Center for Networked Biomedical Research on Neurodegenerative Diseases 1 article published in JoVE Neuroscience Generation of 3-D Collagen-based Hydrogels to Analyze Axonal Growth and Behavior During Nervous System Development Vanessa Gil1,2,3,4, José Antonio Del Río1,2,3,4 1Molecular and Cellular Neurobiotechnology, Institute for Bioengineering of Catalonia (IBEC), The Barcelona Institute of Science and Technology (BIST), Parc Científic de Barcelona, 2Department of Cell Biology, Physiology, and Immunology, Universitat de Barcelona, 3Center for Networked Biomedical Research on Neurodegenerative Diseases (CIBERNED), 4Institute of Neuroscience, University of Barcelona Here, we provide a method for analyzing the behavior of growing axons in 3D matrices, mimicking their natural development.