Subsequent and simultaneous electrophysiological investigation of the retina and the visual cortex in neurodegenerative and psychiatric diseases: what are the forecasts for the medicine of tomorrow?

Visual electrophysiological deficits have been reported in neurodegenerative disorders as well as in mental disorders. Such alterations have been mentioned in both the retina and the cortex, notably affecting the photoreceptors, retinal ganglion cells (RGCs) and the primary visual cortex. Interestingly, such impairments emphasize the functional role of the visual system. For this purpose, the present study reviews the existing literature with the aim of identifying key alterations in electroretinograms (ERGs) and visual evoked potentials electroencephalograms (VEP-EEGs) of subjects with neurodegenerative and psychiatric disorders. We focused on psychiatric and neurodegenerative diseases due to similarities in their neuropathophysiological mechanisms. Our research focuses on decoupled and coupled ERG/VEP-EEG results obtained with black-and-white checkerboards or low-level visual stimuli. A decoupled approach means recording first the ERG, then the VEP-EEG in the same subject with the same visual stimuli. The second method means recording both ERG and VEP-EEG simultaneously in the same participant with the same visual stimuli. Both coupled and decoupled results were found, indicating deficits mainly in the N95 ERG wave and the P100 VEP-EEG wave in Parkinson’s, Alzheimer’s, and major depressive disorder. Such results reinforce the link between the retina and the visual cortex for the diagnosis of psychiatric and neurodegenerative diseases. With that in mind, medical devices using coupled ERG/VEP-EEG measurements are being developed in order to further investigate the relationship between the retina and the visual cortex. These new techniques outline future challenges in mental health and the use of machine learning for the diagnosis of mental disorders, which would be a crucial step toward precision psychiatry

New density estimates of a threatened sifaka species (Propithecus coquereli) in Ankarafantsika National Park

Propithecus coquereli is one of the last sifaka species for which no reliable and extensive density estimates are yet available. Despite its endangered conservation status [IUCN, 2012] and recognition as a flagship species of the northwestern dry forests of Madagascar, its population in its last main refugium, the Ankarafantsika National Park (ANP), is still poorly known. Using line transect distance sampling surveys we estimated population density and abundance in the ANP. Furthermore, we investigated the effects of road, forest edge, river proximity and group size on sighting frequencies, and density estimates. We provide here the first population density estimates throughout the ANP. We found that density varied greatly among surveyed sites (from 5 to ∼100 ind/km2) which could result from significant (negative) effects of road, and forest edge, and/or a (positive) effect of river proximity. Our results also suggest that the population size may be ∼47,000 individuals in the ANP, hinting that the population likely underwent a strong decline in some parts of the Park in recent decades, possibly caused by habitat loss from fires and charcoal production and by poaching. We suggest community-based conservation actions for the largest remaining population of Coquerel's sifaka which will (i) maintain forest connectivity; (ii) implement alternatives to deforestation through charcoal production, logging, and grass fires; (iii) reduce poaching; and (iv) enable long-term monitoring of the population in collaboration with local authorities and researchers.Optimus!Alive- IGC fellowship, FCT fellowship: (SFRH/BD/64875/2009), University of Mahajanga, Groupement de Recherche International (GDRI), "Laboratoire d'Excellence" (LABEX) entitled TULIP (ANR-10-LABX-41), the Rufford Small Grant Foundation grant: (10941-1)

Pourquoi et comment soigner plus précocement les troubles psychotiques?

Chronic psychosis, as for instance schizophrenia, usually begins in young adulthood and may cause severe disability. It causes a mean loss of life expectancy of 22 years. Actual models of psychosis do not trace the beginning of psychosis to the first franc psychotic episode only, but to earlier symptoms. In a classical health system only considering the first psychotic episode, the mean duration of untreated illness (DUI) can last several years. Yet this DUI has a direct impact on the prognosis of the disease. Actual international recommendations prescribe to early detect and treat at risk mental states of psychosis, thus reducing DUI. Such an attitude also helps the patient to integrate care in a moment where she/he is fully in condition to consent and to adhere. Generalist practitioners are crucial actors of early detection. We describe here simple and standardized tools helping early detection of high-risk mental states of psychosis in primary care and the appropriate attitude to do it properly. Numerous countries have developed early detection and treatment centers for psychosis. It has been established that such interventions clearly decrease the risk of transition towards chronic psychosis and improve the prognosis. These recent data about early detection and intervention in psychosis are a major step forward in psychiatry practice. It is now necessary to largely develop such actions in France

Are mixed diets beneficial for the welfare of captive axolotls (Ambystoma mexicanum)? Effects of feeding regimes on growth and behavior

