References of "Moonen, Gustave"
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See detailGlycine Triggers an Intracellular Calcium Influx in Oligodendrocyte Progenitor Cells Which Is Mediated by the Activation of Both the Ionotropic Glycine Receptor and Na+-Dependent Transporters
Belachew, Shibeshih ULg; Malgrange, Brigitte ULg; Rigo, Jean-Michel et al

in European Journal of Neuroscience (2000), 12(6), 1924-30

Using fluo-3 calcium imaging, we demonstrate that glycine induces an increase in intracellular calcium concentration ([Ca2+]i) in cortical oligodendrocyte progenitor (OP) cells. This effect results from a ... [more ▼]

Using fluo-3 calcium imaging, we demonstrate that glycine induces an increase in intracellular calcium concentration ([Ca2+]i) in cortical oligodendrocyte progenitor (OP) cells. This effect results from a calcium entry through voltage-gated calcium channels (VGCC), as it is observed only in OP cells expressing such channels, and it is abolished either by removal of calcium from the extracellular medium or by application of an L-type VGCC blocker. Glycine-triggered Ca2+ influx in OP cells actually results from an initial depolarization that is the consequence of the activation of both the ionotropic glycine receptor (GlyR) and Na+-dependent transporters, most probably the glycine transporters 1 (GLYT1) and/or 2 (GLYT2) which are colocalized in these cells. Through this GlyR- and transporter-mediated effect on OP intrcellular calcium concentration [Ca2+]i, glycine released by neurons may, as well as other neurotransmitters, serve as a signal between neurons and OP during development. [less ▲]

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See detailEpidermal Growth Factor Upregulates Production of Supernumerary Hair Cells in Neonatal Rat Organ of Corti Explants
Lefèbvre, Philippe ULg; Malgrange, Brigitte ULg; Thiry, Marc ULg et al

in Acta Oto-Laryngologica (2000), 120(2), 142-5

The organ of Corti is highly ordered, with a single row of inner hair cells and three rows of outer hair cells. The number of hair cells produced was thought to be limited by the time of their terminal ... [more ▼]

The organ of Corti is highly ordered, with a single row of inner hair cells and three rows of outer hair cells. The number of hair cells produced was thought to be limited by the time of their terminal mitosis (i.e. E14 in the mouse). However, exogenous application of retinoic acid has been shown to stimulate the formation of supernumerary hair cells in organ of Corti explants from E13 to E16 mouse embryos. Using late embryonic and neonatal rat organ of Corti explants, we investigated the potential for production of supernumerary hair cells in more mature auditory sensory epithelia. When newborn rat organ of Corti explants were cultured under control conditions, an area of supernumerary hair cells was observed in a segment of organ of Corti that was at the junction between the basal and middle turns. In these areas of supernumerary hair cells the number of hair cells increased per unit of length, but remained constant per surface unit, further demonstrating the supernumerary character of this phenomenon. Organ of Corti explants treated with epidermal growth factor (EGF) showed a 50% increase in the length of the organ of Corti segment containing supernumerary hair cells. Upregulation of supernumerary hair cell formation by EGF was found to start and be maximal at birth (P0) and to disappear by 2 days after birth (P2). Treatment of EGF stimulated P0 explants with an antimitotic drug, cytosine arabinoside (ARAc), demonstrated that the production of supernumerary hair cells occurred independently of cell division. [less ▲]

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See detailSupernumerary outer hair cells arise external to the last row of sensory cells in the neonatal organ of Corti
Lefèbvre, P; Malgrange, B; Thiry, Marc ULg et al

Conference (2000)

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See detailThe radial glial cell antigen recognized by the RC2 antibody: characterization and modulation in vitro of its expression
Chanas-Sacré, G; Thiry, Marc ULg; Rogister, B et al

in Revista de Neurologia (2000), 24

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See detailBrain activation during somatosensory and auditory stimulation in acute vegetative state of anoxic origin
Laureys, Steven ULg; Faymonville, Marie ULg; Del Fiore, G. et al

in Physiological imaging of the brain with PET (2000)

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See detailAuditory processing in the vegetative state.
Laureys, Steven ULg; Faymonville, Marie ULg; Degueldre, Christian ULg et al

in Brain : A Journal of Neurology (2000), 123 ( Pt 8)

H(2)(15)O-PET was used to investigate changes in regional cerebral blood flow in response to auditory stimulation in patients in the vegetative state. Five patients in a vegetative state of hypoxic origin ... [more ▼]

