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28 results on '"MESH: Nerve Fibers, Myelinated"'

1. Mild musculoskeletal and locomotor alterations in adult rats with white matter injury following prenatal ischemia

Author

Delcour, Maxime, Russier, Michael, Xin, Dong, Massicotte, Vicky, Barbe, Mary, Coq, Jacques-Olivier, Coq, Jacques‐olivier, Unité de Neurobiologie des canaux Ioniques et de la Synapse (UNIS - Inserm U1072), and Aix Marseille Université (AMU)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)

Subjects
[SDV]Life Sciences [q-bio], Physiology, MESH: Rats, Sprague-Dawley, Hindlimb, Nerve Fibers, Myelinated, MESH: Animals, Newborn, Rats, Sprague-Dawley, MESH: Pregnancy, Pregnancy, MESH: Animals, Treadmill, Gait, MESH: Muscle, Skeletal, MESH: Infant, Newborn, MESH: Posture, MESH: Motor Activity, MESH: Nerve Fibers, Myelinated, Astrogliosis, medicine.anatomical_structure, Prenatal Exposure Delayed Effects, Hypoxia-Ischemia, Brain, Female, Psychology, Infant, Premature, Locomotion, MESH: Infant, Premature, MESH: Cerebral Palsy, MESH: Rats, Posture, MESH: Locomotion, Ischemia, Motor Activity, MESH: Prenatal Exposure Delayed Effects, Cerebral palsy, White matter, Developmental Neuroscience, medicine, Animals, Humans, Muscle, Skeletal, MESH: Humans, Cerebral Palsy, MESH: Gait, Infant, Newborn, medicine.disease, Rats, Disease Models, Animal, Animals, Newborn, MESH: Hypoxia-Ischemia, Brain, MESH: Disease Models, Animal, Ankle, MESH: Female, Neuroscience, Developmental Biology
Abstract

Early brain injury including white matter damage (WMD) appears strongly correlated to perinatal hypoxia-ischemia and adverse neurological outcomes in preterm survivors. Indeed, WMD has been widely associated with subtle to major motor disturbances, sensory, behavioral and cognitive impairments in preterm infants who afterward develop cerebral palsy (CP). Prenatal ischemia (PI) has been shown to reproduce the main features of WMD observed in preterm infants. The present study was aimed at determining in adult rats the impact of PI on brain axons, musculoskeletal histology and locomotor activity. PI was induced by unilateral intrauterine artery ligation at E17 in pregnant rats. We found axonal degeneration and reactive astrogliosis in several white matter regions of adult PI rats. We found mild myopathic and secondary joint changes, including increased variability in myofiber size in several hind limb muscles, decreased myofibers numbers but increased Pax 7 cells and myofiber size in the gastrocnemius, and mild knee and ankle chondromalacia. Although treadmill locomotion appeared normal, several kinematic parameters, such as stride length, amplitude, velocity and leg joint angles were altered in adult PI rats compared to shams. Using intra- and inter-group variability of kinematic parameters, PI seemed to impair the maturation of locomotion on the treadmill. In addition, PI rats exhibited spontaneous hyperactivity in open-field test. Musculoskeletal changes appeared concomitant with mild impairments in gait and posture. Our rodent model of WMD based on PI reproduces the mild motor deficits and musculoskeletal changes observed in many preterm infants with a perinatal history of hypoxia-ischemia, and contributes towards a better understanding of the interplay between brain injury, musculoskeletal histopathology and gait disturbances encountered subsequently.

Published
2011

2. Retrospective Identification and Characterization of Mild Cognitive Impairment From a Prospective Population Cohort

Author

Ephrem Beaino, Florence Portet, Christophe Tzourio, Craig W. Ritchie, Claudine Berr, Marie-Laure Ancelin, Karen Ritchie, Anne-Marie Dupuy, Jean-François Dartigues, Sylvaine Artero, Adam M. Brickman, Neuropsychiatrie : recherche épidémiologique et clinique (PSNREC), Université Montpellier 1 (UM1)-Université de Montpellier (UM)-Institut National de la Santé et de la Recherche Médicale (INSERM), Taub Institute for Research on Alzheimer's Disease and the Aging Brain, Columbia University [New York], Epidémiologie, santé publique et développement, Université Bordeaux Segalen - Bordeaux 2-Institut National de la Santé et de la Recherche Médicale (INSERM)-IFR99-ISPED, Neuroépidémiologie, Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut National de la Santé et de la Recherche Médicale (INSERM), Département de biochimie [Montpellier], Université Montpellier 1 (UM1)-Centre Hospitalier Régional Universitaire [Montpellier] (CHRU Montpellier)-Hôpital Lapeyronie, Neuroscience Division, Imperial College London, Caisse Nationale Maladie des Travailleurs Salariés, Direction Générale de la Santé, MGEN, Institut de la Longévité, Agence Française de Sécurité Sanitaire des Produits de Santé, Régions Aquitaine, Bourgogne et Languedoc-Roussillon, Fondation de France, France Alzheimer, Villebrun, Dominique, and Université Montpellier 1 (UM1)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Université de Montpellier (UM)

Subjects
Male, Gerontology, diagnosis, [SDV.MHEP.PSM] Life Sciences [q-bio]/Human health and pathology/Psychiatrics and mental health, Apolipoprotein E4, Neuropsychological Tests, Nerve Fibers, Myelinated, MESH: Genotype, 0302 clinical medicine, cohort studies, Risk Factors, MESH: Risk Factors, Activities of Daily Living, gender, 030212 general & internal medicine, MESH: Apolipoprotein E4, MESH: Geriatric Assessment, MESH: Aged, 2. Zero hunger, education.field_of_study, [SDV.MHEP.GEG] Life Sciences [q-bio]/Human health and pathology/Geriatry and gerontology, [SDV.MHEP.GEG]Life Sciences [q-bio]/Human health and pathology/Geriatry and gerontology, MESH: Neuropsychological Tests, MESH: Dementia, MESH: Nerve Fibers, Myelinated, 3. Good health, Psychiatry and Mental health, Cohort, Disease Progression, Population study, Female, MESH: Disease Progression, Psychology, ApoE, Cohort study, medicine.medical_specialty, Genotype, Population, Article, cardiovascular disorder, 03 medical and health sciences, Internal medicine, medicine, Humans, education, Geriatric Assessment, Aged, Retrospective Studies, MESH: Humans, MESH: Activities of Daily Living, MESH: Retrospective Studies, Retrospective cohort study, Odds ratio, MCI, MESH: Male, Hyperintensity, Confidence interval, MESH: Cognition Disorders, [SDV.SPEE] Life Sciences [q-bio]/Santé publique et épidémiologie, [SDV.MHEP.PSM]Life Sciences [q-bio]/Human health and pathology/Psychiatrics and mental health, [SDV.SPEE]Life Sciences [q-bio]/Santé publique et épidémiologie, Geriatrics and Gerontology, Cognition Disorders, MESH: Female, 030217 neurology & neurosurgery, dementia
Abstract

International audience; OBJECTIVES: Mild cognitive impairment (MCI) case-finding criteria have low specificity in general population studies. This study retrospectively identifies cases of MCI and determines baseline criteria giving the highest discriminability. The ability of these criteria to increase current case detection specificity is estimated. DESIGN: A population-based cohort was recruited from electoral rolls from three French cities. Clinical and environmental characteristics were evaluated at baseline and at 2- and 4-year follow-up. The clinical characteristics of incident cases of dementia were examined retrospectively. PARTICIPANTS: Eight thousand nine hundred nineteen persons aged 65 years and older without dementia (60.8% women) were included in this study. The mean age (SD) of the participants was 74.2 (5.6) years for men and 74.4 (5.6) years for women. RESULTS: Three hundred twenty persons (3.6%) were retrospectively classified as MCI at baseline. This MCI group had poorer performance on all cognitive tests compared with the rest of the cohort, and a subsample undergoing MRI were found to have more white matter hyperintensities. The group were also characterized by the presence of an ApoE ε4 genotype (odds ratio [OR]: 2.17, confidence interval [CI]: 1.44-3.29 for men; OR: 2.27, CI: 1.59-3.24 for women) and instrumental activities of daily living loss (OR: 1.72, CI: 1.01-3.0 for men; OR: 1.49; CI: 0.97-2.3 for women). Women with MCI also had high depressive symptomatology (OR: 1.96; CI: 1.34-2.87), anticholinergic drug use (OR: 1.59; CI: 1.05-2.28), and low body mass index (OR: 1.54, CI: 1.05-2.28) and for men a history of stroke (OR: 2.17, CI: 1.16-4.05) and glycemia (OR: 1.72, CI: 1.13-2.71). Addition of these characteristics to conventional MCI definitions increases their specificity. CONCLUSIONS: This general population study using a retrospective method for classifying persons with MCI identified gender-specific noncognitive clinical variables that may increase specificity.

Published
2010

3. Phenotypic variability in giant axonal neuropathy

Author

Kathrin Huehne, Jean-Michel Vallat, Laurent Magy, S. Assami, D. Grid, Andoni Urtizberea, Tarik Hamadouche, Bernd Rautenstrauss, Meriem Tazir, Sonia Nouioua, Service de Neurologie, Hopital Mustapha, Service de Neurologie [CHU Limoges], CHU Limoges, Biomolécules Thérapies anti-tumorales (EA4021), Université de Limoges (UNILIM)-Génomique, Environnement, Immunité, Santé, Thérapeutique (GEIST FR CNRS 3503), Laboratoire de biologie moléculaire, Université M'Hamed Bougara Boumerdes (UMBB), Medical Genetics Center, Friedrich-Baur Institute, and Ludwig-Maximilians-Universität München (LMU)

Subjects
Male, Pathology, [SDV.NEU.NB]Life Sciences [q-bio]/Neurons and Cognition [q-bio.NC]/Neurobiology, DNA Mutational Analysis, Pyramidal Tracts, MESH: Pyramidal Tracts, medicine.disease_cause, Nerve Fibers, Myelinated, 0302 clinical medicine, MESH: Child, Neural Pathways, Missense mutation, MESH: Syndrome, Age of Onset, MESH: DNA Mutational Analysis, Child, Genetics (clinical), Giant axonal neuropathy, Genetics, 0303 health sciences, Mutation, Gigaxonin, MESH: Genetic Predisposition to Disease, Brain, Peripheral Nervous System Diseases, Syndrome, Phenotype, Pedigree, MESH: Nerve Fibers, Myelinated, MESH: Cerebellar Ataxia, 3. Good health, medicine.anatomical_structure, Neurology, Child, Preschool, Female, [SDV.NEU]Life Sciences [q-bio]/Neurons and Cognition [q-bio.NC], MESH: Peripheral Nervous System Diseases, MESH: Algeria, Adult, MESH: Axons, medicine.medical_specialty, MESH: Mutation, Adolescent, Cerebellar Ataxia, MESH: Pedigree, MESH: Age of Onset, Central nervous system, Nonsense mutation, Biology, MESH: Phenotype, MESH: Brain, 03 medical and health sciences, [SDV.BBM.GTP]Life Sciences [q-bio]/Biochemistry, Molecular Biology/Genomics [q-bio.GN], medicine, Humans, Genetic Predisposition to Disease, [SDV.BBM]Life Sciences [q-bio]/Biochemistry, Molecular Biology, MESH: Gait Disorders, Neurologic, Gene, Gait Disorders, Neurologic, 030304 developmental biology, MESH: Adolescent, MESH: Bone Diseases, Developmental, Bone Diseases, Developmental, [SDV.GEN]Life Sciences [q-bio]/Genetics, MESH: Humans, MESH: Neural Pathways, MESH: Child, Preschool, MESH: Adult, [SDV.BBM.BM]Life Sciences [q-bio]/Biochemistry, Molecular Biology/Molecular biology, medicine.disease, Axons, MESH: Male, [SDV.GEN.GH]Life Sciences [q-bio]/Genetics/Human genetics, Algeria, Pediatrics, Perinatology and Child Health, Neurology (clinical), MESH: Female, [SDV.MHEP]Life Sciences [q-bio]/Human health and pathology, 030217 neurology & neurosurgery
Abstract

International audience; Giant axonal neuropathy (GAN), a severe childhood disorder affecting both the peripheral nerves and the central nervous system, is due to mutations in the GAN gene encoding gigaxonin, a protein implicated in the cytoskeletal functions and dynamics. In the majority of the GAN series reported to date, patients had the classical clinical phenotype characterized by a severe axonal neuropathy with kinky hair and early onset CNS involvement including cerebellar and pyramidal signs. We present 12 patients (6 families) with GAN mutations and different clinical phenotypes. Four families were harbouring an identical homozygous nonsense mutation but with different severe clinical phenotypes, one patient had a novel missense homozygous mutation with a peculiar moderate phenotype and prominent skeletal deformations. The last family (4 patients) harbouring a homozygous missense mutation had the mildest form of the disease. In contrast with recent reported series of patients with typical GAN clinical features, the present series demonstrate obvious clinical heterogeneity.