Good nutritional husbandry is crucial to maintain high welfare standards in captive animals. Both direct effects of diet on growth, development, and maintenance and indirect effects of feeding regimes on behavior may be important. Despite this, many questions remain as to how we should best feed many of the species that are commonly kept in captivity. There is a great deal of speculation among animal keepers as to issues such as whether a mixed diet is better than an invariant one, but little research is available to inform this question. In this study, we investigate the impact of mixed versus invariant diets on growth and behavior in the axolotl (. Ambystoma mexicanum), an aquatic amphibian of severe conservation concern that is frequently maintained in captive collections. We then use our results to provide advice on feeding management in the context of improved welfare. We maintained juvenile axolotls under 1 of 3 "diets" (feeding regimes): bloodworm (invariant), Daphnia (invariant), and alternating these 2 prey items between feeds (mixed). Morphologic and behavioral data were collected over a period of 15weeks and analyzed using generalized linear mixed models to determine whether our feeding treatments influenced growth and behavior. We find that axolotls grew fastest on our bloodworm diet and slowest on our Daphnia diet, with a mixed feeding regime leading to intermediate growth rates. Diet treatment did not significantly influence our measured behaviors, but feeding and locomotion events were more frequent (and resting less frequent) on feeding days than nonfeeding days. These data suggest that providing a mixed diet is not necessarily beneficial to either growth or welfare of captive animals. In the case of axolotls, an invariant diet of bloodworm should increase growth rates, but the diet (mixed vs. invariant) does not influence behavior. Overall, our results suggest that mixed diets in themselves may not be beneficial to the growth or welfare of axolotls as compared with a high-quality invariant diet

Delivering patient decision aids on the Internet: definitions, theories, current evidence, and emerging research areas

BACKGROUND: In 2005, the International Patient Decision Aids Standards Collaboration identified twelve quality dimensions to guide assessment of patient decision aids. One dimension—the delivery of patient decision aids on the Internet—is relevant when the Internet is used to provide some or all components of a patient decision aid. Building on the original background chapter, this paper provides an updated definition for this dimension, outlines a theoretical rationale, describes current evidence, and discusses emerging research areas. METHODS: An international, multidisciplinary panel of authors examined the relevant theoretical literature and empirical evidence through 2012. RESULTS: The updated definition distinguishes Internet-delivery of patient decision aids from online health information and clinical practice guidelines. Theories in cognitive psychology, decision psychology, communication, and education support the value of Internet features for providing interactive information and deliberative support. Dissemination and implementation theories support Internet-delivery for providing the right information (rapidly updated), to the right person (tailored), at the right time (the appropriate point in the decision making process). Additional efforts are needed to integrate the theoretical rationale and empirical evidence from health technology perspectives, such as consumer health informatics, user experience design, and human-computer interaction. Despite Internet usage ranging from 74% to 85% in developed countries and 80% of users searching for health information, it is unknown how many individuals specifically seek patient decision aids on the Internet. Among the 86 randomized controlled trials in the 2011 Cochrane Collaboration’s review of patient decision aids, only four studies focused on Internet-delivery. Given the limited number of published studies, this paper particularly focused on identifying gaps in the empirical evidence base and identifying emerging areas of research. CONCLUSIONS: As of 2012, the updated theoretical rationale and emerging evidence suggest potential benefits to delivering patient decision aids on the Internet. However, additional research is needed to identify best practices and quality metrics for Internet-based development, evaluation, and dissemination, particularly in the areas of interactivity, multimedia components, socially-generated information, and implementation strategies

Expert range maps of global mammal distributions harmonised to three taxonomic authorities

AimComprehensive, global information on species' occurrences is an essential biodiversity variable and central to a range of applications in ecology, evolution, biogeography and conservation. Expert range maps often represent a species' only available distributional information and play an increasing role in conservation assessments and macroecology. We provide global range maps for the native ranges of all extant mammal species harmonised to the taxonomy of the Mammal Diversity Database (MDD) mobilised from two sources, the Handbook of the Mammals of the World (HMW) and the Illustrated Checklist of the Mammals of the World (CMW).LocationGlobal.TaxonAll extant mammal species.MethodsRange maps were digitally interpreted, georeferenced, error-checked and subsequently taxonomically aligned between the HMW (6253 species), the CMW (6431 species) and the MDD taxonomies (6362 species).ResultsRange maps can be evaluated and visualised in an online map browser at Map of Life (mol.org) and accessed for individual or batch download for non-commercial use.Main conclusionExpert maps of species' global distributions are limited in their spatial detail and temporal specificity, but form a useful basis for broad-scale characterizations and model-based integration with other data. We provide georeferenced range maps for the native ranges of all extant mammal species as shapefiles, with species-level metadata and source information packaged together in geodatabase format. Across the three taxonomic sources our maps entail, there are 1784 taxonomic name differences compared to the maps currently available on the IUCN Red List website. The expert maps provided here are harmonised to the MDD taxonomic authority and linked to a community of online tools that will enable transparent future updates and version control

Evaluation of the impact of the regular cannabis use on the retinal functioning by the measure of the electroretinography

