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Deng J, Sun C, Zheng Y, Gao J, Cui X, Wang Y, Zhang L, Tang P. In vivo imaging of the neuronal response to spinal cord injury: a narrative review. Neural Regen Res 2024; 19:811-817. [PMID: 37843216 PMCID: PMC10664102 DOI: 10.4103/1673-5374.382225] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2023] [Revised: 05/15/2023] [Accepted: 07/07/2023] [Indexed: 10/17/2023] Open
Abstract
Deciphering the neuronal response to injury in the spinal cord is essential for exploring treatment strategies for spinal cord injury (SCI). However, this subject has been neglected in part because appropriate tools are lacking. Emerging in vivo imaging and labeling methods offer great potential for observing dynamic neural processes in the central nervous system in conditions of health and disease. This review first discusses in vivo imaging of the mouse spinal cord with a focus on the latest imaging techniques, and then analyzes the dynamic biological response of spinal cord sensory and motor neurons to SCI. We then summarize and compare the techniques behind these studies and clarify the advantages of in vivo imaging compared with traditional neuroscience examinations. Finally, we identify the challenges and possible solutions for spinal cord neuron imaging.
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Affiliation(s)
- Junhao Deng
- Department of Orthopedics, The Fourth Medical Center of Chinese PLA General Hospital, Beijing, China
- National Clinical Research Center for Orthopedics, Sports Medicine and Rehabilitation, Beijing, China
- School of Life Sciences, Tsinghua University, Beijing, China
| | - Chang Sun
- Department of Orthopedics, The Fourth Medical Center of Chinese PLA General Hospital, Beijing, China
- National Clinical Research Center for Orthopedics, Sports Medicine and Rehabilitation, Beijing, China
- Department of Orthopedics, Air Force Medical Center, PLA, Beijing, China
| | - Ying Zheng
- Medical School of Chinese PLA, Beijing, China
| | - Jianpeng Gao
- Department of Orthopedics, The Fourth Medical Center of Chinese PLA General Hospital, Beijing, China
- National Clinical Research Center for Orthopedics, Sports Medicine and Rehabilitation, Beijing, China
| | - Xiang Cui
- Department of Orthopedics, The Fourth Medical Center of Chinese PLA General Hospital, Beijing, China
- National Clinical Research Center for Orthopedics, Sports Medicine and Rehabilitation, Beijing, China
| | - Yu Wang
- Institute of Orthopedics, The First Medical Center, Chinese PLA General Hospital, Beijing, China
- Key Lab of Regenerative Medicine in Orthopedics, Key Laboratory of Musculoskeletal Trauma and War Injuries PLA, Beijing, China
| | - Licheng Zhang
- Department of Orthopedics, The Fourth Medical Center of Chinese PLA General Hospital, Beijing, China
- National Clinical Research Center for Orthopedics, Sports Medicine and Rehabilitation, Beijing, China
| | - Peifu Tang
- Department of Orthopedics, The Fourth Medical Center of Chinese PLA General Hospital, Beijing, China
- National Clinical Research Center for Orthopedics, Sports Medicine and Rehabilitation, Beijing, China
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2
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Yang X, Liu S, Xia F, Wu M, Adie S, Xu C. Simultaneous multimodal three-photon and optical coherence microscopy of the mouse brain in the 1700 nm optical window in vivo. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.09.11.557176. [PMID: 37745620 PMCID: PMC10515788 DOI: 10.1101/2023.09.11.557176] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/26/2023]
Abstract
Multimodal microscopy combining various imaging approaches can provide complementary information about tissue in a single imaging session. Here, we demonstrate a multimodal approach combining three-photon microscopy (3PM) and spectral-domain optical coherence microscopy (SD-OCM). We show that an optical parametric chirped-pulse amplification (OPCPA) laser source, which is the standard source for three-photon fluorescence excitation and third harmonic generation (THG), can be used for simultaneous OCM, 3-photon (3P) fluorescence and THG imaging. We validated the system performance in deep mouse brains in vivo with an OPCPA source operating at 1620 nm center wavelength. We visualized small structures such as myelinated axons, neurons, and large fiber tracts in white matter with high spatial resolution non-invasively using linear and nonlinear contrast at >1 mm depth in intact adult mouse brain. Our results showed that simultaneous OCM and 3PM at the long wavelength window can be conveniently combined for deep tissue imaging in vivo.