Published
2009

4. Ataxia with oculomotor apraxia type 2: A clinical and genetic study of 19 patients

Author

A. M’zahem, Michel Koenig, J. P. Delaunoy, D. Grid, Meriem Tazir, Sonia Nouioua, Jean-Michel Vallat, Abdelmadjid Hamri, S. Assami, Traki Benhassine, M. Fritsch, Lamia Alipacha, Laboratoire de Recherche en Neurosciences, CHU Mustapha, Service de Neurologie, Hôpital Benbadis-CHU Constantine, Service de Neurologie [CHU Limoges], CHU Limoges, Biomolécules Thérapies anti-tumorales (EA4021), and Université de Limoges (UNILIM)-Génomique, Environnement, Immunité, Santé, Thérapeutique (GEIST FR CNRS 3503)

Subjects
Male, Pediatrics, [SDV.NEU.NB]Life Sciences [q-bio]/Neurons and Cognition [q-bio.NC]/Neurobiology, DNA Mutational Analysis, Neural Conduction, Nerve Fibers, Myelinated, Apraxia, MESH: Apraxias, Ocular Motility Disorders, 0302 clinical medicine, MESH: Neural Conduction, Cerebellum, Age of Onset, MESH: DNA Mutational Analysis, Oculomotor apraxia, 0303 health sciences, MESH: RNA Helicases, Autosomal recessive cerebellar ataxia, Pedigree, MESH: Nerve Fibers, Myelinated, MESH: Cerebellar Ataxia, 3. Good health, Phenotype, Neurology, MESH: Young Adult, Disease Progression, Female, MESH: Disease Progression, [SDV.NEU]Life Sciences [q-bio]/Neurons and Cognition [q-bio.NC], Cerebellar atrophy, alpha-Fetoproteins, medicine.symptom, Psychology, Polyneuropathy, RNA Helicases, Adult, medicine.medical_specialty, MESH: Mutation, Ataxia, Adolescent, Cerebellar Ataxia, Apraxias, MESH: Pedigree, MESH: Age of Onset, MESH: Atrophy, MESH: Phenotype, Young Adult, 03 medical and health sciences, [SDV.BBM.GTP]Life Sciences [q-bio]/Biochemistry, Molecular Biology/Genomics [q-bio.GN], medicine, Humans, MESH: Ocular Motility Disorders, [SDV.BBM]Life Sciences [q-bio]/Biochemistry, Molecular Biology, 030304 developmental biology, MESH: Adolescent, [SDV.GEN]Life Sciences [q-bio]/Genetics, MESH: Humans, Cerebellar ataxia, DNA Helicases, MESH: Adult, [SDV.BBM.BM]Life Sciences [q-bio]/Biochemistry, Molecular Biology/Molecular biology, medicine.disease, Multifunctional Enzymes, MESH: Male, MESH: Cerebellum, [SDV.GEN.GH]Life Sciences [q-bio]/Genetics/Human genetics, Mutation, Gait Ataxia, MESH: alpha-Fetoproteins, Neurology (clinical), Atrophy, MESH: Female, Neuroscience, [SDV.MHEP]Life Sciences [q-bio]/Human health and pathology, 030217 neurology & neurosurgery
Abstract

International audience; Ataxia with oculo-motor apraxia type 2 (AOA2) is a recently described autosomal recessive cerebellar ataxia (ARCA) caused by mutations in the senataxin gene (SETX). We analysed the phenotypic spectrum of 19 AOA2 patients with mutations in SETX, which seems to be the third most frequent form of ARCA in Algeria after Freidreich ataxia and Ataxia with vitamin E deficiency. In AOA2 patients, the mean age at onset for all families was in the second decade. Cerebellar ataxia was progressive, slowly leading to disability which was aggravated by axonal polyneuropathy present in almost all the patients. Mean disease duration until wheelchair was around 20 years. Oculo-motor apraxia (OMA) was present in 32% of the patients while convergent strabismus was present in 37%. Strabismus is therefore also very suggestive of AOA2 when associated with ataxia and polyneuropathy even in the absence of OMA. Cerebellar atrophy was more severe in the eldest patients; however it may also be an early sign since it was present in the youngest and paucisymptomatic patients. The initial sign was gait ataxia in all but two patients who presented with head tremor and writer cramp, respectively. Serum alpha-fetoprotein, which was elevated in all tested patients, was a good marker to suggest molecular studies of the SETX gene.

Published
2009

5. Intranervous immunoglobulin deposits: An underestimated mechanism of neuropathy

Author

Karima Ghorab, Didier Cros, Jean-Michel Vallat, Judith Calvo, Laurence Richard, Martine Piaser, Philippe Sindou, Laurent Magy, Service de Neurologie [CHU Limoges], CHU Limoges, Biomolécules Thérapies anti-tumorales (EA4021), and Université de Limoges (UNILIM)-Génomique, Environnement, Immunité, Santé, Thérapeutique (GEIST FR CNRS 3503)

Subjects
Male, Pathology, MESH: Immunoglobulins, Physiology, Biopsy, [SDV.NEU.NB]Life Sciences [q-bio]/Neurons and Cognition [q-bio.NC]/Neurobiology, Neural Conduction, Paraproteinemias, Fluorescent Antibody Technique, Cell Count, Nerve Fibers, Myelinated, MESH: Biopsy, MESH: Paraproteinemias, 0302 clinical medicine, MESH: Neural Conduction, MESH: Microscopy, Immunoelectron, MESH: Cryoglobulins, Nerve Tissue, Microscopy, Immunoelectron, MESH: Fluorescent Antibody Technique, Cryoglobulins, Motor Neurons, MESH: Aged, 0303 health sciences, MESH: Middle Aged, MESH: Polyneuropathies, MESH: Electrophysiology, medicine.diagnostic_test, biology, Electrodiagnosis, MESH: Neurons, Afferent, Middle Aged, Pathophysiology, MESH: Nerve Fibers, Myelinated, 3. Good health, Electrophysiology, Monoclonal, [SDV.IMM]Life Sciences [q-bio]/Immunology, Female, [SDV.NEU]Life Sciences [q-bio]/Neurons and Cognition [q-bio.NC], Antibody, Polyneuropathy, MESH: Motor Neurons, Adult, medicine.medical_specialty, MESH: Nerve Tissue, Immunoglobulins, Polyneuropathies, 03 medical and health sciences, Cellular and Molecular Neuroscience, [SDV.BBM.GTP]Life Sciences [q-bio]/Biochemistry, Molecular Biology/Genomics [q-bio.GN], Physiology (medical), medicine, Humans, [SDV.BBM]Life Sciences [q-bio]/Biochemistry, Molecular Biology, Neurons, Afferent, Aged, 030304 developmental biology, [SDV.GEN]Life Sciences [q-bio]/Genetics, MESH: Humans, Nerve biopsy, MESH: Cell Count, business.industry, MESH: Adult, [SDV.BBM.BM]Life Sciences [q-bio]/Biochemistry, Molecular Biology/Molecular biology, MESH: Electrodiagnosis, medicine.disease, MESH: Male, Lymphoma, Peripheral neuropathy, [SDV.GEN.GH]Life Sciences [q-bio]/Genetics/Human genetics, biology.protein, Neurology (clinical), business, MESH: Female, [SDV.MHEP]Life Sciences [q-bio]/Human health and pathology, 030217 neurology & neurosurgery
Abstract

International audience; There are several pathogenic mechanisms of peripheral nerve involvement in patients with monoclonal dysglobulinemia. Intranervous proliferation of malignant cells, immunoglobulin, or amyloid deposits in the endoneurial space can only be determined by examination of nerve biopsy specimens. We present clinical, electrophysiological, and histological data from seven patients whose polyneuropathy was induced by immunoglobulin deposits in the endoneurial space. As these lesions cannot be demonstrated on clinical and electrophysiological grounds, the indication for nerve biopsy derives from careful analysis of each patient presenting with a polyneuropathy and a monoclonal dysglobulinemia. To visualize and clearly characterize these deposits, electron microscopic examination is indispensable. Immunocytochemical methods using both light and electron microscopy for ultrastructural analysis are of great value. Demonstration of endoneurial immunoglobulin deposits may have major therapeutic consequences. Indeed, identification of these deposits prompted the use of aggressive treatment, which was quite effective in five of our seven patients.

Published
2008

6. Brain networks of spatial awareness: evidence from diffusion tensor imaging tractography

Author

Marika Urbanski, Paolo Bartolomeo, Sebastian Rodrigo, Michel Thiebaut de Schotten, Richard Levy, Catherine Oppenheim, Marco Catani, Bruno Dubois, Sylvie Chokron, Emmanuel Touzé, Jean-François Meder, Neuro-anatomie fonctionnelle du comportement et de ses troubles, Université Pierre et Marie Curie - Paris 6 (UPMC)-IFR70-Institut National de la Santé et de la Recherche Médicale (INSERM), Service de neuroradiologie [Paris], Hôpital Sainte-Anne, Section of Brain Maturation and Centre for Neuroimaging Science, Institute of psychiatry, Service de neurologie, Service de Neurologie [CHU Pitié-Salpêtrière], IFR70-CHU Pitié-Salpêtrière [AP-HP], Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP)-Sorbonne Université (SU)-Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP)-Sorbonne Université (SU), Laboratoire de Psychologie et NeuroCognition (LPNC), Université Pierre Mendès France - Grenoble 2 (UPMF)-Université Joseph Fourier - Grenoble 1 (UJF)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS), Bartolomeo, Paolo, Sorbonne Université (SU)-Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP)-Sorbonne Université (SU)-Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP), Centre National de la Recherche Scientifique (CNRS)-Université Pierre Mendès France - Grenoble 2 (UPMF)-Université Joseph Fourier - Grenoble 1 (UJF)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry]), CHU Pitié-Salpêtrière [AP-HP], Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP)-Sorbonne Université (SU), Institut National de la Santé et de la Recherche Médicale (INSERM)-IFR70-Université Pierre et Marie Curie - Paris 6 (UPMC), Service de neurologie 1 [CHU Pitié-Salpétrière], Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP)-CHU Pitié-Salpêtrière [AP-HP], and Sorbonne Université (SU)-Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP)-Sorbonne Université (SU)

Subjects
Male, MESH: Awareness, Settore M-PSI/02 - PSICOBIOLOGIA E PSICOLOGIA FISIOLOGICA, Nerve Fibers, Myelinated, MESH: Aged, 80 and over, 0302 clinical medicine, Image Processing, Computer-Assisted, media_common, Aged, 80 and over, Cerebral Cortex, MESH: Middle Aged, biology, 05 social sciences, Superior longitudinal fasciculus, MESH: Kinesthesis, Awareness, Middle Aged, MESH: Image Processing, Computer-Assisted, MESH: Nerve Fibers, Myelinated, Stroke, Psychiatry and Mental health, medicine.anatomical_structure, Cerebral cortex, Female, [SDV.NEU]Life Sciences [q-bio]/Neurons and Cognition [q-bio.NC], Psychology, media_common.quotation_subject, MESH: Imaging, Three-Dimensional, MESH: Diffusion Magnetic Resonance Imaging, behavioral disciplines and activities, Article, MESH: Stroke, 050105 experimental psychology, Temporal lobe, Neglect, Perceptual Disorders, 03 medical and health sciences, Imaging, Three-Dimensional, Fasciculus, medicine, Humans, 0501 psychology and cognitive sciences, [SDV.NEU] Life Sciences [q-bio]/Neurons and Cognition [q-bio.NC], Inferior longitudinal fasciculus, Dominance, Cerebral, Kinesthesis, MESH: Perceptual Disorders, MESH: Humans, MESH: Dominance, Cerebral, biology.organism_classification, MESH: Male, MESH: Cerebral Cortex, Diffusion Magnetic Resonance Imaging, MESH: Nerve Net, Unilateral neglect, Surgery, Neurology (clinical), Nerve Net, MESH: Female, Neuroscience, 030217 neurology & neurosurgery, Diffusion MRI
Abstract

International audience; Left unilateral neglect, a dramatic condition which impairs awareness of left-sided events, has been classically reported after right hemisphere cortical lesions involving the inferior parietal region. More recently, the involvement of long range white matter tracts has been highlighted, consistent with the idea that awareness of events occurring in space depends on the coordinated activity of anatomically distributed brain regions. Damage to the superior longitudinal fasciculus (SLF), linking parietal to frontal cortical regions, or to the inferior longitudinal fasciculus (ILF), connecting occipital and temporal lobes, has been described in neglect patients. In this study, four right-handed patients with right hemisphere strokes underwent a high definition anatomical MRI with diffusion tensor imaging (DTI) sequences and a pencil and paper neglect battery of tests. We used DTI tractography to visualise the SLF, ILF and the inferior fronto-occipital fasciculus (IFOF), a pathway running the depth of the temporal lobe, not hitherto associated with neglect. Two patients with cortical involvement of the inferior parietal and superior temporal regions, but intact and symmetrical fasciculi, showed no signs of neglect. The other two patients with signs of left neglect had superficial damage to the inferior parietal cortex and white matter damage involving the IFOF. These findings suggest that superficial damage to the inferior parietal cortex per se may not be sufficient to produce visual neglect. In some cases, a lesion to the direct connections between ventral occipital and frontal regions (ie, IFOF) may contribute to the manifestation of neglect by impairing the top down modulation of visual areas from the frontal cortex.

Published
2008

7. Involvement of both sodium influx and potassium efflux in ciguatoxin-induced nodal swelling of frog myelinated axons

Author

Jordi Molgó, Evelyne Benoit, César Mattei, Institut de Neurobiologie Alfred Fessard (INAF), Centre National de la Recherche Scientifique (CNRS), Institut des Neurosciences Paris-Saclay (NeuroPSI), and Université Paris-Sud - Paris 11 (UP11)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Male, Potassium Channels, [SDV.NEU.NB]Life Sciences [q-bio]/Neurons and Cognition [q-bio.NC]/Neurobiology, Action Potentials, Nerve Fibers, Myelinated, Sodium Channels, Membrane Potentials, chemistry.chemical_compound, Mice, MESH: Sodium, MESH: Animals, MESH: Action Potentials, [SDV.NEU.PC]Life Sciences [q-bio]/Neurons and Cognition [q-bio.NC]/Psychology and behavior, [SDV.NEU.SC]Life Sciences [q-bio]/Neurons and Cognition [q-bio.NC]/Cognitive Sciences, Rana esculenta, MESH: Potassium Channels, Voltage-gated potassium channel, MESH: Nerve Fibers, Myelinated, Biochemistry, MESH: Rana esculenta, MESH: Axons, MESH: Cell Line, Tumor, MESH: Ions, Ciguatoxin, MESH: Rats, Sodium, Ionophore, chemistry.chemical_element, Lithium, MESH: Sodium Channels, Ciguatoxins, Cellular and Molecular Neuroscience, Valinomycin, Chlorides, Cell Line, Tumor, Ranvier's Nodes, MESH: Membrane Potentials, Animals, Channel blocker, MESH: Chlorides, MESH: Mice, Pharmacology, Ions, Tetraethylammonium, MESH: Lithium, Sodium channel, MESH: Ciguatoxins, MESH: Male, Axons, Rats, chemistry, MESH: Potassium, Biophysics, Potassium, MESH: Ranvier's Nodes
Abstract

International audience; Ciguatoxins, mainly produced by benthic dinoflagellate Gambierdiscus species, are responsible for a complex human poisoning known as ciguatera. Previous pharmacological studies revealed that these toxins activate voltage-gated Na+ channels. In frog nodes of Ranvier, ciguatoxins induce spontaneous and repetitive action potentials (APs) and increase axonal volume that may explain alterations of nerve functioning in intoxicated humans. The present study aimed determining the ionic mechanisms involved in Pacific ciguatoxin-1B (P-CTX-1B)-induced membrane hyperexcitability and subsequent volume increase in frog nodes of Ranvier, using electrophysiology and confocal microscopy. The results reveal that P-CTX-1B action is not dependent on external Cl- ions since it was not affected by substituting Cl- by methylsulfate ions. In contrast, substitution of external Na+ by Li+ ions suppressed spontaneous APs and prevented nodal swelling. This suggests that P-CTX-1B-modified Na+ channels are not selective to Li+ ions and/or are blocked by these ions, and that Na+ influx through Na+ channels opened during spontaneous APs is required for axonal swelling. The fact that the K+ channel blocker tetraethylammonium modified, but did not suppress, spontaneous APs and greatly reduced nodal swelling induced by P-CTX-1B indicates that K+ efflux might also be involved. This is supported by the fact that P-CTX-1B, when tested in the presence of both tetraethylammonium and the K+ ionophore valinomycin, produced the characteristic nodal swelling. It is concluded that, during the action of P-CTX-1B, water movements responsible for axonal swelling depend on both Na+ influx and K+ efflux. These results pave the way for further studies regarding ciguatera treatment.

