Papers by Gérard Coureaud
Physiology and Behavior, 2008
In adult mammals, the processing of complex odor mixtures is elemental or configural. Here, we ch... more In adult mammals, the processing of complex odor mixtures is elemental or configural. Here, we challenged these processes in newborn rabbits, in evaluating their perception of a binary odor mixture for which perceptual blending occurs in humans. This model of newborn animal was interesting since general questions remain on how odor cues are processed in immature organisms, and since rabbit pups present abilities of rapid odor learning. In the present study, we first demonstrated (Exp. 1) that rabbit pups rapidly acquired the odor of the binary mixture through associative conditioning (when the mammary pheromone was used as unconditioned stimulus). Then, we compared how they responded to the mixture, its components and the mammary pheromone, after they had learned the mixture or one of its constituents. After they had learned the odor of the mixture, they responded to its odor and the odor of its constituents (Exp. 2). However, after they had learned one constituent's odor, they responded to this odor but not to the mixture's odor (Exp. 3). The response to the mixture appeared nevertheless when pups successively acquired the odor of the two components (Exp. 4). Therefore, both elemental and configural processing of the mixture seem to be displayed by rabbit pups, suggesting that neonatal perception of a simple odor mixture may involve more than the perception of its constituents.
Ethologie et bien-être
HAL (Le Centre pour la Communication Scientifique Directe), Mar 17, 2022
[Thu-P1-027] Pheromone-induced odour learning and outstanding detection abilities in the newborn rabbit
Le Centre pour la Communication Scientifique Directe - HAL - uB, Aug 31, 2022
The transition from prenatal to postnatal environment in the rabbit: Evidence for a transnatal continuity in olfactory cues and function
National audienc
Perinatal odor disruption impairs neonatal milk intake in the rabbit
International audienc
Controlled access to the nest-box in rabbit : effects on pups'mortality
Le Centre pour la Communication Scientifique Directe - HAL - Inria, May 13, 1998
The interaction between pheromone-elicited and odour-elicited behaviour in the newborn rabbit
International audienc
Situación actual y perspectivas de la enterocolitis epizoótica
A pheromone that enforces learning in the newborn rabbit
La tétée initiale du lapereau : influence sur la survie et la croissance
International audienc
Odeurs lactées, survie et croissance chez le lapereau
National audienc
What tools for more robust rabbits around weaning
INRA Productions Animales, 2018
Physiology & Behavior, 2021
Pinnipeds, as any mammal species, use multimodal signals, including olfactory ones, to ensure vit... more Pinnipeds, as any mammal species, use multimodal signals, including olfactory ones, to ensure vital functions. Thus, some pinniped species seem able to use olfaction in both social and foraging contexts and to discriminate between different odors in air including both natural and artificial odors, but studies on that topic remain scarce. Here, we studied the olfactory capabilities of California sea lions living in captivity at La Flèche Zoo (France) in both terrestrial and aquatic environments. We used two categories of odors: social odors (from familiar individuals of the same group, unfamiliar individuals from another Zoo, animal zookeepers and a terrestrial carnivore) and non-social odors (food and odors identified as repellents in certain vertebrates). Several behavioral parameters were measured and analyzed as the number and duration of contact with the odor, mouth openings, vocalizations (air only) and air bubble production (water only). Our results, although limited by the low number of animals monitored (n=5), suggest that California sea lions are able to discriminate between different odors both in the air and under water. In the aquatic environment, the process allowing the perception of odors remains to be characterized. Applications to this work could be considered in captive conditions as well as in the wild.
Chemical Senses, 2020
In a preregistered, cross-sectional study, we investigated whether olfactory loss is a reliable p... more In a preregistered, cross-sectional study, we investigated whether olfactory loss is a reliable predictor of COVID-19 using a crowdsourced questionnaire in 23 languages to assess symptoms in individuals self-reporting recent respiratory illness. We quantified changes in chemosensory abilities during the course of the respiratory illness using 0–100 visual analog scales (VAS) for participants reporting a positive (C19+; n = 4148) or negative (C19−; n = 546) COVID-19 laboratory test outcome. Logistic regression models identified univariate and multivariate predictors of COVID-19 status and post-COVID-19 olfactory recovery. Both C19+ and C19− groups exhibited smell loss, but it was significantly larger in C19+ participants (mean ± SD, C19+: −82.5 ± 27.2 points; C19−: −59.8 ± 37.7). Smell loss during illness was the best predictor of COVID-19 in both univariate and multivariate models (ROC AUC = 0.72). Additional variables provide negligible model improvement. VAS ratings of smell loss ...
