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Roy A, Ben-Yakar A. Numerical study of a convective cooling strategy for increasing safe power levels in two-photon brain imaging. BIOMEDICAL OPTICS EXPRESS 2024; 15:540-557. [PMID: 38404347 PMCID: PMC10890868 DOI: 10.1364/boe.507517] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/04/2023] [Revised: 12/11/2023] [Accepted: 12/18/2023] [Indexed: 02/27/2024]
Abstract
Two-photon excitation fluorescence microscopy has become an effective tool for tracking neural activity in the brain at high resolutions thanks to its intrinsic optical sectioning and deep penetration capabilities. However, advanced two-photon microscopy modalities enabling high-speed and/or deep-tissue imaging necessitate high average laser powers, thus increasing the susceptibility of tissue heating due to out-of-focus absorption. Despite cooling the cranial window by maintaining the objective at a fixed temperature, average laser powers exceeding 100-200 mW have been shown to exhibit the potential for altering physiological responses of the brain. This paper proposes an enhanced cooling technique for inducing a laminar flow to the objective immersion layer while implementing duty cycles. Through a numerical study, we analyze the efficacy of heat dissipation of the proposed method and compare it with that of the conventional, fixed-temperature objective cooling technique. The results show that improved cooling could be achieved by choosing appropriate flow rates and physiologically relevant immersion cooling temperatures, potentially increasing safe laser power levels by up to three times (3×). The proposed active cooling method can provide an opportunity for faster scan speeds and enhanced signals in nonlinear deep brain imaging.
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Affiliation(s)
- Aditya Roy
- The University of Texas at Austin, Department of Mechanical Engineering, 204 East Dean Keeton Street, Stop C2200, Austin, Texas 78712, USA
| | - Adela Ben-Yakar
- The University of Texas at Austin, Department of Mechanical Engineering, 204 East Dean Keeton Street, Stop C2200, Austin, Texas 78712, USA
- The University of Texas at Austin, Department of Biomedical Engineering, 107 West Dean Keeton Street, Stop C0800, Austin, Texas 78712, USA
- The University of Texas at Austin, Department of Electrical and Computer Engineering, 2501 Speedway, Austin, Texas 78712, USA
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2
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Krueger TD, Chen C, Fang C. Targeting Ultrafast Spectroscopic Insights into Red Fluorescent Proteins. Chem Asian J 2023; 18:e202300668. [PMID: 37682793 DOI: 10.1002/asia.202300668] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2023] [Revised: 09/08/2023] [Accepted: 09/08/2023] [Indexed: 09/10/2023]
Abstract
Red fluorescent proteins (RFPs) represent an increasingly popular class of genetically encodable bioprobes and biomarkers that can advance next-generation breakthroughs across the imaging and life sciences. Since the rational design of RFPs with improved functions or enhanced versatility requires a mechanistic understanding of their working mechanisms, while fluorescence is intrinsically an ultrafast event, a suitable toolset involving steady-state and time-resolved spectroscopic techniques has become powerful in delineating key structural features and dynamic steps which govern irreversible photoconverting or reversible photoswitching RFPs, and large Stokes shift (LSS)RFPs. The pertinent cis-trans isomerization and protonation state change of RFP chromophores in their local environments, involving key residues in protein matrices, lead to rich and complicated spectral features across multiple timescales. In particular, ultrafast excited-state proton transfer in various LSSRFPs showcases the resolving power of wavelength-tunable femtosecond stimulated Raman spectroscopy (FSRS) in mapping a photocycle with crucial knowledge about the red-emitting species. Moreover, recent progress in noncanonical RFPs with a site-specifically modified chromophore provides an appealing route for efficient engineering of redder and brighter RFPs, highly desirable for bioimaging. Such an effective feedback loop involving physical chemists, protein engineers, and biomedical microscopists will enable future successes to expand fundamental knowledge and improve human health.
