Intéractions in vitro du carbaryl et du naphtalène avec les cytochromes P-450 de rat, de chien et de singe. Implication dans le métabolisme de la testostérone

In this work, we studied the in vitro interactions between a carbamate insecticide, carbaryl, and its aromatic component, naphtalene, with hepatic cytochrome P-450 (CYP). We first studied these interactions with the induced CYP forms (1A, 2B, 3A) in a well known animal species : rat. We showed that carbaryl and naphtalene are able to bind all studied CYP forms, with a higher affinity with the 2B form. Secondly, we studied the in vitro interaction of carbaryl and naphtalene with hepatic constitutive CYP of untreated rat, monkey and dog (these species are involved in protocols of toxicological evaluation). In spite of interspecies differences, we observed a common effect of these two aromatic molecules, towards the 3A constitutive form, in these three species. / Ce travail porte sur les interactions in vitro entre un insecticide de la famille des carbamates, le carbaryl et sa composante aromatique, le naphtalène, avec les les cytochromes P-450 (CYP) hépatiques. Dans un premier temps, nous avons étudié ces interactions avec les formes induites de CYP (1A, 2B, 3A) chez une espèce animale bien connue : le rat. Nous avons montré que le carbaryl et le naphtalène sont capables de se lier à toutes les formes de CYP étudiées, avec une plus grande affinité pour la forme 2B. Dans un deuxième temps, nous avons étudié l'interaction in vitro du carbaryl et du naphtalène avec les CYP constitutifs de rat, mais aussi de singe et de chien, utilisés dans les protocoles d'évaluation en toxicologie. Malgré de nombreuses différences interespèces, nous avons montré un effet commun des 2 molécules aromatiques qui agissent sur la forme constitutive 3A chez les 3 espèces

Dynamique de l'apprentissage olfactif chez l'abeille domestique

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Differential Combinatorial Coding of Pheromones in Two Olfactory Subsystems of the Honey Bee Brain

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Apprentissage et mémoires olfactifs chez l'abeille : comparaison de différentes procédures de conditionnement classique de la réponse d'extension du probocis

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Individual olfactory learning in Camponotus ants.

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Individual olfactory learning in Camponotus ants

International audienceWe studied olfactory learning in two ant species, Camponotus mus from Argentina and Camponotus fellah from Israel. To this end, we established an experimental laboratory protocol in which individual ants were trained to associate odours with gustatory reinforcers. Ants were trained individually to forage in a Y-maze in which two odours had to be discriminated. One odour was positively reinforced with sucrose solution and the other was negatively reinforced with quinine solution. After a training session of 24 trials, ants of both species learned to differentiate the two odour pairs, the structurally dissimilar limonene and octanal, and the structurally similar heptanal and 2-heptanone. In nonreinforced tests, ants consistently chose the odour previously reinforced with sucrose solution and spent more time searching in the arm of the maze presenting this odour. Learning performances were more robust in the case of limonene versus heptanal. These results thus show for the first time that individual ants perceive and learn odours in controlled laboratory conditions

Learning and discrimination of honey odours by the honey bee

We used classical conditioning of the proboscis extension response to test whether the natural discrimination ability of honey bees could be used to assess the origin of honeys. Five honeys were used as the conditioning stimuli in the procedure: linden (Tilia spp.), oilseed rape (Brassica napus), eucalyptus, sunflower (Helianthus annuus), and black locust (Robinia pseudoacacia). Bees exhibited high levels of conditioned responses to all honey odours. Responses to the conditioned honey were usually the highest, but high levels of generalisation; i.e. behavioural response to other honeys, were recorded. Using a differential conditioning procedure where one honey odour was rewarded and another odour was explicitly unrewarded, we showed that honey bees could not always differentiate between honey types. The potential use of the honey bee as a biological detector to discriminate among honeys is discussed

Olfactory information transfer in the honeybee: compared efficiency of classical conditioning and early exposure

64 ref. DOI: 10.1006/anbe.2000.1395International audienc