H(2)(15)O-PET was used to investigate changes in regional cerebral blood flow in response to auditory stimulation in patients in the vegetative state. Five patients in a vegetative state of hypoxic origin were compared with 18 age-matched controls. In addition, the cerebral metabolism of these patients and 53 age-matched controls was studied using [(18)F]fluorodeoxyglucose. In control subjects, auditory click stimuli activated bilateral auditory cortices [Brodmann areas (BA) 41 and 42] and the contralateral auditory association cortices (BA 22). In the patients, although resting metabolism was decreased to 61% of normal values, bilateral auditory areas 41 and 42 showed activation as seen in the controls, but the temporoparietal junction cortex (BA 22) failed to be activated. Moreover, the auditory association cortex was functionally disconnected from the posterior parietal association area (BA 40), the anterior cingulate cortex (BA 24) and the hippocampus, as revealed by psychophysiological interaction analysis. Thus, despite altered resting metabolism, the auditory primary cortices were still activated during external stimulation, whereas hierarchically higher-order multi- modal association areas were not. Such a cascade of functional disconnections along the auditory cortical pathways, from the primary auditory areas to multimodal and limbic areas, suggests that the residual cortical processing observed in the vegetative state cannot lead to the integrative processes that are thought to be necessary for the attainment of the normal level of awareness. [less ▲]

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See detailPET scanning and neuronal loss in acute vegetative state
Laureys, Steven ULg; Faymonville, Marie ULg; Moonen, Gustave ULg et al

in Lancet (2000), 355(9217), 1825-1826

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See detailIdentification of Psf, the Polypyrimidine Tract-Binding Protein-Associated Splicing Factor, as a Developmentally Regulated Neuronal Protein
Chanas-Sacre, Grazyna; Mazy-Servais, Cécile; Wattiez, Ruddy et al

in Journal of Neuroscience Research (1999), 57(1), 62-73

The polypyrimidine tract-binding protein-associated splicing factor (PSF), which plays an essential role in mammalian spliceosomes, has been found to be expressed by differentiating neurons in developing ... [more ▼]

The polypyrimidine tract-binding protein-associated splicing factor (PSF), which plays an essential role in mammalian spliceosomes, has been found to be expressed by differentiating neurons in developing mouse brain. The sequence of a fragment of mouse PSF was found to be remarkably similar to that of human PSF. Both the expression of PSF mRNA in cortex and cerebellum and PSF immunoreactivity in all brain areas were high during embryonic and early postnatal life and almost disappeared in adult tissue, except in the hippocampus and olfactory bulb where various neuronal populations remained PSF-immunopositive. Double-labeling experiments with anti-PSF antibody and anti-neurofilaments or anti-glial fibrillary acidic protein antibodies on sections of cortex, hippocampus, and cerebellum indicate that PSF is expressed by differentiating neurons but not by astrocytic cells. In vitro, mouse PSF was found to be expressed by differentiating cortical and cerebellar neurons. Radial glia or astrocyte nuclei were not immunopositive; however, oligodendrocytes differentiating in vitro were found to express PSF. The restricted expression of PSF suggests that this splicing factor could be involved in the control of neuronal-specific splicing events occurring at particular stages of neuronal differentiation and maturation. [less ▲]

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See detailGrafts of Meningeal Fibroblasts in Adult Rat Spinal Cord Lesion Promote Axonal Regrowth
Franzen, Rachelle ULg; Martin, Didier ULg; Daloze, A. et al

in Neuroreport (1999), 10(7), 1551-6

We have studied the morphological consequences of implantation into the injured adult rat spinal cord of fibroblasts derived from the meninges overlying the cerebral cortex. Our initial objective was to ... [more ▼]

We have studied the morphological consequences of implantation into the injured adult rat spinal cord of fibroblasts derived from the meninges overlying the cerebral cortex. Our initial objective was to reproduce the well known post-traumatic fibroadhesive scar observed in the clinical situation. One month after implantation, instead of having formed a fibroadhesive scar, fibroblasts had promoted the regeneration of peptidergic axons originating from dorsal root afferents and, to a lesser extent, of supraspinal serotonergic fibers at the periphery of the grafts. Using RT-PCR we were able to identify in cultures of meningeal-derived fibroblasts mRNAs for beta-NGF, NT3, aFGF and bFGF, which suggests that the promoting effect on axonal regeneration of these cells is at least in part due to their capacity to synthesize neurotrophic factors. [less ▲]

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See detailSclérose latérale amyotrophique
Moonen, Gustave ULg; WANG, François-Charles ULg

Scientific conference (1999, May 04)

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See detailNeurotransmitter-Mediated Regulation of Cns Myelination: A Review
Belachew, Shibeshih ULg; Rogister, Bernard ULg; Rigo, Jean-Michel et al

in Acta Neurologica Belgica (1999), 99(1), 21-31

In addition to treatments aimed at preventing or limiting damage to myelin and oligodendrocytes, there is a crucial need for repair strategies in human demyelinating disorders. There is increasing ... [more ▼]

