title: Fiber-optic control and thermometry of single-cell thermosensation logic.
abstract: Thermal activation of transient receptor potential (TRP) cation channels is one of the most striking examples of temperature-controlled processes in cell biology. As the evidence indicating the fundamental role of such processes in thermosensation builds at a fast pace, adequately accurate tools that would allow heat receptor logic behind thermosensation to be examined on a single-cell level are in great demand. Here, we demonstrate a specifically designed fiber-optic probe that enables thermal activation with simultaneous online thermometry of individual cells expressing genetically encoded TRP channels. This probe integrates a fiber-optic tract for the delivery of laser light with a two-wire microwave transmission line. A diamond microcrystal fixed on the fiber tip is heated by laser radiation transmitted through the fiber, providing a local heating of a cell culture, enabling a well-controlled TRP-assisted thermal activation of cells. Online local temperature measurements are performed by using the temperature-dependent frequency shift of optically detected magnetic resonance, induced by coupling the microwave field, delivered by the microwave transmission line, to nitrogen--vacancy centers in the diamond microcrystal. Activation of TRP channels is verified by using genetically encoded fluorescence indicators, visualizing an increase in the calcium flow through activated TRP channels.
authors.affiliation: Physics Department, International Laser Center, M.V. Lomonosov Moscow State University, Moscow 119992, Russia.|Department of Physics and Astronomy, Texas A&M University, College Station TX 77843, USA.|Russian Quantum Center, ul. Novaya 100, Skolkovo, Moscow Region, 143025 Russia.
authors.forename: I V
authors.initials: IV
authors.lastname: Fedotov
authors.affiliation: Physics Department, International Laser Center, M.V. Lomonosov Moscow State University, Moscow 119992, Russia.|Russian Quantum Center, ul. Novaya 100, Skolkovo, Moscow Region, 143025 Russia.
authors.forename: N A
authors.initials: NA
authors.lastname: Safronov
authors.affiliation: M.M. Shemyakin and Yu.A. Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow 117997, Russia.
authors.forename: Yu G
authors.initials: YG
authors.lastname: Ermakova
authors.affiliation: M.M. Shemyakin and Yu.A. Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow 117997, Russia.
authors.forename: M E
authors.initials: ME
authors.lastname: Matlashov
authors.affiliation: Physics Department, International Laser Center, M.V. Lomonosov Moscow State University, Moscow 119992, Russia.|Russian Quantum Center, ul. Novaya 100, Skolkovo, Moscow Region, 143025 Russia.
authors.forename: D A
authors.initials: DA
authors.lastname: Sidorov-Biryukov
authors.affiliation: Physics Department, International Laser Center, M.V. Lomonosov Moscow State University, Moscow 119992, Russia.|Russian Quantum Center, ul. Novaya 100, Skolkovo, Moscow Region, 143025 Russia.
authors.forename: A B
authors.initials: AB
authors.lastname: Fedotov
authors.affiliation: M.M. Shemyakin and Yu.A. Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow 117997, Russia.
authors.forename: V V
authors.initials: VV
authors.lastname: Belousov
authors.affiliation: Physics Department, International Laser Center, M.V. Lomonosov Moscow State University, Moscow 119992, Russia.|Department of Physics and Astronomy, Texas A&M University, College Station TX 77843, USA.|Russian Quantum Center, ul. Novaya 100, Skolkovo, Moscow Region, 143025 Russia.|Kurchatov Institute National Research Center, Moscow 123182, Russia.
authors.forename: A M
authors.initials: AM
authors.lastname: Zheltikov
mesh_terms: D000818:Animals; D002118:Calcium / Q000378:metabolism; D018130:Diamond / Q000737:chemistry; D005336:Fiber Optic Technology / Q000295:instrumentation / Q000379:methods*; D006801:Humans; D007834:Lasers; D008128:Logic; D009682:Magnetic Resonance Spectroscopy / Q000295:instrumentation / Q000379:methods; D008872:Microwaves; D055100:Optical Fibers; D015203:Reproducibility of Results; D059010:Single-Cell Analysis / Q000295:instrumentation / Q000379:methods; D013696:Temperature; D062125:Thermometry / Q000295:instrumentation / Q000379:methods*; D050051:Transient Receptor Potential Channels / Q000235:genetics / Q000378:metabolism
chemical_list: D050051:Transient Receptor Potential Channels; D018130:Diamond; D002118:Calcium