Published
2014

8. White Matter Changes in Comatose Survivors of Anoxic Ischemic Encephalopathy and Traumatic Brain Injury: Comparative Diffusion-Tensor Imaging Study

Author

Paola Sanchez, Omid Khalilzadeh, L. Puybasset, Didier Dormont, Charles Edouard Luyt, Nicolas Menjot de Champfleur, Christine Delmaire, Vincent Perlbarg, Steven Laureys, Audrey Vanhaudenhuyse, Damien Galanaud, Robert D. Stevens, Julien Dinkel, Eléonore Tollard, Habib Benali, Anke W. Van Der Eerden, Rajiv Gupta, Pieter E. Vos, Radiology & Nuclear Medicine, Department of Radiology and Nuclear Medicine [Nijmegen], Radboud University Medical Center [Nijmegen], Department of Radiology [Boston], Brigham and Women's Hospital [Boston], Laboratoire d'imagerie fonctionnelle [CHU Pitié-Salpétriêre] (LIF), Université Pierre et Marie Curie - Paris 6 (UPMC)-CHU Pitié-Salpêtrière [AP-HP], Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP)-Sorbonne Université (SU)-Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP)-Sorbonne Université (SU), Department of Radiology [Heidelberg], Heidelberg University Hospital [Heidelberg], CHU Pitié-Salpêtrière [AP-HP], Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP)-Sorbonne Université (SU), Unité de Recherche sur les Maladies Cardiovasculaires, du Métabolisme et de la Nutrition = Research Unit on Cardiovascular and Metabolic Diseases (ICAN), Université Pierre et Marie Curie - Paris 6 (UPMC)-Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP)-Institut National de la Santé et de la Recherche Médicale (INSERM)-CHU Pitié-Salpêtrière [AP-HP], Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP)-Sorbonne Université (SU)-Sorbonne Université (SU), Argonne National Laboratory [Lemont] (ANL), Université Montpellier 1 (UM1), CHU Montpellier, Centre Hospitalier Régional Universitaire [Montpellier] (CHRU Montpellier), Services de neuroradiologie [Lille], Hôpital Roger Salengro [Lille]-Centre Hospitalier Régional Universitaire [Lille] (CHRU Lille), Service de Radiologie [CHU Rouen], CHU Rouen, Normandie Université (NU)-Normandie Université (NU), Department of Civil Engineering [Hamirpur], National Institute of Technology [Hamirpur], Institut du Cerveau et de la Moëlle Epinière = Brain and Spine Institute (ICM), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut National de la Santé et de la Recherche Médicale (INSERM)-CHU Pitié-Salpêtrière [AP-HP], Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP)-Sorbonne Université (SU)-Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Algorithms, models and methods for images and signals of the human brain (ARAMIS), Inria Paris-Rocquencourt, Institut National de Recherche en Informatique et en Automatique (Inria)-Institut National de Recherche en Informatique et en Automatique (Inria)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut du Cerveau et de la Moëlle Epinière = Brain and Spine Institute (ICM), Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP)-Sorbonne Université (SU)-Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut National de la Santé et de la Recherche Médicale (INSERM)-CHU Pitié-Salpêtrière [AP-HP], Coma Science Group [Liege], Université de Liège, Centre de Recherches du Cyclotron [Liège] (CRC), Laboratoire d'Imagerie Biomédicale [Paris] (LIB), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS), Johns Hopkins University School of Medicine [Baltimore], Laboratoire d'imagerie fonctionnelle [Paris] (LIF), Université Pierre et Marie Curie - Paris 6 (UPMC), Unité de Recherche sur les Maladies Cardiovasculaires, du Métabolisme et de la Nutrition = Institute of cardiometabolism and nutrition (ICAN), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-CHU Pitié-Salpêtrière [AP-HP], Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP)-Sorbonne Université (SU)-Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP)-Sorbonne Université (SU)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-CHU Pitié-Salpêtrière [AP-HP], Service de Neuroradiologie [CHU Pitié-Salpêtrière], Laboratoire d'Imagerie Biomédicale (LIB), Sorbonne Université (SU)-Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP), Sorbonne Université (SU)-Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP)-Sorbonne Université (SU), Sorbonne Université (SU)-Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP)-Sorbonne Université (SU)-Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP), Sorbonne Université (SU)-Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP)-Sorbonne Université (SU)-Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-CHU Pitié-Salpêtrière [AP-HP], and Centre National de la Recherche Scientifique (CNRS)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Université Pierre et Marie Curie - Paris 6 (UPMC)

Subjects
Male, Pathology, [SDV.IB.IMA]Life Sciences [q-bio]/Bioengineering/Imaging, [SDV.NEU.NB]Life Sciences [q-bio]/Neurons and Cognition [q-bio.NC]/Neurobiology, Nerve Fibers, Myelinated, 030218 nuclear medicine & medical imaging, 0302 clinical medicine, MESH: Aged, 80 and over, Prospective Studies, Coma, Prospective cohort study, Aged, 80 and over, MESH: Aged, MESH: Middle Aged, Anoxic-ischemic encephalopathy, Middle Aged, White matter changes, MESH: Case-Control Studies, MESH: Nerve Fibers, Myelinated, Diffusion Tensor Imaging, medicine.anatomical_structure, [INFO.INFO-TI]Computer Science [cs]/Image Processing [eess.IV], Hypoxia-Ischemia, Brain, Cerebral hemisphere, Cardiology, Female, [SPI.SIGNAL]Engineering Sciences [physics]/Signal and Image processing, MESH: Diffusion Tensor Imaging, Adult, medicine.medical_specialty, Traumatic brain injury, White matter, 03 medical and health sciences, Internal medicine, Image Interpretation, Computer-Assisted, medicine, [INFO.INFO-IM]Computer Science [cs]/Medical Imaging, Humans, Radiology, Nuclear Medicine and imaging, MESH: Coma, Aged, MESH: Humans, business.industry, Other Research Radboud Institute for Health Sciences [Radboudumc 0], Case-control study, [INFO.INFO-CV]Computer Science [cs]/Computer Vision and Pattern Recognition [cs.CV], MESH: Adult, medicine.disease, MESH: Male, MESH: Prospective Studies, nervous system diseases, nervous system, Brain Injuries, Case-Control Studies, MESH: Brain Injuries, MESH: Hypoxia-Ischemia, Brain, business, MESH: Image Interpretation, Computer-Assisted, MESH: Female, 030217 neurology & neurosurgery, Diffusion MRI
Abstract

Item does not contain fulltext PURPOSE: To analyze white matter pathologic abnormalities by using diffusion-tensor (DT) imaging in a multicenter prospective cohort of comatose patients following cardiac arrest or traumatic brain injury (TBI). MATERIALS AND METHODS: Institutional review board approval and informed consent from proxies and control subjects were obtained. DT imaging was performed 5-57 days after insult in 49 cardiac arrest and 40 TBI patients. To control for DT imaging-processing variability, patients' values were normalized to those of 111 control subjects. Automated segmentation software calculated normalized axial diffusivity (lambda1) and radial diffusivity (lambda perpendicular) in 19 predefined white matter regions of interest (ROIs). DT imaging variables were compared by using general linear modeling, and side-to-side Pearson correlation coefficients were calculated. P values were corrected for multiple testing (Bonferroni). RESULTS: In central white matter, lambda1 differed from that in control subjects in six of seven TBI ROIs and five of seven cardiac arrest ROIs (all P < .01). The lambda perpendicular differed from that in control subjects in all ROIs in both patient groups (P < .01). In hemispheres, lambda1 was decreased compared with that in control subjects in three of 12 TBI ROIs (P < .05) and nine of 12 cardiac arrest ROIs (P < .01). The lambda perpendicular was increased in all TBI ROIs (P < .01) and in seven of 12 cardiac arrest ROIs (P < .05). Cerebral hemisphere lambda1 was lower in cardiac arrest than in TBI in six of 12 ROIs (P < .01), while lambda perpendicular was higher in TBI than in cardiac arrest in eight of 12 ROIs (P < .01). Diffusivity values were symmetrically distributed in cardiac arrest (P < .001 for side-to-side correlation) but not in TBI patients. CONCLUSION: DT imaging findings are consistent with the known predominance of cerebral hemisphere axonal injury in cardiac arrest and chiefly central myelin injury in TBI. This consistency supports the validity of DT imaging for differentiating axon and myelin damage in vivo in humans. 01 februari 2014

Published
2014

9. Motor function in the elderly: evidence for the reserve hypothesis

Author

Séverine Sabia, Julien Dumurgier, Alexis Elbaz, Christophe Tzourio, Pavla Vicente-Vytopilova, Bernard Mazoyer, Archana Singh-Manoux, Béatrice Tavernier, Centre for Research in Epidemiology and Population Health, U1018, Social and Occupational Determinants of Health, Villejuif, University of Versailles St.-Quentin, UMRS 1018, Villejuif, Department of Epidemiology and Public Health, University College London, UK, Inserm U708, Neuroepidemiology, Paris and Bordeaux, Service de médecine gériatrique (CHU de Dijon - Centre gériatrique de Champmaillot - EHPAD), Centre Hospitalier Universitaire de Dijon - Hôpital François Mitterrand (CHU Dijon), CMRR Paris Nord Ile-de-France, Lariboisiere Fernand Widal Saint Louis Hospital, Assistance Publique-Hôpitaux de Paris, University of Paris Diderot, Paris, Groupe d'Imagerie Neurofonctionnelle (GIN - UMR 5296), Université de Bordeaux (UB)-Centre National de la Recherche Scientifique (CNRS)-Service NEUROSPIN (NEUROSPIN), Université Paris-Saclay-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Centre de Gérontologie, Hôpital Ste Périne, AP-HP, Paris, Université Bordeaux Segalen - Bordeaux 2, SZTAJNBOK, Pascale, Centre de recherche en épidémiologie et santé des populations (CESP), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Université Paris-Sud - Paris 11 (UP11)-Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP)-Hôpital Paul Brousse-Institut National de la Santé et de la Recherche Médicale (INSERM), Department of Epidemiology and Public Health, University College of London [London] (UCL), Neuroépidémiologie, Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut National de la Santé et de la Recherche Médicale (INSERM), Centre Mémoire de Ressources et de Recherche Paris Nord Ile-de-France (CMRR), Groupe Hospitalier Saint Louis - Lariboisière - Fernand Widal [Paris], Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP)-Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP), Service NEUROSPIN (NEUROSPIN), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Bordeaux (UB)-Centre National de la Recherche Scientifique (CNRS), Centre de Gérontologie, Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP)-Hôpital Sainte Perine [AP-HP], Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP), Service Epidémiologie, The 3C Study is conducted under a partnership agreement between theInstitut National de la Santé et de la Recherche Médicale (INSERM), theVictor Segalen-Bordeaux II University, and the Sanofi-Synthélabo Com-pany. The Fondation pour la Recherche Médicale funded the preparationand initiation of the study. The 3C Study is also supported by the CaisseNationale Maladie des Travailleurs Salariés, Direction Générale de laSanté, Institut National de Prévention et d’Education pour la Santé(INPES), Conseils Régionaux of Bourgogne, Fondation de France, Min-istry of Research-INSERM Program Cohortes et collections de donnéesbiologiques, Mutuelle Générale de l’Education Nationale, Institut de laLongévité, Conseil Général de la Côte d’or, Fondation Plan Alzheimer, Hal, GIN, and Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP)-Université Paris-Sud - Paris 11 (UP11)-Hôpital Paul Brousse-Institut National de la Santé et de la Recherche Médicale (INSERM)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)

Subjects
Gerontology, Male, Aging, Poison control, Walking, Nerve Fibers, Myelinated, Cohort Studies, 0302 clinical medicine, MESH: Aged, 80 and over, Cognitive Reserve, Medicine, MESH: Aging, 030212 general & internal medicine, Longitudinal Studies, MESH: Longitudinal Studies, MESH: Cohort Studies, Cognitive reserve, MESH: Aged, Aged, 80 and over, Cognitive ageing, Cognition, MESH: Nerve Fibers, Myelinated, Motor Skills, Educational Status, Female, France, Gait disorders, Article, 03 medical and health sciences, Motor control, Risk factors in epidemiology, MESH: Walking, Humans, Aged, MESH: Humans, business.industry, [SCCO.NEUR]Cognitive science/Neuroscience, [SCCO.NEUR] Cognitive science/Neuroscience, MESH: Cognitive Reserve, Anthropometry, Confidence interval, Hyperintensity, MESH: Male, Preferred walking speed, MESH: France, [SDV.SPEE] Life Sciences [q-bio]/Santé publique et épidémiologie, [SDV.SPEE]Life Sciences [q-bio]/Santé publique et épidémiologie, Neurology (clinical), business, MESH: Educational Status, MESH: Female, 030217 neurology & neurosurgery, Demography, MESH: Motor Skills
Abstract

International audience; The reserve hypothesis accounts for the lack of direct relationship between brain pathology and its clinical manifestations. Research has mostly focused on cognition; our objective is to examine whether the reserve hypothesis applies to motor function. We investigated whether education, a marker of reserve, modifies the association between white matter lesions (WMLs), a marker of vascular brain damage, and maximum walking speed (WS), an objective measure of motor function. We also examined the cross-sectional and longitudinal association between education and WS. Data are from 4,010 participants aged 65-85 years in the longitudinal Three-City-Dijon Study with up to 4 WS measures over 10 years. We examined the interaction between education and WMLs for baseline WS. We studied the association between education and repeated WS measures using linear mixed models, and the role of covariates in explaining the education-WS association. Education was strongly associated with baseline WS; the difference in mean WS between the high and low education groups (0.145 m/s, 95% confidence interval = 0.125-0.165) was equivalent to 7.4 years of age. WMLs were associated with slow WS only in the low education group (p interaction = 0.026). WS declined significantly over time (-0.194 m/s/10 years, 95% confidence interval = -0.206, -0.182), but education did not influence rate of decline. Anthropometric characteristics, parental education, general health, and cognition had the strongest role in explaining the baseline education-WS association. Participants with more education were less susceptible to WMLs' effect on motor function. Higher education was associated with better motor performances but not with motor decline. These results are consistent with the passive reserve hypothesis.