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Affiliation(s)
- Xusan Yang
- School of Applied and Engineering Physics, Cornell University, Ithaca, NY, 14853, USA
- Current address: Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China
| | - Siyang Liu
- School of Electrical and Computer Engineering, Cornell University, Ithaca, NY, 14853, USA
| | - Fei Xia
- School of Applied and Engineering Physics, Cornell University, Ithaca, NY, 14853, USA
- Meinig School of Biomedical Engineering, Cornell University, Ithaca, NY, 14853, USA
- Current address: Laboratoire Kastler Brossel, ENS-Universite PSL, CNRS, Sorbonne Université, Collège de France, Paris, 75005, France
| | - Meiqi Wu
- Meinig School of Biomedical Engineering, Cornell University, Ithaca, NY, 14853, USA
| | - Steven Adie
- Meinig School of Biomedical Engineering, Cornell University, Ithaca, NY, 14853, USA
| | - Chris Xu
- School of Applied and Engineering Physics, Cornell University, Ithaca, NY, 14853, USA
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3
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Aminophenoxazinone near-infrared fluorescent probes for myelin-specific imaging. Tetrahedron 2023. [DOI: 10.1016/j.tet.2023.133358] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/12/2023]
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4
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Kwon J, Lee S, Jo Y, Choi M. All-optical observation on activity-dependent nanoscale dynamics of myelinated axons. NEUROPHOTONICS 2023; 10:015003. [PMID: 36699624 PMCID: PMC9868287 DOI: 10.1117/1.nph.10.1.015003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/25/2022] [Accepted: 01/05/2023] [Indexed: 06/17/2023]
Abstract
SIGNIFICANCE In the mammalian brain, rapid conduction of neural information is supported by the myelin, the functional efficacy of which shows steep dependence on its nanoscale cytoarchitecture. Although previous in vitro studies have suggested that neural activity accompanies nanometer-scale cellular deformations, whether neural activity can dynamically remodel the myelinated axon has remained unexplored due to the technical challenge in observing its nanostructural dynamics in living tissues. AIM We aim to observe activity-dependent nanostructural dynamics of myelinated axons in a living brain tissue. APPROACH We introduced a novel all-optical approach combining a nanoscale dynamic readout based on spectral interferometry and optogenetic control of neural excitation in an acute brain slice preparation. RESULTS In response to optogenetically evoked neuronal burst firing, the myelinated axons exhibited progressive and reversible spectral redshifts, corresponding to the transient swelling at a subnanometer scale. We further revealed that the activity-dependent nanostructural dynamics was localized to the paranode. CONCLUSIONS Our all-optical studies substantiate that myelinated axon exhibits activity-dependent nanoscale swelling, which potentially serves to dynamically tune the transmission speed of neural information.
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Affiliation(s)
- Junhwan Kwon
- Sungkyunkwan University, Department of Biomedical Engineering, Suwon, Republic of Korea
- Institute for Basic Science, Center for Neuroscience Imaging Research, Suwon, Republic of Korea
| | - Sungho Lee
- Seoul National University, School of Biological Sciences, Seoul, Republic of Korea
- Seoul National University, The Institute of Molecular Biology and Genetics, Seoul, Republic of Korea
| | - Yongjae Jo
- Institute for Basic Science, Center for Neuroscience Imaging Research, Suwon, Republic of Korea
| | - Myunghwan Choi
- Seoul National University, School of Biological Sciences, Seoul, Republic of Korea
- Seoul National University, The Institute of Molecular Biology and Genetics, Seoul, Republic of Korea
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5
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Omidi M, Zibaii MI, Granpayeh N. Simulation of nerve fiber based on anti-resonant reflecting optical waveguide. Sci Rep 2022; 12:19356. [PMID: 36369256 PMCID: PMC9652394 DOI: 10.1038/s41598-022-23580-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2022] [Accepted: 11/02/2022] [Indexed: 11/13/2022] Open
Abstract
Light and optical techniques are widely used for the diagnosis and treatment of neurological diseases as advanced methods. Understanding the optical properties of nervous tissue and nerve cells is vital. Using light sources in these methods raises significant challenges, such as finding the place of light transmission in nerve fibers that could be an appropriate substrate for neural signaling. The myelinated axons are a promising candidate for transmitting neural signals and light due to their waveguide structures. On the other hand, with the emergence of diseases such as multiple sclerosis and disorders within the production and transmission of nerve signals, because of the demyelination, understanding the properties of the myelinated axon as a waveguide is obtaining additional necessity. The present study aims to show that the myelinated axon's refractive index (RI) profile plays an essential role in transmitting the beams in it. According to the nerve fiber, RI profile and its similarity to depressed core fiber with lower RI of the core compared to the cladding, the behaviors of the nerve fiber based on anti-resonant reflecting optical waveguide structure are investigated by taking into account the realistic optical imperfections. Light launching to the myelin sheath and axon is shown by introducing the axon and myelin sheath as a waveguide in the presence of both axon and myelin with bends, myelin sheath variation, and node of Ranvier.
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Affiliation(s)
- Marzieh Omidi
- grid.411976.c0000 0004 0369 2065Center of Excellence in Electromagnetics, Faculty of Electrical Engineering, K. N. Toosi University of Technology, Tehran, Iran
| | - Mohammad Ismail Zibaii
- grid.412502.00000 0001 0686 4748Laser and Plasma Research Institute, Shahid Beheshti University, Tehran, Iran
| | - Nosrat Granpayeh
- grid.411976.c0000 0004 0369 2065Center of Excellence in Electromagnetics, Faculty of Electrical Engineering, K. N. Toosi University of Technology, Tehran, Iran
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Guo L, Xu D, Wang K, Sun Y, Zhang Q, Ning H, Lu C, Wang S, Gong Y. Electromagnetic characteristics of in vivo nerve fibers at the terahertz-far-infrared band. Front Bioeng Biotechnol 2022; 10:1055232. [PMID: 36440450 PMCID: PMC9685790 DOI: 10.3389/fbioe.2022.1055232] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2022] [Accepted: 10/14/2022] [Indexed: 12/02/2023] Open
Abstract
How terahertz signals perform in the neural system has attracted widespread interest in the life sciences community. Relevant experimental reveals that in animal nerve cells, the myelin sheath of the nerve axon has a higher refractive index than the intracellular and extracellular fluids in the Terahertz-far-infrared (THz-FIR) frequency band. This makes THz-FIR wave transmission possible in nerve fibers. Based on this premise, this article carries out the following work from the theoretical level to investigate the electromagnetic (EM) characteristics of in vivo nerve fibers at the THz-FIR band. First, the EM transmission model of the nerve fibers is established and studied theoretically. The dispersion curves of THz-FIR wave modals transmission in nerve fibers are calculated, which predict that nerve fibers can act as dielectric waveguides for transmitting THz-FIR waves and the THz-FIR waves can transmit at speeds up to 108 m/s. Second, a mode matching algorithm is proposed, which is named RNMMA, to calculate the transmission characteristics of THz-FIR waves at the nodes of Ranvier. The scattering matrix obtained from the proposed algorithm is in good agreement with the results from EM simulation software, which reveals how THz-FIR signals are transmitted forward through the nodes of Ranvier with low loss.