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Affiliation(s)
- Taylor D Krueger
- Department of Chemistry, Oregon State University, 153 Gilbert Hall, Corvallis, Oregon, 97331-4003, USA
| | - Cheng Chen
- Department of Chemistry, Oregon State University, 153 Gilbert Hall, Corvallis, Oregon, 97331-4003, USA
| | - Chong Fang
- Department of Chemistry, Oregon State University, 153 Gilbert Hall, Corvallis, Oregon, 97331-4003, USA
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3
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Zhang K, Chen FR, Wang L, Hu J. Second Near-Infrared (NIR-II) Window for Imaging-Navigated Modulation of Brain Structure and Function. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2023; 19:e2206044. [PMID: 36670072 DOI: 10.1002/smll.202206044] [Citation(s) in RCA: 12] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/01/2022] [Revised: 11/28/2022] [Indexed: 06/17/2023]
Abstract
For a long time, optical imaging of the deep brain with high resolution has been a challenge. Recently, with the advance in second near-infrared (NIR-II) bioimaging techniques and imaging contrast agents, NIR-II window bioimaging has attracted great attention to monitoring deeper biological or pathophysiological processes with high signal-to-noise ratio (SNR) and spatiotemporal resolution. Assisted with NIR-II bioimaging, the modulation of structure and function of brain is promising to be noninvasive and more precise. Herein, in this review, first the advantage of NIR-II light in brain imaging from the interaction between NIR-II and tissue is elaborated. Then, several specific NIR-II bioimaging technologies are introduced, including NIR-II fluorescence imaging, multiphoton fluorescence imaging, and photoacoustic imaging. Furthermore, the corresponding contrast agents are summarized. Next, the application of various NIR-II bioimaging technologies in visualizing the characteristics of cerebrovascular network and monitoring the changes of the pathology signals will be presented. After that, the modulation of brain structure and function based on NIR-II bioimaging will be discussed, including treatment of glioblastoma, guidance of cell transplantation, and neuromodulation. In the end, future perspectives that would help improve the clinical translation of NIR-II light are proposed.
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Affiliation(s)
- Ke Zhang
- Department of Biomedical Engineering, City University of Hong Kong, Kowloon, Hong Kong SAR, 999077, China
| | - Fu-Rong Chen
- Department of Materials Science and Engineering, City University of Hong Kong, Kowloon, Hong Kong SAR, 999077, China
| | - Lidai Wang
- Department of Biomedical Engineering, City University of Hong Kong, Kowloon, Hong Kong SAR, 999077, China
| | - Jinlian Hu
- Department of Biomedical Engineering, City University of Hong Kong, Kowloon, Hong Kong SAR, 999077, China
- Department of Materials Science and Engineering, City University of Hong Kong, Kowloon, Hong Kong SAR, 999077, China
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4
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Krueger TD, Tang L, Fang C. Delineating Ultrafast Structural Dynamics of a Green-Red Fluorescent Protein for Calcium Sensing. BIOSENSORS 2023; 13:bios13020218. [PMID: 36831983 PMCID: PMC9954042 DOI: 10.3390/bios13020218] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/13/2022] [Revised: 01/27/2023] [Accepted: 01/30/2023] [Indexed: 05/14/2023]
Abstract
Fluorescent proteins (FPs) are indispensable tools for noninvasive bioimaging and sensing. Measuring the free cellular calcium (Ca2+) concentrations in vivo with genetically encodable FPs can be a relatively direct measure of neuronal activity due to the complex signaling role of these ions. REX-GECO1 is a recently developed red-green emission and excitation ratiometric FP-based biosensor that achieves a high dynamic range due to differences in the chromophore response to light excitation with and without calcium ions. Using steady-state electronic measurements (UV/Visible absorption and emission), along with time-resolved spectroscopic techniques including femtosecond transient absorption (fs-TA) and femtosecond stimulated Raman spectroscopy (FSRS), the potential energy surfaces of these unique biosensors are unveiled with vivid details. The ground-state structural characterization of the Ca2+-free biosensor via FSRS reveals a more spacious protein pocket that allows the chromophore to efficiently twist and reach a dark state. In contrast, the more compressed cavity within the Ca2+-bound biosensor results in a more heterogeneous distribution of chromophore populations that results in multi-step excited state proton transfer (ESPT) pathways on the sub-140 fs, 600 fs, and 3 ps timescales. These results enable rational design strategies to enlarge the spectral separation between the protonated/deprotonated forms and the Stokes shift leading to a larger dynamic range and potentially higher fluorescence quantum yield, which should be broadly applicable to the calcium imaging and biosensor communities.