Published
2013

10. Characterization of short white matter fiber bundles in the central area from diffusion tensor MRI

Author

Xavier Morandi, Tristan Moreau, Elsa Magro, Bernard Gibaud, Romuald Seizeur, Service de neurochirurgie [Brest], Hôpital de la Cavale Blanche - CHRU Brest (CHU - BREST ), Laboratoire Traitement du Signal et de l'Image (LTSI), Université de Rennes (UR)-Institut National de la Santé et de la Recherche Médicale (INSERM), Optimisation Continue des Actions Thérapeutiques par l'Intégration d'Informations Multimodales, Université de Brest (UBO)-Télécom Bretagne-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre Hospitalier Régional Universitaire de Brest (CHRU Brest), Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Institut National de la Santé et de la Recherche Médicale (INSERM), and Université de Brest (UBO)-Télécom Bretagne-Centre Hospitalier Régional Universitaire de Brest (CHRU Brest)-Institut National de la Santé et de la Recherche Médicale (INSERM)

Subjects
Male, Nerve Fibers, Myelinated, 030218 nuclear medicine & medical imaging, 0302 clinical medicine, Nuclear magnetic resonance, Gyrus, Neural Pathways, Central area, Handedness, Neuroradiology, education.field_of_study, MESH: Middle Aged, medicine.diagnostic_test, Brain, Middle Aged, MESH: Nerve Fibers, Myelinated, medicine.anatomical_structure, Diffusion tensor imaging, MESH: Young Adult, Female, [SDV.IB]Life Sciences [q-bio]/Bioengineering, [SDV.NEU]Life Sciences [q-bio]/Neurons and Cognition [q-bio.NC], Cardiology and Cardiovascular Medicine, MESH: Diffusion Tensor Imaging, Tractography, Adult, Adolescent, Population, Lateralization of brain function, White matter, 03 medical and health sciences, Young Adult, MESH: Brain, medicine, Humans, Radiology, Nuclear Medicine and imaging, Brain connectivity, education, MESH: Adolescent, MESH: Humans, Fiber bundle, business.industry, MESH: Neural Pathways, Magnetic resonance imaging, MESH: Adult, MESH: Male, nervous system, Neurology (clinical), business, MESH: Female, 030217 neurology & neurosurgery, Diffusion MRI
Abstract

International audience; INTRODUCTION: Diffusion tensor imaging and tractography allow studying white matter fiber bundles in the human brain in vivo. Electrophysiological studies and postmortem dissections permit improving our knowledge about the short association fibers connecting the pre- and postcentral gyri. The aim of this study was first to extract and analyze the features of these short fiber bundles and secondly to analyze their asymmetry according to the subjects' handedness. METHODS: Ten right-handed and ten left-handed healthy subjects were included. White matter fiber bundles were extracted using a streamline tractography approach, with two seed regions of interest (ROI) taken from a parcellation of the pre- and postcentral gyri. This parcellation was achieved using T1 magnetic resonance images (MRI) and semi-automatically generated three ROIs within each gyrus. MRI tracks were reconstructed between all pairs of ROIs connecting the adjacent pre- and postcentral gyri. A quantitative analysis was performed on the number of tracks connecting each ROI pair. A statistical analysis studied the repartition of these MRI tracks in the right and left hemispheres and as a function of the subjects' handedness. RESULTS: The quantitative analysis showed an increased density of MRI tracks in the middle part of the central area in each hemisphere of the 20 subjects. The statistical analysis showed significantly more MRI tracks for the left hemisphere, when we consider the whole population, and this difference was presumably driven by the left-handers. CONCLUSION: These results raise questions about the functional role of these MRI tracks and their relation with laterality.

Published
2012

11. Fluid and white matter suppression with the MP2RAGE sequence

Author

José P. Marques, Rexford D. Newbould, David Erritzoe, Giulio Gambarota, Gunnar Krueger, Tobias Kober, Mark A. Tanner, GlaxoSmithKline, Imperial College London-Clinical Imaging Center, and Ecole Polytechnique Fédérale de Lausanne (EPFL)

Subjects
Brain tissue, Nerve Fibers, Myelinated, Brain mapping, 030218 nuclear medicine & medical imaging, MESH: Magnetic Resonance Imaging, 0302 clinical medicine, [INFO.INFO-TS]Computer Science [cs]/Signal and Image Processing, Healthy volunteers, Image Processing, Computer-Assisted, Segmentation, MESH: Brain Mapping, Mathematics, CIBM-AIT, Brain Mapping, T1, medicine.diagnostic_test, brain tissue segmentation, Pulse sequence, Magnetic Resonance Imaging, MESH: Image Processing, Computer-Assisted, deep brain stimulation, MESH: Nerve Fibers, Myelinated, medicine.anatomical_structure, [SDV.IB]Life Sciences [q-bio]/Bioengineering, [SDV.NEU]Life Sciences [q-bio]/Neurons and Cognition [q-bio.NC], MESH: Image Enhancement, Internal Globus-Pallidus, [SPI.SIGNAL]Engineering Sciences [physics]/Signal and Image processing, MRI, brain, Image processing, MESH: Imaging, Three-Dimensional, Deep Brain-Stimulation, White matter, 03 medical and health sciences, globus pallidus, Imaging, Three-Dimensional, medicine, Humans, Radiology, Nuclear Medicine and imaging, MESH: Humans, business.industry, Parkinsons-Disease, Magnetic resonance imaging, Pattern recognition, Image Enhancement, Pulse Sequence, MPRAGE, Localization, Artificial intelligence, business, Nuclear medicine, 030217 neurology & neurosurgery
Abstract

Purpose: To develop a magnetic resonance imaging (MRI) sequence (fluid and white matter suppression, FLAWS) for generating two sets of images from a single acquisition: one with contrast similar to a T1-weighted magnetization-prepared rapid gradient-echo sequence (MPRAGE) for structural definition; the other with nulled white matter (WM) signal intensity, similar to the fast gray matter T1 inversion recovery (FGATIR) sequence, for improved delineation of subcortical brain structures. Materials and Methods: The recently proposed MP2RAGE, which is a modification of the MPRAGE and generates two image sets at different inversion times, was employed to generate the FGATIR-like contrast (FLAWS1) and MPRAGE-like contrast (FLAWS2). Five healthy volunteers were scanned at 3T and brain tissue contrast and contrast-to-noise were compared. Results: FLAWS1 and FLAWS2 exhibited similar tissue contrast and contrast-to-noise as the `` reference'' sequences, FGATIR and MPRAGE, respectively. Synthetic minimum value images generated from FLAWS1 and FLAWS2 provided a gray matter-dominant image. Conclusion: FLAWS provides two coregistered 3D volumes, one with nulled WM signal intensity and another with nulled cerebrospinal fluid. The coregistered nature of the two datasets allows for generating images that might be helpful in segmentation algorithms and clinical diagnosis. Key Words: brain; MRI; MPRAGE; brain tissue segmentation; globus pallidus; deep brain stimulation J. Magn. Reson. Imaging 2012; 35: 1063-1070. (C) 2011 Wiley Periodicals, Inc.

Published
2012

12. Do we activate specifically somatosensory thin fibres with the concentric planar electrode? A scalp and intracranial EEG study

Author

Caroline Perchet, Cecilia Flores, Michel Magnin, Luis Garcia-Larrea, Maud Frot, Audran Charmarty, Stéphanie Mazza, INSERM E342, Institut National de la Santé et de la Recherche Médicale (INSERM), NeuroPain - CRNL, Centre de recherche en neurosciences de Lyon (CRNL), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Université Jean Monnet [Saint-Étienne] (UJM)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Université Jean Monnet [Saint-Étienne] (UJM)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'Etude des Mécanismes Cognitifs (EMC), and Université Lumière - Lyon 2 (UL2)

Subjects
Male, Spinothalamic Tracts, Stimulation, Lasers, Solid-State, Somatosensory system, Nerve Fibers, Myelinated, 0302 clinical medicine, MESH: Spinothalamic Tracts, MESH: Evoked Potentials, Somatosensory, Evoked potential, MESH: Middle Aged, Chemistry, 05 social sciences, Electroencephalography, Middle Aged, Coactivation, Peripheral, MESH: Nerve Fibers, Myelinated, Electrodes, Implanted, medicine.anatomical_structure, Nociception, Neurology, MESH: Young Adult, [SDV.NEU]Life Sciences [q-bio]/Neurons and Cognition [q-bio.NC], Female, MESH: Pain, Pain, MESH: Scalp, 050105 experimental psychology, MESH: Somatosensory Cortex, 03 medical and health sciences, Young Adult, Evoked Potentials, Somatosensory, MESH: Electroencephalography, medicine, Humans, 0501 psychology and cognitive sciences, Electrodes, MESH: Humans, Scalp, MESH: Electrodes, Somatosensory Cortex, MESH: Male, Anesthesiology and Pain Medicine, Reflex, MESH: Electrodes, Implanted, Neurology (clinical), Neuroscience, MESH: Female, 030217 neurology & neurosurgery, MESH: Lasers, Solid-State
Abstract

International audience; Laser-evoked potentials (LEPs) are acknowledged as the most reliable laboratory tool for assessing thermal and pain pathways. Electrical stimulation with a newly developed planar concentric electrode, delivering stimuli limited to the superficial skin layers, has been suggested to provide selective activation of Aδ fibres without the inconveniences linked to laser stimulation. The aim of our study was to compare the scalp and intracranial responses to planar concentric electrode stimulation (CE-SEPs) with those of LEPs and standard somatosensory-evoked potentials (SEPs). Sixteen healthy subjects, 6 patients with intracortical electrodes, and 2 patients with selective lesions of the spinothalamic pathway were submitted to Neodymium:Yttrium-Aluminium-Perovskite laser stimulations, and electrical stimulations using standard electrodes or planar concentric electrodes (CE). In both healthy controls and epileptic implanted patients, CE- and standard SEPs showed significantly shorter latencies than LEPs. This is consistent with Aβ-fibre activation, peripheral activation time being unable to account for longer LEP latencies. In the patients with spinothalamic lesions, LEPs were absent after stimulation of the affected territory, while CE-SEPs were still present. For these 2 reasons, we conclude that the planar CE does not selectively activate the Aδ and C fibers, but coexcites a significant proportion of large myelinated Aβ fibres that dominate the ensuing cortical response. The use of CE-SEPs for the detection of spinothalamic system lesions is therefore not warranted; the planar electrode can, however, represent a useful tool to study nociceptive reflexes, which can be reliably elicited even in the presence of Aβ coactivation.

Published
2011

13. Disruption of Krox20–Nab Interaction in the Mouse Leads to Peripheral Neuropathy with Biphasic Evolution

Author

Laurence Decker, Patrick Charnay, Jean-Michel Vallat, Anne Desmazières, Pascale Gilardi-Hebenstreit, Génétique moléculaire du développement, Département de Biologie - ENS Paris, École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-IFR36-Institut National de la Santé et de la Recherche Médicale (INSERM), Institut de biologie de l'Ecole Normale Supérieure (IBENS), Centre National de la Recherche Scientifique (CNRS)-Institut National de la Santé et de la Recherche Médicale (INSERM)-École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL), Service de Neurologie [CHU Limoges], CHU Limoges, Biomolécules Thérapies anti-tumorales (EA4021), and Université de Limoges (UNILIM)-Génomique, Environnement, Immunité, Santé, Thérapeutique (GEIST FR CNRS 3503)

Subjects
MESH: Neoplasm Proteins, Male, Time Factors, Early Growth Response Protein 2, MESH: Mice, Mutant Strains, [SDV.NEU.NB]Life Sciences [q-bio]/Neurons and Cognition [q-bio.NC]/Neurobiology, Mutant, medicine.disease_cause, Nerve Fibers, Myelinated, Myelin, Mice, 0302 clinical medicine, MESH: Early Growth Response Protein 2, Chlorocebus aethiops, MESH: Animals, ComputingMilieux_MISCELLANEOUS, Cells, Cultured, Zinc finger transcription factor, 0303 health sciences, Mutation, education.field_of_study, General Neuroscience, Peripheral Nervous System Diseases, Articles, MESH: Amino Acid Substitution, MESH: Nerve Fibers, Myelinated, Cell biology, Neoplasm Proteins, MESH: COS Cells, medicine.anatomical_structure, MESH: Repressor Proteins, COS Cells, [SDV.NEU]Life Sciences [q-bio]/Neurons and Cognition [q-bio.NC], Female, MESH: Peripheral Nervous System Diseases, MESH: Cells, Cultured, Protein Binding, Biology, 03 medical and health sciences, [SDV.BBM.GTP]Life Sciences [q-bio]/Biochemistry, Molecular Biology/Genomics [q-bio.GN], medicine, MESH: Protein Binding, Animals, [SDV.BBM]Life Sciences [q-bio]/Biochemistry, Molecular Biology, education, MESH: Mice, Transcription factor, Loss function, 030304 developmental biology, [SDV.GEN]Life Sciences [q-bio]/Genetics, MESH: Time Factors, [SDV.BBM.BM]Life Sciences [q-bio]/Biochemistry, Molecular Biology/Molecular biology, medicine.disease, MESH: Cercopithecus aethiops, MESH: Male, Mice, Mutant Strains, Repressor Proteins, Peripheral neuropathy, [SDV.GEN.GH]Life Sciences [q-bio]/Genetics/Human genetics, Amino Acid Substitution, MESH: Female, Neuroscience, [SDV.MHEP]Life Sciences [q-bio]/Human health and pathology, 030217 neurology & neurosurgery
Abstract

Krox20/Egr2 is a zinc finger transcription factor that plays essential roles in several developmental processes, including peripheral nervous system myelination by Schwann cells, where it acts as a master gene regulator. Krox20 is known to interact with cofactors of the Nab family and a mutation affecting isoleucine 268, which prevents this interaction, has been shown to result in congenital hypomyelinating neuropathy in humans. To further investigate the role of this interaction, we have introduced such a mutation, Krox20(I268F), in the mouse germ line. Clinical, immunohistochemical, and ultrastructural analyses of the homozygous mutants reveal that they develop a severe hypomyelination phenotype that mimics the human syndrome. Furthermore, a time-course analysis of the disease indicates that it follows a biphasic evolution, the hypomyelination phase being followed by a dramatic demyelination. Although for the regulation of most analyzed Krox20 target genes the mutation behaves as a loss of function, this is not the case for a few of them. This differential effect indicates that the molecular function of the Krox20-Nab interaction is target dependent and might explain the degradation of the residual myelin, because of imbalances in its composition. In conclusion, this work provides a novel and useful model for severe human peripheral neuropathies.