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Affiliation(s)
- Lianghao Guo
- School of Electronic Science and Engineering, University of Electronic Science and Technology of China, Chengdu, Sichuan, China
| | - Duo Xu
- School of Electronic Science and Engineering, University of Electronic Science and Technology of China, Chengdu, Sichuan, China
| | - Kaicheng Wang
- School of Electronic Science and Engineering, University of Electronic Science and Technology of China, Chengdu, Sichuan, China
| | - Yuankun Sun
- School of Electronic Science and Engineering, University of Electronic Science and Technology of China, Chengdu, Sichuan, China
| | - Qin Zhang
- School of Electronic Science and Engineering, University of Electronic Science and Technology of China, Chengdu, Sichuan, China
| | - Hui Ning
- School of Electronic Science and Engineering, University of Electronic Science and Technology of China, Chengdu, Sichuan, China
| | - Chang Lu
- Department of Electronic Communication and Technology, Shenzhen Institute of Information Technology, Shenzhen, China
| | - Shaomeng Wang
- School of Electronic Science and Engineering, University of Electronic Science and Technology of China, Chengdu, Sichuan, China
- National Key Lab on Vacuum Electronics, Medico-Engineering Cooperation on Applied Medicine Research Center, School of Electronic Science and Engineering, University of Electronic Science and Technology of China, Chengdu, China
| | - Yubin Gong
- School of Electronic Science and Engineering, University of Electronic Science and Technology of China, Chengdu, Sichuan, China
- National Key Lab on Vacuum Electronics, Medico-Engineering Cooperation on Applied Medicine Research Center, School of Electronic Science and Engineering, University of Electronic Science and Technology of China, Chengdu, China
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Zhang H, Zhu L, Gao DS, Liu Y, Zhang J, Yan M, Qian J, Xi W. Imaging the Deep Spinal Cord Microvascular Structure and Function with High-Speed NIR-II Fluorescence Microscopy. SMALL METHODS 2022; 6:e2200155. [PMID: 35599368 DOI: 10.1002/smtd.202200155] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/03/2022] [Revised: 04/23/2022] [Indexed: 06/15/2023]
Abstract
The spinal cord (SC) is crucial for a myriad of somatosensory, autonomic signal processing, and transductions. Understanding the SC vascular structure and function thus plays an integral part in neuroscience and clinical research. However, the dense layers of myelinated ascending axons on the dorsal side inconveniently grant the SC tissue with high optical scattering property, which significantly hinders the imaging depth of the SC vasculature in vivo. Commonly used antiscattering techniques such as multiphoton fluorescence microscopy have low imaging speed and cannot capture the rapid vascular particle flow without significant motion blur. Here, advantage of the high penetration of near-infrared (NIR)-II fluorescence is taken to demonstrate a deep SC vascular structural image stack up to 350 µm, comparable to two-photon microscopy. Furthermore, the red blood cells are labelled with the clinically approved NIR dye indocyanine. The combination of a fast NIR camera and indocyanine green-red blood cells (RBCs) makes it possible to attain high-speed 100 frame-per-second NIR-II imaging to identify the corresponding changes in RBC velocity during the external hind leg stimulus. For the first time, it is established that the NIR-II region would be a promising spectral window for SC imaging. NIR-II fluorescence microscopy has excellent potential for clinical and basic science research on SC.
