title: Holographic fiber bundle system for patterned optogenetic activation of large-scale neuronal networks.
abstract: Optogenetic perturbation has become a fundamental tool in controlling activity in neurons. Used to control activity in cell cultures, slice preparations, anesthetized and awake behaving animals, optical control of cell-type specific activity enables the interrogation of complex systems. A remaining challenge in developing optical control tools is the ability to produce defined light patterns such that power-efficient, precise control of neuronal populations is obtained. Here, we describe a system for patterned stimulation that enables the generation of structured activity in neurons by transmitting optical patterns from computer-generated holograms through an optical fiber bundle. The system couples the optical system to versatile fiber bundle configurations, including coherent or incoherent bundles composed of hundreds of up to several meters long fibers. We describe the components of the system, a method for calibration, and a detailed power efficiency and spatial specificity quantification. Next, we use the system to precisely control single-cell activity as measured by extracellular electrophysiological recordings in ChR2-expressing cortical cell cultures. The described system complements recent descriptions of optical control systems, presenting a system suitable for high-resolution spatiotemporal optical control of wide-area neural networks in vitro and in vivo, yielding a tool for precise neural system interrogation.
authors.affiliation: Technion-Israel Institute of Technology, Faculty of Biomedical Engineering, Haifa 3200003, Israel; Bar Ilan University, Optometry Department, Ramat Gan 5290002, Israel.
authors.forename: Nairouz
authors.initials: N
authors.lastname: Farah
authors.affiliation: Technion-Israel Institute of Technology , Technion Autonomous Systems Program, Haifa 3200003, Israel.
authors.forename: Alexandra
authors.initials: A
authors.lastname: Levinsky
authors.affiliation: Technion-Israel Institute of Technology , Faculty of Biomedical Engineering, Haifa 3200003, Israel.
authors.forename: Inbar
authors.initials: I
authors.lastname: Brosh
authors.affiliation: Technion-Israel Institute of Technology , Rappaport Faculty of Medicine and Institute, Haifa 3200003, Israel.
authors.forename: Itamar
authors.initials: I
authors.lastname: Kahn
authors.affiliation: Technion-Israel Institute of Technology , Faculty of Biomedical Engineering, Haifa 3200003, Israel.
authors.forename: Shy
authors.initials: S
authors.lastname: Shoham
keywords: fiber bundles; holography; optogentics; spatial light modulators