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Chen P, Kang Q, Niu J, Jing Y, Zhang X, Yu B, Qu J, Lin D. Fluorescence lifetime tracking and imaging of single moving particles assisted by a low-photon-count analysis algorithm. BIOMEDICAL OPTICS EXPRESS 2023; 14:1718-1731. [PMID: 37078048 PMCID: PMC10110318 DOI: 10.1364/boe.485729] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/17/2023] [Revised: 03/06/2023] [Accepted: 03/06/2023] [Indexed: 05/03/2023]
Abstract
Fluorescence lifetime imaging microscopy (FLIM) has been widely used in the field of biological research because of its high specificity, sensitivity, and quantitative ability in the sensing cellular microenvironment. The most commonly used FLIM technology is based on time-correlated single photon counting (TCSPC). Although the TCSPC method has the highest temporal resolution, the data acquisition time is usually long, and the imaging speed is slow. In this work, we proposed a fast FLIM technology for fluorescence lifetime tracking and imaging of single moving particles, named single particle tracking FLIM (SPT-FLIM). We used feedback-controlled addressing scanning and Mosaic FLIM mode imaging to reduce the number of scanned pixels and the data readout time, respectively. Moreover, we developed a compressed sensing analysis algorithm based on alternating descent conditional gradient (ADCG) for low-photon-count data. We applied the ADCG-FLIM algorithm on both simulated and experimental datasets to evaluate its performance. The results showed that ADCG-FLIM could achieve reliable lifetime estimation with high accuracy and precision in the case of a photon count less than 100. By reducing the photon count requirement for each pixel from, typically, 1000 to 100, the acquisition time for a single frame lifetime image could be significantly shortened, and the imaging speed could be improved to a great extent. On this basis, we obtained lifetime trajectories of moving fluorescent beads using the SPT-FLIM technique. Overall, our work offers a powerful tool for fluorescence lifetime tracking and imaging of single moving particles, which will promote the application of TCSPC-FLIM in biological research.
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Hilzenrat G, Gill ET, McArthur SL. Imaging approaches for monitoring three-dimensional cell and tissue culture systems. JOURNAL OF BIOPHOTONICS 2022; 15:e202100380. [PMID: 35357086 DOI: 10.1002/jbio.202100380] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/12/2021] [Revised: 03/27/2022] [Accepted: 03/28/2022] [Indexed: 06/14/2023]
Abstract
The past decade has seen an increasing demand for more complex, reproducible and physiologically relevant tissue cultures that can mimic the structural and biological features of living tissues. Monitoring the viability, development and responses of such tissues in real-time are challenging due to the complexities of cell culture physical characteristics and the environments in which these cultures need to be maintained in. Significant developments in optics, such as optical manipulation, improved detection and data analysis, have made optical imaging a preferred choice for many three-dimensional (3D) cell culture monitoring applications. The aim of this review is to discuss the challenges associated with imaging and monitoring 3D tissues and cell culture, and highlight topical label-free imaging tools that enable bioengineers and biophysicists to non-invasively characterise engineered living tissues.
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Affiliation(s)
- Geva Hilzenrat
- Bioengineering Engineering Group, School of Science, Computing and Engineering Technologies, Swinburne University of Technology, Hawthorn, Victoria, Australia
- Biomedical Manufacturing, Commonwealth Scientific and Industrial Research Organisation (CSIRO), Clayton, Victoria, Australia
| | - Emma T Gill
- Bioengineering Engineering Group, School of Science, Computing and Engineering Technologies, Swinburne University of Technology, Hawthorn, Victoria, Australia
- Biomedical Manufacturing, Commonwealth Scientific and Industrial Research Organisation (CSIRO), Clayton, Victoria, Australia
| | - Sally L McArthur
- Bioengineering Engineering Group, School of Science, Computing and Engineering Technologies, Swinburne University of Technology, Hawthorn, Victoria, Australia
- Biomedical Manufacturing, Commonwealth Scientific and Industrial Research Organisation (CSIRO), Clayton, Victoria, Australia
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Song X, Guo Y, Chen C, Wang X. A silent two-photon imaging system for studying in vivo auditory neuronal functions. LIGHT, SCIENCE & APPLICATIONS 2022; 11:96. [PMID: 35422090 PMCID: PMC9010453 DOI: 10.1038/s41377-022-00783-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/25/2021] [Revised: 03/28/2022] [Accepted: 03/30/2022] [Indexed: 05/04/2023]
Abstract
Two-photon laser-scanning microscopy has become an essential tool for imaging neuronal functions in vivo and has been applied to different parts of the neural system, including the auditory system. However, many components of a two-photon microscope, such as galvanometer-based laser scanners, generate mechanical vibrations and thus acoustic artifacts, making it difficult to interpret auditory responses from recorded neurons. Here, we report the development of a silent two-photon imaging system and its applications in the common marmoset (Callithrix Jacchus), a non-human primate species sharing a similar hearing range with humans. By utilizing an orthogonal pair of acousto-optical deflectors (AODs), full-frame raster scanning at video rate was achieved without introducing mechanical vibrations. Imaging depth can be optically controlled by adjusting the chirping speed on the AODs without any mechanical motion along the Z-axis. Furthermore, all other sound-generating components of the system were acoustically isolated, leaving the noise floor of the working system below the marmoset's hearing threshold. Imaging with the system in awake marmosets revealed many auditory cortex neurons that exhibited maximal responses at low sound levels, which were not possible to study using traditional two-photon imaging systems. This is the first demonstration of a silent two-photon imaging system that is capable of imaging auditory neuronal functions in vivo without acoustic artifacts. This capacity opens new opportunities for a better understanding of auditory functions in the brain and helps isolate animal behavior from microscope-generated acoustic interference.
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Affiliation(s)
- Xindong Song
- Laboratory of Auditory Neurophysiology, Department of Biomedical Engineering, Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA.
| | - Yueqi Guo
- Laboratory of Auditory Neurophysiology, Department of Biomedical Engineering, Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA
| | - Chenggang Chen
- Laboratory of Auditory Neurophysiology, Department of Biomedical Engineering, Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA
| | - Xiaoqin Wang
- Laboratory of Auditory Neurophysiology, Department of Biomedical Engineering, Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA.
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Yamaguchi A, Karagyozov D, Gershow MH. Compact and adjustable compensator for AOD spatial and temporal dispersion using off-the-shelf components. OPTICS LETTERS 2021; 46:1644-1647. [PMID: 33793507 PMCID: PMC8281507 DOI: 10.1364/ol.419682] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/15/2021] [Accepted: 02/26/2021] [Indexed: 06/12/2023]
Abstract
Random access multiphoton microscopy using two orthogonal acousto-optic deflectors (AODs) allows sampling only particular regions of interest within a plane, greatly speeding up the sampling rate. AODs introduce spatial and temporal dispersions, which distort the point spread function and decrease the peak intensity of the pulse. Both of these effects can be compensated for with a single dispersive element placed a distance before the AODs. An additional acousto-optic modulator, a custom cut prism, and a standard prism used with additional cylindrical optics have been demonstrated. All of these introduce additional cost or complexity and require an extended path length to achieve the needed negative group delay dispersion (GDD). By introducing a telescope between a transmission grating and the AODs, we correct for spatial and temporal dispersions in a compact design using only off-the-shelf components, and we show that the GDD can be tuned by translation of the telescope without adjustment of any other elements.
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Affiliation(s)
- Akihiro Yamaguchi
- Department of Physics and Center for Soft Matter Research, New York University, New York, NY 10003, USA
| | - Doycho Karagyozov
- Department of Physics and Center for Soft Matter Research, New York University, New York, NY 10003, USA
| | - Marc H. Gershow
- Department of Physics and Center for Soft Matter Research, New York University, New York, NY 10003, USA
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Wang Y, Li H, Hu Q, Cheng X, Chen R, Lv X, Zeng S. Aberration-corrected three-dimensional non-inertial scanning for femtosecond lasers. OPTICS EXPRESS 2020; 28:29904-29917. [PMID: 33114879 DOI: 10.1364/oe.405532] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/18/2020] [Accepted: 09/14/2020] [Indexed: 06/11/2023]
Abstract
Large aberrations are induced by non-collimated light when the convergence or divergence of the incident beam on the back-pupil plane of the objective lens is adjusted for 3D non-inertial scanning. These aberrations significantly degrade the focus quality and decrease the peak intensity of the femtosecond laser focal spot. Here, we describe an aberration-corrected 3D non-inertial scanning method for femtosecond lasers based on a digital micromirror device (DMD) that is used for both beam scanning and aberration correction. An imaging setup is used to detect the focal spot in the 3D space, and an iterative optimization algorithm is used to optimize the focal spot. We demonstrate the application of our proposed approach in two-photon imaging. With correction for the 200-µm out-of-focal plane, the optical axial resolution improves from 7.67 to 3.25 µm, and the intensity of the fluorescence signal exhibits an almost fivefold improvement when a 40× objective lens is used. This aberration-corrected 3D non-inertial scanning method for femtosecond lasers offers a new approach for a variety of potential applications, including nonlinear optical imaging, microfabrication, and optical storage.
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Li H, Cheng Y, Tang H, Bi Y, Chen Y, Yang G, Guo S, Tian S, Liao J, Lv X, Zeng S, Zhu M, Xu C, Cheng J, Wang P. Imaging Chemical Kinetics of Radical Polymerization with an Ultrafast Coherent Raman Microscope. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2020; 7:1903644. [PMID: 32440482 PMCID: PMC7237838 DOI: 10.1002/advs.201903644] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/16/2019] [Revised: 01/31/2020] [Accepted: 02/13/2020] [Indexed: 05/21/2023]
Abstract
Numerous mechanisms have been proposed for polymerization to provide qualitative and quantitative prediction of how monomers spatially and temporally arrange into the polymeric chains. However, less is known about this process at the molecular level because the ultrafast chemical reaction is inaccessible for any form of microscope so far. Here, to address this unmet challenge, a stimulated Raman scattering microscope based on collinear multiple beams (COMB-SRS) is demonstrated, which allows label-free molecular imaging of polymer synthesis in action at speed of 2000 frames per second. The field of view of the developed 2 kHz SRS microscope is 30 × 28 µm2 with 50 × 46 pixels and 7 µs dwell time. By catching up the speed of chemical reaction, COMB-SRS is able to quantitatively visualize the ultrafast dynamics of molecular vibrations with submicron spatial resolution and sub-millisecond temporal resolution. The propagating polymer waves driven by reaction rate and persistent UV initiation are observed in situ. This methodology is expected to permit the development of novel functional polymers, controllable photoresists, 3D printing, and other new polymerization technologies.