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Affiliation(s)
- Hequn Zhang
- Interdisciplinary Institute of Neuroscience and Technology (ZIINT), Department of Anesthesiology, the Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, 310020, China
- MOE Frontier Science Center for Brain Research and Brain Machine Integration, Zhejiang University, Hangzhou, 310058, China
| | - Liang Zhu
- Interdisciplinary Institute of Neuroscience and Technology (ZIINT), Department of Anesthesiology, the Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, 310020, China
- MOE Frontier Science Center for Brain Research and Brain Machine Integration, Zhejiang University, Hangzhou, 310058, China
- Interdisciplinary Institute of Neuroscience and Technology (ZIINT), College of Biomedical Engineering and Instrument Science, Zhejiang University, Hangzhou, 310027, China
| | - Dave Schwinn Gao
- Key Laboratory of The Diagnosis and Treatment of Severe Trauma and Burn of Zhejiang Province, Department of Anesthesiology, the Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, 310009, China
| | - Yin Liu
- Interdisciplinary Institute of Neuroscience and Technology (ZIINT), Department of Anesthesiology, the Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, 310020, China
- MOE Frontier Science Center for Brain Research and Brain Machine Integration, Zhejiang University, Hangzhou, 310058, China
| | - Jun Zhang
- Department of Spine Surgery, Zhejiang Provincial People's Hospital, Hangzhou Medical School People's Hospital, Shangtang Road 158th, Hangzhou, Zhejiang Province, 310014, China
| | - Min Yan
- Key Laboratory of The Diagnosis and Treatment of Severe Trauma and Burn of Zhejiang Province, Department of Anesthesiology, the Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, 310009, China
| | - Jun Qian
- State Key Laboratory of Modern Optical Instrumentations, Centre for Optical and Electromagnetic Research, College of Optical Science and Engineering, Zhejiang University, Hangzhou, 310058, China
| | - Wang Xi
- Interdisciplinary Institute of Neuroscience and Technology (ZIINT), Department of Anesthesiology, the Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, 310020, China
- MOE Frontier Science Center for Brain Research and Brain Machine Integration, Zhejiang University, Hangzhou, 310058, China
- Key Laboratory of Biomedical Engineering of Ministry of Education, College of Biomedical Engineering and instrument Science, Zhejiang University, Hangzhou, 310027, China
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8
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Jo Y, Lee YR, Hong JH, Kim DY, Kwon J, Choi M, Kim M, Choi W. Through-skull brain imaging in vivo at visible wavelengths via dimensionality reduction adaptive-optical microscopy. SCIENCE ADVANCES 2022; 8:eabo4366. [PMID: 35895824 PMCID: PMC9328682 DOI: 10.1126/sciadv.abo4366] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/07/2022] [Accepted: 06/13/2022] [Indexed: 05/25/2023]
Abstract
Compensation of sample-induced optical aberrations is crucial for visualizing microscopic structures deep within biological tissues. However, strong multiple scattering poses a fundamental limitation for identifying and correcting the tissue-induced aberrations. Here, we introduce a label-free deep-tissue imaging technique termed dimensionality reduction adaptive-optical microscopy (DReAM) to selectively attenuate multiple scattering. We established a theoretical framework in which dimensionality reduction of a time-gated reflection matrix can attenuate uncorrelated multiple scattering while retaining a single-scattering signal with a strong wave correlation, irrespective of sample-induced aberrations. We performed mouse brain imaging in vivo through the intact skull with the probe beam at visible wavelengths. Despite the strong scattering and aberrations, DReAM offered a 17-fold enhancement of single scattering-to-multiple scattering ratio and provided high-contrast images of neural fibers in the brain cortex with the diffraction-limited spatial resolution of 412 nanometers and a 33-fold enhanced Strehl ratio.
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Affiliation(s)
- Yonghyeon Jo
- Center for Molecular Spectroscopy and Dynamics, Institute for Basic Science, Seoul 02841, Republic of Korea
- Department of Physics, Korea University, Seoul 02855, Republic of Korea
| | - Ye-Ryoung Lee
- Center for Molecular Spectroscopy and Dynamics, Institute for Basic Science, Seoul 02841, Republic of Korea
- Department of Physics, Korea University, Seoul 02855, Republic of Korea
- Institute of Basic Science, Korea University, Seoul 02841, Republic of Korea
| | - Jin Hee Hong
- Center for Molecular Spectroscopy and Dynamics, Institute for Basic Science, Seoul 02841, Republic of Korea
- Department of Physics, Korea University, Seoul 02855, Republic of Korea
| | - Dong-Young Kim
- Center for Molecular Spectroscopy and Dynamics, Institute for Basic Science, Seoul 02841, Republic of Korea
- Department of Physics, Korea University, Seoul 02855, Republic of Korea
| | - Junhwan Kwon
- School of Biological Sciences, Seoul National University, Seoul, Republic of Korea
- The Institute of Molecular Biology and Genetics, Seoul National University, Seoul, Republic of Korea
- Bio & Medical Health Division, Korea Testing Laboratory, 10, Chungui-ro, Jinju-si, Gyeongsangnam-do, Republic of Korea
| | - Myunghwan Choi
- School of Biological Sciences, Seoul National University, Seoul, Republic of Korea
- The Institute of Molecular Biology and Genetics, Seoul National University, Seoul, Republic of Korea
| | - Moonseok Kim
- Department of Medical Life Sciences, College of Medicine, The Catholic University of Korea, Seoul 06591, Republic of Korea
- Department of Biomedicine & Health Sciences, College of Medicine, The Catholic University of Korea, Seoul 06591, Republic of Korea
| | - Wonshik Choi
- Center for Molecular Spectroscopy and Dynamics, Institute for Basic Science, Seoul 02841, Republic of Korea
- Department of Physics, Korea University, Seoul 02855, Republic of Korea
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9
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Leartprapun N, Adie SG. Resolution-enhanced OCT and expanded framework of information capacity and resolution in coherent imaging. Sci Rep 2021; 11:20541. [PMID: 34654877 PMCID: PMC8521598 DOI: 10.1038/s41598-021-99889-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2021] [Accepted: 09/17/2021] [Indexed: 11/09/2022] Open
Abstract
Spatial resolution in conventional optical microscopy has traditionally been treated as a fixed parameter of the optical system. Here, we present an approach to enhance transverse resolution in beam-scanned optical coherence tomography (OCT) beyond its aberration-free resolution limit, without any modification to the optical system. Based on the theorem of invariance of information capacity, resolution-enhanced (RE)-OCT navigates the exchange of information between resolution and signal-to-noise ratio (SNR) by exploiting efficient noise suppression via coherent averaging and a simple computational bandwidth expansion procedure. We demonstrate a resolution enhancement of 1.5 × relative to the aberration-free limit while maintaining comparable SNR in silicone phantom. We show that RE-OCT can significantly enhance the visualization of fine microstructural features in collagen gel and ex vivo mouse brain. Beyond RE-OCT, our analysis in the spatial-frequency domain leads to an expanded framework of information capacity and resolution in coherent imaging that contributes new implications to the theory of coherent imaging. RE-OCT can be readily implemented on most OCT systems worldwide, immediately unlocking information that is beyond their current imaging capabilities, and so has the potential for widespread impact in the numerous areas in which OCT is utilized, including the basic sciences and translational medicine.
