The efficiency and accuracy of neurotransmission strongly depends on two apparently antagonist properties of synaptic membrane: the stability of its organization and its ability to adapt to plasticity events. In addition, the structural stability of synapses has to be reconciled with the notion that cell membranes are fluid. Membrane molecules are compelled to move within the membrane surface due to thermal Brownian agitation, which favors the homogeneous distribution of the molecules. As a result, neurons spend energy to stop or reduce these movements, and maintain molecules in certain locations via mechanisms that decrease this fluidity. The speaker and his research group investigate the regulation of synaptic receptors dynamics by the different (structural and functional) elements that make the synapse. They have approached these conceptual paradoxes by developing new technological and analytical tools that allow the monitoring of the behavior of synaptic components at the molecular level and change of the scale of analysis. The speaker demonstrated rapid exchanges between synaptic and extra-synaptic receptors and he showed that transient stabilization of receptors at synapses occurs by interaction with partners, such as scaffold proteins. Novel super-resolution imaging methods (PALM, STORM) provided a precise insight on the organization of these postsynaptic structures. The combination of single particle tracking and super-resolution methods opens access to molecular counting and energy involved in receptor-scaffold interactions as well as on and off rate of molecular interactions. Thus beyond super-resolution methods is chemistry “in cellulo” accounting for the regulation of receptor number and consecutively that of synaptic strength. Ultimately, the dynamic regulations of receptor-scaffold and scaffold–scaffold interactions appear as a central tenet for the maintenance and plasticity-related changes of receptor numbers at synapses. These processes are likely to be deregulated in pathological situations such as in neurodegenerative diseases.
About the speaker
Prof Antoine Triller received his MD from Pierre and Marie Curie University (UPMC) in 1978. He joined the Institut Pasteur, Institut National de la Santé Et de la Recherche Médicale (INSERM) in 1984 and moved to the Biology Department of the Ecole Normale Supérieure in 1995. In 2010, he created the Institute of Biology at the Ecole Normale Supérieure and of which he is currently the director.
Prof Triller’s research focuses on the regulation of synaptic receptors dynamics by the different (structural and functional) elements that make the synapse. He approached the conceptual paradoxes by developing new technological and analytical tools that allow the monitoring of the behavior of synaptic components at the molecular level and change of the scale of analysis.
Prof Triller received numerous awards including the Physiology and Physiopathology Prize by INSERM (2004) and the Lamonica Prize in Neurology by the French Academy of Sciences (2010). He was also elected a member of the French Academy of Sciences in 2011.
For attendees’ attention
The lecture is free and open to all. Seating is on a first come, first served basis.
Light refreshments will be served from 3:30 to 4:00 pm.
