This session, Diffusion MRI Neuroscience, explores how diffusion-weighted MRI and diffusion MRI methodologies advance the understanding of white and gray matter organization across the central nervous system. Emphasis is placed on diffusion visualization and quantitative characterization of matter microstructure, supported by optimal experimental design, diffusion acquisition strategies, and simulation-based validation. Methodological topics include experimental design for diffusion MRI, mitigation of field inhomogeneity effects, and accurate image registration across brain and spinal cord imaging. Translational applications span neurological and neuropsychiatric conditions, including multiple sclerosis, narcolepsy type disorders, and post-stroke depression, as well as emerging targets such as the parasagittal dura and IVIM-related diffusion processes. By integrating magnetic resonance imaging theory, acquisition, and visualization with neuroscience-driven questions, the session highlights diffusion MRI as a core tool for probing tissue diffusion and microstructural organization in health and disease.