Neurocentre Magendie

Thomas PAPOUIN





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Cursus:
2004-2007 : ENS Ulm & UPMC - Paris
2006 : MNI McGill University - Montréal (M1)
2007 : Institut Pasteur, ENS Ulm & UPMC - Paris (M2)
2008-2011 : PhD, Neurocentre Magendie

Expertise: Eléctrophysiology, NMDAR, Neuron-Glia Interaction





7 publication(s) depuis Septembre 2008:


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* equal contribution
Les IF indiqués ont été collectés par le Web of Sciences en


11/2016 | Cereb Cortex   IF 8.3
Activity-Dependent Neuroplasticity Induced by an Enriched Environment Reverses Cognitive Deficits in Scribble Deficient Mouse
Hilal ML, Moreau MM, Racca C, Pinheiro V, Piguel N, Santoni M-J, Dos santos carvalho S, Blanc JM, Abada Y, Peyroutou R, Medina C, Doat H, Papouin T, Vuillard L, Borg JP, Rachel R, Panatier A, Montcouquiol M*, Oliet SHR*, Sans N*

Abstract:
Planar cell polarity (PCP) signaling is well known to play a critical role during prenatal brain development; whether it plays specific roles at postnatal stages remains rather unknown. Here, we investigated the role of a key PCP-associated gene scrib in CA1 hippocampal structure and function at postnatal stages. We found that Scrib is required for learning and memory consolidation in the Morris water maze as well as synaptic maturation and NMDAR-dependent bidirectional plasticity. Furthermore, we unveiled a direct molecular interaction between Scrib and PP1/PP2A phosphatases whose levels were decreased in postsynaptic density of conditional knock-out mice. Remarkably, exposure to enriched environment (EE) preserved memory formation in CaMK-Scrib−/− mice by recovering synaptic plasticity and maturation. Thus, Scrib is required for synaptic function involved in memory formation and EE has beneficiary therapeutic effects. Our results demonstrate a distinct new role for a PCP-associated protein, beyond embryonic development, in cognitive functions during adulthood.




19/10/2014 | Philos Trans R Soc Lond B Biol Sci   IF 5.1
Organization, control and function of extrasynaptic NMDA receptors.
Papouin T, Oliet SH

Abstract:
N-methyl D-aspartate receptors (NMDARs) exist in different forms owing to multiple combinations of subunits that can assemble into a functional receptor. In addition, they are located not only at synapses but also at extrasynaptic sites. There has been intense speculation over the past decade about whether specific NMDAR subtypes and/or locations are responsible for inducing synaptic plasticity and excitotoxicity. Here, we review the latest findings on the organization, subunit composition and endogenous control of NMDARs at extrasynaptic sites and consider their putative functions. Because astrocytes are capable of controlling NMDARs through the release of gliotransmitters, we also discuss the role of the glial environment in regulating the activity of these receptors.




03/2013 | Med Sci (Paris)
[Importance of the location of NMDA glutamate receptors].
Oliet SH, Papouin T

Abstract:





03/08/2012 | Cell   IF 28.7
Synaptic and Extrasynaptic NMDA Receptors Are Gated by Different Endogenous Coagonists.
Papouin T, Ladepeche L, Ruel J, Sacchi S, Labasque M, Hanini M, Groc L, Pollegioni L, Mothet JP, Oliet SH

Abstract:
N-methyl-d-aspartate receptors (NMDARs) are located in neuronal cell membranes at synaptic and extrasynaptic locations, where they are believed to mediate distinct physiological and pathological processes. Activation of NMDARs requires glutamate and a coagonist whose nature and impact on NMDAR physiology remain elusive. We report that synaptic and extrasynaptic NMDARs are gated by different endogenous coagonists, d-serine and glycine, respectively. The regionalized availability of the coagonists matches the preferential affinity of synaptic NMDARs for d-serine and extrasynaptic NMDARs for glycine. Furthermore, glycine and d-serine inhibit NMDAR surface trafficking in a subunit-dependent manner, which is likely to influence NMDARs subcellular location. Taking advantage of this coagonist segregation, we demonstrate that long-term potentiation and NMDA-induced neurotoxicity rely on synaptic NMDARs only. Conversely, long-term depression requires both synaptic and extrasynaptic receptors. Our observations provide key insights into the operating mode of NMDARs, emphasizing functional distinctions between synaptic and extrasynaptic NMDARs in brain physiology.




