Characterization of the cardiac ganglion in the crab Neohelice granulata and immunohistochemical evidence of GABA-like extrinsic regulation

The aim of the present work is to provide an anatomical description of the cardiac system in the crab Neohelice granulata and evidence of the presence of GABA by means of immunohistochemistry. The ganglionic trunk was found lying on the inner surface of the heart's dorsal wall. After dissection, this structure appeared as a Y-shaped figure with its major axis perpendicular to the major axis of the heart. Inside the cardiac ganglion, we identified four large neurons of 63.7 μm ± 3.7 in maximum diameter, which were similar to the motor neurons described in other decapods. All the GABA-like immunoreactivity (GABAi) was observed as processes entering mainly the ganglionic trunk and branching in slender varicose fibers, forming a network around the large neurons suggesting that GABAi processes contact them. Our findings strengthen previous results suggesting that the GABAergic system mediates the cardio-inhibitory response upon sensory stimulation.Fil: Yang, Margarita.Fil: Carbo, Martin.Fil: Freudenthal, Ramiro A. M..Fil: Hermitte, Gabriela

Mouse sperm membrane potential hyperpolarization is necessary and sufficient to prepare sperm for the acrosome reaction

Mammalian sperm are unable to fertilize the egg immediately after ejaculation; they acquire this capacity during migration in the female reproductive tract. This maturational process is called capacitation and in mouse sperm it involves a plasma membrane reorganization, extensive changes in the state of protein phosphorylation, increases in intracellular pH (pHi) and Ca2+ ([Ca2+]i), and the appearance of hyperactivated motility. In addition, mouse sperm capacitation is associated with the hyperpolarization of the cell membrane potential. However, the functional role of this process is not known. In this work, to dissect the role of this membrane potential change, hyperpolarization was induced in noncapacitated sperm using either the ENaC inhibitor amiloride, the CFTR agonist genistein or the K+ ionophore valinomycin. In this experimental setting, other capacitation-associated processes such as activation of a cAMP-dependent pathway and the consequent increase in protein tyrosine phosphorylation were not observed. However, hyperpolarization was sufficient to prepare sperm for the acrosome reaction induced either by depolarization with high K+ or by addition of solubilized zona pellucida (sZP). Moreover, K+ and sZP were also able to increase [Ca2+]i in non-capacitated sperm treated with these hyperpolarizing agents but not in untreated cells. On the other hand, in conditions that support capacitation-associated processes blocking hyperpolarization by adding valinomycin and increasing K+ concentrations inhibited the agonist-induced acrosome reaction as well as the increase in [Ca2+]i. Altogether, these results suggest that sperm hyperpolarization by itself is key to enabling mice sperm to undergo the acrosome reaction.Fil: de La Vega Beltrán, José Luis. Universidad Nacional Autónoma de México. Instituto de Biotecnología; MéxicoFil: Sánchez Cárdenas, Claudia. Universidad Nacional Autónoma de México. Instituto de Biotecnología; MéxicoFil: Krapf, Dario. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Instituto de Biología Molecular y Celular de Rosario. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas. Instituto de Biología Molecular y Celular de Rosario; ArgentinaFil: Hernández González, Enrique. Instituto Politécnico Nacional. Centro de Investigación y de Estudios Avanzados; MéxicoFil: Wertheimer Hermitte, Eva Victoria. University of Massachussets; Estados UnidosFil: Trevinio, Claudia L.. Universidad Nacional Autónoma de México. Instituto de Biotecnología; MéxicoFil: Visconti, Pablo E.. University of Massachussets; Estados UnidosFil: Darszon, Alberto. Universidad Nacional Autónoma de México. Instituto de Biotecnología; Méxic

Etología. Introducción a la ciencia del comportamiento

1ª ed., 3ª reimp.El objetivo de este libro es proporcionar una introducción a la Etología. Ésta ciencia responde al interés por profundizar en el conocimiento de las costumbres animales; por comprender la variedad de comportamientos que en diferentes situaciones exhiben los individuos de diferentes especies. Una posible definición de Etología podría ser: el estudio científico del comportamiento de los seres vivos. A lo largo de esta obra se analizan todos los aspectos que tienen que ver con el comportamiento animal, desde las causas y mecanismos de actuación o la adaptación y evolución y el bienestar animal.The purpose of this book is to provide an introduction to Ethology. This science responds to the interest in deepening the knowledge of animal customs; to understand the variety of behaviour that in different situations exhibit individuals of different species. A possible definition of ethology could be: the scientific study of the behavior of living beings. Throughout this book all aspects related to animal behavior, from the causes and mechanisms of action or adaptation and evolution and animal welfare, are analyzed

Compartmentalization of distinct cAMP signaling pathways in mammalian sperm.

