GABA-ergic control of prolactin release in rainbow trout (Oncorhynchus mykiss) pituitaries in vitro     

Patrick Prunet  Jean-François Gonnard  Gilles Paboeuf 《Fish physiology and biochemistry》1993,11(1-6):131-137

The involvement of γ-aminobutyric acid (GABA) in the control of prolactin (PRL) release was investigated in rainbow trout using both perifused pituitary fragments and pituitary cells in primary culture. In our perifusion system, infusion of GABA (10⁻⁶ to 10⁻⁴ M) caused an inhibition of PRL release (between 20 and 40%). Administration on perifused pituitary fragments of 3APS, a GABAa agonist, mimicked this inhibitory effect. Moreover, bicuculline, a specific antagonist of GABAa receptors, totally abolished GABA effect. When tested on cultured pituitary cells during 40h exposure, GABA (10⁻⁵ M) caused a significant decrease in PRL release (24.5%). Baclofen, a specific agonist for GABAb receptor tested at 10⁻⁶ and 10⁻⁵ M, also inhibited PRL released from cultured pituitary cells. These results demonstrate that GABA inhibits PRL release by acting directly on pituitary cells and that probably both types of GABA receptor (a and b) are involved in this regulation.

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Résumé Nous avons étudié l'implication de l'acide γ-aminobutirique (GABA) dans le controle de la sécrétion de prolactine (PRL) chez la truite arc-en-ciel en utilisant à la fois des fragments d'hypophyse perifusés et des cellules hypophysaires en culture. Dans notre système de périfusion, le GABA (10⁻⁶ à 10⁻⁴ M) inhibe la libération de PRL (entre 20 et 40%). L'administration sur les fragments d'hypophyse périfusés de 3APS, un agoniste des récepteurs GABAa, reproduit ces effets inhibiteurs. De plus, la bicuculline, un antagoniste spécifique des récepteurs de type GABAa, abolie complètement les effets du GABA. Lorsqu'il est testé pendant 40h sur des cellules en culture, le GABA (10⁻⁵ M) réduit de manière significative la libération de PRL (24.5%). Le Baclofen, un agoniste spécifique des récepteurs GABAb testé à 10⁻⁶ et 10⁻⁵ M, inhibe aussi la libération de PRL par les cellules en culture. Ces résultats démontrent que le GABA inhibe la libération de PRL en agissant directement sur les cellules hypophysaires et que les 2 types de récepteurs GABA (a et b) sont impliqués dans cette régulation.

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Spatial activity and expression of plasma membrane H+-ATPase in stem xylem of walnut during dormancy and growth resumption   总被引：1，自引：0，他引：1  

Alves G  Decourteix M  Fleurat-Lessard P  Sakr S  Bonhomme M  Améglio T  Lacointe A  Julien JL  Petel G  Guilliot A 《Tree physiology》2007,27(10):1471-1480

Plasma membrane H+-ATPase (PM H+-ATPase) plays a key role in nutrient transport, stress responses and growth. To evaluate proton motive force differences between apical and basal parts of acrotonic 1-year-old shoots of walnut (Juglans regia L. cv 'Franquette') trees, spatial and seasonal changes in PM H+-ATPase were studied in mature xylem tissues. During both the dormancy and growth resumption periods, and in both the apical and basal parts of the stem, PM H+-ATPase activity showed positive correlations with the amount of immunodetectable protein. In spring, at the time of growth resumption, higher activities and immunoreactivities of PM H+-ATPase were found in the apical part of the stem than in the basal part of the stem. In spring, the decrease in xylem sugar concentration reflected the high sugar uptake rate. Our data suggest that PM H+-ATPase plays a major role in the uptake of carbohydrates from xylem vessels during growth resumption. These results are discussed in the context of the acrotonic tendency of walnut shoots.  相似文献   

Site fidelity and movements of an amphidromous goby revealed by otolith multi‐elemental signatures along a tropical watershed          下载免费PDF全文

Nils Teichert  Helene Tabouret  Raphaël Lagarde  Henri Grondin  Dominique Ponton  Christophe Pécheyran  Gilles Bareille 《Ecology of Freshwater Fish》2018,27(3):834-846

Otolith microchemistry can provide crucial information to address gaps of knowledge in spatio‐temporal ecology of fish species. However, understanding the seasonal variability of water chemistry and its effect on otolith signatures is needed to interpret fish movements. Otolith multi‐elemental signatures were used to examine the diadromous migration and small‐scale movements of a tropical goby (Sicyopterus lagocephalus) within a watershed in La Réunion Island, Indian Ocean. The elemental ratios Sr:Ca, Ba:Ca and Sr:Ba recorded monthly in the water of nine sampling sites varied between localities and were correlated with otolith signatures, whereas the Mg:Ca signature was not. The incorporation of some trace elements in otoliths was influenced by the size of fish and site where they were caught, reflecting an effect of endogenous and exogenous factors. Despite these sources of variation, the elemental signatures did not overlap for three river sections distributed along the 26‐km‐long watershed. The diadromous migration and fish lifetime movements between these river sections were reconstructed using an original process based on random forest analysis. This approach revealed distinct migratory behaviours after fish entered in the river, with some individuals progressing slowly in the watershed whereas other rapidly reached the upper localities. As adults, S. lagocephalus showed a restricted exploratory behaviour and a strong site fidelity to a particular part of the watershed. The detection of adult movement was typically only between adjacent locations and is possibly explained by shifts in local intraspecific hierarchies and/or displacement during extreme discharge caused by cyclones.  相似文献   

The Role of Traditional Irrigation Canals in a Long Term Environmental Perspective A Case Study in Southern France： The Durance Basin     