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Affiliation(s)
- Nichaluk Leartprapun
- Nancy E. and Peter C. Meinig School of Biomedical Engineering, Cornell University, Ithaca, NY, 14853, USA
| | - Steven G Adie
- Nancy E. and Peter C. Meinig School of Biomedical Engineering, Cornell University, Ithaca, NY, 14853, USA.
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10
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Spectral Reflectometry in Biomedical Imaging and Sensing. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2021. [PMID: 33834442 DOI: 10.1007/978-981-33-6064-8_13] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register]
Abstract
Spectral reflectometry is a spectroscopic measurement technique based on thin-film interference, which has been widely applied in industries to measure thicknesses of thin dielectric layers at the nanoscale. Recent advances in the understanding of biological nanostructures have opened a new field of spectral reflectometry in biomedicine from molecular level sensing to biomedical imaging. This chapter comprehensively covers the relevant topics on spectral reflectometry in biomedicine from its principle to applications.
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11
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Song W, Matlock A, Fu S, Qin X, Feng H, Gabel CV, Tian L, YI J. LED array reflectance microscopy for scattering-based multi-contrast imaging. OPTICS LETTERS 2020; 45:1647-1650. [PMID: 32235964 PMCID: PMC7278208 DOI: 10.1364/ol.387434] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/09/2020] [Accepted: 02/01/2020] [Indexed: 05/24/2023]
Abstract
LED array microscopy is an emerging platform for computational imaging with significant utility for biological imaging. Existing LED array systems often exploit transmission imaging geometries of standard brightfield microscopes that leave the rich backscattered field undetected. This backscattered signal contains high-resolution sample information with superb sensitivity to subtle structural features that make it ideal for biological sensing and detection. Here, we develop an LED array reflectance microscope capturing the sample's backscattered signal. In particular, we demonstrate multimodal brightfield, darkfield, and differential phase contrast imaging on fixed and living biological specimens including Caenorhabditis elegans (C. elegans), zebrafish embryos, and live cell cultures. Video-rate multimodal imaging at 20 Hz records real time features of freely moving C. elegans and the fast beating heart of zebrafish embryos. Our new reflectance mode is a valuable addition to the LED array microscopic toolbox.
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Affiliation(s)
- Weiye Song
- Department of Medicine, Boston University School of Medicine, Boston Medical Center, Boston, Massachusetts 02118, USA
| | - Alex Matlock
- Department of Electrical and Computer Engineering, Boston University, Boston, Massachusetts 02215, USA
| | - Sipei Fu
- Department of Medicine, Boston University School of Medicine, Boston Medical Center, Boston, Massachusetts 02118, USA
| | - Xiaodan Qin
- Departments of Pharmacology and Medicine, Section of Hematology and Medical Oncology, Cancer Research Center, Boston University School of Medicine, Boston, Massachusetts 02118, USA
| | - Hui Feng
- Departments of Pharmacology and Medicine, Section of Hematology and Medical Oncology, Cancer Research Center, Boston University School of Medicine, Boston, Massachusetts 02118, USA
| | - Christopher V. Gabel
- Department of Physiology and Biophysics, Boston University School of Medicine, Boston, Massachusetts 02118, USA
| | - Lei Tian
- Department of Electrical and Computer Engineering, Boston University, Boston, Massachusetts 02215, USA
| | - Ji YI
- Department of Medicine, Boston University School of Medicine, Boston Medical Center, Boston, Massachusetts 02118, USA
- Department of Electrical and Computer Engineering, Boston University, Boston, Massachusetts 02215, USA
- Department of Biomedical Engineering, Boston University, Boston, Massachusetts 02215, USA
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12
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Makhija EP, Espinosa-Hoyos D, Jagielska A, Van Vliet KJ. Mechanical regulation of oligodendrocyte biology. Neurosci Lett 2019; 717:134673. [PMID: 31838017 DOI: 10.1016/j.neulet.2019.134673] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2019] [Revised: 11/25/2019] [Accepted: 12/01/2019] [Indexed: 12/27/2022]
Abstract
Oligodendrocytes (OL) are a subset of glial cells in the central nervous system (CNS) comprising the brain and spinal cord. The CNS environment is defined by complex biochemical and biophysical cues during development and response to injury or disease. In the last decade, significant progress has been made in understanding some of the key biophysical factors in the CNS that modulate OL biology, including their key role in myelination of neurons. Taken together, those studies offer translational implications for remyelination therapies, pharmacological research, identification of novel drug targets, and improvements in methods to generate human oligodendrocyte progenitor cells (OPCs) and OLs from donor stem cells in vitro. This review summarizes current knowledge of how various physical and mechanical cues affect OL biology and its implications for disease, therapeutic approaches, and generation of human OPCs and OLs.
