Modulation of the Ago2-Associated microRNA Induced Silencing Complex during Long-Term Potentiation in the Rat Dentate Gyrus in Vivo

Synaptic plasticity is defined as the ability of a neuronal synapse to change in strength, and is believed to be the basis of learning and memory. An example of synaptic plasticity, by far the most studied, is long-term potentiation (LTP): a stable, activity-induced increase in synaptic efficacy. LTP requires de novo gene expression, protein synthesis and protein degradation. Transcriptional and post-transcriptional regulation controls new protein expression. In the past decade, small non-coding RNAs called microRNAs have emerged as key regulators of translation. MicroRNAs bind to target mRNAs by complementary binding and recruit a protein complex to mediate mRNA silencing. This complex is known as the microRNAinduced silencing complex (miRISC). The goals of this study were to investigate the composition of the miRISC in the rat dentate gyrus in vivo, to study modulation of the miRISC during LTP, and to uncover new candidate binding partners of Ago2. LTP was induced by HFS of the medial perforant path. The miRISC was isolated by immunoprecipitation of its core component, the protein Argonaute 2 (Ago2). Five proteins thought to bind Ago2 were analyzed by co-immunoprecipitation with Ago2. These proteins were GW182, the RNase III enzyme, Dicer, the RNA-binding protein, FMRP, and the RNA helicases, MOV10 and DDX6. DDX6 was the only protein found to be reliably associated with Ago2, even though all the proteins were detected in association with Ago2 in HEK cells expressing EGFP-Ago2. DDX6 was non-significantly dissociated from Ago2 during LTP. In the total lysate, none of the analyzed proteins were significantly modulated during LTP. Nevertheless, Argonaute 2 and GW182 were non-significantly upregulated, and MOV10 was non-significantly downregulated during LTP. The study does not show a significant remodeling of the miRISC during LTP, but neither does it exclude this possibility. Immunoprecipitated samples were analyzed by mass spectrometry. New candidate Ago2 binding partners were uncovered, such as the proteins DDX1 and FXR1, homologs of DDX6 and FMRP. A protein important for translation, poly-A-binding protein 1 (PABP1), was also detected

Effectiveness and limitations of physiological ethological criteria to assess the welfare of pigs in relation to the housing system

International audienc

Pheromonal transmission of an aversive experience in domestic pig

International audienc

Causes de mortalité dans un service de chirurgie générale et viscérale au CHU de Rennes

RENNES1-BU Santé (352382103) / SudocPARIS-BIUM (751062103) / SudocSudocFranceF

Effectiveness and limitations of physiological ethological criteria to assess the welfare of pigs in relation to the housing system

International audienc

Comportement de truies en groupe lors de la réalisation d'un apprentissage : utilisation d'un système alimentaire informatisé

National audienceComputerized feeding systems have been developed, allowing farmers to keep dry sows housed in groups, and simultaneously providing rations adapted to their individual feed requirements. In such a system, sows are individually fed by a complex computer-programmed concentrate dispenser. The major practical problems proceed from the difficulty for naive animals to adapt to such a system. An experiment was designed to objectively assess the problems resulting from training naive gilts to use such a system under the conditions of practical pig farming. The results concern 13 groups of ten pregnant crossbred gilts. Fifty-five percent of them learned spontaneously to feed from the computerized food dispenser during the first 24 hours. Sixteen percent required an additional period of 3 hours during which they were separated from those that had already learned. For the others, some reinforcement given by the experimenter was necessary (eighteen percent) whereas long lasting shaping was required for the remaining ten percent. These differences are related to individual characteristics : the sows which learn spontaneously to use the feeding system have a behavioural profile opposed to those which need the farmer’s help. The latter appeared as leaders in induced movements, exhibit little exploratory behaviour and acted as subordinate in food competition tests. The ability to learn are not related to the emotivity of the gilts as tested by the contact with the man. A precocious familiarisation of young sows to a dispenser having similar characteristics to this feeding system has to be tested, as it could reduce the fear reactions to the first contact.Chez les truies gestantes, la conduite d’élevage, qui implique une alimentation individualisée, n’est plus limitée aux systèmes de contention depuis que les distributeurs informatisés se sont développés. Les femelles sont en liberté et alimentées à l’aide d’un appareil complexe délivrant des rations individuelles programmées. Ce type de système d’élevage répond ainsi aux exigences de la réglementation européenne récemment mise en place en matière de bien-être animal. Cependant, les animaux s’adaptent parfois difficilement à cette technique : les résultats obtenus sur 13 groupes de dix truies montrent que 55,4 % des femelles seulement apprennent spontanément l’utilisation de l’appareil en 24 heures. 16,2 % le font après avoir été séparées des premières, alors que 18,5 % ne réussissent à réaliser cet apprentissage qu’avec l’aide de l’éleveur qui les y attire par la distribution d’aliments. Enfin les 10 % restant demandent un apprentissage plus prolongé. Les différences observées dépendent de caractéristiques individuelles : les truies utilisant facilement l’appareil ont un profil comportemental opposé à celles qui posent des problèmes d’apprentissage. Ces dernières apparaissent comme des individus initiateurs de déplacements provoqués, peu explorateurs et non dominants en situation de compétition alimentaire. Les conditions d’apprentissage sont donc liées à des paramètres individuels difficilement modifiables par des techniques d’élevage. Un moyen de faciliter la tâche des éleveurs serait de familiariser les animaux au stade "cochette" à des dispositifs alimentaires proches de ce type de distributeur. Cette solution permettrait de réduire les réactions de crainte vis-à-vis de l’appareil et des bruits qui résultent de son utilisation

