Détails de la réservation
- Le : 6 May 2022
- De : 11 h 00
- à : 13 h 00
- Salle : Amphi Centre Broca Nouvelle - Aquitaine
Détails de l'évènement
Matthew Grubb
King’s college – London, UK
At 11:30
"Functional recovery and plasticity during naturally occurring neuronal regeneration"
Abstract :
Attempts to repair the damaged or diseased brain have focused on facilitating the regrowth of existing axons, or introducing new neurons to replace lost projections. To achieve functional recovery, however, this is not enough – new projections must not only reach their intended target structures, but also re-connect appropriately to drive information processing in downstream circuits. How regrown or replaced axons can be encouraged to establish such appropriate connections, though, remains unknown. To understand some of the processes underlying successful re-connection of regenerated axons, we seek to learn lessons from part of the adult mammalian nervous system that can regenerate naturally – the projection from olfactory sensory neurons (OSNs) in the nose to their target structure in the brain, the olfactory bulb (OB). Using a simple model of olfactotoxin-induced OSN degeneration and subsequent naturally occurring regeneration, we study the anatomical and physiological properties of OSN axon terminals as they begin to re-connect with target circuits after a couple of weeks. We find that release probability is lower in immature re-connecting versus mature, fully-connected OSN terminals, and that even at the earliest stages of synapse re-establishment there is the potential for characteristic, strong presynaptic inhibition. However, despite immature OSN terminals being lower in density and functionally weaker, OSN-stimulated OB output is actually stronger in the earliest stages of re-connection. We are currently investigating the plastic mechanisms in OB circuits which enable such compensatory changes to occur, and hope that our discoveries will inform interventions to improve functional recovery after damage to the human CNS.
Responsable
- Nom : Rodriguez Arnaud