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Affiliation(s)
- Ekta P Makhija
- BioSystems & Micromechanics (BioSyM) Interdisciplinary Research Group, Singapore-MIT Alliance for Research & Technology (SMART) CREATE, Singapore 138602; Critical Analytics for Manufacturing Personalized-Medicine (CAMP) Interdisciplinary Research Group, Singapore-MIT Alliance for Research & Technology (SMART) CREATE, 138602, Singapore
| | - Daniela Espinosa-Hoyos
- BioSystems & Micromechanics (BioSyM) Interdisciplinary Research Group, Singapore-MIT Alliance for Research & Technology (SMART) CREATE, Singapore 138602; Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139 USA
| | - Anna Jagielska
- BioSystems & Micromechanics (BioSyM) Interdisciplinary Research Group, Singapore-MIT Alliance for Research & Technology (SMART) CREATE, Singapore 138602; Department of Materials Science & Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139 USA.
| | - Krystyn J Van Vliet
- BioSystems & Micromechanics (BioSyM) Interdisciplinary Research Group, Singapore-MIT Alliance for Research & Technology (SMART) CREATE, Singapore 138602; Critical Analytics for Manufacturing Personalized-Medicine (CAMP) Interdisciplinary Research Group, Singapore-MIT Alliance for Research & Technology (SMART) CREATE, 138602, Singapore; Department of Materials Science & Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139 USA; Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139 USA.
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13
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Lim H. Harmonic Generation Microscopy 2.0: New Tricks Empowering Intravital Imaging for Neuroscience. Front Mol Biosci 2019; 6:99. [PMID: 31649934 PMCID: PMC6794408 DOI: 10.3389/fmolb.2019.00099] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2019] [Accepted: 09/17/2019] [Indexed: 01/08/2023] Open
Abstract
Optical harmonic generation, e.g., second- (SHG) and third-harmonic generation (THG), provides intrinsic contrasts for three-dimensional intravital microscopy. Contrary to two-photon excited fluorescence (TPEF), however, they have found relatively specialized applications, such as imaging collagenous and non-specific tissues, respectively. Here we review recent advances that broaden the capacity of SHG and THG for imaging the central nervous system in particular. The fundamental contrast mechanisms are reviewed as they encode novel information including molecular origin, spectroscopy, functional probes, and image analysis, which lay foundations for promising future applications in neuroscience.
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Affiliation(s)
- Hyungsik Lim
- Department of Physics and Astronomy, Hunter College and the Graduate Center of the City University of New York, New York, NY, United States
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14
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Label-free neuroimaging in vivo using synchronous angular scanning microscopy with single-scattering accumulation algorithm. Nat Commun 2019; 10:3152. [PMID: 31316065 PMCID: PMC6637127 DOI: 10.1038/s41467-019-11040-z] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2018] [Accepted: 06/14/2019] [Indexed: 12/21/2022] Open
Abstract
Label-free in vivo imaging is crucial for elucidating the underlying mechanisms of many important biological systems in their most native states. However, the applicability of existing modalities has been limited to either superficial layers or early developmental stages due to tissue turbidity. Here, we report a synchronous angular scanning microscope for the rapid interferometric recording of the time-gated reflection matrix, which is a unique matrix characterizing full light-specimen interaction. By applying single scattering accumulation algorithm to the recorded matrix, we removed both high-order sample-induced aberrations and multiple scattering noise with the effective aberration correction speed of 10,000 modes/s. We demonstrated in vivo imaging of whole neural network throughout the hindbrain of the larval zebrafish at a matured stage where physical dissection used to be required for conventional imaging. Our method will expand the scope of applications for optical imaging, where fully non-invasive interrogation of living specimens is critical. A major challenge of in vivo imaging is imaging deeper, including in turbid tissue. The authors report an adaptive optics based microscope that uses coherent single scattering signal to reduce sample-induced aberrations and enable fast deep-tissue imaging of in vivo larval zebrafish brain.