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Affiliation(s)
- Haozheng Li
- Britton Chance Center for Biomedical PhotonicsWuhan National Laboratory for OptoelectronicsHuazhong University of Science and TechnologyWuhanHubei430074China
- MoE Key Laboratory for Biomedical PhotonicsCollaborative Innovation Center for Biomedical EngineeringSchool of Engineering SciencesHuazhong University of Science and TechnologyWuhanHubei430074China
| | - Yong Cheng
- Britton Chance Center for Biomedical PhotonicsWuhan National Laboratory for OptoelectronicsHuazhong University of Science and TechnologyWuhanHubei430074China
- MoE Key Laboratory for Biomedical PhotonicsCollaborative Innovation Center for Biomedical EngineeringSchool of Engineering SciencesHuazhong University of Science and TechnologyWuhanHubei430074China
| | - Huajun Tang
- Britton Chance Center for Biomedical PhotonicsWuhan National Laboratory for OptoelectronicsHuazhong University of Science and TechnologyWuhanHubei430074China
- MoE Key Laboratory for Biomedical PhotonicsCollaborative Innovation Center for Biomedical EngineeringSchool of Engineering SciencesHuazhong University of Science and TechnologyWuhanHubei430074China
| | - Yali Bi
- Britton Chance Center for Biomedical PhotonicsWuhan National Laboratory for OptoelectronicsHuazhong University of Science and TechnologyWuhanHubei430074China
- MoE Key Laboratory for Biomedical PhotonicsCollaborative Innovation Center for Biomedical EngineeringSchool of Engineering SciencesHuazhong University of Science and TechnologyWuhanHubei430074China
| | - Yage Chen
- Britton Chance Center for Biomedical PhotonicsWuhan National Laboratory for OptoelectronicsHuazhong University of Science and TechnologyWuhanHubei430074China
- MoE Key Laboratory for Biomedical PhotonicsCollaborative Innovation Center for Biomedical EngineeringSchool of Engineering SciencesHuazhong University of Science and TechnologyWuhanHubei430074China
| | - Guang Yang
- Britton Chance Center for Biomedical PhotonicsWuhan National Laboratory for OptoelectronicsHuazhong University of Science and TechnologyWuhanHubei430074China
- MoE Key Laboratory for Biomedical PhotonicsCollaborative Innovation Center for Biomedical EngineeringSchool of Engineering SciencesHuazhong University of Science and TechnologyWuhanHubei430074China
| | - Shoujing Guo
- Britton Chance Center for Biomedical PhotonicsWuhan National Laboratory for OptoelectronicsHuazhong University of Science and TechnologyWuhanHubei430074China
- MoE Key Laboratory for Biomedical PhotonicsCollaborative Innovation Center for Biomedical EngineeringSchool of Engineering SciencesHuazhong University of Science and TechnologyWuhanHubei430074China
| | - Sidan Tian
- Britton Chance Center for Biomedical PhotonicsWuhan National Laboratory for OptoelectronicsHuazhong University of Science and TechnologyWuhanHubei430074China
- MoE Key Laboratory for Biomedical PhotonicsCollaborative Innovation Center for Biomedical EngineeringSchool of Engineering SciencesHuazhong University of Science and TechnologyWuhanHubei430074China
| | - Jiangshan Liao
- Britton Chance Center for Biomedical PhotonicsWuhan National Laboratory for OptoelectronicsHuazhong University of Science and TechnologyWuhanHubei430074China
- MoE Key Laboratory for Biomedical PhotonicsCollaborative Innovation Center for Biomedical EngineeringSchool of Engineering SciencesHuazhong University of Science and TechnologyWuhanHubei430074China
| | - Xiaohua Lv
- Britton Chance Center for Biomedical PhotonicsWuhan National Laboratory for OptoelectronicsHuazhong University of Science and TechnologyWuhanHubei430074China
- MoE Key Laboratory for Biomedical PhotonicsCollaborative Innovation Center for Biomedical EngineeringSchool of Engineering SciencesHuazhong University of Science and TechnologyWuhanHubei430074China
| | - Shaoqun Zeng
- Britton Chance Center for Biomedical PhotonicsWuhan National Laboratory for OptoelectronicsHuazhong University of Science and TechnologyWuhanHubei430074China
- MoE Key Laboratory for Biomedical PhotonicsCollaborative Innovation Center for Biomedical EngineeringSchool of Engineering SciencesHuazhong University of Science and TechnologyWuhanHubei430074China
| | - Mingqiang Zhu
- Britton Chance Center for Biomedical PhotonicsWuhan National Laboratory for OptoelectronicsHuazhong University of Science and TechnologyWuhanHubei430074China
- MoE Key Laboratory for Biomedical PhotonicsCollaborative Innovation Center for Biomedical EngineeringSchool of Engineering SciencesHuazhong University of Science and TechnologyWuhanHubei430074China
| | - Chenjie Xu
- School of Chemical and Biomedical EngineeringNanyang Technological UniversitySingapore637457Singapore
| | - Ji‐Xin Cheng
- Department of Biomedical EngineeringBoston UniversityBostonMA02215USA
| | - Ping Wang
- Britton Chance Center for Biomedical PhotonicsWuhan National Laboratory for OptoelectronicsHuazhong University of Science and TechnologyWuhanHubei430074China
- MoE Key Laboratory for Biomedical PhotonicsCollaborative Innovation Center for Biomedical EngineeringSchool of Engineering SciencesHuazhong University of Science and TechnologyWuhanHubei430074China
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7
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Chong EZ, Panniello M, Barreiros I, Kohl MM, Booth MJ. Quasi-simultaneous multiplane calcium imaging of neuronal circuits. BIOMEDICAL OPTICS EXPRESS 2019; 10:267-282. [PMID: 30775099 PMCID: PMC6363184 DOI: 10.1364/boe.10.000267] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/21/2018] [Revised: 11/12/2018] [Accepted: 11/12/2018] [Indexed: 06/09/2023]
Abstract
Two-photon excitation fluorescence microscopy is widely used to study the activity of neuronal circuits. However, the fast imaging is typically constrained to a single lateral plane for a standard microscope design. Given that cortical neuronal networks in a mouse brain are complex three-dimensional structures organised in six histologically defined layers which extend over many hundreds of micrometres, there is a strong demand for microscope systems that can record neuronal signalling in volumes. Henceforth, we developed a quasi-simultaneous multiplane imaging technique combining an acousto-optic deflector and static remote focusing to provide fast imaging of neurons from different axial positions inside the cortical layers without the need for mechanical disturbance of either the objective lens or the specimen. The hardware and the software are easily adaptable to existing two-photon microscopes. Here, we demonstrated that our imaging method can record, at high speed and high image contrast, the calcium dynamics of neurons in two different imaging planes separated axially with the in-focus and the refocused planes 120 µm and 250 µm below the brain surface respectively.
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Affiliation(s)
- Ee Zhuan Chong
- Department of Engineering Science, University of Oxford, Parks Road, OX1 3PJ, UK
| | - Mariangela Panniello
- Department of Physiology, Anatomy and Genetics, University of Oxford, Parks Road, OX1 3PT, UK
| | - Inês Barreiros
- Department of Physiology, Anatomy and Genetics, University of Oxford, Parks Road, OX1 3PT, UK
| | - Michael M Kohl
- Department of Physiology, Anatomy and Genetics, University of Oxford, Parks Road, OX1 3PT, UK
| | - Martin J Booth
- Department of Engineering Science, University of Oxford, Parks Road, OX1 3PJ, UK
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Schultz SR, Copeland CS, Foust AJ, Quicke P, Schuck R. Advances in two photon scanning and scanless microscopy technologies for functional neural circuit imaging. PROCEEDINGS OF THE IEEE. INSTITUTE OF ELECTRICAL AND ELECTRONICS ENGINEERS 2017; 105:139-157. [PMID: 28757657 PMCID: PMC5526632 DOI: 10.1109/jproc.2016.2577380] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
Recent years have seen substantial developments in technology for imaging neural circuits, raising the prospect of large scale imaging studies of neural populations involved in information processing, with the potential to lead to step changes in our understanding of brain function and dysfunction. In this article we will review some key recent advances: improved fluorophores for single cell resolution functional neuroimaging using a two photon microscope; improved approaches to the problem of scanning active circuits; and the prospect of scanless microscopes which overcome some of the bandwidth limitations of current imaging techniques. These advances in technology for experimental neuroscience have in themselves led to technical challenges, such as the need for the development of novel signal processing and data analysis tools in order to make the most of the new experimental tools. We review recent work in some active topics, such as region of interest segmentation algorithms capable of demixing overlapping signals, and new highly accurate algorithms for calcium transient detection. These advances motivate the development of new data analysis tools capable of dealing with spatial or spatiotemporal patterns of neural activity, that scale well with pattern size.
