le 13 mai 2016 à 11 h
Delphine Debarre, Laboratoire Interdisciplinaire de Physique, CNRS – Université Grenoble Alpes, St-Martin d’Hères

Lieu(x) :         Amphithéatre Becquerel, Ecole Polytechnique

Contact :       Emmanuel Beaurepaire
                      emmanuel.beaurepaire at polytechnique.edu

Bone is a complex organ with several essential functions : beyond supporting the body and protecting soft tissues, bones are also responsible for the storage and homeostasis of e.g. calcium, and for the production of blood cells. To achieve these different functions, bones have a highly hierarchical structure that has to be studied at different scales to understand the structure/function relationship. Our research has focussed on two different aspects of bone morphology at the microscopic scale : the organization of bone matrix, formed from mineralized collagen fibrils; and that of the cellular network of osteocytes, dendritic cells that create a dense network of porosities in the bone and have a central role in ion homeostasis and bone remodelling. Using combined third- and second-harmonic generation microscopies, we have demonstrated that we can image simultaneously the cell network and the collagen organization with submicrometric resolution at the scale of the organ, thereby allowing to study, for example, their relationship with the mechanical constrains on the bone.
I will show examples of THG/SHG images in various human and animal models, and some preliminary results on the quantification of the cellular network and the collagen organization.