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15
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Nelson NA, Wang X, Cook D, Carey EM, Nimmerjahn A. Imaging spinal cord activity in behaving animals. Exp Neurol 2019; 320:112974. [PMID: 31175843 DOI: 10.1016/j.expneurol.2019.112974] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2019] [Revised: 06/02/2019] [Accepted: 06/04/2019] [Indexed: 01/06/2023]
Abstract
The spinal cord is the primary neurological link between the brain and peripheral organs. How important it is in everyday life is apparent in patients with spinal cord injury or motoneuron disease, who have dramatically reduced musculoskeletal control or capacity to sense their environment. Despite its crucial role in sensory and motor processing little is known about the cellular and molecular signaling events that underlie spinal cord function under naturalistic conditions. While genetic, electrophysiological, pharmacological, and circuit tracing studies have revealed important roles for different molecularly defined neurons, these approaches insufficiently describe the moment-to-moment neuronal and non-neuronal activity patterns that underlie sensory-guided motor behaviors in health and disease. The recent development of imaging methods for real-time interrogation of cellular activity in the spinal cord of behaving mice has removed longstanding technical obstacles to spinal cord research and allowed new insight into how different cell types encode sensory information from mechanoreceptors and nociceptors in the skin. Here, we review the current state-of-the-art in interrogating cellular and microcircuit function in the spinal cord of behaving mammals and discuss current opportunities and technological challenges.
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Affiliation(s)
- Nicholas A Nelson
- Waitt Advanced Biophotonics Center, Salk Institute for Biological Studies, 10010 North Torrey Pines Road, La Jolla, CA 92037, USA; Biologial Sciences Graduate Program, University of California, San Diego, La Jolla, CA 92037, USA
| | - Xiang Wang
- Waitt Advanced Biophotonics Center, Salk Institute for Biological Studies, 10010 North Torrey Pines Road, La Jolla, CA 92037, USA
| | - Daniela Cook
- Waitt Advanced Biophotonics Center, Salk Institute for Biological Studies, 10010 North Torrey Pines Road, La Jolla, CA 92037, USA
| | - Erin M Carey
- Waitt Advanced Biophotonics Center, Salk Institute for Biological Studies, 10010 North Torrey Pines Road, La Jolla, CA 92037, USA
| | - Axel Nimmerjahn
- Waitt Advanced Biophotonics Center, Salk Institute for Biological Studies, 10010 North Torrey Pines Road, La Jolla, CA 92037, USA.
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16
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Xia F, Wu C, Sinefeld D, Li B, Qin Y, Xu C. In vivo label-free confocal imaging of the deep mouse brain with long-wavelength illumination. BIOMEDICAL OPTICS EXPRESS 2018; 9:6545-6555. [PMID: 31065448 PMCID: PMC6490975 DOI: 10.1364/boe.9.006545] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/11/2018] [Revised: 11/06/2018] [Accepted: 11/20/2018] [Indexed: 05/03/2023]
Abstract
Optical microscopy is a valuable tool for in vivo monitoring of biological structures and functions because of its non-invasiveness. However, imaging deep into biological tissues is challenging due to the scattering and absorption of light. Previous research has shown that 1300 nm and 1700 nm are the two best wavelength windows for deep brain imaging. Here, we combined long-wavelength illumination of ~1700 nm with reflectance confocal microscopy and achieved an imaging depth of ~1.3 mm with ~1-micrometer spatial resolution in adult mouse brains, which is 3-4 times deeper than that of conventional confocal microscopy using visible wavelength. We showed that the method can be added to any laser-scanning microscopy with simple and low-cost sources and detectors, such as continuous-wave diode lasers and InGaAs photodiodes. The long-wavelength, reflectance confocal imaging we demonstrated is label-free, and requires low illumination power. Furthermore, the imaging system is simple and low-cost, potentially creating new opportunities for biomedical research and clinical applications.
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Affiliation(s)
- Fei Xia
- School of Applied and Engineering Physics, Cornell University, Ithaca, NY 14853, USA
- Meinig School of Biomedical Engineering, Cornell University, Ithaca, NY 14853, USA
- These authors contributed equally
| | - Chunyan Wu
- School of Applied and Engineering Physics, Cornell University, Ithaca, NY 14853, USA
- College of Veterinary Medicine, Cornell University, Ithaca, NY 14853, USA
- These authors contributed equally
| | - David Sinefeld
- School of Applied and Engineering Physics, Cornell University, Ithaca, NY 14853, USA
| | - Bo Li
- School of Applied and Engineering Physics, Cornell University, Ithaca, NY 14853, USA
| | - Yifan Qin
- School of Applied and Engineering Physics, Cornell University, Ithaca, NY 14853, USA
- National Key Laboratory of Science and Technology on Tunable Laser, Harbin Institute of Technology, Harbin 150080, China
| | - Chris Xu
- School of Applied and Engineering Physics, Cornell University, Ithaca, NY 14853, USA
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17
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Williamson JM, Lyons DA. Myelin Dynamics Throughout Life: An Ever-Changing Landscape? Front Cell Neurosci 2018; 12:424. [PMID: 30510502 PMCID: PMC6252314 DOI: 10.3389/fncel.2018.00424] [Citation(s) in RCA: 83] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2018] [Accepted: 10/30/2018] [Indexed: 02/04/2023] Open
Abstract
Myelin sheaths speed up impulse propagation along the axons of neurons without the need for increasing axon diameter. Subsequently, myelin (which is made by oligodendrocytes in the central nervous system) allows for highly complex yet compact circuitry. Cognitive processes such as learning require central nervous system plasticity throughout life, and much research has focused on the role of neuronal, in particular synaptic, plasticity as a means of altering circuit function. An increasing body of evidence suggests that myelin may also play a role in circuit plasticity and that myelin may be an adaptable structure which could be altered to regulate experience and learning. However, the precise dynamics of myelination throughout life remain unclear – does the production of new myelin require the differentiation of new oligodendrocytes, and/or can existing myelin be remodelled dynamically over time? Here we review recent evidence for both de novo myelination and myelin remodelling from pioneering longitudinal studies of myelin dynamics in vivo, and discuss what remains to be done in order to fully understand how dynamic regulation of myelin affects lifelong circuit function.