21/07/2010 | J Neurosci   IF 5.9
The planar polarity protein Scribble1 is essential for neuronal plasticity and brain function.
Moreau MM, Piguel N, Papouin T, Koehl M, Durand CM, Rubio ME, Loll F, Richard EM, Mazzocco C, Racca C, Oliet SH, Abrous DN, Montcouquiol M, Sans N

Abstract:
Scribble (Scrib) is a key regulator of apicobasal polarity, presynaptic architecture, and short-term synaptic plasticity in Drosophila. In mammals, its homolog Scrib1 has been implicated in cancer, neural tube closure, and planar cell polarity (PCP), but its specific role in the developing and adult nervous system is unclear. Here, we used the circletail mutant, a mouse model for PCP defects, to show that Scrib1 is located in spines where it influences actin cytoskeleton and spine morphing. In the hippocampus of these mutants, we observed an increased synapse pruning associated with an increased number of enlarged spines and postsynaptic density, and a decreased number of perforated synapses. This phenotype was associated with a mislocalization of the signaling pathway downstream of Scrib1, leading to an overall activation of Rac1 and defects in actin dynamic reorganization. Finally, Scrib1-deficient mice exhibit enhanced learning and memory abilities and impaired social behavior, two features relevant to autistic spectrum disorders. Our data identify Scrib1 as a crucial regulator of brain development and spine morphology, and suggest that Scrib1(crc/+) mice might be a model for studying synaptic dysfunction and human psychiatric disorders.




14/01/2010 | Nature   IF 38.1
Long-term potentiation depends on release of D-serine from astrocytes
Henneberger C, Papouin T, Oliet S*, Rusakov D*

Abstract:
Long-term potentiation (LTP) of synaptic transmission provides an experimental model for studying mechanisms of memory1. The classical form of LTP relies on N-methyl-D-aspartate receptors (NMDARs), and it has been shown that astroglia can regulate their activation through Ca21-dependent release of the NMDAR coagonist D-serine24. Release of D-serine from glia enables LTP in cultures5 and explains a correlation between glial coverage of synapses and LTP in the supraoptic nucleus4. However, increases in Ca21 concentration in astroglia can also release other signalling molecules, most prominently glutamate68, ATP9 and tumour necrosis factor-a10,11, whereas neurons themselves can synthesize and supply D-serine12,13. Furthermore, loading an astrocyte with exogenous Ca21 buffers does not suppress LTP in hippocampal area CA1 (refs 1416), and the physiological relevance of experiments in cultures or strong exogenous stimuli applied to astrocytes has been questioned17,18. The involvement of glia in LTP induction therefore remains controversial. Here we show that clamping internal Ca21 in individual CA1 astrocytes blocks LTP induction atnearby excitatory synapsesbydecreasing the occupancy of the NMDAR co-agonist sites. This LTP blockade can be reversed by exogenous D-serine or glycine, whereas depletion of D-serine or disruption of exocytosis in an individual astrocyte blocks local LTP. We therefore demonstrate that Ca21-dependent release of D-serine from an astrocyte controls NMDAR-dependent plasticity in many thousands of excitatory synapses nearby.




11/09/2008 | Cereb Cortex   IF 8.3
Downregulation of Tonic GABAergic Inhibition in a Mouse Model of Fragile X Syndrome
Curia G, Papouin T, Seguela P, Avoli M

Abstract:
The absence of fragile X mental retardation protein results in the fragile X syndrome (FXS), a common form of mental retardation associated with attention deficit, autistic behavior, and epileptic seizures. The phenotype of FXS is reproduced in fragile X mental retardation 1 (fmr1) knockout (KO) mice that have region-specific altered expression of some gamma-aminobutyric acid (GABA(A)) receptor subunits. However, little is known about the characteristics of GABAergic inhibition in the subiculum of these animals. We employed patch-clamp recordings from subicular pyramidal cells in an in vitro slice preparation. In addition, semiquantitative polymerase chain reaction and western blot experiments were performed on subiculum obtained from wild-type (WT) and KO mice. We found that tonic GABA(A) currents were downregulated in fmr1 KO compared with WT neurons, whereas no significant differences were observed in phasic GABA(A) currents. Molecular biology analysis revealed that the tonic GABA(A) receptor subunits alpha5 and delta were underexpressed in the fmr1 KO mouse subiculum compared with WT. Because the subiculum plays a role in both cognitive functions and epileptic disorders, we propose that altered tonic inhibition in this structure contributes to the behavioral deficits and epileptic activity seen in FXS patients. This conclusion is in line with evidence implicating tonic GABA(A) inhibition in learning and memory.