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5
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Drobizhev M, Molina RS, Franklin J. Multiphoton Bleaching of Red Fluorescent Proteins and the Ways to Reduce It. Int J Mol Sci 2022; 23:770. [PMID: 35054953 PMCID: PMC8775990 DOI: 10.3390/ijms23020770] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2021] [Revised: 01/06/2022] [Accepted: 01/07/2022] [Indexed: 11/16/2022] Open
Abstract
Red fluorescent proteins and biosensors built upon them are potentially beneficial for two-photon laser microscopy (TPLM) because they can image deeper layers of tissue, compared to green fluorescent proteins. However, some publications report on their very fast photobleaching, especially upon excitation at 750-800 nm. Here we study the multiphoton bleaching properties of mCherry, mPlum, tdTomato, and jREX-GECO1, measuring power dependences of photobleaching rates K at different excitation wavelengths across the whole two-photon absorption spectrum. Although all these proteins contain the chromophore with the same chemical structure, the mechanisms of their multiphoton bleaching are different. The number of photons required to initiate a photochemical reaction varies, depending on wavelength and power, from 2 (all four proteins) to 3 (jREX-GECO1) to 4 (mCherry, mPlum, tdTomato), and even up to 8 (tdTomato). We found that at sufficiently low excitation power P, the rate K often follows a quadratic power dependence, that turns into higher order dependence (K~Pα with α > 2) when the power surpasses a particular threshold P*. An optimum intensity for TPLM is close to the P*, because it provides the highest signal-to-background ratio and any further reduction of laser intensity would not improve the fluorescence/bleaching rate ratio. Additionally, one should avoid using wavelengths shorter than a particular threshold to avoid fast bleaching due to multiphoton ionization.
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Affiliation(s)
- Mikhail Drobizhev
- Department of Microbiology and Cell Biology, Montana State University, Bozeman, MT 59717, USA;
| | - Rosana S. Molina
- Department of Microbiology and Cell Biology, Montana State University, Bozeman, MT 59717, USA;
| | - Jacob Franklin
- Vidrio Technologies LLC, 19955 Highland Vista Drive Suite 150, Ashburn, VA 20147, USA;
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6
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Molina RS, King J, Franklin J, Clack N, McRaven C, Goncharov V, Flickinger D, Svoboda K, Drobizhev M, Hughes TE. High throughput instrument to screen fluorescent proteins under two-photon excitation. BIOMEDICAL OPTICS EXPRESS 2020; 11:7192-7203. [PMID: 33408990 PMCID: PMC7747914 DOI: 10.1364/boe.409353] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/07/2020] [Revised: 10/21/2020] [Accepted: 11/10/2020] [Indexed: 06/12/2023]
Abstract
Two-photon microscopy together with fluorescent proteins and fluorescent protein-based biosensors are commonly used tools in neuroscience. To enhance their experimental scope, it is important to optimize fluorescent proteins for two-photon excitation. Directed evolution of fluorescent proteins under one-photon excitation is common, but many one-photon properties do not correlate with two-photon properties. A simple system for expressing fluorescent protein mutants is E. coli colonies on an agar plate. The small focal volume of two-photon excitation makes creating a high throughput screen in this system a challenge for a conventional point-scanning approach. We present an instrument and accompanying software that solves this challenge by selectively scanning each colony based on a colony map captured under one-photon excitation. This instrument, called the GIZMO, can measure the two-photon excited fluorescence of 10,000 E. coli colonies in 7 hours. We show that the GIZMO can be used to evolve a fluorescent protein under two-photon excitation.
