatment at a dose of 16g/kg. Based on our finding, Cur I has shown features of a potent chemical compound able to restore the neuronal and the relative locomotor behaviors disturbances induced by lead intoxication. Therefore, this chemical can be recommended as a new therapeutic trial against lead induced neurotoxicity.</p></div

Mouvements paysans face à la politique agricole commune et à la mondialisation (1957-2011)

Cette publication s'inscrit dans le cadre du programme de recherche du Centre de Recherches en Histoire Internationale et Atlantique de l'université de Nantes sur l'Histoire des mouvements sociaux dans l'Europe Atlantique. Réfléchissant aux réactions des sociétés civiles de l'ère contemporaine face aux grands événements internationaux de leur temps, ce programme, mené en lien avec les ressources du Centre d'Histoire du Travail (CHT), s'est intéressé à l'histoire des mouvements paysans face aux mutations agricoles conditionnées par la création de la Politique Agricole Commune et face aux changements induits par le développement de l'Organisation Mondiale du Commerce. Outre des mises en perspective larges sur les problématiques de la PAC et de l'OMC, cet ouvrage collectif, issu d'une journée d'études, a cherché à approfondir certains conflits sociaux par la publication d'études scientifiques et monographiques portant sur les régions de l'Ouest, du Sud-Ouest et du monde méditerranéen, de témoignages ou de documents d'archives venant des organisations agricoles (le plan Mansholt, les grèves du lait, les conflits viticoles, les conflits de l'agroalimentaire…)

Biofouling protection by electro-chlorination on optical windows for oceanographic sensors and imaging devices

Oceans environmental monitoring and seafloor exploitation need in situ sensors and optical devices (cameras, lights) in various locations and on various carriers in order to initiate and to calibrate environmental models or to operate underwater industrial process supervision. For more than 10 years Ifremer deploys in situ monitoring systems for various seawater parameters and in situ observation systems based on lights and HD Cameras. To be economically operational, these systems must be equipped with a biofouling protection dedicated to the sensors and optical devices used in situ. Indeed, biofouling, in less than 15 days [1] will modify the transducing interfaces of the sensors and causes unacceptable bias on the measurements provided by the in situ monitoring system. In the same way biofouling will decrease the optical properties of windows and thus altering the lighting and the quality fot he images recorded by the camera