ÉTUDE ÉLECTROMYOGRAPHIQUE DE L'ORGANISATION DE LA MOTRICITÉ UTÉRINE AU COURS DE L'ŒSTRUS CHEZ LA BREBIS

International audienc

Uterine motor responses to an α-adrenergic agonist (phenylephrine) in the ewe during oestrus and at the end of gestation

International audienc

ÉTUDE ÉLECTROMYOGRAPHIQUE DE LA MOTRICITÉ DE L'UTÉRUS CHEZ LA BREBIS. ACTION DES HORMONES

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Etude des réponses motrices de l'utérus aux stimulations vaginales et utérines chez la Brebis en œstrus

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Etude des réponses motrices de l'utérus aux catécholamines chez la brebis sous différentes imprégnations stéroïdiennes. Mise en évidence du rôle des catécholamines endogènes

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Activité électromyographique de l'utérus chez la brebis pendant la saison sexuelle : comparaison de l'œstrus naturel et de l'œstrus induit par les progestagènes seuls ou avec une supplémentation de PMSG

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Motricité utérine de la Brebis, avant, pendant et après la parturition spontanée ou après traitement par la dexaméthasone

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Nutritional impact on odor induced activity in the olfactory buld

National audienceThe detection of olfactory nutritive cues is crucial for survival and implies modifications of activities in the olfactory system. Odorants activate the olfactory receptor neurons (ORNs) of the mucosa which project to the olfactory bulb (OB). OSNs axons connect apical dendrites of mitral cells in olfactory glomeruli which are surrounded by juxtaglomerular cells. Then, after having interacted with granular cells in deeper layers of the OB, mitral cells send the information towards the cortex. In this context, we use c-fos immunodetection and optical imaging in vivo to question the impact of the nutritive state at the first stage of olfactory coding in the OB. Using fos activity, we first show that cellular responses to familiar odors (known isoamyl acetate and pellet odors) of juxtaglomerular, mitral and granular cells were significantly decreased in fed rats compared to 48-hrs fasted ones. We then demonstrate that orexins and leptin were partly responsible for this modulation: the administration of orexin receptors antagonist or of leptin per se in fasted rats led to OB responses to pellet odors similar to those observed in fed rats. In a second series of experiments, we are currently using Intrinsic optical signals (IOS) imaging to study specific glomerular activation patterns in response to a set of odorants in anesthetized rats. IOS are due to changes in blood oxygenation and flow and light scattering during activation and reliably map functional sensory modules. We are analyzing the intensity and time course of odor-evoked optical signals from each spot of the olfactory maps. To bring insights into the putative nutritional plasticity on odor-induced maps in the OB, we aim to apply this optical imaging technique to the same groups studied by c-fos