|Abstract Number: ||270 - 6|
|Author Name: ||Christian A Amatore - CNRS & ENS|
|Session Title: ||Neurotransmission at Single and Nano-Resolved Bio-Structures|
|Event Type: ||Symposia|
|Event Title: ||Full Fusion During Vesicular Exocytosis: A Real Release Stage or a Hoax?|
|Presider Name:||Mei Shen|
|Affiliation:||University of Illinois at Urbana-Champaign|
|Date: ||Monday, March 7, 2016|
|Start Time: ||10:35 AM (Slot #6)|
|Vesicular exocytosis involves a connection between nanometric vesicles and the cell membrane through a nanopore across the two membranes. Single exocytotic events are recorded by the ‘artificial synapse’ amperometric method  at carbon fiber microelectrodes. Analysis of the current time dependence and intensity afford topological, energetic and dynamic information about these nanopores [2-3]. However, the main physicochemical parameters characterizing a spike are not known a priori. Yet, complete reconstruction requires that at least one independent entry. To this end, we used initial fusion nanopore radius values (1.2±0.35 nm) from patch-clamp measurements  to determine the mean neurotransmitter diffusion rate ( = D/Rves2) within the vesicle, so the fusion nanopore dynamics could be reconstructed for any given spike. |
This afforded statistically significant analysis of size distributions of initial and final fusion pores . This evidences that the “full fusion” stage does not end into full fusion but stops after less than ca. 1% of the vesicle membrane surface area is exposed. This shows that fusion mechanism is more complex than thought and most involves also the actin cytoskeleton or proteins. In functional. Probing inside neuronal synapses with nano-conical carbon fiber electrodes supported these views [5,6].
1. C. Amatore, S. Arbault, M. Guille, F. Lemaître, Chem. Rev. 108, 2585-2621 (2008).
2. C. Amatore, A. I. Oleinick, I. Svir, ChemPhysChem 11, 149-158 (2010).
3. C. Amatore, A. I. Oleinick, I. Svir, ChemPhysChem 11, 159-174 (2010).
4. A. Oleinick, F. Lemaître, M. Guille Collignon, I. Svir, C. Amatore, Faraday Discuss. 164, 33–55 (2013).
5. Y.-T. Li, S.H. Zhang, L. Wang, R.-R. Xiao, W. Liu, X.-W. Zhang, Z. Zhou, C. Amatore, W.-H. Huang, Angew. Chem. Int. Ed., 53, 12456-12460 (2013).
6. Y.T. Li, S.H. Zhang, X.Y. Wang, X.W. Zhang, A.I. Oleinick, I. Svir, C. Amatore, W.H. Huang. Angew. Chem., 54, 9313–9318 (2015).