Ecole Pratique des Hautes Etudes
Section des sciences de la vie et de la terre
Le sommaire de ce numéro https://www.john-libbey-eurotext.fr/fr/ revues/medecine/nrp/sommaire.md?type= text.html Montrouge, le 15/05/2013 Fanny Dégeilh Vous trouverez ci-après le tiréà part de votre article au formatélectronique (pdf) :... more
Le sommaire de ce numéro https://www.john-libbey-eurotext.fr/fr/ revues/medecine/nrp/sommaire.md?type= text.html Montrouge, le 15/05/2013 Fanny Dégeilh Vous trouverez ci-après le tiréà part de votre article au formatélectronique (pdf) : Altérations mnésiques dans l'état de stress post-traumatique : résultats comportementaux et neuro-imagerie paru dans Revue de neuropsychologie, 2013, Volume 5, Numéro 1 John Libbey Eurotext Ce tiréà part numérique vous est délivré pour votre propre usage et ne peutêtre transmisà des tiers qu'à des fins de recherches personnelles ou scientifiques. En aucun cas, il ne doit faire l'objet d'une distribution ou d'une utilisation promotionnelle, commerciale ou publicitaire. Tous droits de reproduction, d'adaptation, de traduction et de diffusion réservés pour tous pays. Correspondance : B. Guillery-Girard © John Libbey Eurotext, 2013 T i r é à p a r t a u t e u r REVUE DE NEUROPSYCHOLOGIE NEUROSCIENCES COGNITIVES ET CLINIQUES 46
- by Armelle Viard and +4
- •
Please cite this article in press as: Guillery-Girard, B., et al. ''Disorganized in time'': Impact of bottom-up and top-down negative emotion generation on memory formation among healthy and traumatized adolescents. J. Physiol. (2013),... more
Please cite this article in press as: Guillery-Girard, B., et al. ''Disorganized in time'': Impact of bottom-up and top-down negative emotion generation on memory formation among healthy and traumatized adolescents. J. Physiol. (2013), https://dx.
- by Jacques Dayan and +3
- •
- Emotion, Attention, Adolescent, Episodic Memory
The human anterior cingulate cortex (ACC), which is active during conflict-monitoring tasks, is thought to participate with prefrontal cortices in a distributed network for conscious self-regulation. This hypothesis predicts that... more
The human anterior cingulate cortex (ACC), which is active during conflict-monitoring tasks, is thought to participate with prefrontal cortices in a distributed network for conscious self-regulation. This hypothesis predicts that conflict-related ACC activation should occur only when the conflicting stimuli are consciously perceived. To dissociate conflict from consciousness, we measured the behavioral and brain imaging correlates of a motor conflict induced by task-irrelevant subliminal or conscious primes. The same task was studied in normal subjects and in patients with schizophrenia in whom the ACC and prefrontal cortex are thought to be dysfunctional. Conscious, but not subliminal, conflict affected anterior cingulate activity in normal subjects. Furthermore, patients with schizophrenia, who exhibited a hypoactivation of the ACC and other frontal, temporal, hippocampal, and striatal sites, showed impaired conscious priming but normal subliminal priming. Those findings suggest that subliminal conflicts are resolved without ACC contribution and that the ACC participates in a distributed conscious control network that is altered in schizophrenia.
- by Eric Artiges and +1
- •
- Brain Imaging, Schizophrenia, Behavior, Anterior Cingulate
Background. Failure to resist chronic obsessive-compulsive symptoms may denote an altered state of cognitive control. We searched for the cerebral regions engaged in this dysfunction.