Published
2008

14. Asynchrony of the early maturation of white matter bundles in healthy infants: quantitative landmarks revealed noninvasively by diffusion tensor imaging

Author

Lucie Hertz-Pannier, Ghislaine Dehaene-Lambertz, Muriel Perrin, Jessica Dubois, Denis Le Bihan, Jean-François Mangin, Y. Cointepas, Edouard Duchesnay, Département de radiothérapie, CRLCC Val d'Aurelle - Paul Lamarque, Institut de recherche en cancérologie de Montpellier (IRCM - U896 Inserm - UM1), Université Montpellier 1 (UM1)-CRLCC Val d'Aurelle - Paul Lamarque-Institut National de la Santé et de la Recherche Médicale (INSERM)-Université de Montpellier (UM), Institut d'imagerie neurofonctionnelle (IIN), Institut National de la Santé et de la Recherche Médicale (INSERM)-Ecole Nationale Supérieure des Télécommunications (ENST)-Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-École des hautes études en sciences sociales (EHESS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Université Paris-Sud - Paris 11 (UP11)-Centre National de la Recherche Scientifique (CNRS), Neuroimagerie cognitive (LCogn), Université Paris-Sud - Paris 11 (UP11)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de la Santé et de la Recherche Médicale (INSERM), Service central de radiologie et d'imagerie médicale, CHU Grenoble-Hôpital Michallon, Laboratoire d'Énergétique Moléculaire et Macroscopique, Combustion (EM2C), Université Paris Saclay (COmUE)-Centre National de la Recherche Scientifique (CNRS)-CentraleSupélec, Laboratoire de Neuroimagerie Assistée par Ordinateur (LNAO), Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Service Hospitalier Frédéric Joliot (SHFJ), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Center for Neuroscience and Behavioral Medicine, Children's National Medical Center, Laboratoire Traitement et Communication de l'Information (LTCI), Télécom ParisTech-Institut Mines-Télécom [Paris] (IMT)-Centre National de la Recherche Scientifique (CNRS), Human Brain Research Center [Kyoto] (HBRC), Kyoto University [Kyoto], Service NEUROSPIN (NEUROSPIN), National Institutes of Health [Bethesda] (NIH), IFR de Neuroimagerie Fonctionnelle (IFR 49), Université Paris-Saclay-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), CHU Necker - Enfants Malades [AP-HP], Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP), Épilepsie de l'enfant et plasticité cérébrale (Inserm U663), Université Paris Descartes - Paris 5 (UPD5)-Institut National de la Santé et de la Recherche Médicale (INSERM), and Le Bihan, Denis

Subjects
Male, Aging, MESH: Internal Capsule, Internal capsule, Spinothalamic Tracts, [SDV.IB.IMA]Life Sciences [q-bio]/Bioengineering/Imaging, Fornix, Brain, Pyramidal Tracts, MESH: Pyramidal Tracts, Corpus callosum, Nerve Fibers, Myelinated, 030218 nuclear medicine & medical imaging, Corpus Callosum, Diffusion, 0302 clinical medicine, Internal Capsule, MESH: Spinothalamic Tracts, Neural Pathways, MESH: Aging, Research Articles, Cerebral Cortex, Radiological and Ultrasound Technology, Fornix, MESH: Diffusion, Anatomy, MESH: Infant, MESH: Nerve Fibers, Myelinated, medicine.anatomical_structure, Neurology, Female, Tractography, Adult, Biology, MESH: Diffusion Magnetic Resonance Imaging, MESH: Corpus Callosum, White matter, 03 medical and health sciences, medicine, Humans, Radiology, Nuclear Medicine and imaging, Pyramidal tracts, MESH: Humans, MESH: Neural Pathways, Infant, MESH: Adult, MESH: Male, MESH: Cerebral Cortex, MESH: Fornix, Brain, [SDV.IB.IMA] Life Sciences [q-bio]/Bioengineering/Imaging, Diffusion Magnetic Resonance Imaging, Corticospinal tract, MESH: Anisotropy, Anisotropy, Neurology (clinical), Neuroscience, MESH: Female, 030217 neurology & neurosurgery, Diffusion MRI
Abstract

Normal cognitive development in infants follows a well‐known temporal sequence, which is assumed to be correlated with the structural maturation of underlying functional networks. Postmortem studies and, more recently, structural MR imaging studies have described qualitatively the heterogeneous spatiotemporal progression of white matter myelination. However, in vivo quantification of the maturation phases of fiber bundles is still lacking. We used noninvasive diffusion tensor MR imaging and tractography in twenty‐three 1–4‐month‐old healthy infants to quantify the early maturation of the main cerebral fascicles. A specific maturation model, based on the respective roles of different maturational processes on the diffusion phenomena, was designed to highlight asynchronous maturation across bundles by evaluating the time‐course of mean diffusivity and anisotropy changes over the considered developmental period. Using an original approach, a progression of maturation in four relative stages was determined in each tract by estimating the maturation state and speed, from the diffusion indices over the infants group compared with an adults group on one hand, and in each tract compared with the average over bundles on the other hand. Results were coherent with, and extended previous findings in 8 of 11 bundles, showing the anterior limb of the internal capsule and cingulum as the most immature, followed by the optic radiations, arcuate and inferior longitudinal fascicles, then the spinothalamic tract and fornix, and finally the corticospinal tract as the most mature bundle. Thus, this approach provides new quantitative landmarks for further noninvasive research on brain‐behavior relationships during normal and abnormal development. Hum Brain Mapp, 2008. © 2007 Wiley‐Liss, Inc.

Published
2008

15. Early postnatal development of corpus callosum and corticospinal white matter assessed with quantitative tractography

Author

Hongbin Gu, J. K. Smith, Robert M. Hamer, Chaeryon Kang, John H. Gilmore, Y. S.K. Vetsa, Weili Lin, Isabelle Corouge, Guido Gerig, Jeffrey A. Lieberman, Schizophrenia Research Center, University of North Carolina [Chapel Hill] (UNC), University of North Carolina System (UNC)-University of North Carolina System (UNC), Department of Psychiatry, Department of Radiology, Department of Computer Science, Department of Biostatistics, Columbia University [New York], Medical Image Display and Analysis Group [MIDAG], and Corouge, Isabelle

Subjects
Male, [INFO.INFO-IM] Computer Science [cs]/Medical Imaging, Pyramidal Tracts, tractography, MESH: Pyramidal Tracts, Corpus callosum, Nerve Fibers, Myelinated, Pediatrics, Corpus Callosum, 030218 nuclear medicine & medical imaging, MESH: Magnetic Resonance Imaging, 0302 clinical medicine, [INFO.INFO-TS]Computer Science [cs]/Signal and Image Processing, Medicine, quantitative analysis, MESH: Infant, Newborn, Anatomy, Magnetic Resonance Imaging, MESH: Nerve Fibers, Myelinated, postnatal development, medicine.anatomical_structure, [INFO.INFO-TI] Computer Science [cs]/Image Processing [eess.IV], [INFO.INFO-TI]Computer Science [cs]/Image Processing [eess.IV], Female, [SDV.NEU]Life Sciences [q-bio]/Neurons and Cognition [q-bio.NC], [SPI.SIGNAL]Engineering Sciences [physics]/Signal and Image processing, Tractography, [INFO.INFO-TS] Computer Science [cs]/Signal and Image Processing, Splenium, MESH: Corpus Callosum, Midbrain, White matter, 03 medical and health sciences, Image Interpretation, Computer-Assisted, Fractional anisotropy, [INFO.INFO-IM]Computer Science [cs]/Medical Imaging, Humans, Radiology, Nuclear Medicine and imaging, [SDV.NEU] Life Sciences [q-bio]/Neurons and Cognition [q-bio.NC], [SPI.SIGNAL] Engineering Sciences [physics]/Signal and Image processing, MESH: Humans, business.industry, Infant, Newborn, MESH: Male, Corticospinal tract, Neurology (clinical), business, MESH: Female, MESH: Image Interpretation, Computer-Assisted, 030217 neurology & neurosurgery, Diffusion MRI, Diffusion Tensor MRI
Abstract

International audience; BACKGROUND AND PURPOSE: The early postnatal period is perhaps the most dynamic phase of white matter development. We hypothesized that the early postnatal development of the corpus callosum and corticospinal tracts could be studied in unsedated healthy neonates by using novel approaches to diffusion tensor imaging (DTI) and quantitative tractography. MATERIALS AND METHODS: Isotropic 2 x 2 x 2 mm(3) DTI and structural images were acquired from 47 healthy neonates. DTI and structural images were coregistered and fractional anisotropy (FA), mean diffusivity (MD), and normalized T1-weighted (T1W) and T2-weighted (T2W) signal intensities were determined in central midline and peripheral cortical regions of the white matter tracts of the genu and splenium of the corpus callosum and the central midbrain and peripheral cortical regions of the corticospinal tracts by using quantitative tractography. RESULTS: We observed that central regions exhibited lower MD, higher FA values, higher T1W intensity, and lower T2W intensity than peripheral cortical regions. As expected, MD decreased, FA increased, and T2W signal intensity decreased with increasing age in the genu and corticospinal tract, whereas there was no significant change in T1W signal intensity. The central midline region of the splenium fiber tract has a unique pattern, with no change in MD, FA, or T2W signal intensity with age, suggesting different growth trajectory compared with the other tracts. FA seems to be more dependent on tract organization, whereas MD seems to be more sensitive to myelination. CONCLUSIONS: Our novel approach may detect small regional differences and age-related changes in the corpus callosum and corticospinal white matter tracts in unsedated healthy neonates and may be used for future studies of pediatric brain disorders that affect developing white matter.

Published
2007

16. Uncinate fasciculus fiber tracking in mesial temporal lobe epilepsy. Initial findings

Author

D. Le Bihan, Catherine Oppenheim, J.-F. Mangin, Y. Cointepas, F. Semah, Sebastian Rodrigo, C. Poupon, Narly Golestani, Francine Chassoux, Jean-François Meder, service de neuroradiologie [Paris], Hôpital Sainte-Anne, Commissariat à l'Energie Atomique, Direction des Sciences du Vivant, Département de Recherche Médicale, Service Hospitalier Frédéric Joliot, Service de Neurochirurgie, Hôpital Saint-Anne, Institut d'imagerie neurofonctionnelle ( IIN ), Institut National de la Santé et de la Recherche Médicale ( INSERM ) -ENST-Assistance publique - Hôpitaux de Paris (AP-HP)-Commissariat à l'énergie atomique et aux énergies alternatives ( CEA ) -École des hautes études en sciences sociales ( EHESS ) -Université Pierre et Marie Curie - Paris 6 ( UPMC ) -Université Paris-Sud - Paris 11 ( UP11 ) -Centre National de la Recherche Scientifique ( CNRS ), Laboratoire Traitement et Communication de l'Information ( LTCI ), Télécom ParisTech-Institut Mines-Télécom [Paris]-Centre National de la Recherche Scientifique ( CNRS ), Laboratoire d'Imagerie et de Spectroscopie ( LRMN ), Commissariat à l'énergie atomique et aux énergies alternatives ( CEA ), Laboratoire de Neuroimagerie Assistée par Ordinateur ( LNAO ), Service Hospitalier Frédéric Joliot ( SHFJ ), Direction de Recherche Fondamentale (CEA) ( DRF (CEA) ), Commissariat à l'énergie atomique et aux énergies alternatives ( CEA ) -Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives ( CEA ) -Université Paris-Saclay, Center for Neuroscience and Behavioral Medicine, Children's National Medical Center, Human Brain Research Center [Kyoto] ( HBRC ), Kyoto University [Kyoto], Service NEUROSPIN ( NEUROSPIN ), National Institutes of Health [Bethesda] ( NIH ), IFR de Neuroimagerie Fonctionnelle ( IFR 49 ), DIMF, Université Paris Descartes - Paris 5 ( UPD5 ) -Centre Hospitalier Sainte-Anne, Service de neuroradiologie [Paris], Service Hospitalier Frédéric Joliot (SHFJ), Université Paris-Saclay-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Institut d'imagerie neurofonctionnelle (IIN), Université Paris-Sud - Paris 11 (UP11)-Université Pierre et Marie Curie - Paris 6 (UPMC)-École des hautes études en sciences sociales (EHESS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP)-Ecole Nationale Supérieure des Télécommunications (ENST)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS), Laboratoire Traitement et Communication de l'Information (LTCI), Télécom ParisTech-Institut Mines-Télécom [Paris] (IMT)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'Imagerie et de Spectroscopie (LRMN), Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Laboratoire de Neuroimagerie Assistée par Ordinateur (LNAO), Human Brain Research Center [Kyoto] (HBRC), Kyoto University, Service NEUROSPIN (NEUROSPIN), National Institutes of Health [Bethesda] (NIH), IFR de Neuroimagerie Fonctionnelle (IFR 49), Université Paris Descartes - Paris 5 (UPD5)-Centre Hospitalier Sainte-Anne, Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Institut National de la Santé et de la Recherche Médicale (INSERM)-Ecole Nationale Supérieure des Télécommunications (ENST)-Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-École des hautes études en sciences sociales (EHESS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Université Paris-Sud - Paris 11 (UP11)-Centre National de la Recherche Scientifique (CNRS), and Institut National de la Santé et de la Recherche Médicale (INSERM)-ENST-Assistance publique - Hôpitaux de Paris (AP-HP) (APHP)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-École des hautes études en sciences sociales (EHESS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Université Paris-Sud - Paris 11 (UP11)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Male, MESH: Hippocampus, [SDV.IB.IMA]Life Sciences [q-bio]/Bioengineering/Imaging, MESH: Frontal Lobe, MESH : Hippocampus, Hippocampus, Nerve Fibers, Myelinated, 030218 nuclear medicine & medical imaging, 0302 clinical medicine, MESH : Neural Pathways, Reference Values, Neural Pathways, Image Processing, Computer-Assisted, MESH : Anisotropy, MESH : Female, [ SDV.IB.IMA ] Life Sciences [q-bio]/Bioengineering/Imaging, MESH: Energy Metabolism, MESH: Reference Values, General Medicine, Human brain, Anatomy, MESH : Adult, MESH : Diffusion Magnetic Resonance Imaging, MESH: Image Processing, Computer-Assisted, Temporal Lobe, Frontal Lobe, MESH: Nerve Fibers, Myelinated, medicine.anatomical_structure, MESH: Epilepsy, Temporal Lobe, MESH : Imaging, Three-Dimensional, Female, Radiology, MESH : Image Processing, Computer-Assisted, Adult, medicine.medical_specialty, Adolescent, MESH : Male, Uncinate fasciculus, MESH: Imaging, Three-Dimensional, MESH: Diffusion Magnetic Resonance Imaging, MESH : Dominance, Cerebral, Insular cortex, MESH : Reference Values, behavioral disciplines and activities, Temporal lobe, White matter, 03 medical and health sciences, Imaging, Three-Dimensional, MESH : Adolescent, MESH : Nerve Fibers, Myelinated, Fractional anisotropy, medicine, Humans, MESH: Temporal Lobe, MESH : Frontal Lobe, Radiology, Nuclear Medicine and imaging, Ictal, Dominance, Cerebral, MESH : Temporal Lobe, MESH: Adolescent, Hippocampal sclerosis, Sclerosis, MESH: Humans, business.industry, MESH: Neural Pathways, MESH : Humans, MESH: Adult, MESH: Dominance, Cerebral, medicine.disease, MESH: Male, MESH : Sclerosis, MESH : Energy Metabolism, MESH : Epilepsy, Temporal Lobe, Diffusion Magnetic Resonance Imaging, Epilepsy, Temporal Lobe, nervous system, MESH: Anisotropy, Anisotropy, MESH: Sclerosis, business, Energy Metabolism, MESH: Female, 030217 neurology & neurosurgery
Abstract

International audience; In temporal lobe epilepsy (TLE) due to hippocampal sclerosis (HS), ictal discharge spread to the frontal and insulo-perisylvian cortex is commonly observed. The implication of white matter pathways in this propagation has not been investigated. We compared diffusion tensor imaging (DTI) measurements along the uncinate fasciculus (UF), a major tract connecting the frontal and temporal lobes, in patients and controls. Ten right-handed patients referred for intractable TLE due to a right HS were investigated on a 1.5-T MR scanner including a DTI sequence. All patients had interictal fluorodeoxyglucose PET showing an ipsilateral temporal hypometabolism associated with insular and frontal or perisylvian hypometabolism. The controls consisted of ten right-handed healthy subjects. UF fiber tracking was performed, and its fractional anisotropy (FA) values were compared between patients and controls, separately for the right and left UF. The left-minus-right FA UF asymmetry index was computed to test for intergroup differences. Asymmetries were found in the control group with right-greater-than-left FA. This asymmetrical pattern was lost in the patient group. Right FA values were lower in patients with right HS versus controls. Although preliminary, these findings may be related to the preferential pathway of seizure spread from the mesial temporal lobe to frontal and insulo-perisylvian areas.

