Guy Bouvier Synaptic plasticity rule between parallel fibres and Purkinje cells in the cerebellum
14h à 16h
La soutenance de thèse de Guy Bouvier aura lieu dans l’ amphi Rataud, ENS 45 rue d’Ulm 75005 Paris
Numerous studies have related cerebellar function to plasticity of parallel fibre to Purkinje cell synapses. However, in spite of decades of research, how specific input patterns affect plasticity outcomes, and the biophysics of plasticity of these synapses are still unclear. Here, we characterize the patterns of activity that lead to LTP using both in vivo and in vitro experiments. Similarly to LTD, we find that high-frequency bursts are necessary to trigger LTP, and that this burst-dependent plasticity depends on presynaptic NMDA receptors and NO signalling. We provide the first direct evidence of calcium entry through presynaptic NMDA receptors in a subpopulation of parallel fibre varicosities. Finally
we develop and verify experimentally a novel mechanistic plasticity model based on nitric oxide and calcium signalling. The model reproduces plasticity outcomes from data and predicts the effect of arbitrary patterns of synaptic inputs on Purkinje cells, thereby providing a unified description of plasticity.