Thierry Galli

Role of Membrane Traffic in Axon Morphogenesis: Role of Membrane Traffic, Through Snares, in Brain Development and Regeneration Thierry Galli

During development, attractive and repulsive guidance molecules, such as semaphorins, are responsible for proper wiring of axons and dendrites. Attractive and repulsive external guidance cues bind to receptors which activate intracellular signalling pathways and reshape the growth cone. The role of vesicular traffic in axonal guidance is still largely unknown. Vesicular traffic requires SNAREs proteins for membrane fusion. The exocytic vesicular SNARE Synaptobrevin2 mediates neurotransmitter release in mature neurons while TI-VAMP is mainly known for mediating axon growth. Their potential roles in axon guidance remain elusive. According to a previous model, attraction would rely solely on Synaptobrevin2-dependent exocytosis while repulsion would exclusively require endocytosis. However, this PhD work has hinted a more complex view on guidance mechanisms. Moreover, we explored the effects of the absence of TI-VAMP in brain development and behaviour and obtained unexpected but interesting results. Therefore we reviewed the role of SNAREs in axon guidance and cell migration.