Published
2007

17. The postnatal development of the optic nerve of a reptile (Vipera aspis): A quantitative ultrastructural study

Author

Jean-Paul Rio, S.Ba M'hamed, Jacques Repérant, Mohamed Bennis, Roger Ward, Bruno Jay, Evolution des régulations endocriniennes (ERE), and Muséum national d'Histoire naturelle (MNHN)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Male, Embryology, MESH: Viperidae, Cell Count, Biology, Nerve Fibers, Myelinated, MESH: Animals, Newborn, MESH: Viviparity, Nonmammalian, Necrosis, Nerve Fibers, Viviparity, Nonmammalian, [SDV.BA.ZV]Life Sciences [q-bio]/Animal biology/Vertebrate Zoology, Viperidae, Animals, MESH: Animals, [SDV.BDD]Life Sciences [q-bio]/Development Biology, Vipera aspis, MESH: Nerve Fibers, MESH: Necrosis, MESH: Cell Count, Optic Nerve, Cell Biology, Anatomy, MESH: Optic Nerve, biology.organism_classification, MESH: Male, MESH: Nerve Fibers, Myelinated, Animals, Newborn, Electron micrographs, Optic nerve, Ultrastructure, Female, MESH: Neuroglia, Neuroglia, MESH: Female, Adult level, Developmental Biology
Abstract

The number of axons in the optic nerve of the ovoviviparous reptile Vipera aspis was estimated from electron micrographs taken during the first 5 weeks of postnatal life. One to two days after birth, the optic nerve contains about 170,000 fibres, of which about 9% are myelinated. At the end of the fifth postnatal week, the number of optic fibres has fallen to about 100,000, of which about 42% are myelinated. This fibre loss continues after the fifth postnatal week, since in the adult viper the nerve contains about 60,000 fibres, of which 85% are myelinated; overall, about 65% of the optic nerve fibres present at birth disappear before the number of axons stabilises at the adult level. This study shows, for the first time, that the mode of development of the visual axons of reptiles is not that of anamniote vertebrates but similar to that of birds and mammals.

Published
2006

18. The ectodomain of the viral receptor YueB forms a fiber that triggers ejection of bacteriophage SPP1 DNA

Author

Paulo Tavares, Rudi Lurz, Ronald Melki, Carlos São-José, Jean Lepault, Sophie Lhuillier, Mário A. Santos, Unidade Retrovirus & Infeccoes Associadas, Ctr Patogenese Mol, Fac Farm, University of Lisbon, Virologie moléculaire et structurale (VMS), Institut National de la Recherche Agronomique (INRA)-Centre National de la Recherche Scientifique (CNRS), Max-Planck-Institut für Molekulare Genetik (MPIMG), Max-Planck-Gesellschaft, Laboratoire d'Enzymologie et Biochimie Structurales (LEBS), Centre National de la Recherche Scientifique (CNRS), and Universidade de Lisboa (ULISBOA)

Subjects
MECHANISM, [SDV]Life Sciences [q-bio], bacillus subtillis, Bacillus Phages, Biochemistry, Nerve Fibers, Myelinated, Cell membrane, chemistry.chemical_compound, COILED-COIL STRUCTURE, MESH: Protein Structure, Tertiary, CELL-WALL, bactérie, Host cell surface, 0303 health sciences, Virus receptor, Cell biology, MESH: Nerve Fibers, Myelinated, medicine.anatomical_structure, Ectodomain, protéine, Host cell cytoplasm, BACILLUS-SUBTILIS 168, PHAGE, RESOLUTION, TRANSPORT, RELEASE, Receptors, Virus, Dimerization, Bacillus subtilis, MESH: Computational Biology, Biology, 03 medical and health sciences, MESH: Bacillus Phages, medicine, Molecular Biology, 030304 developmental biology, 030306 microbiology, Computational Biology, Cell Biology, MESH: Bacillus subtilis, Molecular biology, MESH: Receptors, Virus, Protein Structure, Tertiary, MESH: DNA, Viral, chemistry, MESH: Dimerization, adsorption, Viral Receptor, DNA, Viral, Peptidoglycan, DNA
Abstract

International audience; The irreversible binding of bacteriophages to their receptor(s) in the host cell surface triggers release of the naked genome from the virion followed by transit of viral DNA to the host cell cytoplasm. We have purified, for the first time, a receptor from a Gram-positive bacterium that is active to trigger viral DNA ejection in vitro. This extracellular region ("ectodomain") of the Bacillus subtilis protein YueB (YueB780) was a 7 S elongated dimer forming a 36.5-nm-long fiber. YueB780 bound to the tail tip of bacteriophage SPP1. Although a stable receptor-phage interaction occurred between 0 and 37 degrees C, complete blocking of phage DNA release or partial ejection events were observed at temperatures below 15 degrees C. We also showed that the receptor was exposed to the B. subtilis surface. YueB differed structurally from phage receptors from Gram-negative bacteria. Its properties revealed a fiber spanning the full length of the 30-nm-thick peptidoglycan layer. The fiber is predicted to be anchored in the cell membrane through transmembrane segments. These features, highly suitable for a virus receptor in Gram-positive bacteria, are very likely shared by a large number of phage receptors.

Published
2006

19. Postnatal development of alkaline phosphatase activity correlates with the maturation of neurotransmission in the cerebral cortex

Author

László Négyessy, Caroline Fonta, Pascal Barone, Luc Renaud, Centre de recherche cerveau et cognition (CERCO), Institut des sciences du cerveau de Toulouse. (ISCT), Université Toulouse - Jean Jaurès (UT2J)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-CHU Toulouse [Toulouse]-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Université Toulouse - Jean Jaurès (UT2J)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-CHU Toulouse [Toulouse]-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Department of Anatomy, Histology and Embryology, and Semmelweis University [Budapest]

Subjects
Aging, Neuropil, MESH: Callithrix, Nerve Fibers, Myelinated, Synaptic Transmission, MESH: Animals, Newborn, MESH: Synapses, Myelin, 0302 clinical medicine, MESH: Alkaline Phosphatase, Thalamus, MESH: Presynaptic Terminals, MESH: Glial Fibrillary Acidic Protein, MESH: Aging, MESH: Animals, Visual Cortex, MESH: Thalamus, 0303 health sciences, Node of Ranvier, General Neuroscience, Callithrix, Cell Differentiation, Immunohistochemistry, MESH: Nerve Fibers, Myelinated, medicine.anatomical_structure, Cerebral cortex, MESH: Microscopy, Electron, Transmission, Alkaline phosphatase, [SDV.NEU]Life Sciences [q-bio]/Neurons and Cognition [q-bio.NC], MESH: Cell Differentiation, Synaptic cleft, Presynaptic Terminals, Biology, Neurotransmission, Electron Transport Complex IV, 03 medical and health sciences, MESH: Neuropil, MESH: Electron Transport Complex IV, Microscopy, Electron, Transmission, Neuroplasticity, Glial Fibrillary Acidic Protein, Ranvier's Nodes, medicine, MESH: Synaptic Transmission, Animals, Visual Pathways, 030304 developmental biology, MESH: Visual Pathways, MESH: Visual Cortex, MESH: Biological Markers, MESH: Immunohistochemistry, Alkaline Phosphatase, Visual cortex, nervous system, Animals, Newborn, Synapses, MESH: Ranvier's Nodes, Neuroscience, 030217 neurology & neurosurgery, Biomarkers
Abstract

International audience; We have shown previously that the tissue nonspecific alkaline phosphatase (TNAP) is selectively expressed in the synaptic cleft of sensory cortical areas in adult mammals and, by using sensory deprivation, that TNAP activity depends on thalamocortical activity. We further analyzed this structural functional relationship by comparing the developmental pattern of TNAP activity to the maturation of the thalamocortical afferents in the primate brain (Callithrix jacchus). Cortical expression of alkaline phosphatase (AP) activity reflects the sequential maturation of the modality-specific sensory areas. Within the visual cortex, the regional and laminar distribution of AP correlates with the differential maturation of the magno- and parvocellular streams. AP activity, which is transiently expressed in the white matter, exhibits a complementary distributional pattern with myelin staining. Ultrastructural analysis revealed that AP activity is localized exclusively to the myelin-free axonal segments, including the node of Ranvier. It was also found that AP activity is gradually expressed in parallel with the maturation of synaptic contacts in the neuropile. These data suggest the involvement of AP, in addition to neurotransmitter synthesis previously suggested in the adult, in synaptic stabilization and in myelin pattern formation and put forward a role of AP in cortical plasticity and brain disorders.

Published
2005

20. Assessment of the early organization and maturation of infants' cerebral white matter fiber bundles: a feasibility study using quantitative diffusion tensor imaging and tractography

Author

Y. Cointepas, Ghislaine Dehaene-Lambertz, D. Le Bihan, Jessica Dubois, Lucie Hertz-Pannier, Service Hospitalier Frédéric Joliot (SHFJ), Université Paris-Saclay-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), IFR49 - Neurospin - CEA, Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Épilepsie de l'enfant et plasticité cérébrale (Inserm U663), Université Paris Descartes - Paris 5 (UPD5)-Institut National de la Santé et de la Recherche Médicale (INSERM), CHU Necker - Enfants Malades [AP-HP], Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP), Neuroimagerie cognitive (LCogn), Université Paris-Sud - Paris 11 (UP11)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de la Santé et de la Recherche Médicale (INSERM), Le Bihan, Denis, Département de radiothérapie, CRLCC Val d'Aurelle - Paul Lamarque, Institut de recherche en cancérologie de Montpellier (IRCM - U896 Inserm - UM1), Université Montpellier 1 (UM1)-CRLCC Val d'Aurelle - Paul Lamarque-Institut National de la Santé et de la Recherche Médicale (INSERM)-Université de Montpellier (UM), Institut d'imagerie neurofonctionnelle (IIN), Institut National de la Santé et de la Recherche Médicale (INSERM)-Ecole Nationale Supérieure des Télécommunications (ENST)-Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-École des hautes études en sciences sociales (EHESS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Université Paris-Sud - Paris 11 (UP11)-Centre National de la Recherche Scientifique (CNRS), Laboratoire Traitement et Communication de l'Information (LTCI), Télécom ParisTech-Institut Mines-Télécom [Paris] (IMT)-Centre National de la Recherche Scientifique (CNRS), Service NEUROSPIN (NEUROSPIN), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, IFR de Neuroimagerie Fonctionnelle (IFR 49), Human Brain Research Center [Kyoto] (HBRC), and Kyoto University [Kyoto]

Subjects
Male, Spinothalamic Tracts, [SDV.IB.IMA]Life Sciences [q-bio]/Bioengineering/Imaging, Pyramidal Tracts, MESH: Pyramidal Tracts, Corpus callosum, Brain mapping, Nerve Fibers, Myelinated, 030218 nuclear medicine & medical imaging, 0302 clinical medicine, MESH: Spinothalamic Tracts, Reference Values, Neural Pathways, Image Processing, Computer-Assisted, Cingulum (brain), MESH: Brain Mapping, Cerebral Cortex, Brain Mapping, MESH: Reference Values, Age Factors, Brain, MESH: Image Processing, Computer-Assisted, MESH: Infant, MESH: Nerve Fibers, Myelinated, medicine.anatomical_structure, Neurology, Female, Psychology, Algorithms, Tractography, Cognitive Neuroscience, MESH: Algorithms, MESH: Imaging, Three-Dimensional, MESH: Diffusion Magnetic Resonance Imaging, White matter, MESH: Brain, 03 medical and health sciences, Imaging, Three-Dimensional, Fractional anisotropy, medicine, Humans, MESH: Infant Behavior, Dominance, Cerebral, MESH: Age Factors, MESH: Humans, Pyramidal tracts, MESH: Neural Pathways, Infant, MESH: Dominance, Cerebral, MESH: Cerebral Cortex, MESH: Male, [SDV.IB.IMA] Life Sciences [q-bio]/Bioengineering/Imaging, Diffusion Magnetic Resonance Imaging, Infant Behavior, MESH: Anisotropy, Anisotropy, MESH: Female, Neuroscience, 030217 neurology & neurosurgery, Diffusion MRI
Abstract

International audience; The human infant is particularly immature at birth and brain maturation, with the myelination of white matter fibers, is protracted until adulthood. Diffusion tensor imaging offers the possibility to describe non invasively the fascicles spatial organization at an early stage and to follow the cerebral maturation with quantitative parameters that might be correlated with behavioral development. Here, we assessed the feasibility to study the organization and maturation of major white matter bundles in eighteen 1- to 4-month-old healthy infants, using a specific acquisition protocol customized to the immature brain (with 15 orientations of the diffusion gradients and a 700 s mm(-2)b factor). We were able to track most of the main fascicles described at later ages despite the low anisotropy of the infant white matter, using the FACT algorithm. This mapping allows us to propose a new method of quantification based on reconstructed tracts, split between specific regions, which should be more sensitive to specific changes in a bundle than the conventional approach, based on regions-of-interest. We observed variations in fractional anisotropy and mean diffusivity over the considered developmental period in most bundles (corpus callosum, cerebellar peduncles, cortico-spinal tract, spino-thalamic tract, capsules, radiations, longitudinal and uncinate fascicles, cingulum). The results are in good agreement with the known stages of white matter maturation and myelination, and the proposed approach might provide important insights on brain development.