Objective: Altered anterior cingulate cortex activity has been consistently detected by functional imaging in schizophrenia patients. In the present study, we hypothesized that the detection of such local hypoactivity varies when the... more
Objective: Altered anterior cingulate cortex activity has been consistently detected by functional imaging in schizophrenia patients. In the present study, we hypothesized that the detection of such local hypoactivity varies when the subjects' local gyrification is monitored. Using a group-statistical approach, we investigated whether the presence or absence of a paracingulate sulcus (PCS) does influence the detection of the activation patterns in the cognitive division of the anterior cingulate cortex (ACcd). Method: fMRI data were acquired using an event-related paradigm during a task involving both priming and interference between stimuli. In the fMRI dataset collected from 13 schizophrenia patients and 16 healthy subjects, subgroups were defined according to the presence or absence of a PCS. Regional activations during interference between stimuli were examined in the ACcd of each hemisphere, using for each region of interest both voxel-based random-effects and non-parametric analyses. Results: ACcd activation was left-sided in healthy subjects with a PCS, and right-sided in healthy subjects devoid of a PCS. ACcd activations were detected bilaterally in schizophrenia patients with a PCS, whereas left ACcd was deactivated in patients without a PCS. Subgroup comparisons revealed no difference between healthy subjects with a PCS and patients with a PCS, whereas in the subgroups devoid of PCS, the patients exhibited a bilateral ACcd hypoactivation relative to healthy subjects. Conclusions: PCS presence or absence influences the detection of ACcd activations in group-analysis of schizophrenia patients. D
Semantic dementia (SD) is characterized by gradual loss of semantic memory. While episodic autobiographical memory seems relatively preserved, behavioral studies suggest that episodic future thinking is impaired. We used fMRI to measure... more
Semantic dementia (SD) is characterized by gradual loss of semantic memory. While episodic autobiographical memory seems relatively preserved, behavioral studies suggest that episodic future thinking is impaired. We used fMRI to measure brain activity in four SD patients (JPL, EP, LL, EG) while they envisioned future events and remembered personal past events. Twelve healthy elders served as controls. Episodic quality, emotion, mental imagery and level of consciousness (via remember/know judgements) were checked at debriefing. We analyzed the future compared to the past for each patient. All patients presented lateral temporal atrophy, but varied in terms of frontal and anterior hippocampal atrophy. Patient JPL presented atrophy in bilateral superior medial frontal gyri and left anterior hippocampus and was unable to engage in episodic future thinking, despite hyperactivations in frontal and occipital regions. Patient EP presented no atrophy in the anterior hippocampus, but atrophy in bilateral superior medial frontal gyrus and had difficulties to engage in episodic future thinking. Patient LL presented atrophy in left anterior hippocampus, but hyperactivated its right counterpart for future compared to past thinking, permitting her to project efficiently in the future in an episodic way. Patient EG presented no atrophy in the superior medial frontal gyri or anterior hippocampi and was able to engage in episodic future thinking. Altogether, patients' future projections differed depending on the severity and localization of their atrophy. The functional integrity of bilateral superior medial frontal gyri and anterior hippocampus appear crucial for episodic future thinking: atrophy of both structures strongly impairs future projection, while integrity of these structures or hyperactivation of residual tissue normalizes episodic future projection. Citation: Viard A, Piolino P, Belliard S, de La Sayette V, Desgranges B, et al. (2014) Episodic Future Thinking in Semantic Dementia: A Cognitive and fMRI Study. PLoS ONE 9(10): e111046.
Imagerie fonctionnelle de la mémoire aux stades précoces de la maladie d'Alzheimer : dysfonctionnements et mécanismes compensatoires Functional imaging studies of memory in early Alzheimer's disease: dysfunction and compensatory... more
Imagerie fonctionnelle de la mémoire aux stades précoces de la maladie d'Alzheimer : dysfonctionnements et mécanismes compensatoires Functional imaging studies of memory in early Alzheimer's disease: dysfunction and compensatory mechanisms Résumé Depuis une quinzaine d'années, de nombreux travaux d'imagerie en activation ont été entrepris dans la maladie d'Alzheimer et dans la phase prédémentielle de la maladie, c'est-à-dire chez des patients répondant aux critères de troubles cognitifs légers. Ces études permettent d'examiner les substrats cérébraux des troubles cognitifs et d'analyser les signes précurseurs de la maladie. Elles servent également à mettre en évidence les mécanismes de compensation mis en place pour faire face aux anomalies neuropathologiques. Du fait de son atteinte privilégiée et précoce, la mémoire, et notamment la mémoire épisodique, a tout particulièrement suscité l'intérêt des chercheurs. Cet article se propose de synthétiser les principales données, obtenues auprès de patients et concernant la mémoire épisodique, la mémoire sémantique et la mémoire de travail. Il ressort principalement des résultats une altération fonctionnelle de structures clés associées à chacun de ces systèmes mnésiques. Le dysfonctionnement affecte tant les activations que les désactivations induites par des tâches cognitives. En outre, des phénomènes de plasticité cérébrale sont observés. Ils pourraient refléter la mise en place de processus compensatoires. Aux stades prédémentiels, ces mécanismes reposeraient surtout sur des structures attendues compte tenu des processus en jeu. L'entrée dans la démence se traduirait par des modifications compensatoires moins spécifiques et plus distribuées.
