Neurocentre Magendie

Les actualités de l'équipe



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Hottopic
26/02/2020 10h30
Jennifer STANIC from Montcouquiol-Sans's lab will give a presentation entitled 'The PSD-95 spatial nano-architecture is altered by Scribble-dependent signaling'

Revue de presse
14/01/2020
Carvalho et al in Elife - January 2020

Vangl2 acts at the interface between actin and N-cadherin to modulate mammalian neuronal outgrowth. Steve Dos-Santos Carvalho, Maite M Moreau, Yeri Esther Hien, Michael Garcia, Nathalie Aubailly, Deborah J Henderson, Vincent Studer, Nathalie Sans, Olivier Thoumine, Mireille Montcouquiol. eLife. 2020-01-07. 9.

Here, we show that an early deletion of vangl2 in neuronal progenitors of the forebrain leads to the spatially restricted deficit of only two commissural axon bundles. Mechanistically, we show that the absence of vangl2 leads to an increase in axonal outgrowth due to a reduced turnover of N-cadherin, and a better coupling between the adhesion molecule and the dynamic actin flow in the growth cone. Our results support a model in which Vangl2 acts as a regulator of membrane protein endocytosis and junctional remodeling during growth cone exploration, thereby modulating its outgrowth.

This study benefited from a close collaboration between the groups of Montcouquiol/Sans (Neurocentre Magendie), O. Thoumine (IINS), and V. Studer (IINS), funded by the Labex BRAIN (project PCP Compass).

https://www.bordeaux-neurocampus.fr/steve-dos-santos-carvalho-et-al-in-elife/
https://elifesciences.org/articles/51822




Hottopic
18/12/2019 10h00
Noémie DEPRET from Montcouquiol-Sans's lab will give a presentation entitled "Planar cell polarity protein Vangl2 : a key player in the morphofonctional development of hippocampal network"

Info Générale
25/09/2019
Good luck Steph!

Congratulations to our colleague Dr Stephanie Mauriac (Equipe Montcouquiol/Sans), who will join the Holt/Geleoc' lab at the Boston Children's Hospital, Harvard Medical School https://oto.hms.harvard.edu/people/jeffrey-holt

Stephanie will be working on the cochlear system to restore cellular and systems level function in models of human deafness in the US. Good luck Steph!






Info Générale
12/09/2019
Bravo Sybille ! (Equipe Polarité Planaire et Plasticité)

Félicitations à notre étudiante de M2 , Sybille Marchese (Equipe Montcouquiol/Sans), qui décroche un contrat doctoral à l'Université de Saint Andrews en Ecosse dans la jeune équipe du Dr Juan Alberto Varela, lauréat du prestigieux programme ERC (https://risweb.st-andrews.ac.uk/portal/en/persons/juan-alberto-varela(bf1154ef-1d43-41e1-b529-7dd9660cea91).html).

Sybille utilisera des techniques d'imagerie à super résolution pour élucider le trafic extracellulaire des agrégats de protéines (bêta-amyloïde et alpha-synucléine) dans le cerveau et leur rôle direct dans la neurodégénération précoce.

Bonne continuation Sybille !






Mireille Montcouquiol est lauréate d'un financement de la très sélective Fondation pour l'Audition créée par Françoise Bettencourt Meyers, Jean-Pierre Meyers et la Fondation Bettencourt Schueller. Bravo !!




Soutenance
17/06/2019 13h30
Stéphanie MAURIAC from Montcouquiol-Sans's lab will give a presentation entitled ...

from Montcouquiol-Sans's lab will give a presentation entitled ...
Date de la soutenance: 17/06/2019 - 13h30
Lieu: Neurocentre Magendie Seminar room


Séminaire
15/02/2019 11h30
Isabelle Brunet, Collège de France - Molecular Control of Neuro-Vascular Development

Meeting room: CGFB Seminar room

Invitant : Mireille Montcouquiol (Neurocentre Magendie, Montcouquiol-Sans's lab)

Sympathetic arterial innervation and EphrinaA4/EPHA4 Signaling: Arteries under pressure?

Abstract

Arteries receive a sympathetic innervation which is crucial to control their contraction level. Sympathetic nerves establish „“en passant““ synapses, called neurovascular junctions with arterial smooth muscle cells. Gene expres- sion comparison of non-innervated and innervated arteries revealed that the re- pulsive axon guidance molecule EphrinA4 is surprisingly expressed by arteries ar the onset of innervation (Postnatal day 2 P2). We here investigated the role of EphrinA4 signalization in the development and physiology of arterial innervation in mice. We showed that EphrinA4 is expressed by smooth muscle cells of resistance arteries and identified its receptor EphA4, expressed by sympathetic neurons. Binding and collapse experiments showed that EphrinA4 mediates the collapse of sympathetic growth cones in vitro via EphA4. EphrinA4 KO and EphA4 KO mice exhibited an increased arterial innervation at P2, consistent with a loss of repulsion. We then generated EphA4 flox-TH CRE mice who exhibited the same enhanced arterial innervation at P2 , which remained in adult mice. Increased arterial innervation in EPhA4 flox-TH CRE mice was correlated with a higher number of neurovascular junctions and a modifcation of their structure visible by eletronic microscopy. Measurement of cutaneous blood flow using laser doppler revealed an enhanced vasoconstriction in this mice. Resistivity and pulstility index of ca- rotids calculated from ultrasound views were increased, suggesting enhanced vascular resistivity. Thus EphrinA4 expressed by arterial smooth muscles cells induces collapse of sympathetic growth cones via the receptor EphA4 to refine sympathetic arterial innervation. Impairment of EphrinA4/EphA4 signaling leads to increased arterial innervation, vascular resistance and vasoconstriction. As systemic blood pressure depends on cardiac output but also vascular resistance, we are currently testing if those functional defects could lead to hypertension from sympathetic origin, or at least aggravate pre-existing hypertension.




Hottopic
28/11/2018 10h00
Mehdi BHOURI from Montcouquiol-Sans's lab will give a presentation entitled 'Role of the planar cell polarity protein Vangl2 in hippocampal circuits involved in memory.'

Hottopic
31/10/2018 10h00
Jerome EZAN from Montcouquiol-Sans's lab will give a presentation entitled 'Magendie Scientific life: why it is important to register to Hot-topics'