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Affiliation(s)
- Simon R Schultz
- Center for Neurotechnology and Department of Bioengineering Imperial College London, South Kensington, LondonSW7 2AZ, UK
| | - Caroline S Copeland
- Center for Neurotechnology and Department of Bioengineering Imperial College London, South Kensington, LondonSW7 2AZ, UK
| | - Amanda J Foust
- Center for Neurotechnology and Department of Bioengineering Imperial College London, South Kensington, LondonSW7 2AZ, UK
| | - Peter Quicke
- Center for Neurotechnology and Department of Bioengineering Imperial College London, South Kensington, LondonSW7 2AZ, UK
| | - Renaud Schuck
- Center for Neurotechnology and Department of Bioengineering Imperial College London, South Kensington, LondonSW7 2AZ, UK
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9
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Hu Q, Zhou Z, Lv X, Zeng S. Compensation of spatial dispersion of an acousto-optic deflector with a special Keplerian telescope. OPTICS LETTERS 2016; 41:207-210. [PMID: 26766675 DOI: 10.1364/ol.41.000207] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Compensation of spatial dispersion caused by the acousto-optic deflector (AOD) when using a femtosecond laser is difficult across the whole scanning range of the system, and this is a significant impediment to its use. In conventional methods, the dispersion of the AOD was compensated only when it was at a particular position, while at other positions, the quality of the light beam was reduced. We developed a novel method for compensating the spatial dispersion within the entire scanning range using a special Keplerian telescope. Our experimental results show that the residual dispersion of the AOD is compensated sufficiently, and the focal spots of the laser reach the diffraction limit within a 40-MHz ultrasound bandwidth.
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Reddy GD, Cotton RJ, Tolias AS, Saggau P. Random-Access Multiphoton Microscopy for Fast Three-Dimensional Imaging. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2015; 859:455-72. [PMID: 26238064 DOI: 10.1007/978-3-319-17641-3_18] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
Abstract
Studies in several important areas of neuroscience, including analysis of single neurons as well as neural networks, continue to be limited by currently available experimental tools. By combining molecular probes of cellular function, such as voltage-sensitive or calcium-sensitive dyes, with advanced microscopy techniques such as multiphoton microscopy, experimental neurophysiologists have been able to partially reduce this limitation. These approaches usually provide the needed spatial resolution along with convenient optical sectioning capabilities for isolating regions of interest. However, they often fall short in providing the necessary temporal resolution, primarily due to their restrained laser scanning mechanisms. In this regard, we review a method of laser scanning for multiphoton microscopy that overcomes the temporal limitations of pervious approaches and allows for what is known as 3D Random Access Multiphoton (3D RAMP) microscopy, an imaging technique that supports full three dimensional recording of many sites of interest on physiologically relevant time scales.
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Cha JW, Yew EYS, Kim D, Subramanian J, Nedivi E, So PTC. Non-descanned multifocal multiphoton microscopy with a multianode photomultiplier tube. AIP ADVANCES 2015; 5:084802. [PMID: 25874160 PMCID: PMC4387602 DOI: 10.1063/1.4916040] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/09/2014] [Accepted: 09/28/2014] [Indexed: 05/25/2023]
Abstract
Multifocal multiphoton microscopy (MMM) improves imaging speed over a point scanning approach by parallelizing the excitation process. Early versions of MMM relied on imaging detectors to record emission signals from multiple foci simultaneously. For many turbid biological specimens, the scattering of emission photons results in blurred images and degrades the signal-to-noise ratio (SNR). We have recently demonstrated that a multianode photomultiplier tube (MAPMT) placed in a descanned configuration can effectively collect scattered emission photons from each focus into their corresponding anodes significantly improving image SNR for highly scattering specimens. Unfortunately, a descanned MMM has a longer detection path resulting in substantial emission photon loss. Optical design constraints in a descanned geometry further results in significant optical aberrations especially for large field-of-view (FOV), high NA objectives. Here, we introduce a non-descanned MMM based on MAPMT that substantially overcomes most of these drawbacks. We show that we improve signal efficiency up to fourfold with limited image SNR degradation due to scattered emission photons. The excitation foci can also be spaced wider to cover the full FOV of the objective with minimal aberrations. The performance of this system is demonstrated by imaging interneuron morphological structures deep in the brains of living mice.
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Affiliation(s)
- Jae Won Cha
- Department of Mechanical Engineering, Massachusetts Institute of Technology , Cambridge, MA, USA
| | - Elijah Y S Yew
- Department of Mechanical Engineering, Massachusetts Institute of Technology , Cambridge, MA, USA
| | - Daekeun Kim
- Department of Mechanical Engineering, Dankook University , Korea
| | - Jaichandar Subramanian
- Picower Institute for Learning and Memory, Massachusetts Institute of Technology , Cambridge, MA, USA
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Zhou Z, Li L, Wang J, Hu Q, Zeng S. Beam deformation within an acousto-optic lens. OPTICS LETTERS 2015; 40:2197-2200. [PMID: 26393698 DOI: 10.1364/ol.40.002197] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
The acousto-optic lens (AOL) is becoming a popular tool in the neuroscience field. Here we analyzed the deformation of the diffraction beam after passage through an AOL consisting of a pair of acousto-optic deflectors using both theoretical and experimental data. The results showed that, because of the high sensitivity of optical spatial frequencies of acousto-optic deflectors, the boundary strength of the diffraction beam of the AOL decreases significantly. When the focal length of AOL diminishes, the deformation of the diffraction beam becomes more serious with a smaller beam size. This deformation of the diffraction beam finally leads to a decreased illuminative numerical aperture, which worsens the image's spatial resolution.
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13
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Li H, Cui Q, Zhang Z, Fu L, Luo Q. Nonlinear optical microscopy for immunoimaging: a custom optimized system of high-speed, large-area, multicolor imaging. Quant Imaging Med Surg 2015; 5:30-9. [PMID: 25694951 DOI: 10.3978/j.issn.2223-4292.2014.11.07] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2014] [Accepted: 10/31/2014] [Indexed: 01/09/2023]
Abstract
BACKGROUND The nonlinear optical microscopy has become the current state-of-the-art for intravital imaging. Due to its advantages of high resolution, superior tissue penetration, lower photodamage and photobleaching, as well as intrinsic z-sectioning ability, this technology has been widely applied in immunoimaging for a decade. However, in terms of monitoring immune events in native physiological environment, the conventional nonlinear optical microscope system has to be optimized for live animal imaging. Generally speaking, three crucial capabilities are desired, including high-speed, large-area and multicolor imaging. Among numerous high-speed scanning mechanisms used in nonlinear optical imaging, polygon scanning is not only linearly but also dispersion-freely with high stability and tunable rotation speed, which can overcome disadvantages of multifocal scanning, resonant scanner and acousto-optical deflector (AOD). However, low frame rate, lacking large-area or multicolor imaging ability make current polygonbased nonlinear optical microscopes unable to meet the requirements of immune event monitoring. METHODS We built up a polygon-based nonlinear optical microscope system which was custom optimized for immunoimaging with high-speed, large-are and multicolor imaging abilities. RESULTS Firstly, we validated the imaging performance of the system by standard methods. Then, to demonstrate the ability to monitor immune events, migration of immunocytes observed by the system based on typical immunological models such as lymph node, footpad and dorsal skinfold chamber are shown. Finally, we take an outlook for the possible advance of related technologies such as sample stabilization and optical clearing for more stable and deeper intravital immunoimaging. CONCLUSIONS This study will be helpful for optimizing nonlinear optical microscope to obtain more comprehensive and accurate information of immune events.
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Affiliation(s)
- Hui Li
- 1 Wuhan National Laboratory for Optoelectronics-Huazhong University of Science and Technology, Britton Chance Center for Biomedical Photonics, Wuhan 430074, China ; 2 MoE Key Laboratory for Biomedical Photonics, Department of Biomedical Engineering, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Quan Cui
- 1 Wuhan National Laboratory for Optoelectronics-Huazhong University of Science and Technology, Britton Chance Center for Biomedical Photonics, Wuhan 430074, China ; 2 MoE Key Laboratory for Biomedical Photonics, Department of Biomedical Engineering, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Zhihong Zhang
- 1 Wuhan National Laboratory for Optoelectronics-Huazhong University of Science and Technology, Britton Chance Center for Biomedical Photonics, Wuhan 430074, China ; 2 MoE Key Laboratory for Biomedical Photonics, Department of Biomedical Engineering, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Ling Fu
- 1 Wuhan National Laboratory for Optoelectronics-Huazhong University of Science and Technology, Britton Chance Center for Biomedical Photonics, Wuhan 430074, China ; 2 MoE Key Laboratory for Biomedical Photonics, Department of Biomedical Engineering, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Qingming Luo
- 1 Wuhan National Laboratory for Optoelectronics-Huazhong University of Science and Technology, Britton Chance Center for Biomedical Photonics, Wuhan 430074, China ; 2 MoE Key Laboratory for Biomedical Photonics, Department of Biomedical Engineering, Huazhong University of Science and Technology, Wuhan 430074, China
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Liu X, Lv X, Quan T, Zeng S. Error estimation for reconstruction of neuronal spike firing from fast calcium imaging. BIOMEDICAL OPTICS EXPRESS 2015; 6:421-432. [PMID: 25780733 PMCID: PMC4354587 DOI: 10.1364/boe.6.000421] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/17/2014] [Revised: 12/22/2014] [Accepted: 12/28/2014] [Indexed: 06/04/2023]
Abstract
Calcium imaging is becoming an increasingly popular technology to indirectly measure activity patterns in local neuronal networks. Calcium transients reflect neuronal spike patterns allowing for spike train reconstructed from calcium traces. The key to judging spiking train authenticity is error estimation. However, due to the lack of an appropriate mathematical model to adequately describe this spike-calcium relationship, little attention has been paid to quantifying error ranges of the reconstructed spike results. By turning attention to the data characteristics close to the reconstruction rather than to a complex mathematic model, we have provided an error estimation method for the reconstructed neuronal spiking from calcium imaging. Real false-negative and false-positive rates of 10 experimental Ca(2+) traces were within the estimated error ranges and confirmed that this evaluation method was effective. Estimation performance of the reconstruction of spikes from calcium transients within a neuronal population demonstrated a reasonable evaluation of the reconstructed spikes without having real electrical signals. These results suggest that our method might be valuable for the quantification of research based on reconstructed neuronal activity, such as to affirm communication between different neurons.