Cancer involves stressful events. One aspect of cognition that is impacted by stress is episodic autobiographical memory (EAM). EAM is intimately linked to self-representation. Some studies have revealed impairment of EAM in patients with... more
Cancer involves stressful events. One aspect of cognition that is impacted by stress is episodic autobiographical memory (EAM). EAM is intimately linked to self-representation. Some studies have revealed impairment of EAM in patients with breast cancer in remission. Yet, these studies failed to differentiate between the influence of adjuvant treatments and that of psychosocial factors. We therefore assessed the psychological impact of breast cancer diagnosis on EAM and self-representation profiles prior to any adjuvant treatment. Patients newly diagnosed with breast cancer (n=31) and women without any history of cancer (n=49) were compared on state anxiety, EAM and its emotional characteristics, and self-representations. The most anxious patients retrieved fewer emotional details for memories than the controls, and had lower self-representation scores than the least anxious patients, who had no deficits in emotional detail retrieval. Our results revealed distinct EAM profiles for pa...
Conservation plans of European amphibians usually take into account: (1) species in dramatic decline due to a series of humaninduced factors, and (2) species with a narrow distribution area and/or particular ecological requirements.... more
Conservation plans of European amphibians usually take into account: (1) species in dramatic decline due to a series of humaninduced factors, and (2) species with a narrow distribution area and/or particular ecological requirements. Salamandra lanzai belongs to the second group, being limited to the SW Alps. Furthermore, it is a high altitude amphibian, living in sites above 1200 m, and it is also a unique endemic vertebrate of the Alps. We here summarise information regarding its distribution and ecology to be interpreted for conservation. In this sense, we also provide new data regarding the age structure of a recently studied low altitude population in the Germanasca Valley. We then compare this population (exemplified as "low altitude population") to a population living at 2200 m in the Guil Valley (example of a "high altitude population"). The knowledge obtained on these different life-history traits has allowed us to devise an age-structured model useful in identifying the main demographic parameters which influence population growth. Some simulations are conducted with parameters obtained in populations exposed to contrasting environments. The results are then used to propose guidelines for conservation.
Fifty individuals of the endemic Alpine salamander, Salamandra atra , representing 13 populations throughout the range of the two currently recognized subspecies, atra and aurorae , were examined for sequence variation in a large portion... more
Fifty individuals of the endemic Alpine salamander, Salamandra atra , representing 13 populations throughout the range of the two currently recognized subspecies, atra and aurorae , were examined for sequence variation in a large portion (1050 bp) of the mitochondrial cytochrome b gene. We revealed a large number of mitochondrial DNA (mtDNA) haplotypes (10). Interpopulation sequence divergence was very low, ranging from 0 to 3.1%. The relationships among haplotypes were poorly resolved. The divergence time estimate between several mtDNA haplotypes suggested a pre-Pleistocene differentiation approximately 3 million years ago. Moreover, the impact of the Pleistocene glaciations on the phylogeographical patterns appears to have been secondary, although a somewhat reduced genetic variability was found in populations living in areas that were directly affected by the glaciation.
We describe the age structures of two neighbouring terrestrial salamander populations. The skeletochrono- logical method was also used on larvae in utero and on new-born individuals. The age of adults was 8-24 years in population A, while... more
We describe the age structures of two neighbouring terrestrial salamander populations. The skeletochrono- logical method was also used on larvae in utero and on new-born individuals. The age of adults was 8-24 years in population A, while males reached maturity at 3-5 years old and the youngest females were 6 years old in population B. Males and females from population
The pattern of genetic differentiation of the endemic alpine salamander, Salamandra atra, has been studied using amplified fragment length polymorphism (AFLP) from 11 populations throughout the range of the two currently recognized... more
The pattern of genetic differentiation of the endemic alpine salamander, Salamandra atra, has been studied using amplified fragment length polymorphism (AFLP) from 11 populations throughout the range of the two currently recognized subspecies, atra and aurorae. Five different primer combinations produced 706 bands and were analyzed by constructing a phylogenetic tree using NJ and principal component analysis. Significant genetic variation was revealed by AFLP between and within populations but, our results show a lack of genetic structure. AFLP markers seems to be unsuitable to investigate complex and recent diversification.
