UMR-9197, CNRS/Universite Paris Sud 1 article published in JoVE Neuroscience In Vivo Functional Brain Imaging Approach Based on Bioluminescent Calcium Indicator GFP-aequorin Arianna R. Lark1,2, Toshihiro Kitamoto2,3, Jean-René Martin1 1Equipe: Imagerie Cérébrale Fonctionnelle et Comportements (ICFC), Institut des Neurosciences Paris-Saclay (Nero-PSI), UMR-9197, CNRS/Université Paris Sud, 2Interdisciplinary Program in Neuroscience, Graduate College, University of Iowa, 3Department of Anesthesia, Carver College of Medicine, University of Iowa Here we present a novel Ca2+-imaging approach using a bioluminescent reporter. This approach uses a fused construct GFP-aequorin which binds to Ca2+ and emits light, eliminating the need for light excitation. Significantly this method permits long continuous imaging, access to deep brain structures and high temporal resolution.