Lieu : Salle Picard (Bat 1R2 Salle 129)
Notes de dernières minutes : Cell migration is a fundamental phenomenon involved in physiological and pathological processes. To ensure these functions, cells are able to migration in very different environments, thanks to their internal organization : a large number of subunits permanently interact on different time and space scales. Moreover, this activity results from stochastic and redondant reactions, so that cells macroscopic behaviours are hardly predictable. Mathematical modelling therefore constitutes an important tool, and is also challenging. In this talk, I will study the case of a cell crawling on a surface. To model this out-of-equilibrium multiscale system, I developped two approaches. In a first stochastic model, the cell is a point which displacement results from the dynamics of observable characters of the cell. Then, in a deterministic model, intracellular multiscale interactions are described, for a fixed cell shape. I will present these two approaches, and show how they allow to capture key mechanisms of migration, and to show different migratory behaviours. This work is a collaboration with Nicolas Meunier (MAP5, Paris Descartes) and Raphaël Voituriez (LJP, LPTMC, CNRS, UPMC).