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Affiliation(s)
- Rosana S Molina
- Department of Cell Biology & Neuroscience, Montana State University, 109 Lewis Hall, Bozeman, MT 59717, USA
| | - Jonathan King
- Vidrio Technologies, LLC, PO Box 1870, Leesburg, VA 20177, USA
| | - Jacob Franklin
- Vidrio Technologies, LLC, PO Box 1870, Leesburg, VA 20177, USA
| | - Nathan Clack
- Vidrio Technologies, LLC, PO Box 1870, Leesburg, VA 20177, USA
| | - Christopher McRaven
- Janelia Research Campus, 19700 Helix Drive, Ashburn, VA 20147, USA
- Current address: Advanced Engineering Laboratory, Woods Hole Oceanographic Institution, 86 Water Street, Woods Hole, MA 02543, USA
| | - Vasily Goncharov
- Janelia Research Campus, 19700 Helix Drive, Ashburn, VA 20147, USA
| | | | - Karel Svoboda
- Janelia Research Campus, 19700 Helix Drive, Ashburn, VA 20147, USA
| | - Mikhail Drobizhev
- Department of Cell Biology & Neuroscience, Montana State University, 109 Lewis Hall, Bozeman, MT 59717, USA
| | - Thomas E Hughes
- Department of Cell Biology & Neuroscience, Montana State University, 109 Lewis Hall, Bozeman, MT 59717, USA
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7
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Hussein W, Berlin S. Red Photoactivatable Genetic Optical-Indicators. Front Cell Neurosci 2020; 14:113. [PMID: 32547366 PMCID: PMC7270359 DOI: 10.3389/fncel.2020.00113] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2020] [Accepted: 04/08/2020] [Indexed: 11/13/2022] Open
Abstract
Emerging genetically-encoded Ca2+-indicators (GECIs) are intensiometric reporters that increase in fluorescence when bound to Ca2+; highly suited for studying calcium-signaling in many cell types, notably neurons. Today, major efforts are devoted toward optimizing red-emitting [red fluorescent protein (RFP)-based] GECIs (R-GECI), as these provide several advantages over GFP-based reporters, for instance, increased imaging depth, reduced photodamage by longer imaging wavelengths and, in principle, are better suited for use with prevalent blue-absorbing optogenetic tools (e.g., channelrhodopsin). However, excessive fluorescence from intersecting neighboring cells in very dense tissues, notably the brain, hinders the ability to collect signals from single cells and their processes. This challenge can be addressed by photoactivatable (PA) fluorescent proteins that can be rendered fluorescent on demand by user-defined targeted light. This allows activation and, thereby, collection of fluorescent signals exclusively from desired cells and their processes, while leaving all neighboring cells in the dark (i.e., non-fluorescent). Nevertheless, there are no PA R-GECIs. Here, we sought to develop PA-R-GECIs. To do so, we initially explored a recently discovered phenomenon of Ca2+-independent increases in fluorescence (i.e., artifacts) in an emerging R-GECI, which has led us to rationally engineer several functional PA-R-GECIs. We also take advantage of our findings to quickly engineer a novel PA-RFP, namely, PA-mRuby3.