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Affiliation(s)
- Jill M Williamson
- Centre for Discovery Brain Sciences, The University of Edinburgh, Edinburgh, United Kingdom
| | - David A Lyons
- Centre for Discovery Brain Sciences, The University of Edinburgh, Edinburgh, United Kingdom
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18
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Abstract
Fluorescent optical probes have rapidly transformed our understanding of complex biological systems by providing specific information on biological targets in the natural living state. However, their utility is often limited by insufficient brightness, photostability, and multiplexing capacity. Here, we report a conceptually new optical probe, termed ‘reflectophore’, which is based on the spectral interference from a dielectric microsphere. Reflectophores are orders-of-magnitudes brighter than conventional fluorophores and are free from photobleaching, enabling practically unlimited readout at high fidelity. They also offer high-degree multiplexing, encoded in their optical size, which can be readily decoded through interferometric detection with nanoscale accuracy, even in turbid biological media. Furthermore, we showcase their biological applications in cellular barcoding and microenvironmental sensing of a target protein and local electric field. Tagging and tracking cells with multiplexed labels can help study complex cellular behaviors in living systems. Here, Jo et al. propose and demonstrate the use of Fabry-Perot-like resonances in dielectric microspheres as such a label and call these reflectophores.
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19
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Abstract
In a mammalian nervous system, myelin provides an electrical insulation by enwrapping the axon fibers in a multilayered spiral. Inspired by its highly-organized subcellular architecture, we recently developed a new imaging modality, named spectral reflectometry (SpeRe), which enables unprecedented label-free nanoscale imaging of the live myelinated axons in situ. The underlying principle is to obtain nanostructural information by analyzing the reflectance spectrum of the multilayered subcellular structure. In this article, we describe a detailed step-by-step protocol for performing a basic SpeRe imaging of the nervous tissues using a commercial confocal microscopic system, equipped with a white-light laser and a tunable filter. We cover the procedures of sample preparation, acquisition of spectral data, and image processing for obtaining nanostructural information.
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Affiliation(s)
- Junhwan Kwon
- Department of Biomedical Engineering, Sungkyunkwan University; Center for Neuroscience Imaging Research, Institute for Basic Science (IBS)
| | - Myunghwan Choi
- Department of Biomedical Engineering, Sungkyunkwan University; Center for Neuroscience Imaging Research, Institute for Basic Science (IBS);
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20
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Song W, Zhou L, Zhang S, Ness S, Desai M, Yi J. Fiber-based visible and near infrared optical coherence tomography (vnOCT) enables quantitative elastic light scattering spectroscopy in human retina. BIOMEDICAL OPTICS EXPRESS 2018; 9:3464-3480. [PMID: 29984110 PMCID: PMC6033571 DOI: 10.1364/boe.9.003464] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/21/2018] [Revised: 06/09/2018] [Accepted: 06/21/2018] [Indexed: 05/18/2023]
Abstract
Elastic light scattering spectroscopy (ELSS) has been proven a powerful method in measuring tissue structures with exquisite nanoscale sensitivity. However, ELSS contrast in the living human retina has been relatively underexplored, primarily due to the lack of imaging tools with a large spectral bandwidth. Here, we report a simple all fiber-based setup to implement dual-channel visible and near infrared (NIR) optical coherence tomography (vnOCT) for human retinal imaging, bridging over a 300nm spectral gap. Remarkably, the fiber components in our vnOCT system support single-mode propagation for both visible and NIR light, both of which maintain excellent interference efficiencies with fringe visibility of 97% and 90%, respectively. The longitudinal chromatic aberration from the eye is corrected by a custom-designed achromatizing lens. The elegant fiber-based design enables simultaneous imaging for both channels and allows comprehensive ELSS analysis on several important anatomical layers, including nerve fiber layer, outer segment of the photoreceptors and retinal pigment epithelium. This vnOCT platform and method of ELSS analysis open new opportunities in understanding structure-function relationship in the human retina and in exploring new biomarkers for retinal diseases.
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Affiliation(s)
- Weiye Song
- Department of Medicine, Boston University School of Medicine, Boston Medical Center, Boston, MA 02118, USA
| | - Libo Zhou
- College of Electronic Science and Engineering, Jilin University, Changchun, Jilin, 130012, China
| | - Sui Zhang
- Danna-Farber Cancer Institute, Boston, MA 02215, USA
| | - Steven Ness
- Department of Ophthalmology, Boston Medical Center, Boston University School of Medicine, Boston, MA 02118, USA
| | - Manishi Desai
- Department of Ophthalmology, Boston Medical Center, Boston University School of Medicine, Boston, MA 02118, USA
| | - Ji Yi
- Department of Medicine, Boston University School of Medicine, Boston Medical Center, Boston, MA 02118, USA
- Department of Biomedical Engineering, Boston University, Boston, MA 02118, USA
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21
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Myelin quantification at nanoscale. Nat Methods 2018. [DOI: 10.1038/nmeth.4586] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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