Ecole Doctorale

Sciences de la Vie et de la Santé

Spécialité

Biologie-Santé - Spécialité Neurosciences

Etablissement

Aix-Marseille Université

Mots Clés

Neurones GABAergiques,Hippocampe,Organisation fonctionnelle,,

Keywords

GABAergic neurons,Hippocampus,Functional organization,,

Titre de thèse

Propriétés morpho-fonctionnelles des neurones GABAergiques générés tôt dans la région CA1 de l'hippocampe adulte et en développement
Functional properties of early-born GABAergic neurones in developing and adult hippocampal circuits

Date

Wednesday 31 October 2018 à 14:00

Adresse

Inmed UMR1249 Parc scientifique de Luminy 163 avenue de Luminy BP13 - 13273 Marseille cedex 09 - France Salle de Conférence (INMED)

Jury

Directeur de these Mme Rosa COSSART Institut de Neurobiologie de la Méditerranée UMR1249
Rapporteur M. Fabrice ANGO Institut de Génomique Fonctionnelle
Examinateur M. Frédéric BROCARD Institut de Neurosciences de la Timone
Examinateur Mme Lydia KERKERIAN – LE GOFF Institut de Biologie du Développement de Marseille
Rapporteur Mme Michèle STUDER Institut de Biologie Valrose
Examinateur Mme Julie PERROY Institut de Génomique Fonctionnelle

Résumé de la thèse

The diversity between GABAergic cells appears to be in part predefined by a developmental program. The proliferative area in which interneurons are generated from precursors (spatial embrryonic origin) shapes the morphological and physiological properties that interneurons will exhibit in adult circuits (Butt et al., 2005). Together with the spatial origin, the temporal origin during embryogenesis is another important factor determining the fate of GABAergic cells. For example, neuronal birth date shapes the features that parvalbumin-expressing neurons will display in adulthood: parvalbumin-positive basket cells are generated earlier than axo-axonic cells (Inan et al., 2012; Taniguchi et al., 2013); additionally, parvalbumin-positive cells display different forms of plasticity upon learning that depend on their birth date (Donato et al., 2015). Our group discovered that neurons generated early in neurogenesis act as ‘hub’ neurons in the CA3 area of the neonatal (P5-P7) mouse hippocampus, suggesting that an early birth date endows GABAergic neurons with a unique role during postnatal development. Early born GABAergic cells (ebGABA) cells are not a transient developmental phenomenon because they persist in adulthood. At least some of these cells form a population of GABAergic projection neurons innervating the medial septum (Villette et al., 2016). This indicates that an early birth date could lead to distinct morphophysiological properties even in adulthood.

Thesis resume

The diversity between GABAergic cells appears to be in part predefined by a developmental program. The proliferative area in which interneurons are generated from precursors (spatial embrryonic origin) shapes the morphological and physiological properties that interneurons will exhibit in adult circuits (Butt et al., 2005). Together with the spatial origin, the temporal origin during embryogenesis is another important factor determining the fate of GABAergic cells. For example, neuronal birth date shapes the features that parvalbumin-expressing neurons will display in adulthood: parvalbumin-positive basket cells are generated earlier than axo-axonic cells (Inan et al., 2012; Taniguchi et al., 2013); additionally, parvalbumin-positive cells display different forms of plasticity upon learning that depend on their birth date (Donato et al., 2015). Our group discovered that neurons generated early in neurogenesis act as ‘hub’ neurons in the CA3 area of the neonatal (P5-P7) mouse hippocampus, suggesting that an early birth date endows GABAergic neurons with a unique role during postnatal development. Early born GABAergic cells (ebGABA) cells are not a transient developmental phenomenon because they persist in adulthood. At least some of these cells form a population of GABAergic projection neurons innervating the medial septum (Villette et al., 2016). This indicates that an early birth date could lead to distinct morphophysiological properties even in adulthood.