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Affiliation(s)
- Wessal Hussein
- Department of Neuroscience, The Ruth and Bruce Rappaport Faculty of Medicine, Technion - Israel Institute of Technology, Haifa, Israel
| | - Shai Berlin
- Department of Neuroscience, The Ruth and Bruce Rappaport Faculty of Medicine, Technion - Israel Institute of Technology, Haifa, Israel
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8
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Grabarek D, Andruniów T. Assessment of Functionals for TDDFT Calculations of One- and Two-Photon Absorption Properties of Neutral and Anionic Fluorescent Proteins Chromophores. J Chem Theory Comput 2018; 15:490-508. [PMID: 30485096 DOI: 10.1021/acs.jctc.8b00769] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
Performance of DFT functionals with different percentages of exact Hartree-Fock exchange energy (EX) is assessed for recovery of the CC2 reference one- (OPA) and two-photon absorption (TPA) spectra of fluorescent proteins chromophores in vacuo. The investigated DFT functionals, together with their EX contributions are BLYP (0%), B3LYP (20%), B1LYP (25%), BHandHLYP (50%), and CAM-B3LYP (19% at short range and 65% at long range). Our test set consists of anionic and neutral chromophores as naturally occurring in the fluorescent proteins. For the first time, we compare TDDFT and CC2 methods for higher excited states than the S1 state, exhibiting relatively large TPA intensity. Our TDDFT results for neutral chromophores reveal an increase in excitation energies as well as TPA and OPA intensities errors, compared to CC2-derived results, as the DFT functional contains less exact exchange. The long-range-corrected CAM-B3LYP functional performs the best, closely followed by BHandHLYP, while BLYP usually significantly underestimates all investigated spectral properties, hence being the worst in reproducing the reference CC2 results. The hybrid B3LYP and B1LYP functionals can be roughly placed in between. We propose that TDDFT may underestimate the TPA intensities for neutral chromophores of fluorescent proteins due to underestimated oscillator strengths between some excited states. In the case of anionic chromophores, we find that B3LYP and B1LYP functionals overcome others in terms of reproducing CC2 excitation energies. On the other hand, however, TPA intensity is usually significantly underestimated, and in this respect, CAM-B3LYP functional seems to be again superior. In contrast to the case of neutral chromophores, it seems that a large magnitude of excited-state dipole moments or changes in dipole moments upon excitation may be the driving force behind high TPA transition moments.
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Affiliation(s)
- Dawid Grabarek
- Advanced Materials Engineering and Modelling Group , Wroclaw University of Science and Technology , Wyb. Wyspianskiego 27 , 50-370 Wroclaw , Poland
| | - Tadeusz Andruniów
- Advanced Materials Engineering and Modelling Group , Wroclaw University of Science and Technology , Wyb. Wyspianskiego 27 , 50-370 Wroclaw , Poland
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9
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Mikhaylov A, de Reguardati S, Pahapill J, Callis PR, Kohler B, Rebane A. Two-photon absorption spectra of fluorescent isomorphic DNA base analogs. BIOMEDICAL OPTICS EXPRESS 2018; 9:447-452. [PMID: 29552385 PMCID: PMC5854050 DOI: 10.1364/boe.9.000447] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/25/2017] [Revised: 12/12/2017] [Accepted: 12/20/2017] [Indexed: 05/14/2023]
Abstract
Fluorescent DNA base analogs and intrinsic fluorophores are gaining importance for multiphoton microscopy and imaging, however, their quantitative nonlinear excitation properties have been poorly documented. Here we present the two-photon absorption (2PA) spectra of 2-aminopurine (2AP), 7-methyl guanosine (7MG), isoxanthopterin (IXP), 6-methyl isoxanthopterin (6MI), as well as L-tryptophan (L-trp) and 3-methylindole (3MI) in aqueous solution and some organic solvents measured in the wavelength range 550 - 810 nm using femtosecond two-photon excited fluorescence (2PEF) and nonlinear transmission (NLT) methods. The peak 2PA cross section values range from 0.1 GM (1 GM = 10-50 cm4 s photon-1) for 2AP to 2.0 GM for IXP and 7MG. Assuming typical excitation conditions for a scanning 2PEF microscope, we estimate a maximum image frame rate of ~175 frames per second (FPS).