Aspe Chantal  Gilles Andre  Jacque Marie 《农业科学与技术》2014,(1):1-12

The agricultural sector is often considered to be the largest water consumer and the policy aimed at saving irrigation water exists across Europe. The flip-side of such policy, however, is the disappearance of traditional irrigation canals since farmers are encouraged to turn to drip irrigation and overhead irrigation gradually. Given this, we would like to argue that traditional irrigation canals need to be reexamined. Such canals are not only built aquatic infrastructure, they are also the product of a culture and social relationship with water in the Mediterranean region. Canals form a complex system which is driven by environmental, economic and social factors. Our sociological and environmental research in Provence （and around the Durance basin more specifically） points up how the very dense territorial network of gravity-fed canals is useful in water management, as well as in other shared uses over the long-term. The findings underscore the positive environmental role played by these historical and anthropogenic constructions. They contribute to refilling the aquifer and also act as a valuable environmental good and service （e.g., run-off regulation, biodiversity, landscape, recreation, etc.）. Further, several local actors have underscored their role as part of an intangible cultural heritage and as important for the area＇s economic and social development. Such canals play a central role in sustainable development since beyond their productive role in agriculture, they play a social role （new uses） and an ecological role （as reservoirs for biodiversity and ecological corridors）.  相似文献   

A human genome diversity cell line panel     

Cann HM  de Toma C  Cazes L  Legrand MF  Morel V  Piouffre L  Bodmer J  Bodmer WF  Bonne-Tamir B  Cambon-Thomsen A  Chen Z  Chu J  Carcassi C  Contu L  Du R  Excoffier L  Ferrara GB  Friedlaender JS  Groot H  Gurwitz D  Jenkins T  Herrera RJ  Huang X  Kidd J  Kidd KK  Langaney A  Lin AA  Mehdi SQ  Parham P  Piazza A  Pistillo MP  Qian Y  Shu Q  Xu J  Zhu S  Weber JL  Greely HT  Feldman MW  Thomas G  Dausset J  Cavalli-Sforza LL 《Science (New York, N.Y.)》2002,296(5566):261-262

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Oscillations and sparsening of odor representations in the mushroom body     

Perez-Orive J  Mazor O  Turner GC  Cassenaer S  Wilson RI  Laurent G 《Science (New York, N.Y.)》2002,297(5580):359-365

In the insect olfactory system, oscillatory synchronization is functionally relevant and reflects the coherent activation of dynamic neural assemblies. We examined the role of such oscillatory synchronization in information transfer between networks in this system. The antennal lobe is the obligatory relay for olfactory afferent signals and generates oscillatory output. The mushroom body is responsible for formation and retrieval of olfactory and other memories. The format of odor representations differs significantly across these structures. Whereas representations are dense, dynamic, and seemingly redundant in the antennal lobe, they are sparse and carried by more selective neurons in the mushroom body. This transformation relies on a combination of oscillatory dynamics and intrinsic and circuit properties that act together to selectively filter and synthesize the output from the antennal lobe. These results provide direct support for the functional relevance of correlation codes and shed some light on the role of oscillatory synchronization in sensory networks.  相似文献   

Strategic success for hydropower in Laos     

Guerrier G  Paul R  Sananikhom P  Kaul S  Luthi R  Katz JP  Robino M  Khammanithong P  Brey PT 《Science (New York, N.Y.)》2011,334(6052):38

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Normalization for sparse encoding of odors by a wide-field interneuron     

Papadopoulou M  Cassenaer S  Nowotny T  Laurent G 《Science (New York, N.Y.)》2011,332(6030):721-725

Sparse coding presents practical advantages for sensory representations and memory storage. In the insect olfactory system, the representation of general odors is dense in the antennal lobes but sparse in the mushroom bodies, only one synapse downstream. In locusts, this transformation relies on the oscillatory structure of antennal lobe output, feed-forward inhibitory circuits, intrinsic properties of mushroom body neurons, and connectivity between antennal lobe and mushroom bodies. Here we show the existence of a normalizing negative-feedback loop within the mushroom body to maintain sparse output over a wide range of input conditions. This loop consists of an identifiable "giant" nonspiking inhibitory interneuron with ubiquitous connectivity and graded release properties.  相似文献   

The use of geostatistics for sampling a core collection of perennial ryegrass populations     

Gilles Charmet  François Balfourier 《Genetic Resources and Crop Evolution》1995,42(4):303-309

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Correlates of diet quality in the Quebec population     

Huot I  Paradis G  Receveur O  Ledoux M;Quebec Heart Health Demonstration Project Research Group 《Public health nutrition》2004,7(8):1009-1016

OBJECTIVE: To determine the correlates of a high-fat diet in urban, suburban and rural areas of Quebec, Canada. DESIGN: A secondary analysis of data collected as part of a 5-year multi-factorial, multi-setting, community-intervention project. SETTING: Urban, suburban and rural settings of the province of Quebec, 1997. SUBJECTS: Data were analysed from a sample of 5214 participants (2227 males, 2987 females). A food-frequency questionnaire was completed and a global index of food quality was calculated. Logistic regression was used to identify correlates of a diet high in total fats, saturated fat and cholesterol. RESULTS: In both genders, lower level of education, smoking status, French and English languages compared with other languages spoken at home, and a rural environment were associated with poor diet quality. Having no intention to eat low-fat dairy products more often was associated with a high-fat diet. In men, obesity (body mass index >/=30 kg m(-2)) and absence of reported health problems were correlates of a high-fat diet, while, in women, lower physical activity was a correlate. CONCLUSIONS: Future health interventions in Quebec should target people with low education, smokers and those living in a rural environment. Obese men and sedentary women should have access to specific dietetic resources.  相似文献