Un des obstacles majeurs de la recherche en neurosciences est la difficulté d’accéder de manière directe au fonctionnement du cerveau afin de comprendre les mécanismes biologiques à l’origine des dysfonctionnements cérébraux dans les troubles psychiatriques. En tant qu’extension anatomique et développementale du système nerveux central, la rétine pourrait permettre d’offrir un accès indirect aux fonctions neurologiques cérébrales. Ainsi, l’investigation de la fonction rétinienne apporte l’unique opportunité d’étudier de manière objective un réseau neuronal complexe présentant des similarités avec celui du cerveau. Le cannabis est une substance neurotoxique identifiée comme modulant la transmission synaptique cérébrale par l’intermédiaire du système cannabinoïde mais les mécanismes précis à l’origine de ces anomalies sont peu connus. La première partie de ce travail consiste à présenter les bases neurobiologiques et les hypothèses physiopathologiques justifiant l’étude de la fonction rétinienne chez les usagers de cannabis, en se basant sur la présence du système cannabinoïde dans la rétine et son implication dans la régulation de la libération synaptique de neurotransmetteurs. La seconde partie discute l’intérêt de l’étude de la fonction rétinienne dans la recherche en psychiatrie avec des méthodes électrophysiologiques. Enfin, la dernière partie présente les dysfonctions rétiniennes présentes chez les usagers de cannabis, après un usage aigu ou régulier, évaluées par les techniques électrophysiologiques comme l’électrorétinogramme. Toutes ces données renforcent la pertinence de la rétine comme site d’investigation du cerveau et ouvrent éventuellement la perspective au développement de marqueurs fonctionnelsOne of major obstacles in neuroscience research is the difficulty of directly accessing the brain function to understand the biological mechanisms underlying brain dysfunctions in psychiatric disorders. As an anatomical and developmental extension of the central nervous system, the retina could afford to offer an indirect access to brain neurological functions. Investigating the retinal function provides the unique opportunity to study in an objective way a complex neuronal network which shares similar properties with the brain. Cannabis is a neurotoxic substance identified as modulating brain synaptic transmission through the cannabinoid system, but the precise mechanisms underpinning these anomalies are poorly understood. The first part of this work is dedicated to present the neurobiological basis and pathophysiological hypotheses justifying the study of retinal function in cannabis users and is based on the presence of the cannabinoid system in the retina and its involvement in the regulation of synaptic neurotransmission. The second part discusses the interest of the study of retinal function with electrophysiological methods in psychiatric research. The last part presents the retinal dysfunctions detected in cannabis users, after acute or regular use, and assessed by electrophysiological techniques such as electroretinogram. All these data reinforce the relevance of the retina as a site of brain investigation and possibly open the prospect for the development of functional marker

Évaluation de l’impact de l’usage régulier de cannabis sur le fonctionnement rétinien par la mesure de l’électrorétinogramme

One of major obstacles in neuroscience research is the difficulty of directly accessing the brain function to understand the biological mechanisms underlying brain dysfunctions in psychiatric disorders. As an anatomical and developmental extension of the central nervous system, the retina could afford to offer an indirect access to brain neurological functions. Investigating the retinal function provides the unique opportunity to study in an objective way a complex neuronal network which shares similar properties with the brain. Cannabis is a neurotoxic substance identified as modulating brain synaptic transmission through the cannabinoid system, but the precise mechanisms underpinning these anomalies are poorly understood. The first part of this work is dedicated to present the neurobiological basis and pathophysiological hypotheses justifying the study of retinal function in cannabis users and is based on the presence of the cannabinoid system in the retina and its involvement in the regulation of synaptic neurotransmission. The second part discusses the interest of the study of retinal function with electrophysiological methods in psychiatric research. The last part presents the retinal dysfunctions detected in cannabis users, after acute or regular use, and assessed by electrophysiological techniques such as electroretinogram. All these data reinforce the relevance of the retina as a site of brain investigation and possibly open the prospect for the development of functional markersUn des obstacles majeurs de la recherche en neurosciences est la difficulté d’accéder de manière directe au fonctionnement du cerveau afin de comprendre les mécanismes biologiques à l’origine des dysfonctionnements cérébraux dans les troubles psychiatriques. En tant qu’extension anatomique et développementale du système nerveux central, la rétine pourrait permettre d’offrir un accès indirect aux fonctions neurologiques cérébrales. Ainsi, l’investigation de la fonction rétinienne apporte l’unique opportunité d’étudier de manière objective un réseau neuronal complexe présentant des similarités avec celui du cerveau. Le cannabis est une substance neurotoxique identifiée comme modulant la transmission synaptique cérébrale par l’intermédiaire du système cannabinoïde mais les mécanismes précis à l’origine de ces anomalies sont peu connus. La première partie de ce travail consiste à présenter les bases neurobiologiques et les hypothèses physiopathologiques justifiant l’étude de la fonction rétinienne chez les usagers de cannabis, en se basant sur la présence du système cannabinoïde dans la rétine et son implication dans la régulation de la libération synaptique de neurotransmetteurs. La seconde partie discute l’intérêt de l’étude de la fonction rétinienne dans la recherche en psychiatrie avec des méthodes électrophysiologiques. Enfin, la dernière partie présente les dysfonctions rétiniennes présentes chez les usagers de cannabis, après un usage aigu ou régulier, évaluées par les techniques électrophysiologiques comme l’électrorétinogramme. Toutes ces données renforcent la pertinence de la rétine comme site d’investigation du cerveau et ouvrent éventuellement la perspective au développement de marqueurs fonctionnel