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Affiliation(s)
| | | | - Jüri Pahapill
- National Institute of Chemical Physics and Biophysics, Tallinn 12618, Estonia
| | - Patrik R. Callis
- Department of Chemistry and Biochemistry, Montana State University, Bozeman, MT 59717, USA
| | - Bern Kohler
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, OH 43210, USA
| | - Aleksander Rebane
- Department of Physics, Montana State University, Bozeman, MT 59717, USA
- National Institute of Chemical Physics and Biophysics, Tallinn 12618, Estonia
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10
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Podgorski K, Ranganathan G. Brain heating induced by near-infrared lasers during multiphoton microscopy. J Neurophysiol 2016; 116:1012-23. [PMID: 27281749 PMCID: PMC5009202 DOI: 10.1152/jn.00275.2016] [Citation(s) in RCA: 159] [Impact Index Per Article: 19.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2016] [Accepted: 06/08/2016] [Indexed: 12/27/2022] Open
Abstract
Two-photon imaging and optogenetic stimulation rely on high illumination powers, particularly for state-of-the-art applications that target deeper structures, achieve faster measurements, or probe larger brain areas. However, little information is available on heating and resulting damage induced by high-power illumination in the brain. In the current study we used thermocouple probes and quantum dot nanothermometers to measure temperature changes induced by two-photon microscopy in the neocortex of awake and anaesthetized mice. We characterized heating as a function of wavelength, exposure time, and distance from the center of illumination. Although total power is highest near the surface of the brain, heating was most severe hundreds of micrometers below the focal plane, due to heat dissipation through the cranial window. Continuous illumination of a 1-mm(2) area produced a peak temperature increase of ∼1.8°C/100 mW. Continuous illumination with powers above 250 mW induced lasting damage, detected with immunohistochemistry against Iba1, glial fibrillary acidic protein, heat shock proteins, and activated caspase-3. Higher powers were usable in experiments with limited duty ratios, suggesting an approach to mitigate damage in high-power microscopy experiments.
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Affiliation(s)
- Kaspar Podgorski
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, Virginia
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11
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Steindal AH, Beerepoot MTP, Ringholm M, List NH, Ruud K, Kongsted J, Olsen JMH. Open-ended response theory with polarizable embedding: multiphoton absorption in biomolecular systems. Phys Chem Chem Phys 2016; 18:28339-28352. [DOI: 10.1039/c6cp05297e] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
We present the theory and implementation of an open-ended framework for electric response properties that includes effects from the molecular environment modeled by the polarizable embedding model.
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Affiliation(s)
- Arnfinn Hykkerud Steindal
- Centre of Theoretical and Computational Chemistry
- Department of Chemistry
- University of Tromsø—The Arctic University of Norway
- N-9037 Tromsø
- Norway
| | - Maarten T. P. Beerepoot
- Centre of Theoretical and Computational Chemistry
- Department of Chemistry
- University of Tromsø—The Arctic University of Norway
- N-9037 Tromsø
- Norway
| | - Magnus Ringholm
- Centre of Theoretical and Computational Chemistry
- Department of Chemistry
- University of Tromsø—The Arctic University of Norway
- N-9037 Tromsø
- Norway
| | - Nanna Holmgaard List
- Department of Physics
- Chemistry and Pharmacy
- University of Southern Denmark
- DK-5230 Odense
- Denmark
| | - Kenneth Ruud
- Centre of Theoretical and Computational Chemistry
- Department of Chemistry
- University of Tromsø—The Arctic University of Norway
- N-9037 Tromsø
- Norway
| | - Jacob Kongsted
- Department of Physics
- Chemistry and Pharmacy
- University of Southern Denmark
- DK-5230 Odense
- Denmark
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12
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Huss D, Benazeraf B, Wallingford A, Filla M, Yang J, Fraser SE, Lansford R. A transgenic quail model that enables dynamic imaging of amniote embryogenesis. Development 2015; 142:2850-9. [PMID: 26209648 PMCID: PMC4550965 DOI: 10.1242/dev.121392] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2015] [Accepted: 07/05/2015] [Indexed: 01/30/2023]
Abstract
Embryogenesis is the coordinated assembly of tissues during morphogenesis through changes in individual cell behaviors and collective cell movements. Dynamic imaging, combined with quantitative analysis, is ideal for investigating fundamental questions in developmental biology involving cellular differentiation, growth control and morphogenesis. However, a reliable amniote model system that is amenable to the rigors of extended, high-resolution imaging and cell tracking has been lacking. To address this shortcoming, we produced a novel transgenic quail that ubiquitously expresses nuclear localized monomer cherry fluorescent protein (chFP). We characterize the expression pattern of chFP and provide concrete examples of how Tg(PGK1:H2B-chFP) quail can be used to dynamically image and analyze key morphogenetic events during embryonic stages X to 11.
