Search results for "Omero"

Sexual dimorphism in the vomeronasal system of the rabbit.

2006

Abstract Studies have shown that the vomeronasal system (VNS), an olfactory neural network that participates in the control of reproductive physiology and behavior, is sexually dimorphic in the rat. These works have also shown two main characteristics of brain sexual dimorphism: (a) dimorphism appears in neural networks related to reproduction and (b) it can present two morphological patterns: one in which males present greater morphological measures than females (male > female) and another in which the opposite is true (female > male). The present work extends the hypothesis to the rabbit, as a representative species of Lagomorpha. In addition, the locus coeruleus (LC), which is known to s…

Refining the dual olfactory hypothesis: Pheromone reward and odour experience

2009

In rodents, sexual advertisement and gender recognition are mostly (if not exclusively) mediated by chemosignals. Specifically, there is ample evidence indicating that female mice are ‘innately’ attracted by male sexual pheromones that have critical non-volatile components and are detected by the vomeronasal organ. These pheromones can only get access to the vomeronasal organ by active pumping mechanisms that require close contact with the source of the stimulus (e.g. urine marks) during chemoinvestigation. We have hypothesised that male sexual pheromones are rewarding to female mice. Indeed, male-soiled bedding can be used as a reinforcer to induce conditioned place preference, provided co…

Attraction to male pheromones and sexual behaviour show different regulatory mechanisms in female mice.

2004

In rodents, female sexual behaviour is under hormonal control. The attraction females show for male-derived nonvolatile chemicals (pheromones) can be regarded as the first step of this behaviour, but it is unknown whether this attraction is also modulated by sexual steroids. To test this possibility, ovariectomized adult female mice with no experience of chemical signals from adult males were randomly assigned to four groups that received oil (control), progesterone, estradiol (E) or estradiol+progesterone (E+P) injections, respectively. Females were then tested for their attraction to male-soiled bedding and, subsequently, for their proceptive behaviour when confronted to adult males. Fema…

Mating Increases Neuronal Tyrosine Hydroxylase Expression and Selectively Gates Transmission of Male Chemosensory Information in Female Mice

2013

Exposure to chemosensory signals from unfamiliar males can terminate pregnancy in recently mated female mice. The number of tyrosine hydroxylase-positive neurons in the main olfactory bulb has been found to increase following mating and has been implicated in preventing male-induced pregnancy block during the post-implantation period. In contrast, pre-implantation pregnancy block is mediated by the vomeronasal system, and is thought to be prevented by selective inhibition of the mate's pregnancy blocking chemosignals, at the level of the accessory olfactory bulb. The objectives of this study were firstly to identify the level of the vomeronasal pathway at which selective inhibition of the m…

Role of nitric oxide in pheromone-mediated intraspecific communication in mice

2009

Nitric oxide is known to take part in the control of sexual and agonistic behaviours. This is usually attributed to its role in neural transmission in the hypothalamus and other structures of the limbic system. However, socio-sexual behaviours in rodents are mainly directed by chemical signals detected by the vomeronasal system, and nitric oxide is abundant in key structures along the vomeronasal pathway. Thus, here we check whether pharmacological treatments interfering with nitrergic transmission could affect socio-sexual behaviour by impairing the processing of chemical signals. Treatment with an inhibitor of nitric oxide synthesis (Nomega-Nitro-l-arginine methyl ester hydrochloride, L-N…

Estradiol masculinizes the posteromedial cortical nucleus of the amygdala in the rat

2000

It has been demonstrated that the posteromedial cortical amygdaloid nucleus (PMCo), is sexually dimorphic. It is shown (Experiment 1) that male orchidectomy on the day of birth (D1) decreases the volume and number of neurons of the PMCo, while a single injection of propionate testosterone to the female on D1 masculinizes the PMCo in this gender. Since male gonadectomy on D1 (Experiment 2) is counteracted by a single injection of estradiol benzoate in males it has been suggested that the masculinization of the PMCo is due to the aromatization of testosterone to estradiol in this structure. These findings support the hypothesis that the development of sex differences in structures that belong…

Kalmbergin kartasto R V : List 9

1855

Influence des facteurs naturels sur la maturation du raisin, en 1979, à Pomerol et Saint-Emilion

1981

<p style="text-align: justify;">Les vignobles de Pomerol et Saint-Emilion sont implantés sur des sols dérivant de roches-mères variées; ils produisent des vins de haute qualité mais différents suivant leur origine géologique.</p><p style="text-align: justify;">Dans les meilleurs crus, nous avons pu vérifier que les variations mésoclimatiques sont très faibles et ont peu d'influence sur les caractères des vins. Par contre, en 1979, une relation a été mise en évidence entre les conditions de l'alimentation en eau de la vigne (étroitement liées aux propriétés physiques des sols) et la constitution des raisins à maturité (<em>V. vinifera</em> var. Merlot noir).<…

La construcción del tipo del 'salvaje' en Homero

1999

Estudio del mito del 'hombre salvaje' en la épica homérica, sobre todo en la 'Odisea' y en el canto IX, en el que se narra la visita de Odiseo y sus amigos al país de los cíclopes, en contraste con la visita posterior a la tierra de los feacios, modelos respectivos de salvajes y de civilizados. Este prototipo de 'salvaje', antropófago, orgulloso y soberbio, impío y cruel, aislado y desconocedor de la agricultura, la navegación y la hospitalidad, marcará la historia de Occidente, en la que sufre una serie de aleccionadoras transformaciones.

Da Eolo a San Bartolomeo

2009

L'articolo fa il punto su risultati innovativi della ricerca archeologica relativamente alle isole Lipari inserendoli nel contesto filologico-letterario.