Brain Research, 2020
HIGHLIGHTS • Perception of odor mixtures can be either configural or elemental. • Single-unit ens... more HIGHLIGHTS • Perception of odor mixtures can be either configural or elemental. • Single-unit ensemble responses to these mixtures were assessed in aPCX and pPCX. • Anterior PCX coding matched known odor mixture perceptual characteristics. • In contrast, mixture perception did not predict posterior PCX ensemble coding.
Attraction of newborn rabbits
Journal of Experimental Biology, 2020
How animals perceive and learn complex stimuli, such as mixtures of odorants is a difficult probl... more How animals perceive and learn complex stimuli, such as mixtures of odorants is a difficult problem, for which the definition of general rules across the animal kingdom remains elusive. Recent experiments conducted in human and rodent adults as well as newborn rabbits suggested that these species process particular odor mixtures in a similar, configural manner. Thus, the binary mixture of ethyl isobutyrate (EI) and ethyl maltol (EM) induces configural processing in humans, who perceive a mixture odor quality (pineapple) that is distinct from the quality of each component (strawberry and caramel). Similarly, rabbit neonates treat the mixture differently, at least in part, from its components. In the present study, we asked if the properties of the EI.EM mixture extend to an influential invertebrate model, the honey bee Apis mellifera. We used appetitive conditioning of the proboscis extension response to evaluate how bees perceive the EI.EM mixture. In a first experiment, we measured...
Journal of Comparative Physiology A, 2010
Birth is part of a continuum and is a major developmental change. Newborns need to adapt rapidly ... more Birth is part of a continuum and is a major developmental change. Newborns need to adapt rapidly to the environment in terms of physiology and behaviour, and ability to locate the maternal source of milk is vital. Mechanisms have evolved resulting in the emission of olfactory cues by the mother and the processing of these cues by the young. Here, we focus on some sensory, cognitive and behavioural strategies developed by the European rabbit (Oryctolagus cuniculus) that optimize the early development of offspring. In this species, chemosensory communication between the mother and young plays a critical role in eliciting adaptive neonatal responses. In particular, lactating females release a molecule, the mammary pheromone, which has several functional impacts. It triggers orocephalic responses involved in the quick localization of nipples and sucking. Moreover, this unconditioned signal promotes rapid appetitive learning of novel odorants, acting as a potent organizer of neonatal cognition. The mammary-pheromoneinduced odour memory requires consolidation/reconsolidation processes to be maintained in the long term. Finally, as this mode of conditioning also promotes learning of mixtures of odorants, it supports investigations related to the capacity of neonatal olfaction to extract biological value from the complex environment.
Transnatal olfactory continuity in the rabbit: Behavioral evidence and short-term consequence of its disruption
Developmental Psychobiology, 2002
This study investigates the role of prenatal odor learning on postnatal adaptive orientation resp... more This study investigates the role of prenatal odor learning on postnatal adaptive orientation responses in the newborn rabbit. Preference tests revealed that pups are equally attracted to the odors of placentae and colostrum (Experiments 1-4), suggesting that an odor continuity may exist between the fetal and neonatal environments. To test some predictions derived from this hypothesis, we manipulated the odor of the diet of pregnant-lactating does to control the chemical niches of their perinates. Fetuses exposed in this way to the odor of cumin (C) were selectively attracted as neonates to the odor of pure C (Experiment 6). Prenatal exposure to C also was followed, to a certain extent, by enhanced attraction to C odor in the placenta or colostrum from females which had consumed it (Experiments 5 & 7). Finally, the functional implications of perinatal odor continuity were tested by disrupting it. The odor component of the feto-neonatal transitional environment revealed indeed to affect the ability of certain pups to gain colostrum and milk at the very first sucking opportunities (Experiment 8).
animal, 2007
Newborn rabbits depend on a daily nursing interaction with the mother to gain milk and to survive... more Newborn rabbits depend on a daily nursing interaction with the mother to gain milk and to survive. During this interaction, they localise and seize the nipples displaying a typical behaviour triggered by maternal odour cues. The mammary pheromone constitutes such a signal in domestic rabbits: it elicits sucking-related movements in more than 90% of the pups. However, some newborns remain unresponsive to the presentation of the pheromone, even pups apparently healthy and highly motivated to suck. The main goal of the present study was therefore to explore the link between the unresponsiveness of rabbit pups to the mammary pheromone and their growth and survival in breeding conditions. To that end, 293 newborns from 30 litters were tested for their head searching-oral grasping responses to the mammary pheromone on days 1 and 3, and their milk intake and mortality were followed up from days 1 to 21. It was hypothesised that unresponsive newborns would have subsequent difficulties in fi...
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Papers by Gérard Coureaud