MEMOLIFE Laboratory of excellence and Paris Sciences et Lettres 2 articles published in JoVE Immunology and Infection Imaging Ca2+ Responses During Shigella Infection of Epithelial Cells Yasmine Smail1,2,3,4, Chunhui Sun1,2,3,4, Laurent Combettes5, Guy Tran Van Nhieu1,2,3,4 1Equipe Communication Intercellulaire et Infections Microbiennes, Centre de Recherche Interdisciplinaire en Biologie (CIRB), Collège de France, 2Institut National de la Santé et de la Recherche Médicale (Inserm), U1050, 3Centre Nationale de la Recherche Scientifique (CNRS), UMR7241, 4MEMOLIFE Laboratory of Excellence and Paris Sciences et Lettres, 5Inserm, UMRS1174, Université Paris Sud Here, we present protocols to visualize calcium (Ca2+) responses elicited by HeLa cells infected by Shigella. By optimizing the parameters of bacterial infection and imaging with Ca2+ fluorescent probes, atypical global and local Ca2+ signals induced by bacteria over a large range of infection kinetics are characterized. Neuroscience Purification of Mouse Brain Vessels Anne-Cécile Boulay1,2,3, Bruno Saubaméa4, Xavier Declèves4, Martine Cohen-Salmon1,2,3 1Collège de France, Center for Interdisciplinary Research in Biology (CIRB), Centre National de la Recherche Scientifique CNRS, Unité Mixte de Recherche 7241, Institut National de la Santé et de la Recherche Médicale, 2Centre Interdisciplinaire de Recherche en Biologie, 3MEMOLIFE Laboratory of Excellence and Paris Science, Lettre Research University, 4Université Paris Descartes, Faculté de Pharmacie, Université Paris Diderot We describe a protocol allowing the purification of the mouse brain's vascular compartment. Isolated brain vessels include endothelial cells linked by tight junctions and surrounded by a continuous basal lamina, pericytes, vascular smooth muscle cells, as well as perivascular astroglial membranes.