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Affiliation(s)
- David Huss
- Department of Radiology and Developmental Neuroscience Program, Saban Research Institute, Children's Hospital Los Angeles, Los Angeles, CA 90027, USA Department of Biological Sciences, University of Southern California, Los Angeles, CA 90089, USA
| | - Bertrand Benazeraf
- Department of Radiology and Developmental Neuroscience Program, Saban Research Institute, Children's Hospital Los Angeles, Los Angeles, CA 90027, USA Institut de Génétique et de Biologie Moléculaire et Cellulaire, CNRS (UMR 7104), Illkirch 67400, France
| | - Allison Wallingford
- Department of Radiology and Developmental Neuroscience Program, Saban Research Institute, Children's Hospital Los Angeles, Los Angeles, CA 90027, USA
| | - Michael Filla
- Department of Anatomy and Cell Biology, University of Kansas Medical Center, Kansas City, KS 66160, USA
| | - Jennifer Yang
- Division of Biology, California Institute of Technology, Pasadena, CA 94720, USA
| | - Scott E Fraser
- Department of Biological Sciences, University of Southern California, Los Angeles, CA 90089, USA Division of Biology, California Institute of Technology, Pasadena, CA 94720, USA
| | - Rusty Lansford
- Department of Radiology and Developmental Neuroscience Program, Saban Research Institute, Children's Hospital Los Angeles, Los Angeles, CA 90027, USA Division of Biology, California Institute of Technology, Pasadena, CA 94720, USA Keck School of Medicine, University of Southern California, Los Angeles, CA 90033, USA
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13
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Moreno J, Dobryakov AL, Ioffe IN, Granovsky AA, Hecht S, Kovalenko SA. Broadband transient absorption spectroscopy with 1- and 2-photon excitations: Relaxation paths and cross sections of a triphenylamine dye in solution. J Chem Phys 2015; 143:024311. [DOI: 10.1063/1.4926574] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Affiliation(s)
- J. Moreno
- Department of Chemistry, Humboldt-Universität zu Berlin, Brook-Taylor-St. 2, 12489 Berlin, Germany
| | - A. L. Dobryakov
- Department of Chemistry, Humboldt-Universität zu Berlin, Brook-Taylor-St. 2, 12489 Berlin, Germany
| | - I. N. Ioffe
- Department of Chemistry, Lomonosov Moscow State University, 119991 Moscow, Russia
| | | | - S. Hecht
- Department of Chemistry, Humboldt-Universität zu Berlin, Brook-Taylor-St. 2, 12489 Berlin, Germany
| | - S. A. Kovalenko
- Department of Chemistry, Humboldt-Universität zu Berlin, Brook-Taylor-St. 2, 12489 Berlin, Germany
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14
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Manna P, Jimenez R. Time and frequency-domain measurement of ground-state recovery times in red fluorescent proteins. J Phys Chem B 2015; 119:4944-54. [PMID: 25781915 DOI: 10.1021/acs.jpcb.5b00950] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
The field of bioimaging and biosensors has been revolutionized by the discovery of fluorescent proteins (FPs) and their use in live cells. FPs are characterized with rich photodynamics due to the presence of nonfluorescent or dark states which are responsible for fluorescence intermittency or "blinking", which has been exploited in several localization-based super-resolution techniques that surpass the diffraction-limited resolution of conventional microscopy. Molecules that convert to these dark states recover to the ground states either spontaneously or upon absorption of another photon, depending on the particular FP and the structural transition that is involved. In this work, we