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Affiliation(s)
- Xiuli Liu
- Britton Chance Center for Biomedical Photonics, Wuhan National Laboratory for Optoelectronics-Huazhong University of Science and Technology, Wuhan 430074,
China
- MoE Key Laboratory for Biomedical Photonics, Department of Biomedical Engineering, Huazhong University of Science and Technology, Wuhan 430074,
China
| | - Xiaohua Lv
- Britton Chance Center for Biomedical Photonics, Wuhan National Laboratory for Optoelectronics-Huazhong University of Science and Technology, Wuhan 430074,
China
- MoE Key Laboratory for Biomedical Photonics, Department of Biomedical Engineering, Huazhong University of Science and Technology, Wuhan 430074,
China
| | - Tingwei Quan
- Britton Chance Center for Biomedical Photonics, Wuhan National Laboratory for Optoelectronics-Huazhong University of Science and Technology, Wuhan 430074,
China
- MoE Key Laboratory for Biomedical Photonics, Department of Biomedical Engineering, Huazhong University of Science and Technology, Wuhan 430074,
China
- College of Mathematics and Economics, Hubei University of Education, Wuhan 430205,
China
| | - Shaoqun Zeng
- Britton Chance Center for Biomedical Photonics, Wuhan National Laboratory for Optoelectronics-Huazhong University of Science and Technology, Wuhan 430074,
China
- MoE Key Laboratory for Biomedical Photonics, Department of Biomedical Engineering, Huazhong University of Science and Technology, Wuhan 430074,
China
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15
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Wang C, Liu R, Milkie DE, Sun W, Tan Z, Kerlin A, Chen TW, Kim DS, Ji N. Multiplexed aberration measurement for deep tissue imaging in vivo. Nat Methods 2014; 11:1037-40. [PMID: 25128976 PMCID: PMC4180771 DOI: 10.1038/nmeth.3068] [Citation(s) in RCA: 73] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2014] [Accepted: 06/27/2014] [Indexed: 11/09/2022]
Abstract
We describe an adaptive optics method that modulates the intensity or phase of light rays at multiple pupil segments in parallel to determine the sample-induced aberration. Applicable to fluorescent protein-labeled structures of arbitrary complexity, it allowed us to obtain diffraction-limited resolution in various samples in vivo. For the strongly scattering mouse brain, a single aberration correction improved structural and functional imaging of fine neuronal processes over a large imaging volume.
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Affiliation(s)
- Chen Wang
- 1] Janelia Farm Research Campus, Howard Hughes Medical Institute, Ashburn, Virginia, USA. [2] State Key Laboratory of High Field Laser Physics, Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai, China. [3]
| | - Rui Liu
- 1] Janelia Farm Research Campus, Howard Hughes Medical Institute, Ashburn, Virginia, USA. [2]
| | - Daniel E Milkie
- 1] Coleman Technologies, Inc., Newtown Square, Pennsylvania, USA. [2]
| | - Wenzhi Sun
- Janelia Farm Research Campus, Howard Hughes Medical Institute, Ashburn, Virginia, USA
| | - Zhongchao Tan
- Janelia Farm Research Campus, Howard Hughes Medical Institute, Ashburn, Virginia, USA
| | - Aaron Kerlin
- Janelia Farm Research Campus, Howard Hughes Medical Institute, Ashburn, Virginia, USA
| | - Tsai-Wen Chen
- Janelia Farm Research Campus, Howard Hughes Medical Institute, Ashburn, Virginia, USA
| | - Douglas S Kim
- Janelia Farm Research Campus, Howard Hughes Medical Institute, Ashburn, Virginia, USA
| | - Na Ji
- Janelia Farm Research Campus, Howard Hughes Medical Institute, Ashburn, Virginia, USA
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16
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Cha JW, Singh VR, Kim KH, Subramanian J, Peng Q, Yu H, Nedivi E, So PTC. Reassignment of scattered emission photons in multifocal multiphoton microscopy. Sci Rep 2014; 4:5153. [PMID: 24898470 PMCID: PMC4046171 DOI: 10.1038/srep05153] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2014] [Accepted: 05/14/2014] [Indexed: 01/02/2023] Open
Abstract
Multifocal multiphoton microscopy (MMM) achieves fast imaging by simultaneously scanning multiple foci across different regions of specimen. The use of imaging detectors in MMM, such as CCD or CMOS, results in degradation of image signal-to-noise-ratio (SNR) due to the scattering of emitted photons. SNR can be partly recovered using multianode photomultiplier tubes (MAPMT). In this design, however, emission photons scattered to neighbor anodes are encoded by the foci scan location resulting in ghost images. The crosstalk between different anodes is currently measured a priori, which is cumbersome as it depends specimen properties. Here, we present the photon reassignment method for MMM, established based on the maximum likelihood (ML) estimation, for quantification of crosstalk between the anodes of MAPMT without a priori measurement. The method provides the reassignment of the photons generated by the ghost images to the original spatial location thus increases the SNR of the final reconstructed image.
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Affiliation(s)
- Jae Won Cha
- 1] Massachusetts Institute of Technology, Department of Mechanical Engineering, Cambridge, MA 02139 [2]
| | - Vijay Raj Singh
- 1] Singapore-MIT Alliance for Research and Technology (SMART), BioSyM, Singapore 138602 [2]
| | - Ki Hean Kim
- Pohang University of Science and Technology, Department of Mechanical Engineering, Pohang 790-784, KOREA
| | - Jaichandar Subramanian
- Massachusetts Institute of Technology, Picower Institute for Learning and Memory, Cambridge, MA 02139
| | - Qiwen Peng
- 1] Institute of Bioengineering and Nanotechnology, A*Star, Singapore 138669 [2] Singapore-MIT Alliance, Computation and System Biology, Singapore 117576
| | - Hanry Yu
- 1] Singapore-MIT Alliance for Research and Technology (SMART), BioSyM, Singapore 138602 [2] Institute of Bioengineering and Nanotechnology, A*Star, Singapore 138669 [3] National University of Singapore, School of Medicine, Singapore 119077
| | - Elly Nedivi
- 1] Massachusetts Institute of Technology, Picower Institute for Learning and Memory, Cambridge, MA 02139 [2] Massachusetts Institute of Technology, Departments of Biology, and Brain and Cognitive Sciences, Cambridge, MA 02139
| | - Peter T C So
- 1] Massachusetts Institute of Technology, Department of Mechanical Engineering, Cambridge, MA 02139 [2] Singapore-MIT Alliance for Research and Technology (SMART), BioSyM, Singapore 138602 [3] Massachusetts Institute of Technology, Department of Biomedical Engineering, Cambridge, MA 02139
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17
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Grewe BF, Helmchen F. High-speed two-photon calcium imaging of neuronal population activity using acousto-optic deflectors. Cold Spring Harb Protoc 2014; 2014:618-29. [PMID: 24890212 DOI: 10.1101/pdb.prot081778] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Two-photon calcium imaging of neuronal populations allows optical measurements of spiking activity in living animals. However, laser-scanning microscopes with galvanometric scan mirrors are too slow to capture population activity on a millisecond timescale. This protocol describes a two-photon microscope that is based on two-dimensional laser scanning with acousto-optic deflectors (AODs), enabling high-speed in vivo recording of neuronal population activity at temporal resolutions of several hundred hertz. The detailed construction plan of the AOD-based microscope is accompanied by equally detailed optimization procedures. We also introduce a novel random-access pattern scanning (RAPS) technique for high-speed in vivo measurements of neuronal population activity. AOD-based RAPS can measure calcium transients in neocortical neuronal populations, revealing spike trains with near-millisecond precision. The current limitations of the AOD-based microscope are discussed, and we provide an outlook of its future applications.
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18
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Yan W, Peng X, Qi J, Gao J, Fan S, Wang Q, Qu J, Niu H. Dynamic fluorescence lifetime imaging based on acousto-optic deflectors. JOURNAL OF BIOMEDICAL OPTICS 2014; 19:116004. [PMID: 25375349 DOI: 10.1117/1.jbo.19.11.116004] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/19/2014] [Accepted: 10/13/2014] [Indexed: 06/04/2023]
Abstract
We report a dynamic fluorescence lifetime imaging (D-FLIM) system that is based on a pair of acousto-optic deflectors for the random regions of interest (ROI) study in the sample. The two-dimensional acousto-optic deflector devices are used to rapidly scan the femtosecond excitation laser beam across the sample, providing specific random access to the ROI. Our experimental results using standard fluorescent dyes in live cancer cells demonstrate that the D-FLIM system can dynamically monitor the changing process of the microenvironment in the ROI in live biological samples.
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19
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Tu J, Yang F, Wan J, Liu Y, Zhang J, Wu B, Liu Y, Zeng S, Wang L. Light-controlled astrocytes promote human mesenchymal stem cells toward neuronal differentiation and improve the neurological deficit in stroke rats. Glia 2013; 62:106-21. [PMID: 24272706 DOI: 10.1002/glia.22590] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2013] [Revised: 09/25/2013] [Accepted: 10/07/2013] [Indexed: 01/08/2023]
Abstract
Astrocytes are key components of the central nervous system (CNS) and release factors to support neural stem cell proliferation, differentiation, and migration. Adenosine 5'-triphosphate (ATP) is one of the key factors released upon activation of astrocytes that regulates the neural stem cell's function. However, it is not clear whether ATP derived from the depolarized astrocytes plays a vital role in promoting the neuronal differentiation of mesenchymal stem cells (MSCs) in vitro and in vivo. Herein, for the first time, we co-cultured MSCs with light-stimulated-channelrhodopsin-2 (ChR2)-astrocytes, and observed that the neuronal differentiation of MSCs was enhanced by expressing more neuronal markers, Tuj1 and NeuN. The ChR2-astrocyte-conditioned medium also stimulated MSCs differentiating into neuronal lineage cells by expressing more Tuj1 and Pax6, which was blocked by the P2X receptor antagonist, TNP-ATP. Then we found that light-depolarization of astrocytes significantly increased ATP accumulation in their bathing medium without impairing the cell membrane. We further found that ATP up-regulated the Tuj1, Pax6, FZD8 and β-catenin mRNA levels of MSCs, which could be reversed by application of TNP-ATP. Together these in vitro data provided convergent evidence that ATP from light-depolarized-astrocytes activated the wnt/β-catenin signaling of MSCs through binding to the P2X receptors, and promoted the neuronal differentiation of MSCs. Finally but importantly, our study also demonstrated in stroke rats that light-controlled astrocytes stimulated endogenous ATP release into the ischemic area to influence the transplanted MSCs, resulting in promoting the MSCs towards neuronal differentiation and improvements of neurological deficit.
