Periodic Reporting for period 3 - MODEM (Multipoint Optical DEvices for Minimally invasive neural circuits interface)
Reporting period: 2019-10-01 to 2021-03-31
MODEM aspires to develop innovative technologies for multipoint optical neural interfacing with the mammalian brain in vivo. We are developing new approaches for modal multiplexing and de-multiplexing of light into a single, thin, minimally invasive tapered optical fiber serving as a carrier for multipoint signals to and from the brain. This will be achieved through nano- and micro-structuring of the taper edge, capitalizing on the photonic properties of the tapered waveguide to precisely control light delivery and collection in vivo.
The overall objectives of the MODEM project are: 1) Development of minimally invasive technologies for versatile, user-defined optogenetic control over deep brain regions; 2) Development of fully integrated high signal-to- noise-ratio optrodes; 3) Development of minimally invasive technologies for multi-point in vivo all-optical “electrophysiology” through a single waveguide; 4) Development of new optical methodologies for dissecting brain circuitry at small and large scales.
The probes we are developing are indeed unique because the propagation constants of the guided lights are modified by the taper itself. This is a key feature to control light emission intensity at the different sections of the taper, in order to design a new generation of photonic implants.
The team is now working on the possibility to monitor neural activity by collecting functional fluorescent signals with tapered fibers in vivo [bioRxiv 455766 2018, Front in Neuroscience 13 82 2019] and by integrating electrodes for extracellular recording on the taper edge.