demonstrate time- and frequency-domain methods for the measurement of the ground-state recovery (GSR) times of FPs both in live cells and in solutions. In the time-domain method, we excited the sample with millisecond pulses at varying dark times to obtain percent-recovery. In the frequency-domain method, dark-state hysteresis was employed to obtain the positive phase shift or "phase advance". We extracted the GSR time constants from our measurements using calculations and simulations based on a three-state model system. The GSR time constants of the red FPs studied in these experiments fall in the range from μs to msec time-scales. We find that the time- and frequency-domain techniques are complementary to each other. While accurate GSR times can be extracted from the time-domain technique, frequency-domain measurements are primarily sensitive to the rates of dark-state conversion (DSC) processes. A correlation between GSR times, DSC, and photobleaching rates for the red FPs mCherry, TagRFP-T, and Kriek were observed. These time- and frequency-domain methods can be used in high-throughput screening and sorting of FPs clones based on GSR time constant and photostability and will therefore be valuable for the development of new photoswitchable or photoactivatable FPs.
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Affiliation(s)
- Premashis Manna
- †Department of Chemistry and Biochemistry, University of Colorado at Boulder, 215 UCB, Boulder, Colorado 80309, United States
- ‡JILA, University of Colorado at Boulder and National Institute of Standards and Technology, 440 UCB, Boulder, Colorado 80309, United States
| | - Ralph Jimenez
- †Department of Chemistry and Biochemistry, University of Colorado at Boulder, 215 UCB, Boulder, Colorado 80309, United States
- ‡JILA, University of Colorado at Boulder and National Institute of Standards and Technology, 440 UCB, Boulder, Colorado 80309, United States
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15
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Vegh RB, Bloch DA, Bommarius AS, Verkhovsky M, Pletnev S, Iwaï H, Bochenkova AV, Solntsev KM. Hidden photoinduced reactivity of the blue fluorescent protein mKalama1. Phys Chem Chem Phys 2015; 17:12472-85. [DOI: 10.1039/c5cp00887e] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
We report a complete photocycle of the blue fluorescent protein exhibiting two delayed branches coupled to hidden proton transfer events.
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Affiliation(s)
- Russell B. Vegh
- School of Chemistry and Biochemistry
- Georgia Institute of Technology
- Atlanta
- USA
- Petit Institute of Bioengineering and Bioscience
| | - Dmitry A. Bloch
- Research Program in Structural Biology and Biophysics
- Institute of Biotechnology
- University of Helsinki
- Helsinki 00014
- Finland
| | - Andreas S. Bommarius
- School of Chemistry and Biochemistry
- Georgia Institute of Technology
- Atlanta
- USA
- Petit Institute of Bioengineering and Bioscience
| | - Michael Verkhovsky
- Research Program in Structural Biology and Biophysics
- Institute of Biotechnology
- University of Helsinki
- Helsinki 00014
- Finland
| | - Sergei Pletnev
- Synchrotron Radiation Research Section
- Macromolecular Crystallography Laboratory
- National Cancer Institute
- Argonne
- USA
| | - Hideo Iwaï
- Research Program in Structural Biology and Biophysics
- Institute of Biotechnology
- University of Helsinki
- Helsinki 00014
- Finland
| | | | - Kyril M. Solntsev
- School of Chemistry and Biochemistry
- Georgia Institute of Technology
- Atlanta
- USA
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