Optogenetic entrainment of neural oscillations with hybrid fiber probes
Name
nihms1500078.pdf
Description
Accepted version
Size
2.09 MB
Format
Unknown
Checksum (MD5)
dc80f65652df17ad8dfe3c791705ebce
Author(s)
Kilias, Antje
Canales, Andres
Froriep, Ulrich
Park, Seongjun
Egert, Ulrich
Anikeeva, Polina Olegovna
Date Issued
2018
Journal
Journal of Neural Engineering
Publisher
IOP Publishing
Version
Author's final manuscript
Abstract
© 2018 IOP Publishing Ltd. Objective. Optogenetic modulation of neural activity is a ubiquitous tool for basic investigation of brain circuits. While the majority of optogenetic paradigms rely on short light pulses to evoke synchronized activity of optically sensitized cells, many neurobiological processes are associated with slow local field potential (LFP) oscillations. Therefore, we developed a hybrid fiber probe capable of simultaneous electrophysiological recording and optical stimulation and used it to investigate the utility of sinusoidal light stimulation for evoking oscillatory neural activity in vivo across a broad frequency range. Approach. We fabricated hybrid fiber probes comprising a hollow cylindrical array of 9 electrodes and a flexible optical waveguide integrated within the core. We implanted these probes in the hippocampus of transgenic Thy1-ChR2-YFP mice that broadly express the blue-light sensitive cation channel channelrhodopsin 2 (ChR2) in excitatory neurons across the brain. The effects of the sinusoidal light stimulation were characterized and contrasted with those corresponding to pulsed stimulation in the frequency range of physiological LFP rhythms (3-128 Hz). Main results. Within hybrid probes, metal electrode surfaces were vertically aligned with the waveguide tip, which minimized optical stimulation artifacts in neurophysiological recordings. Sinusoidal stimulation resulted in reliable and coherent entrainment of LFP oscillations up to 70 Hz, the cutoff frequency of ChR2, with response amplitudes inversely scaling with the stimulation frequencies. Effectiveness of the stimulation was maintained for two months following implantation. Significance. Alternative stimulation patterns complementing existing pulsed protocols, in particular sinusoidal light stimulation, are a prerequisite for investigating the physiological mechanisms underlying brain rhythms. So far, studies applying sinusoidal stimulation in vivo were limited to single stimulation frequencies. We show the feasibility of sinusoidal stimulation in vivo to induce coherent LFP oscillations across the entire frequency spectrum supported by the gating dynamics of ChR2 and introduce a hybrid fiber probe tailored to continuous light stimulation.
MIT Department
Massachusetts Institute of Technology. Department of Materials Science and Engineering
Simons Center for the Social Brain (Massachusetts Institute of Technology)
Massachusetts Institute of Technology. Department of Electrical Engineering and Computer Science
Massachusetts Institute of Technology. Research Laboratory of Electronics
Terms of Use
Creative Commons Attribution-Noncommercial-Share Alike
Persistent DSpace Link
DOI of Published Version
https://doi.org/10.1088/1741-2552/AACDB9
