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 (22330198) |
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Dynamic development of the first synapse impinging on adult-born neurons in the olfactory bulb circuit. |
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| auteur(s) : |
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Hiroyuki Katagiri1, Marta Pallotto1, 2, Antoine Nissant1, Kerren Murray1, Marco Sassoè-Pognetto2, Pierre-Marie Lledo ( ) 1 |
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| résumé : |
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ABSTRACT: The olfactory bulb (OB) receives and integrates newborn interneurons throughout life. This process is important for the proper functioning of the OB circuit and consequently, for the sense of smell. Although we know how these new interneurons are produced, the way in which they integrate into the pre-existing ongoing circuits remains poorly documented. Bearing in mind that glutamatergic inputs onto local OB interneurons are crucial for adjusting the level of bulbar inhibition, it is important to characterize when and how these inputs from excitatory synapses develop on newborn OB interneurons. We studied early synaptic events that lead to the formation and maturation of the first glutamatergic synapses on adult-born granule cells (GCs), the most abundant subtype of OB interneuron. Patch-clamp recordings and electron microscopy (EM) analysis were performed on adult-born interneurons shortly after their arrival in the adult OB circuits. We found that both the ratio of N-methyl-D-aspartate receptor (NMDAR) to α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor (AMPAR), and the number of functional release sites at proximal inputs reached a maximum during the critical period for the sensory-dependent survival of newborn cells, well before the completion of dendritic arborization. EM analysis showed an accompanying change in postsynaptic density shape during the same period of time. Interestingly, the latter morphological changes disappeared in more mature newly-formed neurons, when the NMDAR to AMPAR ratio had decreased and functional presynaptic terminals expressed only single release sites. Together, these findings show that the first glutamatergic inputs to adult-generated OB interneurons undergo a unique sequence of maturation stages. |
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| domaine : |
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Sciences du Vivant/Neurosciences
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langue du texte
intégral : |
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Anglais |
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| ISSN : |
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2042-1001 |
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| type de publication : |
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Articles dans des revues avec comité de lecture |
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| DOI : |
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10.1186/2042-1001-1-6 |
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Neural Systems & Circuits |
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| Audience : |
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internationale |
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| date de publication : |
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2011 |
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date de publication
électronique : |
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01/02/2011 |
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| volume : |
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1 |
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| numéro : |
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1 |
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| page, identifiant, ... : |
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6 |
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This work was supported by the Fondation pour la Recherche Médicale "Equipe FRM", the Groupe "Novalis-Taitbout" and the Ecole des Neurosciences de Paris (ENP), Compagnia di San Paolo and Regione Piemonte (Ricerca Sanitaria Finalizzata 2006 and 2008). HK was supported by the Association Pasteur-Japon fellowship. MP is the recipient of a doctoral fellowship from 'Università Italo-Francese' (Progetto Vinci) and Servier. The laboratory is also supported by the Agence Nationale de la Recherche "ANR-09-NEUR-004" in the frame of "ERA-NET NEURON" of FP7 program by the European Commission. Dr. Lledo's visit to the Department of Molecular and Cellular Biology, Harvard University (Murthy's laboratory), was funded by the Philippe Foundation. |
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| Projet ANR : |
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| Référence du projet |
ANR-09-NEUR-004 |
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| Projet Européen : |
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| Numéro Cordis |
291840 |
| Acronyme |
ERA-NET NEURON II |
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Network of European funding for Neuroscience research |
| Financé par |
HEALTH |
| Début |
0000-00-00 |
| Date de fin |
0000-00-00 |
| Identifiant de l'appel |
FP7-ERANET-2011-RTD |
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