Pheromonal transmission of an aversive experience in domestic pig

International audienc

Comportement de truies en groupe lors de la réalisation d'un apprentissage : utilisation d'un système alimentaire informatisé

National audienceComputerized feeding systems have been developed, allowing farmers to keep dry sows housed in groups, and simultaneously providing rations adapted to their individual feed requirements. In such a system, sows are individually fed by a complex computer-programmed concentrate dispenser. The major practical problems proceed from the difficulty for naive animals to adapt to such a system. An experiment was designed to objectively assess the problems resulting from training naive gilts to use such a system under the conditions of practical pig farming. The results concern 13 groups of ten pregnant crossbred gilts. Fifty-five percent of them learned spontaneously to feed from the computerized food dispenser during the first 24 hours. Sixteen percent required an additional period of 3 hours during which they were separated from those that had already learned. For the others, some reinforcement given by the experimenter was necessary (eighteen percent) whereas long lasting shaping was required for the remaining ten percent. These differences are related to individual characteristics : the sows which learn spontaneously to use the feeding system have a behavioural profile opposed to those which need the farmer’s help. The latter appeared as leaders in induced movements, exhibit little exploratory behaviour and acted as subordinate in food competition tests. The ability to learn are not related to the emotivity of the gilts as tested by the contact with the man. A precocious familiarisation of young sows to a dispenser having similar characteristics to this feeding system has to be tested, as it could reduce the fear reactions to the first contact.Chez les truies gestantes, la conduite d’élevage, qui implique une alimentation individualisée, n’est plus limitée aux systèmes de contention depuis que les distributeurs informatisés se sont développés. Les femelles sont en liberté et alimentées à l’aide d’un appareil complexe délivrant des rations individuelles programmées. Ce type de système d’élevage répond ainsi aux exigences de la réglementation européenne récemment mise en place en matière de bien-être animal. Cependant, les animaux s’adaptent parfois difficilement à cette technique : les résultats obtenus sur 13 groupes de dix truies montrent que 55,4 % des femelles seulement apprennent spontanément l’utilisation de l’appareil en 24 heures. 16,2 % le font après avoir été séparées des premières, alors que 18,5 % ne réussissent à réaliser cet apprentissage qu’avec l’aide de l’éleveur qui les y attire par la distribution d’aliments. Enfin les 10 % restant demandent un apprentissage plus prolongé. Les différences observées dépendent de caractéristiques individuelles : les truies utilisant facilement l’appareil ont un profil comportemental opposé à celles qui posent des problèmes d’apprentissage. Ces dernières apparaissent comme des individus initiateurs de déplacements provoqués, peu explorateurs et non dominants en situation de compétition alimentaire. Les conditions d’apprentissage sont donc liées à des paramètres individuels difficilement modifiables par des techniques d’élevage. Un moyen de faciliter la tâche des éleveurs serait de familiariser les animaux au stade "cochette" à des dispositifs alimentaires proches de ce type de distributeur. Cette solution permettrait de réduire les réactions de crainte vis-à-vis de l’appareil et des bruits qui résultent de son utilisation

Comportement de truies en groupe lors de la réalisation d’un apprentissage : utilisation d’un système alimentaire informatisé

International audienc