Search results for "Neurone"
showing 10 items of 42 documents
Impact of perturbations on the neuron response
2017
International audience; We propose an overview of the effects of deterministic and stochastic perturbations on the response of a neuron. Our study is based on numerical simulations and experiments with an elementary neural circuit. We use different excitations to highlight various phenomena such as Mode locking, Vibrational Resonance, Ghost Stochastic Resonance... We close the study with a lattice of coupled circuit.
Mouse olfactory sensory neurons' plasticity induced by postnatal odorant exposure: anatomical, molecular and physiological consequences
2012
Mouse olfactory sensory neurons' plasticity induced by postnatal odorant exposure: anatomical, molecular and physiological consequences. 8. FENS forum of neuroscience
Cholestérol-24S-hydroxylase (CYP46A1) et homéostasie du cholestérol dans la rétine en conditions physiologiques et pathologiques
2012
Cholesterol is the major sterol found in the retina. In its free form, cholesterol is present in all cell layers of the retina, whereas cholesteryl esters mainly accumulate at the basement of the retinal pigment epithelium. The intrinsic capacity of the retina to synthetize cholesterol appears limited. Some extra-retinal pathways actively participate to cholesterol uptake to the retina. Müller glial cells may contribute to cholesterol supply to retinal neurons, especially for synaptic formation. Cholesterol accumulation or conversely deficiency have deleterious consequences on neuron survival. Maintaining the equilibrium between cholesterol supply and neosynthesis in the one hand and choles…
Microglia and α-synuclein implication in Parkinson's disease
2011
Age-related neurodegenerative disorders like Parkinson’s disease take an enormous toll on individuals and on society. Despite extensive efforts, Parkinson’s disease remains incurable and only very limited treatments exist. Indeed, Parkinson’s pathogenesis is still not clear and research on its molecular mechanisms is ongoing. In this study, we focused our interest on two abnormal events occurring in Parkinson’s patients, namely α-synuclein aggregation and microglial activation. We first investigated α-synuclein and its abnormal polymerisation. For this purpose, we developed novel methods, which allowed the in vitro production of different types of α-synuclein oligomers. Using highly sensiti…
Performances of neural networks for deriving LAI estimates from existing CYCLOPES and MODIS products
2008
International audience; This paper evaluates the performances of a neural network approach to estimate LAI from CYCLOPES and MODIS nadir normalized reflectance and LAI products. A data base was generated from these products over the BELMANIP sites during the 2001-2003 period. Data were aggregated at 3 km x 3 km, resampled at 1/16 days temporal frequency and filtered to reject outliers. VEGETATION and MODIS reflectances show very consistent values in the red, near infrared and short wave infrared bands. Neural networks were trained over part of this data base for each of the 6 MODIS biome classes to retrieve both MODIS and CYCLOPES LAI products. Results show very good performances of neural …
An Intercellular Flow of Glutathione Regulated by Interleukin 6 Links Astrocytes and the Liver in the Pathophysiology of Amyotrophic Lateral Sclerosis
2021
Oxidative stress has been proposed as a major mechanism of damage to motor neurons associated with the progression of amyotrophic lateral sclerosis (ALS). Astrocytes are the most numerous glial cells in the central nervous system and, under physiological conditions, protect neurons from oxidative damage. However, it is uncertain how their reactive phenotype may affect motor neurons during ALS progression. In two different ALS mouse models (SOD1G93A and FUS-R521C), we found that increased levels of proinflammatory interleukin 6 facilitate glutathione (GSH) release from the liver to blood circulation, which can reach the astrocytes and be channeled towards motor neurons as a mechanism of anti…
L'iconicité phonologique dans les neurosciences cognitives et dans la tradition linguistique française
2014
A significant part of the recent research in language neuropsychology and neurophysiology seems to revive the long-standing hypothesis of an originally motivated relations hip between phonetics and semantics. Even if phonological iconicity is a long neglected subject in linguistics, particularly in French linguistics of the second half of the XXth century, a long tradition of researches does exist. It can be traced back to Plato in the old age and to Leibniz in modern age, and it has important manifestations in France too. This article aims to illustrate critically the theories of phonological iconicity developed by Charles de Brosses at the age of Enlightenment (1765), by Maurice Grammont …
Estudi de la plasticitat estructural en malalties psiquiàtriques amb models animals
2021
El concepte científic de l’estrès s’associa a una resposta adaptativa front a un estímul ambiental o una demanda. Tot i això, si les pertorbacions al medi ambient són constants, es produeix un desgast a l’organisme que té efectes perjudicials en aquest. El cervell es pot considerar l’òrgan central de l’estrès, ja que en ell comença la principal resposta biològica. És conegut que esdeveniments estressants de curta duració poden potenciar les funcions neuronals i millorar el rendiment cognitiu. D’altra banda, llargs períodes d’estrès poden alterar més profundament la fisiologia de diverses regions del sistema nerviós i afectar al seu funcionament, produint dèficits cognitius i d’aprenentatge.…
Genetic counselling in ALS: facts, uncertainties and clinical suggestions
2013
The clinical approach to patients with amyotrophic lateral sclerosis (ALS) has been largely modified by the identification of novel genes, the detection of gene mutations in apparently sporadic patients, and the discovery of the strict genetic and clinical relation between ALS and frontotemporal dementia (FTD). As a consequence, clinicians are increasingly facing the dilemma on how to handle genetic counselling and testing both for ALS patients and their relatives. On the basis of existing literature on genetics of ALS and of other late-onset life-threatening disorders, we propose clinical suggestions to enable neurologists to provide optimal clinical and genetic counselling to patients and…
Avaluació de l’efectivitat d’un programa d’intervenció basat en marxa virtual i exercici terapèutic en la funció motora, el to i el dolor de persones…
2023
Estudis previs han mostrat el potencial de les teràpies basades en l’activació del sistema de neurones mirall, concretament les teràpies de marxa virtual (MV) en persones amb afectació del sistema nerviós central (SNC). Malgrat això, aquestes teràpies no han estat estudiades com a potenciador de l’exercici terapèutic (ET) utilitzat com a rehabilitació usual sobre persones amb LM incompleta. La hipòtesi principal de la present tesi és que l’aplicació de la teràpia de MV combinada amb un programa d’ET produeix la millora de la funcionalitat, la disminució del dolor neuropàtic i la millora del to muscular en persones amb LM incompleta. Per tal de validar aquesta hipòtesi, l'objectiu de l’estud…