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Affiliation(s)
- Jie Tu
- Shenzhen Key Lab of Neuropsychiatric Modulation, Key Laboratory for Health Informatics at Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, People's Republic of China
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20
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Kikuta S, Fletcher ML, Homma R, Yamasoba T, Nagayama S. Odorant response properties of individual neurons in an olfactory glomerular module. Neuron 2013; 77:1122-35. [PMID: 23522047 DOI: 10.1016/j.neuron.2013.01.022] [Citation(s) in RCA: 78] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/16/2013] [Indexed: 11/26/2022]
Abstract
Neuronal networks that are directly associated with glomeruli in the olfactory bulb are thought to comprise functional modules. However, this has not yet been experimentally proven. In this study, we explored the anatomical and functional architecture of glomerular modules using in vivo two-photon calcium imaging. Surprisingly, the deep portions of the glomerular modules showed considerable spatial overlap with other modules. Juxtaglomerular cells showed similar excitatory odorant response profiles to presynaptic olfactory sensory neuron inputs. Mitral cells exhibited a more sharply tuned molecular receptive range compared to juxtaglomerular cells, and their odorant response profiles varied depending on their interneuronal horizontal distances. These data suggest that glomerular modules are composed of functionally distinct neurons, and that homogenous odor inputs to each glomerulus may be parsed and processed in different fashions within the modules before being sent to higher olfactory centers.
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Affiliation(s)
- Shu Kikuta
- Department of Neurobiology and Anatomy, University of Texas Medical School at Houston, Houston, TX 77030, USA
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21
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Zheng T, Yang Z, Li A, Lv X, Zhou Z, Wang X, Qi X, Li S, Luo Q, Gong H, Zeng S. Visualization of brain circuits using two-photon fluorescence micro-optical sectioning tomography. OPTICS EXPRESS 2013; 21:9839-50. [PMID: 23609690 DOI: 10.1364/oe.21.009839] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
Neural circuits are fundamental for brain functions. However, obtaining long range continuous projections of neurons in the entire brain is still challenging. Here a two-photon fluorescence micro-optical sectioning tomography (2p-fMOST) method is developed for high-throughput, high-resolution visualization of the brain circuits. Two-photon imaging technology is used to obtain high resolution, and acoustical optical deflector (AOD), an inertia-free beam scanner is used to realize fast and prolonged stable imaging. The combination of these techniques with imaging and then sectioning method of a plastic-embedded mouse brain facilitated the acquisition of a three-dimensional data set of a fluorescent mouse brain with a resolution adequate to resolve the spines. In addition, the brain circuit tracing ability is showed by several neurons projecting across different brain regions. Besides brain imaging, 2p-fMOST could be used in many studies that requires sub-micro resolution or micro resolution imaging of a large sample.
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Affiliation(s)
- Ting Zheng
- Britton Chance Center for Biomedical Photonics, Huazhong University of Science and Technology-Wuhan National Laboratory for Optoelectronics, Wuhan 430074, China
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22
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Abstract
The small size of neuronal dendrites and spines combined with the high speed of neurophysiological signals, such as transients in membrane potential or ion concentration, necessitates that any functional study of these structures uses recording methods with both high spatial and high temporal resolutions. In this regard, conventional two-photon microscopy, in combination with fluorescent indicators sensitive to physiological parameters, has proved to be only a partial solution by providing near-diffraction-limited spatial resolution even when imaging structures deep inside light-scattering tissue. This is because the relatively slow beam-scanning methods used in most conventional two-photon microscopes severely limit the extent to which functional data can be recorded. Here, we detail developments to create high-speed two-photon imaging systems that overcome this limitation and discuss important considerations that must be taken into account when attempting to construct such systems.
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23
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Abstract
Neurons in the mammalian brain receive thousands of synaptic inputs on their dendrites. In many types of neurons, such as cortical pyramidal neurons, excitatory synapses are formed on fine dendritic protrusions called spines. Usually, an individual spine forms a single synaptic contact with an afferent axon. In this protocol, we describe a recently established experimental procedure for measuring intracellular calcium signals from dendritic spines in cortical neurons in vivo by using a combination of two-photon microscopy and whole-cell patch-clamp recordings. We have used mice as an experimental model system, but the protocol may be readily adapted to other species. This method involves data acquisition at high frame rates and low-excitation laser power, and is termed low-power temporal oversampling (LOTOS). Because of its high sensitivity of fluorescence detection and reduced phototoxicity, LOTOS allows for prolonged and stable calcium imaging in vivo. Key aspects of the protocol, which can be completed in 5-6 h, include the use of a variant of high-speed two-photon imaging, refined surgery procedures and optimized tissue stabilization.
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24
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Ranganathan GN, Koester HJ. Optical recording of suprathreshold neural activity with single-cell and single-spike resolution. J Vis Exp 2012:e4052. [PMID: 22972033 DOI: 10.3791/4052] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022] Open
Abstract
Signaling of information in the vertebrate central nervous system is often carried by populations of neurons rather than individual neurons. Also propagation of suprathreshold spiking activity involves populations of neurons. Empirical studies addressing cortical function directly thus require recordings from populations of neurons with high resolution. Here we describe an optical method and a deconvolution algorithm to record neural activity from up to 100 neurons with single-cell and single-spike resolution. This method relies on detection of the transient increases in intracellular somatic calcium concentration associated with suprathreshold electrical spikes (action potentials) in cortical neurons. High temporal resolution of the optical recordings is achieved by a fast random-access scanning technique using acousto-optical deflectors (AODs). Two-photon excitation of the calcium-sensitive dye results in high spatial resolution in opaque brain tissue. Reconstruction of spikes from the fluorescence calcium recordings is achieved by a maximum-likelihood method. Simultaneous electrophysiological and optical recordings indicate that our method reliably detects spikes (>97% spike detection efficiency), has a low rate of false positive spike detection (< 0.003 spikes/sec), and a high temporal precision (about 3 msec). This optical method of spike detection can be used to record neural activity in vitro and in anesthetized animals in vivo.
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25
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Shao Y, Liu H, Qin W, Qu J, Peng X, Niu H, Gao BZ. Addressable, large-field second harmonic generation microscopy based on 2D acousto-optical deflector and spatial light modulator. APPLIED PHYSICS. B, LASERS AND OPTICS 2012; 108:10.1007/s00340-012-5164-9. [PMID: 24307756 PMCID: PMC3846096 DOI: 10.1007/s00340-012-5164-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
We present an addressable, large-field second harmonic generation microscope by combining a 2D acousto-optical deflector with a spatial light modulator. The SLM shapes an incoming mode-locked, near-infrared Ti:Sapphire laser beam into a multifocus array, which can be rapidly scanned by changing the incident angle of the laser beam using a 2D acousto-optical deflector. Compared to the single-beam-scan technique, the multifocus array scan can increase the scanning rate and the field-of-view size with the multi-region imaging ability.
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Affiliation(s)
- Yonghong Shao
- College of Optoelectronics Engineering, Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong Province, Shenzhen University, Shenzhen 518060, China
| | - Honghai Liu
- Department of Bioengineering and COMSET, Clemson University, Clemson, SC 29634, USA
| | - Wan Qin
- Department of Bioengineering and COMSET, Clemson University, Clemson, SC 29634, USA
| | - Junle Qu
- College of Optoelectronics Engineering, Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong Province, Shenzhen University, Shenzhen 518060, China
| | - Xiang Peng
- College of Optoelectronics Engineering, Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong Province, Shenzhen University, Shenzhen 518060, China
| | - Hanben Niu
- College of Optoelectronics Engineering, Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong Province, Shenzhen University, Shenzhen 518060, China
| | - Bruce Z. Gao
- Department of Bioengineering and COMSET, Clemson University, Clemson, SC 29634, USA
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26
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Random-access Two-photon Microscopy for Neural Activity Observation*. PROG BIOCHEM BIOPHYS 2012. [DOI: 10.3724/sp.j.1206.2012.00234] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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27
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Shao Y, Qin W, Liu H, Qu J, Peng X, Niu H, Gao BZ. Ultrafast, large-field multiphoton microscopy based on an acousto-optic deflector and a spatial light modulator. OPTICS LETTERS 2012; 37:2532-4. [PMID: 22743445 PMCID: PMC3698978 DOI: 10.1364/ol.37.002532] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
We present an ultrafast, large-field multiphoton excitation fluorescence microscope with high lateral and axial resolutions based on a two-dimensional (2-D) acousto-optical deflector (AOD) scanner and spatial light modulator (SLM). When a phase-only SLM is used to shape the near-infrared light from a mode-locked titanium:sapphire laser into a multifocus array including the 0-order beam, a 136 μm × 136 μm field of view is achieved with a 60× objective using a 2-D AOD scanner without any mechanical scan element. The two-photon fluorescence image of a neuronal network that was obtained using this system demonstrates that our microscopy permits observation of dynamic biological events in a large field with high-temporal and -spatial resolution.
