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5 novembre 2018: 1 événement

  • Séminaires Invités

    Lundi 5 novembre 2018 14:00-15:30 - Alexandra PACUREANU - European Synchrotron Radiation Facility, Grenoble, France

    Coherent, Bright and Focused Light to Resolve Neural Circuits

    Résumé : Scientists have been seeking for over a century to uncover the neural circuits controlling brain functions. This requires visualization of complex nanometre size structures over millimetre size tissue volumes. Today only electron microscopes are capable of generating data with sufficient resolving power to access directly the neural connections. But mapping just one cubic mm of brain tissue would require years of sample sectioning and data collection, leading to prohibitive costs. For these reasons, this goal has not been reached yet and the largest brain ever mapped corresponds to a fruit fly, which took about five years of work. In this context, I will discuss the potential of phase contrast X-ray microscopy to probe large tissue samples at nanometre scale in a short time. X-ray holographic nano-tomography is a coherent imaging technique which is capable of generating exceptional contrast in soft tissue through phase shift retrieval. The penetrating power of X-rays and the full-field, free space propagation setup enable rapid multiscale 3D imaging of large samples which are opaque to visible light. By combining a highly brilliant X-ray nanoprobe, a carefully designed nanopositioning system, a cutting edge detection system and cryogenics for sample preservation, isotropic 3D spatial resolution better than 30 nm is conceivable. Additionally, I will discuss the possibility to use machine learning approaches, specifically convolutional neural networks, to extract the knowledge from highly complex and large 3D images.

    contact : Aurélien Gourrier

    Lieu : LIPhy, conference room - 140 Avenue de la Physique 38402 Saint Martin d’Hères

    En savoir plus : Séminaires Invités