Published
2005

21. Fiber Tract-Oriented Statistics for Quantitative Diffusion Tensor MRI Analysis

Author

Sylvain Gouttard, P. Thomas Fletcher, Isabelle Corouge, Guido Gerig, Sarang Joshi, Department of Computer Science, University of North Carolina [Chapel Hill] (UNC), University of North Carolina System (UNC)-University of North Carolina System (UNC), Scientific Computing and Imaging Institute (SCI Institute), University of Utah, Department of Radiation Oncology, Department of Psychiatry, and Corouge, Isabelle

Subjects
Geodesic, [INFO.INFO-IM] Computer Science [cs]/Medical Imaging, Information Storage and Retrieval, Nerve Fibers, Myelinated, Pattern Recognition, Automated, 030218 nuclear medicine & medical imaging, 0302 clinical medicine, [INFO.INFO-TS]Computer Science [cs]/Signal and Image Processing, Neural Pathways, Statistics, MESH: Pattern Recognition, Automated, Anisotropy, Mathematics, Radiological and Ultrasound Technology, Mathematical analysis, Brain, Diffusion tensor interpolation, Computer Graphics and Computer-Aided Design, MESH: Nerve Fibers, Myelinated, MESH: Reproducibility of Results, medicine.anatomical_structure, [INFO.INFO-TI] Computer Science [cs]/Image Processing [eess.IV], [INFO.INFO-TI]Computer Science [cs]/Image Processing [eess.IV], diffusion tensor statistics, [SDV.NEU]Life Sciences [q-bio]/Neurons and Cognition [q-bio.NC], Computer Vision and Pattern Recognition, MESH: Image Enhancement, [SPI.SIGNAL]Engineering Sciences [physics]/Signal and Image processing, Algorithms, Tractography, Interpolation, [INFO.INFO-TS] Computer Science [cs]/Signal and Image Processing, Fiber tract modeling, Models, Neurological, Health Informatics, MESH: Algorithms, MESH: Imaging, Three-Dimensional, MESH: Diffusion Magnetic Resonance Imaging, Sensitivity and Specificity, behavioral disciplines and activities, DTI analysis, White matter, MESH: Brain, 03 medical and health sciences, Imaging, Three-Dimensional, MESH: Computer Simulation, MESH: Models, Neurological, Artificial Intelligence, Image Interpretation, Computer-Assisted, Fractional anisotropy, [INFO.INFO-IM]Computer Science [cs]/Medical Imaging, medicine, MESH: Artificial Intelligence, Humans, Radiology, Nuclear Medicine and imaging, Computer Simulation, [SDV.NEU] Life Sciences [q-bio]/Neurons and Cognition [q-bio.NC], Tensor, [SPI.SIGNAL] Engineering Sciences [physics]/Signal and Image processing, MESH: Humans, Models, Statistical, Fiber (mathematics), fiber tract modeling, MESH: Neural Pathways, MESH: Information Storage and Retrieval, Reproducibility of Results, Image Enhancement, MESH: Sensitivity and Specificity, Data set, Diffusion Magnetic Resonance Imaging, nervous system, Symmetric space, Feasibility Studies, MESH: Feasibility Studies, MESH: Image Interpretation, Computer-Assisted, MESH: Models, Statistical, 030217 neurology & neurosurgery, Diffusion MRI
Abstract

International audience; Quantitative diffusion tensor imaging (DTI) has become the major imaging modality to study properties of white matter and the geometry of fiber tracts of the human brain. Clinical studies mostly focus on regional statistics of fractional anisotropy (FA) and mean diffusivity (MD) derived from tensors. Existing analysis techniques do not sufficiently take into account that the measurements are tensors, and thus require proper interpolation and statistics of tensors, and that regions of interest are fiber tracts with complex spatial geometry. We propose a new framework for quantitative tract-oriented DTI analysis that systematically includes tensor interpolation and averaging, using nonlinear Riemannian symmetric space. A new measure of tensor anisotropy, called geodesic anisotropy (GA) is applied and compared with FA. As a result, tracts of interest are represented by the geometry of the medial spine attributed with tensor statistics (average and variance) calculated within cross-sections. Feasibility of our approach is demonstrated on various fiber tracts of a single data set. A validation study, based on six repeated scans of the same subject, assesses the reproducibility of this new DTI data analysis framework.

Published
2005

22. Fiber tracking in q-ball fields using regularized particle trajectories

Author

Cyril Poupon, Bernard Rieul, Narly Golestani, André Constantinesco, Christophe Pallier, Y. Cointepas, Denis Rivière, Muriel Perrin, D. Le Bihan, J.-F. Mangin, Service central de radiologie et d'imagerie médicale, CHU Grenoble-Hôpital Michallon, Laboratoire d'Énergétique Moléculaire et Macroscopique, Combustion (EM2C), CentraleSupélec-Centre National de la Recherche Scientifique (CNRS)-Université Paris Saclay (COmUE), Service NEUROSPIN (NEUROSPIN), Université Paris-Saclay-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Laboratoire d'Imagerie et de Spectroscopie (LRMN), Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Institut d'imagerie neurofonctionnelle (IIN), Université Paris-Sud - Paris 11 (UP11)-Université Pierre et Marie Curie - Paris 6 (UPMC)-École des hautes études en sciences sociales (EHESS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP)-Ecole Nationale Supérieure des Télécommunications (ENST)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS), Laboratoire Traitement et Communication de l'Information (LTCI), Télécom ParisTech-Institut Mines-Télécom [Paris] (IMT)-Centre National de la Recherche Scientifique (CNRS), Neuroimagerie cognitive (LCogn), Université Paris-Sud - Paris 11 (UP11)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de la Santé et de la Recherche Médicale (INSERM), Service Hospitalier Frédéric Joliot (SHFJ), Génomique métabolique (UMR 8030), Genoscope - Centre national de séquençage [Evry] (GENOSCOPE), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université d'Évry-Val-d'Essonne (UEVE)-Centre National de la Recherche Scientifique (CNRS), Service d'exploration de la fonction respiratoire et de médecine du sport, Centre Hospitalier Universitaire de Toulouse (CHU Toulouse), Service de Biophysique et Médecine Nucléaire, CHU Strasbourg-Université Louis Pasteur - Strasbourg I-Hôpital de Hautepierre [Strasbourg], Human Brain Research Center [Kyoto] (HBRC), Kyoto University, National Institutes of Health [Bethesda] (NIH), IFR de Neuroimagerie Fonctionnelle (IFR 49), Laboratoire de Neuroimagerie Assistée par Ordinateur (LNAO), Center for Neuroscience and Behavioral Medicine, Children's National Medical Center, CentraleSupélec-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Institut National de la Santé et de la Recherche Médicale (INSERM)-ENST-Assistance publique - Hôpitaux de Paris (AP-HP) (APHP)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-École des hautes études en sciences sociales (EHESS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Université Paris-Sud - Paris 11 (UP11)-Centre National de la Recherche Scientifique (CNRS), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Université d'Évry-Val-d'Essonne (UEVE), CHU Toulouse [Toulouse], Kyoto University [Kyoto], Université Paris Saclay (COmUE)-Centre National de la Recherche Scientifique (CNRS)-CentraleSupélec, and Institut National de la Santé et de la Recherche Médicale (INSERM)-Ecole Nationale Supérieure des Télécommunications (ENST)-Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-École des hautes études en sciences sociales (EHESS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Université Paris-Sud - Paris 11 (UP11)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Computer science, [SDV.IB.IMA]Life Sciences [q-bio]/Bioengineering/Imaging, MESH: Algorithms, MESH: Imaging, Three-Dimensional, MESH: Diffusion Magnetic Resonance Imaging, Tracking (particle physics), computer.software_genre, Nerve Fibers, Myelinated, Sensitivity and Specificity, Imaging phantom, Pattern Recognition, Automated, 030218 nuclear medicine & medical imaging, 03 medical and health sciences, MESH: Brain, Imaging, Three-Dimensional, 0302 clinical medicine, Artificial Intelligence, Voxel, Image Interpretation, Computer-Assisted, Humans, MESH: Artificial Intelligence, MESH: Pattern Recognition, Automated, Computer vision, Tensor, MESH: Humans, Radon transform, Orientation (computer vision), business.industry, Fiber (mathematics), Brain, Reproducibility of Results, Image Enhancement, MESH: Sensitivity and Specificity, MESH: Nerve Fibers, Myelinated, MESH: Reproducibility of Results, Diffusion Magnetic Resonance Imaging, Bundle, Artificial intelligence, MESH: Image Enhancement, business, computer, MESH: Image Interpretation, Computer-Assisted, Algorithms, 030217 neurology & neurosurgery
Abstract

International audience; Most of the approaches dedicated to fiber tracking from diffusion-weighted MR data rely on a tensor model. However, the tensor model can only resolve a single fiber orientation within each imaging voxel. New emerging approaches have been proposed to obtain a better representation of the diffusion process occurring in fiber crossing. In this paper, we adapt a tracking algorithm to the q-ball representation, which results from a spherical Radon transform of high angular resolution data. This algorithm is based on a Monte-Carlo strategy, using regularized particle trajectories to sample the white matter geometry. The method is validated using a phantom of bundle crossing made up of haemodialysis fibers. The method is also applied to the detection of the auditory tract in three human subjects.

Published
2005

23. MR diffusion-based inference of a fiber bundle model from a population of subjects

Author

D. Rivière, D. Le Bihan, J.-F. Mangin, Narly Golestani, Jean-Baptiste Poline, V. El Kouby, Y. Cointepas, C. Poupon, Institut d'imagerie neurofonctionnelle (IIN), Université Paris-Sud - Paris 11 (UP11)-Université Pierre et Marie Curie - Paris 6 (UPMC)-École des hautes études en sciences sociales (EHESS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP)-Ecole Nationale Supérieure des Télécommunications (ENST)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS), Laboratoire Traitement et Communication de l'Information (LTCI), Télécom ParisTech-Institut Mines-Télécom [Paris] (IMT)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'Imagerie et de Spectroscopie (LRMN), Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Génomique métabolique (UMR 8030), Genoscope - Centre national de séquençage [Evry] (GENOSCOPE), Université Paris-Saclay-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université d'Évry-Val-d'Essonne (UEVE)-Centre National de la Recherche Scientifique (CNRS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Service d'exploration de la fonction respiratoire et de médecine du sport, Centre Hospitalier Universitaire de Toulouse (CHU Toulouse), Service Hospitalier Frédéric Joliot (SHFJ), Service NEUROSPIN (NEUROSPIN), IFR de Neuroimagerie Fonctionnelle (IFR 49), Human Brain Research Center [Kyoto] (HBRC), Kyoto University, National Institutes of Health [Bethesda] (NIH), Laboratoire de Neuroimagerie Assistée par Ordinateur (LNAO), Center for Neuroscience and Behavioral Medicine, Children's National Medical Center, Institut National de la Santé et de la Recherche Médicale (INSERM)-Ecole Nationale Supérieure des Télécommunications (ENST)-Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-École des hautes études en sciences sociales (EHESS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Université Paris-Sud - Paris 11 (UP11)-Centre National de la Recherche Scientifique (CNRS), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Université d'Évry-Val-d'Essonne (UEVE), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, CHU Toulouse [Toulouse], and Kyoto University [Kyoto]

Subjects
[SDV.IB.IMA]Life Sciences [q-bio]/Bioengineering/Imaging, Population, Inference, MESH: Algorithms, MESH: Imaging, Three-Dimensional, MESH: Diffusion Magnetic Resonance Imaging, Machine learning, computer.software_genre, Nerve Fibers, Myelinated, Sensitivity and Specificity, Pattern Recognition, Automated, 030218 nuclear medicine & medical imaging, Set (abstract data type), 03 medical and health sciences, MESH: Brain, Imaging, Three-Dimensional, 0302 clinical medicine, Artificial Intelligence, Image Interpretation, Computer-Assisted, Humans, MESH: Artificial Intelligence, MESH: Pattern Recognition, Automated, Cluster analysis, education, Mathematics, education.field_of_study, MESH: Humans, business.industry, Brain, Reproducibility of Results, Pattern recognition, Image Enhancement, MESH: Sensitivity and Specificity, MESH: Nerve Fibers, Myelinated, MESH: Reproducibility of Results, Diffusion Magnetic Resonance Imaging, Bundle, Spatial normalization, Artificial intelligence, MESH: Image Enhancement, Mr diffusion, business, computer, MESH: Image Interpretation, Computer-Assisted, Algorithms, 030217 neurology & neurosurgery, Diffusion MRI
Abstract

International audience; This paper proposes a method to infer a high level model of the white matter organization from a population of subjects using MR diffusion imaging. This method takes as input for each subject a set of trajectories stemming from any tracking algorithm. Then the inference results from two nested clustering stages. The first clustering converts each individual set of trajectories into a set of bundles supposed to represent large white matter pathways. The second clustering matches these bundles across subjects in order to provide a list of candidates for the bundle model. The method is applied on a population of eleven subjects and leads to the inference of 17 such candidates.

Published
2005

24. Syndecan-3 and syndecan-4 are enriched in Schwann cell perinodal processes

Author

Boutterin Marie-Claude, Denisenko Natalia, Carnaud Michèle, Goutebroze Laurence, Girault Jean-Antoine, Transduction du Signal et Plasticite Dans Le Systeme Nerveux, Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut National de la Santé et de la Recherche Médicale (INSERM), This work was supported in part by grants of Association pour la Recherche contre le Cancer, Fondation Schlumberger pour l'Enseignement et la Recherche, Fondation pour la Recherche Médicale, and Fondation NRJ, Maylin, Françoise, Institut du Fer à Moulin (IFM - Inserm U1270 - SU), and Institut National de la Santé et de la Recherche Médicale (INSERM)-Sorbonne Université (SU)

Subjects
MESH: Rats, [SDV.NEU.NB]Life Sciences [q-bio]/Neurons and Cognition [q-bio.NC]/Neurobiology, MESH: Membrane Glycoproteins, [SDV.CAN]Life Sciences [q-bio]/Cancer, Transfection, MESH: Research Support, Non-U.S. Gov't, Nerve Fibers, Myelinated, MESH: Phosphoproteins, Sodium Channels, lcsh:RC321-571, MESH: Sodium Channels, [SDV.CAN] Life Sciences [q-bio]/Cancer, Antibody Specificity, Chlorocebus aethiops, Ranvier's Nodes, Animals, MESH: Animals, [SDV.NEU] Life Sciences [q-bio]/Neurons and Cognition [q-bio.NC], MESH: Tra, MESH: Antibody Specificity, lcsh:Neurosciences. Biological psychiatry. Neuropsychiatry, ComputingMilieux_MISCELLANEOUS, Membrane Glycoproteins, lcsh:QP351-495, Phosphoproteins, Sciatic Nerve, MESH: Cercopithecus aethiops, Rats, MESH: Nerve Fibers, Myelinated, MESH: COS Cells, Cytoskeletal Proteins, MESH: Sciatic Nerve, lcsh:Neurophysiology and neuropsychology, nervous system, MESH: Proteoglycans, COS Cells, Syndecan-3, Proteoglycans, Syndecan-4, MESH: Ranvier's Nodes, [SDV.NEU]Life Sciences [q-bio]/Neurons and Cognition [q-bio.NC], Schwann Cells, MESH: Schwann Cells, Research Article
Abstract

Background Nodes of Ranvier correspond to specialized axonal domains where voltage-gated sodium channels are highly concentrated. In the peripheral nervous system, they are covered by Schwann cells microvilli, where three homologous cytoskeletal-associated proteins, ezrin, radixin and moesin (ERM proteins) have been found, to be enriched. These glial processes are thought to play a crucial role in organizing axonal nodal domains during development. However, little is known about the molecules present in Schwann cell processes that could mediate axoglial interactions. The aim of this study is to identify by immunocytochemistry transmembrane proteins enriched in Schwann cells processes that could interact, directly or indirectly, with axonal proteins. Results We show that syndecan-3 (S3) and syndecan-4 (S4), two proteoglycans expressed in Schwann cells, are enriched in perinodal processes in rat sciatic nerves. S3 labeling was localized in close vicinity of sodium channels as early as post-natal day 2, and highly concentrated at nodes of Ranvier in the adult. S4 immunoreactivity accumulated at nodes later, and was also prominent in internodal regions of myelinated fibers. Both S3 and S4 were co-localized with ezrin in perinodal processes. Conclusions Our data identify S3 and S4 as transmembrane proteins specifically enriched in Schwann cell perinodal processes, and suggest that S3 may be involved in early axoglial interactions during development.