In addition to treatments aimed at preventing or limiting damage to myelin and oligodendrocytes, there is a crucial need for repair strategies in human demyelinating disorders. There is increasing evidence that besides growth factors, neurotransmitters can regulate different steps of the oligodendrogliogenesis. The present review on neurotransmitter receptor expression and function in the oligodendrocyte lineage emphasizes the concept that in this lineage cell proliferation and differentiation can be controlled through the modulation of the functional state of channel proteins and receptors, such as the delayed K+ rectifier, the AMPA/kainate, dopamine or muscarinic receptors, and, most likely, others yet to be found. We anticipate that a better understanding of the neurotransmitter-mediated neuronal oligodendroglial communication network opens prospects in the field of central nervous system (CNS) myelin repair, allowing the recruitment of the myelinating machinery that is known to remain present but quiescent in the CNS of multiple sclerosis patients. [less ▲]

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See detailOligodendrocytes: From Development to Demyelinated Lesion Repair
Rogister, Bernard ULg; Belachew, Shibeshih ULg; Moonen, Gustave ULg

in Acta Neurologica Belgica (1999), 99(1), 32-9

Spontaneous but incomplete remyelination is observed after a demyelinating lesion. We know since ten years now that oligodendrocyte progenitors, (OP) and totipotent neural stem cells remain present in the ... [more ▼]

Spontaneous but incomplete remyelination is observed after a demyelinating lesion. We know since ten years now that oligodendrocyte progenitors, (OP) and totipotent neural stem cells remain present in the central nervous system of adult mammals. [less ▲]

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See detailNeonatal rat organ of Corti forms supernumerary hair cells in response to growth factor treatment
Lefebvre, P; Malgrange, B; Thiry, Marc ULg et al

Conference (1999)

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See detailNeonatal rat organ of Corti forms supernumerary hair cells in response to growth factor treatment
Malgrange, B; Lefebvre, P; Rigo, J-M et al

Poster (1999)

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See detailNeonatal rat organ of Corti forms supernumerary hair cells in response to growth factor treatment
Lefèbvre, P; Malgrange, B; Thiry, Marc ULg et al

Conference (1999)

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See detailA 295 kDa intermediate filament-associated protein in radial glial and developing muscle cells in vivo and in vitro
Leprince, P; Chanas-Sacré, G; Thiry, Marc ULg et al

Poster (1999)

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See detailCultured Oligodendrocyte Progenitors Derived from Cerebral Cortex Express a Glycine Receptor Which Is Pharmacologically Distinct from the Neuronal Isoform
Belachew, Shibeshih ULg; Rogister, Bernard ULg; Rigo, Jean-Michel et al

in European Journal of Neuroscience (1998), 10(11), 3556-64

Using the whole-cell patch-clamp technique, we demonstrate glycine-induced currents in oligosphere-derived oligodendrocyte progenitors cultured from newborn rats. Similar inward currents are also ... [more ▼]

Using the whole-cell patch-clamp technique, we demonstrate glycine-induced currents in oligosphere-derived oligodendrocyte progenitors cultured from newborn rats. Similar inward currents are also triggered by beta-alanine and taurine, two established glycine receptor agonists. In our recording conditions, glycine-gated currents in oligodendrocyte progenitors reverse about 0 mV and are reversibly inhibited by the glycine competitive antagonist strychnine, the Cl- channel blocker picrotoxinin and the non-competitive antagonist cyanotriphenylborate. The oligodendrocyte progenitors glycine receptor (GlyR) differs from the corresponding neuronal receptor: [3H]strychnine binding data and the strychnine inhibition curve of glycine-induced currents in oligodendrocyte progenitor cultures suggest the existence of two strychnine binding sites on the oligodendroglial GlyR. Using total RNA isolated from oligodendrocyte progenitors cultures, reverse transcription-polymerase chain reaction analysis of glycine receptor subunit expression shows the presence of alpha2 and beta subunits and immunocytochemical stainings confirm that this GlyR contains an alpha subunit which is not alpha1. The molecular structure of the oligodendroglial GlyR could be either homopentameric alpha2 or heteromeric alpha2beta but in both cases, the sequence of the alpha2 or beta subunits have to be different from the known neuronal sequences in order to explain, respectively, the cyanotriphenylborate (alpha2) and picrotoxinin (beta) sensitivities. This work thus demonstrates that GlyR are expressed by oligodendrocytes obtained not only from spinal cord but also from supraspinal structures. The pharmacological properties and presumably the molecular structure of oligodendroglial GlyR are original. The physiological meaning of the presence of such receptors on developing and mature oligodendrocytes remains unknown. [less ▲]

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