title: Depth-specific optogenetic control in vivo with a scalable, high-density μLED neural probe.
abstract: Controlling neural circuits is a powerful approach to uncover a causal link between neural activity and behaviour. Optogenetics has been widely adopted by the neuroscience community as it offers cell-type-specific perturbation with millisecond precision. However, these studies require light delivery in complex patterns with cellular-scale resolution, while covering a large volume of tissue at depth in vivo. Here we describe a novel high-density silicon-based microscale light-emitting diode (μLED) array, consisting of up to ninety-six 25 μm-diameter μLEDs emitting at a wavelength of 450 nm with a peak irradiance of 400 mW/mm(2). A width of 100 μm, tapering to a 1 μm point, and a 40 μm thickness help minimise tissue damage during insertion. Thermal properties permit a set of optogenetic operating regimes, with ~0.5 °C average temperature increase. We demonstrate depth-dependent activation of mouse neocortical neurons in vivo, offering an inexpensive novel tool for the precise manipulation of neural activity.
authors.affiliation: Institute of Photonics, Dept. of Physics, SUPA, University of Strathclyde, Glasgow G1 1RD, UK.
authors.forename: Robert
authors.initials: R
authors.lastname: Scharf
authors.affiliation: Strathclyde Institute of Pharmacy and Biomedical Sciences, University of Strathclyde, Glasgow G4 0RE, UK.
authors.forename: Tomomi
authors.initials: T
authors.lastname: Tsunematsu
authors.affiliation: Institute of Photonics, Dept. of Physics, SUPA, University of Strathclyde, Glasgow G1 1RD, UK.
authors.forename: Niall
authors.initials: N
authors.lastname: McAlinden
authors.affiliation: Institute of Photonics, Dept. of Physics, SUPA, University of Strathclyde, Glasgow G1 1RD, UK.
authors.forename: Martin D
authors.initials: MD
authors.lastname: Dawson
authors.affiliation: Strathclyde Institute of Pharmacy and Biomedical Sciences, University of Strathclyde, Glasgow G4 0RE, UK.
authors.forename: Shuzo
authors.initials: S
authors.lastname: Sakata
authors.affiliation: Institute of Photonics, Dept. of Physics, SUPA, University of Strathclyde, Glasgow G1 1RD, UK.
authors.forename: Keith
authors.initials: K
authors.lastname: Mathieson
mesh_terms: D000818:Animals; D051379:Mice; D009474:Neurons / Q000502:physiology*; D062308:Optogenetics / Q000295:instrumentation*; D010775:Photic Stimulation