Published
2003

25. From the diffusion coefficient to the diffusion tensor

Author

Denis Le Bihan, Peter C.M. van Zijl, Service NEUROSPIN (NEUROSPIN), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, IFR de Neuroimagerie Fonctionnelle (IFR 49), Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Human Brain Research Center [Kyoto] (HBRC), Kyoto University [Kyoto], Service Hospitalier Frédéric Joliot (SHFJ), Université Paris-Saclay-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), and Kyoto University

Subjects
Field (physics), Computer science, [SDV.IB.IMA]Life Sciences [q-bio]/Bioengineering/Imaging, MESH: Diffusion Magnetic Resonance Imaging, Nerve Fibers, Myelinated, 030218 nuclear medicine & medical imaging, Diffusion, 03 medical and health sciences, MESH: Brain, MESH: Neural Networks (Computer), 0302 clinical medicine, Nuclear magnetic resonance, MESH: Water, Radiology, Nuclear Medicine and imaging, Statistical physics, MESH: Brain Chemistry, Diffusion (business), Spectroscopy, Brain Chemistry, Brain, Water, MESH: Diffusion, MESH: Nerve Fibers, Myelinated, Diffusion Magnetic Resonance Imaging, MESH: Anisotropy, Molecular Medicine, Anisotropy, Neural Networks, Computer, 030217 neurology & neurosurgery, Diffusion MRI, Tractography
Abstract

With diffusion tensor MRI one has access to the organization in space of tissue microstructural components. This outstanding potential adds, however, another layer of complexity to the diffusion MRI data acquisition and analysis processes. Over the last few years many articles have been published dealing with those matters. This special issue is thus timely to provide readers with the synthesis and the overall viewpoints from leading contributors to the field. Copyright © 2002 John Wiley & Sons, Ltd.

Published
2002

26. A framework based on spin glass models for the inference of anatomical connectivity from diffusion-weighted MR data - a technical review

Author

Mangin, J.-F., Poupon, C., Cointepas, Y., Rivière, D., Papadopoulos-Orfanos, Dimitri, Clark, C. A., Régis, J., Le Bihan, D., Laboratoire de Neuroimagerie Assistée par Ordinateur (LNAO), Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Service Hospitalier Frédéric Joliot (SHFJ), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Center for Neuroscience and Behavioral Medicine, Children's National Medical Center, Laboratoire d'Imagerie et de Spectroscopie (LRMN), Institut d'imagerie neurofonctionnelle (IIN), Institut National de la Santé et de la Recherche Médicale (INSERM)-Ecole Nationale Supérieure des Télécommunications (ENST)-Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-École des hautes études en sciences sociales (EHESS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Université Paris-Sud - Paris 11 (UP11)-Centre National de la Recherche Scientifique (CNRS), Laboratoire Traitement et Communication de l'Information (LTCI), Télécom ParisTech-Institut Mines-Télécom [Paris] (IMT)-Centre National de la Recherche Scientifique (CNRS), Génomique métabolique (UMR 8030), Genoscope - Centre national de séquençage [Evry] (GENOSCOPE), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Université d'Évry-Val-d'Essonne (UEVE), Service d'exploration de la fonction respiratoire et de médecine du sport, CHU Toulouse [Toulouse], Epilepsies, Lesions Cerebrales et Systemes Neuraux de la Cognition, Université de la Méditerranée - Aix-Marseille 2-Institut National de la Santé et de la Recherche Médicale (INSERM), Service de neurochirurgie, Université de la Méditerranée - Aix-Marseille 2-Assistance Publique - Hôpitaux de Marseille (APHM)- Hôpital de la Timone [CHU - APHM] (TIMONE), Service NEUROSPIN (NEUROSPIN), IFR de Neuroimagerie Fonctionnelle (IFR 49), Human Brain Research Center [Kyoto] (HBRC), Kyoto University [Kyoto], Université Paris-Saclay-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Université Paris-Sud - Paris 11 (UP11)-Université Pierre et Marie Curie - Paris 6 (UPMC)-École des hautes études en sciences sociales (EHESS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP)-Ecole Nationale Supérieure des Télécommunications (ENST)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université d'Évry-Val-d'Essonne (UEVE)-Centre National de la Recherche Scientifique (CNRS), Centre Hospitalier Universitaire de Toulouse (CHU Toulouse), Service de neurochirurgie [CHU Marseille], and Kyoto University

Subjects
Quality Control, [SDV.IB.IMA]Life Sciences [q-bio]/Bioengineering/Imaging, MESH: Quality Control, MESH: Algorithms, MESH: Imaging, Three-Dimensional, MESH: Diffusion Magnetic Resonance Imaging, Models, Biological, Nerve Fibers, Myelinated, Pattern Recognition, Automated, MESH: Brain, Imaging, Three-Dimensional, Neural Pathways, MESH: Spin Labels, Methods, Humans, MESH: Pattern Recognition, Automated, MESH: Methods, MESH: Brain Mapping, Brain Mapping, MESH: Humans, Quantitative Biology::Neurons and Cognition, MESH: Neural Pathways, MESH: Models, Biological, Brain, Image Enhancement, MESH: Nerve Fibers, Myelinated, MESH: Astrocytes, Diffusion Magnetic Resonance Imaging, MESH: Nerve Net, Astrocytes, Spin Labels, Nerve Net, MESH: Image Enhancement, Algorithms
Abstract

International audience; A family of methods aiming at the reconstruction of a putative fascicle map from any diffusion-weighted dataset is proposed. This fascicle map is defined as a trade-off between local information on voxel microstructure provided by diffusion data and a priori information on the low curvature of plausible fascicles. The optimal fascicle map is the minimum energy configuration of a simulated spin glass in which each spin represents a fascicle piece. This spin glass is embedded into a simulated magnetic external field that tends to align the spins along the more probable fiber orientations according to diffusion models. A model of spin interactions related to the curvature of the underlying fascicles introduces a low bending potential constraint. Hence, the optimal configuration is a trade-off between these two kind of forces acting on the spins. Experimental results are presented for the simplest spin glass model made up of compass needles located in the center of each voxel of a tensor based acquisition.

Published
2002

27. A molecular view on paranodal junctions of myelinated fibers

Author

Catherine Faivre-Sarrailh, Laurence Goutebroze, Natalia Denisenko-Nehrbass, Jean-Antoine Girault, Institut du Fer à Moulin (IFM - Inserm U1270 - SU), and Institut National de la Santé et de la Recherche Médicale (INSERM)-Sorbonne Université (SU)

Subjects
MESH: Axons, Molecular composition, [SDV.NEU.NB]Life Sciences [q-bio]/Neurons and Cognition [q-bio.NC]/Neurobiology, MESH: Membrane Glycoproteins, Biology, MESH: Neuropeptides, Nerve Fibers, Myelinated, 03 medical and health sciences, Myelin, 0302 clinical medicine, Physiology (medical), Axonal membrane, Ranvier's Nodes, medicine, Transmembrane glycoprotein, Animals, Humans, MESH: Animals, Axon, 030304 developmental biology, 0303 health sciences, Membrane Glycoproteins, MESH: Humans, General Neuroscience, Neuropeptides, Ranvier node, Intracellular Membranes, Axolemma, Axons, Cell biology, MESH: Nerve Fibers, Myelinated, MESH: Extracellular Space, MESH: Intracellular Membranes, medicine.anatomical_structure, nervous system, MESH: Ranvier's Nodes, Extracellular Space, 030217 neurology & neurosurgery, Intracellular
Abstract

International audience; The axoglial paranodal junctions, flanking the Ranvier nodes, are specialized adhesion sites between the axolemma and myelinating glial cells. Unraveling the molecular composition of paranodal junctions is crucial for understanding the mechanisms involved in the regulation of myelination, and positioning and segregation of the voltage-gated Na+ and K+ channels, essential for the generation and conduction of action potentials. Paranodin/Caspr was the first neuronal transmembrane glycoprotein identified at the paranodal junctions. Paranodin/Caspr is associated on the axonal membrane with contactin/F3, a glycosylphosphatidylinositol-anchored protein, essential for its correct targeting. The extra and intracellular regions of paranodin encompass multiple domains which can be involved in protein-protein interactions with other axonal proteins and glial proteins. Thus, paranodin plays a central role in the assembly of multiprotein complexes necessary for the formation and maintenance of paranodal junctions.

Published
2002

28. Diffusion tensor imaging study of subcortical gray matter in cadasil

Author

C. Poupon, Hugues Chabriat, Sabina Pappatà, J.-F. Mangin, Antoinette Jobert, Nicolas Molko, Katayoun Vahedi, Marie-Germaine Bousser, Denis LeBihan, Laboratoire de Neuroimagerie Assistée par Ordinateur (LNAO), Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Service Hospitalier Frédéric Joliot (SHFJ), Université Paris-Saclay-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Center for Neuroscience and Behavioral Medicine, Children's National Medical Center, Laboratoire d'Imagerie et de Spectroscopie (LRMN), IFR de Neuroimagerie Fonctionnelle (IFR 49), Institutions et Dynamiques Historiques de l'Economie (IDHE), École normale supérieure - Cachan (ENS Cachan)-Université Paris 1 Panthéon-Sorbonne (UP1)-Université Paris 8 Vincennes-Saint-Denis (UP8)-Université Paris Nanterre (UPN)-Centre National de la Recherche Scientifique (CNRS), Service NEUROSPIN (NEUROSPIN), Service de neurologie [Univ. Paris VII], Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP)-Hôpital Lariboisière-Fernand-Widal [APHP], Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP)-Université Paris Diderot - Paris 7 (UPD7), Centre de biophysique moléculaire (CBM), Université d'Orléans (UO)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Université d'Orléans (UO)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC), École normale supérieure - Cachan (ENS Cachan)-Université Panthéon-Sorbonne (UP1)-Université Paris 8 Vincennes-Saint-Denis (UP8)-Université Paris Nanterre (UPN)-Centre National de la Recherche Scientifique (CNRS), Assistance publique - Hôpitaux de Paris (AP-HP) (APHP)-Hôpital Lariboisière-Université Paris Diderot - Paris 7 (UPD7), and Université d'Orléans (UO)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Pathology, [SDV.IB.IMA]Life Sciences [q-bio]/Bioengineering/Imaging, Neuropsychological Tests, Nerve Fibers, Myelinated, 030218 nuclear medicine & medical imaging, MESH: Putamen, MESH: Magnetic Resonance Imaging, Diffusion, Leukoencephalopathy, 0302 clinical medicine, Thalamus, Centrum semiovale, CADASIL, MESH: Receptors, Cell Surface, MESH: Thalamus, MESH: Middle Aged, Putamen, MESH: Diffusion, MESH: Neuropsychological Tests, Cerebral Infarction, Middle Aged, Magnetic Resonance Imaging, Subcortical gray matter, MESH: Nerve Fibers, Myelinated, medicine.anatomical_structure, MESH: Dementia, Multi-Infarct, Cardiology and Cardiovascular Medicine, medicine.medical_specialty, Receptors, Cell Surface, Grey matter, White matter, 03 medical and health sciences, Proto-Oncogene Proteins, MESH: Analysis of Variance, medicine, MESH: Cerebral Infarction, Humans, Advanced and Specialized Nursing, Analysis of Variance, MESH: Humans, business.industry, CADASIL Syndrome, medicine.disease, MESH: Proto-Oncogene Proteins, Dementia, Multi-Infarct, nervous system, MESH: Anisotropy, Anisotropy, Neurology (clinical), business, 030217 neurology & neurosurgery, Diffusion MRI
Abstract

Background and Purpose — In cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL), water diffusion changes suggestive of microstructural tissue alterations have been recently reported in abnormal- and normal-appearing white matter as seen on T2-weighted images. In the subcortical gray matter, typical lacunar infarcts are repeatedly observed. Whether microstructural tissue changes are also present outside these lesions within the putamen or thalamus remains unknown. Methods — We used diffusion tensor imaging, an MRI method highly sensitive to cerebral microstructure, in 20 CADASIL patients and 12 controls. Both the trace of the diffusion tensor [Tr(D)] and an anisotropic diffusion index (volume ratio) of diffusion were measured within the putamen and thalamus outside typical lacunar infarcts as detected on both T1- and T2-weighted images. Results — A significant increase in Tr(D) and a decrease in anisotropy were observed in the putamen and thalamus in patients. The right/left indices of Tr(D) in the thalamus, but not in the putamen, were strongly correlated with the corresponding indices calculated in the white matter of the centrum semiovale. In addition, the diffusion increase in the thalamus was positively correlated with Tr(D) and with the load of small deep infarcts within the white matter and negatively correlated with the Mini-Mental State Examination score. Conclusions — Our results suggest that microstructural tissue alterations are present in the putamen and thalamus, outside the typical lacunar infarcts in CADASIL. In the thalamus, these microstructural changes appear constant and are even observed in asymptomatic subjects. Some of these thalamic changes appear to result from degeneration of thalamocortical pathways secondary to ischemic white matter damage. The importance of this degenerative phenomenon in the pathophysiology of CADASIL requires further investigation.

Published
2001

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