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Affiliation(s)
- Yonghong Shao
- College of Optoelectronics Engineering, Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong Province, Shenzhen University, Shenzhen 518060, China
| | - Wan Qin
- Department of Bioengineering and COMSET, Clemson University, Clemson, South Carolina 29634, USA
| | - Honghai Liu
- Department of Bioengineering and COMSET, Clemson University, Clemson, South Carolina 29634, USA
| | - Junle Qu
- College of Optoelectronics Engineering, Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong Province, Shenzhen University, Shenzhen 518060, China
| | - Xiang Peng
- College of Optoelectronics Engineering, Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong Province, Shenzhen University, Shenzhen 518060, China
| | - Hanben Niu
- College of Optoelectronics Engineering, Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong Province, Shenzhen University, Shenzhen 518060, China
| | - Bruce Z. Gao
- Department of Bioengineering and COMSET, Clemson University, Clemson, South Carolina 29634, USA
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28
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Jiang R, Zhou Z, Lv X, Zeng S. Wide-band acousto-optic deflectors for large field of view two-photon microscope. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2012; 83:043709. [PMID: 22559541 DOI: 10.1063/1.4705972] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Acousto-optic deflector (AOD) is an attractive scanner for two-photon microscopy because it can provide fast and versatile laser scanning and does not involve any mechanical movements. However, due to the small scan range of available AOD, the field of view (FOV) of the AOD-based microscope is typically smaller than that of the conventional galvanometer-based microscope. Here, we developed a novel wide-band AOD to enlarge the scan angle. Considering the maximum acceptable acoustic attenuation in the acousto-optic crystal, relatively lower operating frequencies and moderate aperture were adopted. The custom AOD was able to provide 60 MHz 3-dB bandwidth and 80% peak diffraction efficiency at 840 nm wavelength. Based on a pair of such AOD, a large FOV two-photon microscope was built with a FOV up to 418.5 μm (40× objective). The spatiotemporal dispersion was compensated simultaneously with a single custom-made prism. By means of dynamic power modulation, the variation of laser intensity within the FOV was reduced below 5%. The lateral and axial resolution of the system were 0.58-2.12 μm and 2.17-3.07 μm, respectively. Pollen grain images acquired by this system were presented to demonstrate the imaging capability at different positions across the entire FOV.
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Affiliation(s)
- Runhua Jiang
- Britton Chance Center for Biomedical Photonics, Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan, 430074, China
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29
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Christensen DJ, Nedergaard M. Random access multiphoton (RAMP) microscopy for investigation of cerebral blood flow regulation mechanisms. PROCEEDINGS OF SPIE--THE INTERNATIONAL SOCIETY FOR OPTICAL ENGINEERING 2012; 8226. [PMID: 34267415 DOI: 10.1117/12.907141] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
The processes by which blood flow is regulated at the capillary network level in the brain has been a source of continual debate. It is generally accepted that cerebral blood flow regulation occurs primarily at the arteriolar level. It has been recently suggested, however, that the capillary network is likewise under dynamic regulation. The exact mechanisms of capillary regulation remain unknown. Previously, the limiting factor in determining how the cerebrovascular network is regulated has been the speed at which multiphoton images of large (~200μm2) capillary and arteriole systems can be acquired. Conventional laser scanning microscopy systems are temporally limited in two dimensions. We have developed a Random Access Multiphoton (RAMP) microscope, which operates on the principles of Acousto-optic beam scanning and therefore has no moving parts, specifically for the purpose of imaging blood flow virtually simultaneously throughout the capillary network. We demonstrate the ability to survey blood flow simultaneously in 100 capillaries.
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Affiliation(s)
- Daniel J Christensen
- The Institute of Optics, 121 Wilmot Bldg./River Campus, Rochester NY, USA.,University of Rochester Medical Center, 610 Elmwood Ave., Rochester NY, USA
| | - Maiken Nedergaard
- University of Rochester Medical Center, 610 Elmwood Ave., Rochester NY, USA
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30
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Precise spatiotemporal control of optogenetic activation using an acousto-optic device. PLoS One 2011; 6:e28468. [PMID: 22174813 PMCID: PMC3235127 DOI: 10.1371/journal.pone.0028468] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2011] [Accepted: 11/08/2011] [Indexed: 12/27/2022] Open
Abstract
Light activation and inactivation of neurons by optogenetic techniques has emerged as an important tool for studying neural circuit function. To achieve a high resolution, new methods are being developed to selectively manipulate the activity of individual neurons. Here, we report that the combination of an acousto-optic device (AOD) and single-photon laser was used to achieve rapid and precise spatiotemporal control of light stimulation at multiple points in a neural circuit with millisecond time resolution. The performance of this system in activating ChIEF expressed on HEK 293 cells as well as cultured neurons was first evaluated, and the laser stimulation patterns were optimized. Next, the spatiotemporally selective manipulation of multiple neurons was achieved in a precise manner. Finally, we demonstrated the versatility of this high-resolution method in dissecting neural circuits both in the mouse cortical slice and the Drosophila brain in vivo. Taken together, our results show that the combination of AOD-assisted laser stimulation and optogenetic tools provides a flexible solution for manipulating neuronal activity at high efficiency and with high temporal precision.
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31
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Liu X, Quan T, Zeng S, Lv X. Identification of the direction of the neural network activation with a cellular resolution by fast two-photon imaging. JOURNAL OF BIOMEDICAL OPTICS 2011; 16:080506. [PMID: 21895306 DOI: 10.1117/1.3613918] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Spatiotemporal activity patterns in local neural networks are fundamental to understanding how information is processed and stored in brain microcircuits. Currently, imaging techniques are able to map the directional activation of macronetworks across brain areas; however, these strategies still fail to resolve the activation direction for fine microcircuits with cellular spatial resolution. Here, we show the capability to identify the activation direction of a multicell network with a cellular resolution and millisecond precision by using fast two-photon microscopy and cross correlation procedures. As an example, we characterized a directional neuronal network in an epilepsy brain slice to provide different initiation delay among multiple neurons defined at a millisecond scale.
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Wang C, Qiao L, He F, Cheng Y, Xu Z. Extension of imaging depth in two-photon fluorescence microscopy using a long-wavelength high-pulse-energy femtosecond laser source. J Microsc 2011; 243:179-83. [PMID: 21388374 DOI: 10.1111/j.1365-2818.2011.03492.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
We experimentally demonstrate, for the first time to the best of our knowledge, two-photon fluorescence imaging with a femtosecond optical parametric amplifier. In particular, we systematically compare the imaging depths of two-photon fluorescence microscopes based on three different excitation sources, including a femtosecond oscillator, a femtosecond regenerative amplifier and the optical parametric amplifier. The results show that the optical parametric amplifier can greatly extend the penetration depth by approximately 227% as compared with that obtained with the femtosecond oscillator due to effective suppression of scattering at longer wavelength and enhanced excitation efficiency enabled by higher pulse energy.
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Affiliation(s)
- C Wang
- State Key Laboratory of High Field Laser Physics, Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Science, P.O. Box 800-211, Shanghai 201800, China
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33
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Losavio BE, Iyer V, Patel S, Saggau P. Acousto-optic laser scanning for multi-site photo-stimulation of single neuronsin vitro. J Neural Eng 2010; 7:045002. [DOI: 10.1088/1741-2560/7/4/045002] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
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34
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Liang X, Hu W, Fu L. Pulse compression in two-photon excitation fluorescence microscopy. OPTICS EXPRESS 2010; 18:14893-14904. [PMID: 20639976 DOI: 10.1364/oe.18.014893] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
The use of shorter pulses is a practical way to improve the signal in two-photon excitation fluorescence microscopy. We report on the theoretical and experimental results of pulse compression in a two-photon excitation fluorescence microscope by using approximately 100-fs Ti:Sapphire laser and highly nonlinear photonic crystal fiber. Effects of the fiber parameters, transmitted power, and group-delay dispersion provided by the gratings have been investigated to optimize the compressor performance. By using a 20-mm-long photonic crystal fiber with a zero dispersion wavelength of 850 nm, a compressed pulse of 23.6 fs starting from 94 fs at 790 nm is experimentally demonstrated as a verification of our simulations. By integrating the compressor with a two-photon excitation fluorescence microscope, 5.6 times increase in autofluorescence intensity of NAD(P)H in Nasopharyngeal carcinoma cells is demonstrated, showing its potential in enhanced imaging and sensing for disease diagnosis.
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Affiliation(s)
- Xiaobao Liang
- Britton Chance Center for Biomedical Photonics, Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan 430074, China
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35
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High-speed in vivo calcium imaging reveals neuronal network activity with near-millisecond precision. Nat Methods 2010; 7:399-405. [PMID: 20400966 DOI: 10.1038/nmeth.1453] [Citation(s) in RCA: 312] [Impact Index Per Article: 22.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2009] [Accepted: 03/29/2010] [Indexed: 11/08/2022]
Abstract
Two-photon calcium imaging of neuronal populations enables optical recording of spiking activity in living animals, but standard laser scanners are too slow to accurately determine spike times. Here we report in vivo imaging in mouse neocortex with greatly improved temporal resolution using random-access scanning with acousto-optic deflectors. We obtained fluorescence measurements from 34-91 layer 2/3 neurons at a 180-490 Hz sampling rate. We detected single action potential-evoked calcium transients with signal-to-noise ratios of 2-5 and determined spike times with near-millisecond precision and 5-15 ms confidence intervals. An automated 'peeling' algorithm enabled reconstruction of complex spike trains from fluorescence traces up to 20-30 Hz frequency, uncovering spatiotemporal trial-to-trial variability of sensory responses in barrel cortex and visual cortex. By revealing spike sequences in neuronal populations on a fast time scale, high-speed calcium imaging will facilitate optical studies of information processing in brain microcircuits.
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36
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Zhu D, Wang J, Zhi Z, Wen X, Luo Q. Imaging dermal blood flow through the intact rat skin with an optical clearing method. JOURNAL OF BIOMEDICAL OPTICS 2010; 15:026008. [PMID: 20459253 DOI: 10.1117/1.3369739] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
Noninvasive detection of skin microcirculation is very significant for clinical diagnosis and therapy of peripheral vascular disease. In this study, an optical clearing method enables a laser speckle contrast imaging (LSCI) technique to image dermal blood flow through intact rat skin. The optical clearing effect of rat skin in vitro caused by a mixture of PEG-400 and Thiazone is evaluated by a commercially available spectrophotometer with an integrating sphere. A LSCI system is applied to image the dermal blood flow of in vivo rat skin after topical treatment of the agents. The results show that the reduced scattering coefficient (630 nm) is down to 60% of the initial value after 40 min of topical treatment of the mixture on skin in vitro. In vivo experimental results show that a 12-min treatment of the mixture on the epidermis can make the skin transparent and dermal vessels can be observed, while treatment with pure PEG-400 cannot. The process of skin optical clearing lasts, and the skin can be recovered by treatment of saline solution. Because optical clearing decreases the temporal contrast, dermal blood flow can be obtained by the laser speckle contrast imaging technique.
