Kedves Kollegak, Caroline Fonta (Cerveau & Cognition, CNRS Universite Paul Sabatier, Toulouse, France, http://www.cerco.ups-tlse.fr/fr_vers/annuaire/caroline_fonta.htm) <http://www.cerco.ups-tlse.fr/fr_vers/annuaire/caroline_fonta.htm> alabbi eloadasra varunk minden erdeklodot *december 4.-en csutortokon 14.30*-kor a SOTE Anatomi konyvtaraban (1094 Tűzoltó u. 58). *A 3D methodological approach to the study of intra-cortical vessel networks.* The organization of the cerebral micro-vascular network is an important issue in various biological fields, considering clinical as well as fundamental questions, such as normal and pathological vascularization, functional brain imaging interpretation, stroke consequences, therapeutic strategies or hemodynamic modelling. Investigations aiming at describing postnatal angiogenesis, defining malignancy criteria in tumours or analysing the effects of therapies need relevant structural parameters of the network angiogenesis. However they have to face the complexity of the networks. Classical methods have been used to describe vasculature and recent promising techniques provide in vivo functional data. These powerful methods present however some restrictions : small field of view, exploration of cortical depth limited to a few hundreds of micrometres, information limited to qualitative description. We present an alternative method developed to image volumes as large as several tens of cube millimetres of cortical tissue with a micro-metric resolution, by using x-ray micro-tomography. We discuss the interest of the qualitative and quantitative data obtained, focusing on the comparisons between vessel networks in newborn and adult monkey cortex, and between normal and tumor brain tissue. This work results from a tight collaboration between several disciplines (biology, dynamics of fluids, physics, image analysis and statistics) and has been partly published. Plouraboué F, Cloetens P, Fonta C, Steyer A, Lauwers F, Marc-Vergnes JP. 2004. X-ray high-resolution vascular network imaging. *J Microscopy* 215(Pt 2):139-148. Risser L, Plouraboué F, Steyer A, Cloetens P, Le Duc G, Fonta C. 2007. From homogeneous to fractal normal and tumorous microvascular networks in the brain.* J Cereb Blood Flow Metab* 27(2): 293-303. Risser L, Plouraboué F, Descombes X (2008) Gap Filling of 3-D Microvascular Networks by Tensor Voting *IEEE Trans Med Imaging* 27*:* 674-687. Risser L, Plouraboué F, Cloetens P, Fonta C. 2008. A 3d-investigation shows that angiogenesis in primate cerebral cortex mainly occurs at capillary level. *Int J Dev Neurosci* (accepted for publication).** udvozlettel, -- Laszlo Negyessy Neurobionics Research Group, Hungarian Academy of Sciences - Peter Pazmany Catholic University - Semmelweis University Tuzolto u. 58 H-1094 Budapest Hungary Tel.: +36-12156920 ext. 53712 Fax: +36-12176937 E-mail: negyessy(a)ana.sote.hu, negyessy(a)gmail.com