Biological invasions and land-use changes are two major causes of the global modifications of biodiversity. Habitat suitability models are the tools of choice to predict potential distributions of invasive species. Although land-use is a... more
Biological invasions and land-use changes are two major causes of the global modifications of biodiversity. Habitat suitability models are the tools of choice to predict potential distributions of invasive species. Although land-use is a key driver of alien species invasions, it is often assumed that land-use is constant in time. Here we combine historical and present day information, to evaluate whether land-use changes could explain the dynamic of invasion of the American bullfrog Rana catesbeiana ( 5 Lithobathes catesbeianus) in Northern Italy, from the 1950s to present-day. We used MAXENT to build habitat suitability models, on the basis of past (1960s, 1980s) and present-day data on land-uses and species distribution. For example, we used models built using the 1960s data to predict distribution in the 1980s, and so on. Furthermore, we used land-use scenarios to project suitability in the future. Habitat suitability models predicted well the spread of bullfrogs in the subsequent temporal step. Models considering land-use changes predicted invasion dynamics better than models assuming constant land-use over the last 50 years. Scenarios of future land-use suggest that suitability will remain similar in the next years. Habitat suitability models can help to understand and predict the dynamics of invasions; however, land-use is not constant in time: land-use modifications can strongly affect invasions; furthermore, both land management and the suitability of a given land-use class may vary in time. An integration of land-use changes in studies of biological invasions can help to improve management strategies.
Les variations intra-et interpopulationnelles des traits d'histoire de vie chez les amphibiens à grande aire de répartition font l'objet d'une attention soutenue. Pour de nombreux problèmes (eg les changements climatiques,... more
Les variations intra-et interpopulationnelles des traits d'histoire de vie chez les amphibiens à grande aire de répartition font l'objet d'une attention soutenue. Pour de nombreux problèmes (eg les changements climatiques, variations clinales, conservation), cette information est ...
- by Claude Miaud and +1
- •
Polycyclic Aromatic Hydrocarbons (PAHs) are damaging for aquatic organisms such as amphibians. In this study, toxicity of a mixture of three PAHs (naphthalene (2 rings), phenanthrene (3 rings) and pyrene (4 rings)) was tested on Common... more
Polycyclic Aromatic Hydrocarbons (PAHs) are damaging for aquatic organisms such as amphibians. In this study, toxicity of a mixture of three PAHs (naphthalene (2 rings), phenanthrene (3 rings) and pyrene (4 rings)) was tested on Common frog (Rana temporaria) embryos. The protective role of the jelly coat surrounding the eggs was studied by exposing embryos with and without jelly coat to PAHs dissolved in an aqueous solution without organic solvent. Results showed that the mixture of these three PAHs significantly increase embryonic mortality rate after a few hours of exposure. Embryos with jelly coat tend to suffer a lower mortality rate than embryos without jelly. The jelly surrounding eggs is filled by water of the breeding site, which can contain pollutants. Because jelly characteristics vary among species, sensitivity to environmental pollutants and levels of embryonic protection could be different among amphibian species.
The isolation of animal populations due to urban activities provides a useful framework for studying the consequences of landscape fragmentation. We studied a population of natterjack toads (Bufo calamita) in an urban park near Paris,... more
The isolation of animal populations due to urban activities provides a useful framework for studying the consequences of landscape fragmentation. We studied a population of natterjack toads (Bufo calamita) in an urban park near Paris, France. In 2001 and 2002 we used radio-tracking to estimate the terrestrial movements of adults around their breeding sites. Twenty-four toads were equipped with internal transmitters in 2001 to record movements during and after the breeding period. In 2002, 19 males were released at 300 and 380 meters from their breeding ponds. Natterjack toad movements around and outside their breeding ponds were reduced compared to previous observations on this species. The only exchanges that were observed occurred between closely neighbouring breeding sites. During a translocation experiment in 2002, 58% of the displaced males returned to their site of capture and this happened mainly during the breeding period. The remaining 42% stayed close to the release site. There was no exchange of males between distant breeding sites. Natterjack toad conservation needs to take into account the high fidelity to a breeding site and the reduced breeding dispersal and homing ability of these animals. Conservation biology in urban landscapes constitutes a specific urban ecology with specific concepts such as 'population area'. Information from this study can assist land managers in establishing protected areas of high habitat quality around breeding ponds in urban areas, and managing parks for the protection of amphibian populations, particularly by facilitating exchanges between available areas.
A l'échelle mondiale, les amphibiens subissent d'importants déclins de populations dûs à la Chytridiomycose, une maladie émergente provoquée par le champignon Batrachochytrium dendrobatidis (noté par la suite Bd). Des déclins... more
A l'échelle mondiale, les amphibiens subissent d'importants déclins de populations dûs à la Chytridiomycose, une maladie émergente provoquée par le champignon Batrachochytrium dendrobatidis (noté par la suite Bd). Des déclins catastrophiques ont été observés en Australie, Amérique du Nord, Amérique centrale, Amérique du Sud et dans les Caraïbes. En Europe, des mortalités massives associées à Bd ont été observées en Espagne et en France, mais nos connaissances sur la prévalence de Bd en Europe ne sont encore que fragmentaires.
- by Claude Miaud
- •