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Affiliation(s)
- Dan Zhu
- Huazhong University of Science and Technology, Britton Chance Center for Biomedical Photonics, Wuhan National Laboratory for Optoelectronics, Wuhan 430074, China
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37
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Wen X, Mao Z, Han Z, Tuchin VV, Zhu D. In vivo skin optical clearing by glycerol solutions: mechanism. JOURNAL OF BIOPHOTONICS 2010; 3:44-52. [PMID: 19937846 DOI: 10.1002/jbio.200910080] [Citation(s) in RCA: 71] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
The penetration of light in biological tissues can be enhanced by using optical-clearing techniques. However, researches on the mechanism are limited to in vitro experiments. In this study, rat dorsal skin was used to discuss the mechanism for in vivo optical clearing. Glycerol solutions with different concentrations were applied by dermal injection; then the skin reflectance spectrum, SHG imaging and microstructural changes were monitored. The results showed that with the skin becoming transparent, the corresponding reflectance decreased, and the thickness of dermis and diameter of collagen fibril decreased, but no collagen fiber was dissolved or fractured. Hence, it can be concluded that the thickness decrease of dermis and corresponding more regular packing of tissue fibers plays an important role in the mechanism for glycerol-induced optical clearing of skin in vivo.
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Affiliation(s)
- Xiang Wen
- Britton Chance Center for Biomedical Photonics, Huazhong University of Science and Technology, Wuhan, HuBei, China
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38
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Wen X, Tuchin VV, Luo Q, Zhu D. Controling the scattering of intralipid by using optical clearing agents. Phys Med Biol 2009; 54:6917-30. [PMID: 19887711 DOI: 10.1088/0031-9155/54/22/011] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Optical clearing agents (OCAs) with high refractive indices and hyperosmolarity can enhance the penetration of light in tissues by reducing scattering in tissues. However, the mechanism of tissue optical clearing is not much clear for the complex interaction between tissues and OCAs. In this work, Intralipid was mixed with different concentrations of OCAs, i.e. dimethyl sulfoxide (DMSO), glycerol, 1,4-butanediol, 1,2-propanediol, poly-ethylene glycol 200 (PEG200) and poly-ethylene glycol 400 (PEG400). Except for PEG200 and PEG400 that make aggregation of particles, the others kept the mixture uniform. The reduced scattering coefficients of uniform mixtures were predicted with Mie theory and measured by a commercially available spectrophotometer with an integrating sphere. The results show that all of the OCAs used enhance the optical clearing effect of Intralipid. If OCAs do not change the structure of Intralipid, Mie theory prediction matches well with the measurements. And the higher the refractive index of OCA, the smaller the reduced scattering coefficient. A simple formula deduced can quantitatively predict the optical clearing effect caused by OCAs. This work is helpful for clarifying the mechanism of tissue optical clearing, which will make the effect of optical clearing of tissue predictable and controllable.
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Affiliation(s)
- Xiang Wen
- Wuhan National Laboratory for Optoelectronics, Britton Chance Center for Biomedical Photonics, Huazhong University of Science and Technology Wuhan People's Republic of China
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39
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Losavio BE, Iyer V, Saggau P. Two-photon microscope for multisite microphotolysis of caged neurotransmitters in acute brain slices. JOURNAL OF BIOMEDICAL OPTICS 2009; 14:064033. [PMID: 20059271 PMCID: PMC2809696 DOI: 10.1117/1.3275468] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
We developed a two-photon microscope optimized for physiologically manipulating single neurons through their postsynaptic receptors. The optical layout fulfills the stringent design criteria required for high-speed, high-resolution imaging in scattering brain tissue with minimal photodamage. We detail the practical compensation of spectral and temporal dispersion inherent in fast laser beam scanning with acousto-optic deflectors, as well as a set of biological protocols for visualizing nearly diffraction-limited structures and delivering physiological synaptic stimuli. The microscope clearly resolves dendritic spines and evokes electrophysiological transients in single neurons that are similar to endogenous responses. This system enables the study of multisynaptic integration and will assist our understanding of single neuron function and dendritic computation.
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Affiliation(s)
- Bradley E Losavio
- Baylor College of Medicine, Department of Neuroscience, One Baylor Plaza, Houston, Texas 77030, USA
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40
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Wilt BA, Burns LD, Wei Ho ET, Ghosh KK, Mukamel EA, Schnitzer MJ. Advances in light microscopy for neuroscience. Annu Rev Neurosci 2009; 32:435-506. [PMID: 19555292 DOI: 10.1146/annurev.neuro.051508.135540] [Citation(s) in RCA: 177] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Since the work of Golgi and Cajal, light microscopy has remained a key tool for neuroscientists to observe cellular properties. Ongoing advances have enabled new experimental capabilities using light to inspect the nervous system across multiple spatial scales, including ultrastructural scales finer than the optical diffraction limit. Other progress permits functional imaging at faster speeds, at greater depths in brain tissue, and over larger tissue volumes than previously possible. Portable, miniaturized fluorescence microscopes now allow brain imaging in freely behaving mice. Complementary progress on animal preparations has enabled imaging in head-restrained behaving animals, as well as time-lapse microscopy studies in the brains of live subjects. Mouse genetic approaches permit mosaic and inducible fluorescence-labeling strategies, whereas intrinsic contrast mechanisms allow in vivo imaging of animals and humans without use of exogenous markers. This review surveys such advances and highlights emerging capabilities of particular interest to neuroscientists.
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Affiliation(s)
- Brian A Wilt
- James H. Clark Center and Howard Hughes Medical Institute, Stanford University, Stanford, California 94305, USA
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41
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Li D, Lv X, Bowlan P, Du R, Zeng S, Luo Q. Evolution of the frequency chirp of Gaussian pulses and beams when passing through a pulse compressor. OPTICS EXPRESS 2009; 17:17070-17081. [PMID: 19770925 DOI: 10.1364/oe.17.017070] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
The evolution of the frequency chirp of a laser pulse inside a classical pulse compressor is very different for plane waves and Gaussian beams, although after propagating through the last (4th) dispersive element, the two models give the same results. In this paper, we have analyzed the evolution of the frequency chirp of Gaussian pulses and beams using a method which directly obtains the spectral phase acquired by the compressor. We found the spatiotemporal couplings in the phase to be the fundamental reason for the difference in the frequency chirp acquired by a Gaussian beam and a plane wave. When the Gaussian beam propagates, an additional frequency chirp will be introduced if any spatiotemporal couplings (i.e. angular dispersion, spatial chirp or pulse front tilt) are present. However, if there are no couplings present, the chirp of the Gaussian beam is the same as that of a plane wave. When the Gaussian beam is well collimated, the introduced frequency chirp predicted by the plane wave and Gaussian beam models are in closer agreement. This work improves our understanding of pulse compressors and should be helpful for optimizing dispersion compensation schemes in many applications of femtosecond laser pulses.
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Affiliation(s)
- Derong Li
- Britton Chance Center for Biomedical Photonics, Wuhan National Laboratory for Optoelectronics, Huazhong University of Science & Technology, Wuhan, 430074, China
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42
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Du R, Jiang R, Fu L. Enhanced dispersion compensation capability of angular elements based on beam expansion. OPTICS EXPRESS 2009; 17:16415-16422. [PMID: 19770855 DOI: 10.1364/oe.17.016415] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
We demonstrate that beam size manipulation plays an important role in dispersion compensation. With expanded beam, the maximal negative group delay dispersion (GDD) provided by angular elements increases by an order of magnitude compared with original beam. Both calculation and experimental results show that a modest 2 x and 4 x expanded beams can improve dispersion compensation capability of prisms or acousto-optical deflectors: the restored minimal pulse width decreases by 50% and the corresponding distance between angular elements is shortened more than 70 cm. These findings will be helpful for designing dispersion compensation schemes for femtosecond pulse laser application systems such as multiphoton microscopy or laser micromachining.
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Affiliation(s)
- Rui Du
- Britton Chance Center for Biomedical Photonics, Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan 430074, People's Republic of China
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43
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Carriles R, Schafer DN, Sheetz KE, Field JJ, Cisek R, Barzda V, Sylvester AW, Squier JA. Invited review article: Imaging techniques for harmonic and multiphoton absorption fluorescence microscopy. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2009; 80:081101. [PMID: 19725639 PMCID: PMC2736611 DOI: 10.1063/1.3184828] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/17/2008] [Accepted: 06/14/2009] [Indexed: 05/20/2023]
Abstract
We review the current state of multiphoton microscopy. In particular, the requirements and limitations associated with high-speed multiphoton imaging are considered. A description of the different scanning technologies such as line scan, multifoci approaches, multidepth microscopy, and novel detection techniques is given. The main nonlinear optical contrast mechanisms employed in microscopy are reviewed, namely, multiphoton excitation fluorescence, second harmonic generation, and third harmonic generation. Techniques for optimizing these nonlinear mechanisms through a careful measurement of the spatial and temporal characteristics of the focal volume are discussed, and a brief summary of photobleaching effects is provided. Finally, we consider three new applications of multiphoton microscopy: nonlinear imaging in microfluidics as applied to chemical analysis and the use of two-photon absorption and self-phase modulation as contrast mechanisms applied to imaging problems in the medical sciences.