Fertilization competence is acquired in the female tract in a process known as capacitation. Capacitation is needed for the activation of motility (e.g. hyperactivation) and to prepare the sperm for an exocytotic process known as acrosome reaction. While the HCO3--dependent soluble adenylyl cyclase Adcy10 plays a role in motility, less is known about the source of cAMP in the sperm head. Transmembrane adenylyl cyclases (tmACs) are another possible source of cAMP. These enzymes are regulated by stimulatory heterotrimeric Gs proteins; however, the presence of Gs or tmACs in mammalian sperm has been controversial. In this manuscript, we used Western blotting and cholera toxin-dependent ADP ribosylation to show Gs presence in the sperm head. Also, we showed that forskolin, a tmAC specific activator, induces cAMP accumulation in sperm from both WT and Adcy10 null mice. This increase is blocked by the tmAC inhibitor SQ-22536 but not by the Adcy10 inhibitor KH7. While Gs immunoreactivity and tmAC activity are detected in the sperm head, PKA is only found in the tail, where Adcy10 was previously shown to reside. Consistent with an acrosomal localization, Gs reactivity is lost in acrosome reacted sperm, and forskolin is able to increase intracellular Ca2+ and induce the acrosome reaction. Altogether, these data suggest that cAMP pathways are compartmentalized in sperm, with Gs and tmAC in the head and Adcy10 and PKA in the flagellum.Fil: Wertheimer Hermitte, Eva Victoria. University Of Massachussets; Estados Unidos. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Centro de Estudios Farmacológicos y Botánicos; ArgentinaFil: Krapf, Dario. Universidad Nacional de Rosario; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Rosario. Instituto de Biología Molecular y Celular de Rosario; ArgentinaFil: de la Vega Beltran, José L.. Universidad Nacional Autónoma de México; MéxicoFil: Sánchez Cárdenas, Claudia. Universidad Nacional Autónoma de México; MéxicoFil: Navarrete, Felipe. University Of Massachussets; Estados UnidosFil: Haddad, Douglas. University Of Massachussets; Estados UnidosFil: Escoffier, Jessica. University Of Massachussets; Estados UnidosFil: Salicioni, Ana M.. University Of Massachussets; Estados UnidosFil: Levin, Lonny R.. Cornell University; Estados UnidosFil: Buck, Jochen. Cornell University; Estados UnidosFil: Mager, Jesse. University Of Massachussets; Estados UnidosFil: Darszon, Alberto. Universidad Nacional Autónoma de México; MéxicoFil: Visconti, Pablo E.. University Of Massachussets; Estados Unido

La circulation des ressources génétiques végétales

What is to be done to regulate the circulation of plant-breeding in the world ? A first model had been based on the free access to all genetic resources, either wild or ancient or contained in an improved variety. A second model is being set up, in which every genetic resource will be appropriated either on the ground of patents right or on the base of national sovereignt

Do Incidental Environmental Anchors Bias Consumers’ Price Estimations?

It is well-established that decision makers bias their estimates of unknown quantities in the direction of a salient numerical anchor. Some standard anchoring paradigms have been shown to yield pervasive biases, such as Tversky and Kahneman’s (1974) classic 2-step task which includes a comparative question followed by an estimation question. In contrast there is much less evidence for the claim that incidental environmental anchors can produce assimilative effects on judgments, such as the amount people are willing to pay for a meal being greater at a restaurant called Studio 97 compared to one called Studio 17. Three studies are reported in which the basic incidental environmental anchoring method of Critcher and Gilovich (2008) is employed to measure consumer price estimations. No statistically significant evidence of incidental anchoring was obtained. In contrast, robust standard anchoring effects were found. The results suggest that anchoring is limited to situations which require explicit thinking about the anchor

Mecanismos asociativos en el aprendizaje apetitivamente motivado del cangrejo Chasmagnathus granulatus : memoria del contexto

Fil:Hermitte, Gabriela. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina

Sciences et État de droit

Marie-Angèle Hermitte, directeur d’études Après avoir travaillé la notion d’État de droit et la notion de risque, le séminaire a formulé une hypothèse. Les risques faisaient jusqu’à une période récente l’objet de réglementations séparées n’ayant pas de cohérence entre elles ; ils étaient d’autre part appréhendés par le droit de la responsabilité et le droit des assurances. Mais l’ensemble n’avait pas la cohérence d’un système. L’énoncé de droits fondamentaux et le développement du droit const..

Sciences et État de droit

Marie-Angèle Hermitte, directeur d’études J’avais compté séparer le séminaire en deux parties. Une partie portant sur le principe de précaution, une partie sur la révision des lois de bioéthique. Or, au regard de l’actualité foisonnante du principe de précaution cette année, et de la lenteur de la révision, j’ai fait toute l’année sur le principe de précaution. J’ai donc expliqué ses origines historiques, lorsque quelques scientifiques, lassés de voir que leurs alertes ne sont pas prises au s..