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Affiliation(s)
- Ramón Carriles
- Department of Photonics, Centro de Investigaciones en Optica, León, Mexico
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44
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Wang L, Chen T, Qu J, Wei X. Photobleaching-based quantitative analysis of fluorescence resonance energy transfer inside single living cell. J Fluoresc 2009; 20:27-35. [PMID: 19588234 DOI: 10.1007/s10895-009-0518-3] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2009] [Accepted: 07/02/2009] [Indexed: 10/20/2022]
Abstract
The current advances of fluorescence microscopy and new fluorescent probes make fluorescence resonance energy transfer (FRET) a powerful technique for studying protein-protein interactions inside living cells. It is very hard to quantitatively analyze FRET efficiency using intensity-based FRET imaging microscopy due to the presence of autofluorescence and spectral crosstalks. In this study, we for the first time developed a novel photobleaching-based method to quantitatively detect FRET efficiency (Pb-FRET) by selectively photobleaching acceptor. The Pb-FRET method requires two fluorescence detection channels: a donor channel (CH ( 1 )) to selectively detect the fluorescence from donor, and a FRET channel (CH ( 2 )) which normally includes the fluorescence from both acceptor and donor due to emission spectral crosstalk. We used the Pb-FRET method to quantitatively measure the FRET efficiency of SCAT3, a caspase-3 indicator based on FRET, inside single living cells stably expressing SCAT3 during STS-induced apoptosis. At 0, 6 and 12 h after STS treatment, the FRET efficiency of SCAT3 obtained by Pb-FRET inside living cells was verified by two-photon excitation (TPE) fluorescence lifetime imaging microscopy (FLIM). The temporal resolution of Pb-FRET method is in second time-scale for ROI photobleaching, even in microsecond time-scale for spot photobleaching. Our results demonstrate that the Pb-FRET method is independent of photobleaching degree, and is very useful for quantitatively monitoring protein-protein interactions inside single living cell.
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Affiliation(s)
- Longxiang Wang
- MOE Key laboratory of Laser Life Science & Institute of Laser Life Science, South China Normal University, Guangzhou, 510631, China
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45
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Zeng Y, Lv X, Zeng S, Shi J. Activity-dependent neuronal control of gap-junctional communication in fibroblasts. Brain Res 2009; 1280:13-22. [DOI: 10.1016/j.brainres.2009.05.037] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2009] [Revised: 05/07/2009] [Accepted: 05/13/2009] [Indexed: 10/20/2022]
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46
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Zeng S, Luo Q, Li D, Lü X. Femtosecond pulse laser scanning using Acousto-Optic Deflector. ACTA ACUST UNITED AC 2009. [DOI: 10.1007/s11433-009-0101-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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47
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FLIM and emission spectral analysis of caspase-3 activation inside single living cell during anticancer drug-induced cell death. EUROPEAN BIOPHYSICS JOURNAL: EBJ 2009; 38:447-56. [DOI: 10.1007/s00249-008-0390-0] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/18/2008] [Revised: 12/05/2008] [Accepted: 12/07/2008] [Indexed: 01/11/2023]
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48
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Reduction of the pulse duration of the ultrafast laser pulses of the Two-Photon Laser Scanning Microscopy (2PLSM). BMC Res Notes 2008; 1:39. [PMID: 18710492 PMCID: PMC2519073 DOI: 10.1186/1756-0500-1-39] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2008] [Accepted: 07/09/2008] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND We provide an update of our two-photon laser scanning microscope by compressing or reducing the broadening of the pulse width of ultrafast laser pulses for dispersion precompensation, to enable the pulses to penetrate deeply inside the sample. FINDINGS The broadening comes as the pulses pass through the optical elements. We enhanced and modified the quality and the sharpness of images by enhancing the resolution using special polarizer namely Glan Laser polarizer GL10. This polarizer consists of two prisms separated by air space. This air separation between the two prisms uses to delay the red wavelength when the light leaves the first prism to the air then to second prism. We note a considerable enhancing with using the GL polarizer, and we can see the details of the leaf structure in early stages when we trying to get focus through z-stacks of images in comparison to exactly the same measurements without using GL polarizer. Hence, with this modification we able to reduce the time of exposure the sample to the laser radiation thereby we will reduce the probability of photobleaching and phototoxicity. When the pulse width reduced, the average power of the laser pulses maintained at a constant level. Significant enhancement is found between the two kinds of images of the Two-Photon Excitation Fluorescence (TPEF). CONCLUSION In summary reduction the laser pulse width allowed to collect more diffraction orders which will used to form the images. The more diffraction orders the higher resolution images.
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Otsu Y, Bormuth V, Wong J, Mathieu B, Dugué GP, Feltz A, Dieudonné S. Optical monitoring of neuronal activity at high frame rate with a digital random-access multiphoton (RAMP) microscope. J Neurosci Methods 2008; 173:259-70. [PMID: 18634822 DOI: 10.1016/j.jneumeth.2008.06.015] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2008] [Revised: 06/10/2008] [Accepted: 06/16/2008] [Indexed: 01/15/2023]
Abstract
Two-photon microscopy offers the promise of monitoring brain activity at multiple locations within intact tissue. However, serial sampling of voxels has been difficult to reconcile with millisecond timescales characteristic of neuronal activity. This is due to the conflicting constraints of scanning speed and signal amplitude. The recent use of acousto-optic deflector scanning to implement random-access multiphoton microscopy (RAMP) potentially allows to preserve long illumination dwell times while sampling multiple points-of-interest at high rates. However, the real-life abilities of RAMP microscopy regarding sensitivity and phototoxicity issues, which have so far impeded prolonged optical recordings at high frame rates, have not been assessed. Here, we describe the design, implementation and characterisation of an optimised RAMP microscope. We demonstrate the application of the microscope by monitoring calcium transients in Purkinje cells and cortical pyramidal cell dendrites and spines. We quantify the illumination constraints imposed by phototoxicity and show that stable continuous high-rate recordings can be obtained. During these recordings the fluorescence signal is large enough to detect spikes with a temporal resolution limited only by the calcium dye dynamics, improving upon previous techniques by at least an order of magnitude.
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Affiliation(s)
- Yo Otsu
- Laboratoire de Neurobiologie, CNRS UMR 8544, Ecole Normale Supérieure, 46 rue d'Ulm 75005, Paris, France
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50
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Lowry M, Fakayode SO, Geng ML, Baker GA, Wang L, McCarroll ME, Patonay G, Warner IM. Molecular Fluorescence, Phosphorescence, and Chemiluminescence Spectrometry. Anal Chem 2008; 80:4551-74. [DOI: 10.1021/ac800749v] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Affiliation(s)
- Mark Lowry
- Department of Chemistry, Louisiana State University, Baton Rouge, Louisiana 70803, Department of Chemistry, Winston-Salem State University, Winston-Salem, North Carolina 27110, Department of Chemistry, Nanoscience and Nanotechnology Institute and the Optical Science and Technology Center, University of Iowa, Iowa City, Iowa 52242, Chemical Sciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, Department of Chemistry and Biochemistry, Southern Illinois University, Carbondale,
| | - Sayo O. Fakayode
- Department of Chemistry, Louisiana State University, Baton Rouge, Louisiana 70803, Department of Chemistry, Winston-Salem State University, Winston-Salem, North Carolina 27110, Department of Chemistry, Nanoscience and Nanotechnology Institute and the Optical Science and Technology Center, University of Iowa, Iowa City, Iowa 52242, Chemical Sciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, Department of Chemistry and Biochemistry, Southern Illinois University, Carbondale,
| | - Maxwell L. Geng
- Department of Chemistry, Louisiana State University, Baton Rouge, Louisiana 70803, Department of Chemistry, Winston-Salem State University, Winston-Salem, North Carolina 27110, Department of Chemistry, Nanoscience and Nanotechnology Institute and the Optical Science and Technology Center, University of Iowa, Iowa City, Iowa 52242, Chemical Sciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, Department of Chemistry and Biochemistry, Southern Illinois University, Carbondale,
| | - Gary A. Baker
- Department of Chemistry, Louisiana State University, Baton Rouge, Louisiana 70803, Department of Chemistry, Winston-Salem State University, Winston-Salem, North Carolina 27110, Department of Chemistry, Nanoscience and Nanotechnology Institute and the Optical Science and Technology Center, University of Iowa, Iowa City, Iowa 52242, Chemical Sciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, Department of Chemistry and Biochemistry, Southern Illinois University, Carbondale,
| | - Lin Wang
- Department of Chemistry, Louisiana State University, Baton Rouge, Louisiana 70803, Department of Chemistry, Winston-Salem State University, Winston-Salem, North Carolina 27110, Department of Chemistry, Nanoscience and Nanotechnology Institute and the Optical Science and Technology Center, University of Iowa, Iowa City, Iowa 52242, Chemical Sciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, Department of Chemistry and Biochemistry, Southern Illinois University, Carbondale,
| | - Matthew E. McCarroll
- Department of Chemistry, Louisiana State University, Baton Rouge, Louisiana 70803, Department of Chemistry, Winston-Salem State University, Winston-Salem, North Carolina 27110, Department of Chemistry, Nanoscience and Nanotechnology Institute and the Optical Science and Technology Center, University of Iowa, Iowa City, Iowa 52242, Chemical Sciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, Department of Chemistry and Biochemistry, Southern Illinois University, Carbondale,
| | - Gabor Patonay
- Department of Chemistry, Louisiana State University, Baton Rouge, Louisiana 70803, Department of Chemistry, Winston-Salem State University, Winston-Salem, North Carolina 27110, Department of Chemistry, Nanoscience and Nanotechnology Institute and the Optical Science and Technology Center, University of Iowa, Iowa City, Iowa 52242, Chemical Sciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, Department of Chemistry and Biochemistry, Southern Illinois University, Carbondale,
| | - Isiah M. Warner
- Department of Chemistry, Louisiana State University, Baton Rouge, Louisiana 70803, Department of Chemistry, Winston-Salem State University, Winston-Salem, North Carolina 27110, Department of Chemistry, Nanoscience and Nanotechnology Institute and the Optical Science and Technology Center, University of Iowa, Iowa City, Iowa 52242, Chemical Sciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, Department of Chemistry and Biochemistry, Southern Illinois University, Carbondale,
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