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Hu G, Greene J, Zhu J, Yang Q, Zheng S, Li Y, Alido J, Guo R, Mertz J, Tian L. HiLo microscopy with caustic illumination. BIOMEDICAL OPTICS EXPRESS 2024; 15:4101-4110. [PMID: 39022539 PMCID: PMC11249696 DOI: 10.1364/boe.527264] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/18/2024] [Revised: 05/18/2024] [Accepted: 05/19/2024] [Indexed: 07/20/2024]
Abstract
HiLo microscopy is an optical sectioning structured illumination microscopy technique based on computationally combining two images: one with uniform illumination and the other with structured illumination. The most widely used structured illumination in HiLo microscopy is random speckle patterns, due to their simplicity and resilience to tissue scattering. Here, we present a novel HiLo microscopy strategy based on random caustic patterns. Building on an off-the-shelf diffuser and a low-coherence LED source, we demonstrate that caustic HiLo can achieve 4.5 µm optical sectioning capability with a 20× 0.75 NA objective. In addition, with the distinct intensity statistical properties of caustic patterns, we show that our caustic HiLo outperforms speckle HiLo, achieving enhanced optical sectioning capability and preservation of fine features by imaging scattering fixed brain sections of 100 µm, 300 µm, and 500 µm thicknesses. We anticipate that this new structured illumination technique may find various biomedical imaging applications.
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Affiliation(s)
- Guorong Hu
- Department of Electrical & Computer Engineering, Boston University
, Boston, Massachusetts 02215, USA
| | - Joseph Greene
- Department of Electrical & Computer Engineering, Boston University
, Boston, Massachusetts 02215, USA
| | - Jiabei Zhu
- Department of Electrical & Computer Engineering, Boston University
, Boston, Massachusetts 02215, USA
| | - Qianwan Yang
- Department of Electrical & Computer Engineering, Boston University
, Boston, Massachusetts 02215, USA
| | - Shuqi Zheng
- Department of Electrical & Computer Engineering, Boston University
, Boston, Massachusetts 02215, USA
| | - Yunzhe Li
- Department of Electrical & Computer Engineering, Boston University
, Boston, Massachusetts 02215, USA
- Currently with the Department of Electrical Engineering & Computer Sciences, University of California, Berkeley, California 94720, USA
| | - Jeffrey Alido
- Department of Electrical & Computer Engineering, Boston University
, Boston, Massachusetts 02215, USA
| | - Ruipeng Guo
- Department of Electrical & Computer Engineering, Boston University
, Boston, Massachusetts 02215, USA
| | - Jerome Mertz
- Department of Electrical & Computer Engineering, Boston University
, Boston, Massachusetts 02215, USA
- Department of Biomedical Engineering, Boston University
, Boston, Massachusetts 02215, USA
| | - Lei Tian
- Department of Electrical & Computer Engineering, Boston University
, Boston, Massachusetts 02215, USA
- Department of Biomedical Engineering, Boston University
, Boston, Massachusetts 02215, USA
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Jiao Z, Pan M, Yousaf K, Doveiko D, Maclean M, Griffin D, Chen Y, Li DDU. Smartphone-based optical sectioning (SOS) microscopy with a telecentric design for fluorescence imaging. J Microsc 2024. [PMID: 38808665 DOI: 10.1111/jmi.13334] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2023] [Revised: 04/15/2024] [Accepted: 05/17/2024] [Indexed: 05/30/2024]
Abstract
We propose a smartphone-based optical sectioning (SOS) microscope based on the HiLo technique, with a single smartphone replacing a high-cost illumination source and a camera sensor. We built our SOS with off-the-shelf optical, mechanical cage systems with 3D-printed adapters to seamlessly integrate the smartphone with the SOS main body. The liquid light guide can be integrated with the adapter, guiding the smartphone's LED light to the digital mirror device (DMD) with neglectable loss. We used an electrically tuneable lens (ETL) instead of a mechanical translation stage to realise low-cost axial scanning. The ETL was conjugated to the objective lens's back pupil plane (BPP) to construct a telecentric design by a 4f configuration to maintain the lateral magnification for different axial positions. SOS has a 571.5 µm telecentric scanning range and an 11.7 µm axial resolution. The broadband smartphone LED torch can effectively excite fluorescent polystyrene (PS) beads. We successfully used SOS for high-contrast fluorescent PS beads imaging with different wavelengths and optical sectioning imaging of multilayer fluorescent PS beads. To our knowledge, the proposed SOS is the first smartphone-based HiLo optical sectioning microscopy (£1965), which can save around £7035 compared with a traditional HiLo system (£9000). It is a powerful tool for biomedical research in resource-limited areas.
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Affiliation(s)
- Ziao Jiao
- Department of Biomedical Engineering, University of Strathclyde, Glasgow, Scotland, UK
- Strathclyde Institute of Pharmacy and Biomedical Sciences, University of Strathclyde, Glasgow, Scotland, UK
| | - Mingliang Pan
- Department of Biomedical Engineering, University of Strathclyde, Glasgow, Scotland, UK
| | - Khadija Yousaf
- Department of Physics, University of Strathclyde, Glasgow, Scotland, UK
| | - Daniel Doveiko
- Department of Physics, University of Strathclyde, Glasgow, Scotland, UK
| | - Michelle Maclean
- Department of Biomedical Engineering, University of Strathclyde, Glasgow, Scotland, UK
- Department of Electronic & Electrical Engineering, The Robertson Trust Laboratory for Electronic Sterilisation Technologies (ROLEST), University of Strathclyde, Glasgow, UK
| | - David Griffin
- Department of Biomedical Engineering, University of Strathclyde, Glasgow, Scotland, UK
| | - Yu Chen
- Department of Physics, University of Strathclyde, Glasgow, Scotland, UK
| | - David Day Uei Li
- Department of Biomedical Engineering, University of Strathclyde, Glasgow, Scotland, UK
- Strathclyde Institute of Pharmacy and Biomedical Sciences, University of Strathclyde, Glasgow, Scotland, UK
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Zheng S, Koyama M, Mertz J. Multiplane HiLo microscopy with speckle illumination and non-local means denoising. JOURNAL OF BIOMEDICAL OPTICS 2023; 28:116502. [PMID: 38078150 PMCID: PMC10704089 DOI: 10.1117/1.jbo.28.11.116502] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/06/2023] [Revised: 10/27/2023] [Accepted: 11/03/2023] [Indexed: 12/18/2023]
Abstract
Significance HiLo microscopy synthesizes an optically sectioned image from two images, one obtained with uniform and another with patterned illumination, such as laser speckle. Speckle-based HiLo has the advantage of being robust to aberrations but is susceptible to residual speckle noise that is difficult to control. We present a computational method to reduce this residual noise without undermining resolution. In addition, we improve the versatility of HiLo microscopy by enabling simultaneous multiplane imaging (here nine planes). Aim Our goal is to perform fast, high-contrast, multiplane imaging with a conventional camera-based fluorescence microscope. Approach Multiplane HiLo imaging is achieved with the use of a single camera and z-splitter prism. Speckle noise reduction is based on the application of a non-local means (NLM) denoising method to perform ensemble averaging of speckle grains. Results We demonstrate the capabilities of multiplane HiLo with NLM denoising both with synthesized data and by imaging cardiac and brain activity in zebrafish larvae at 40 Hz frame rates. Conclusions Multiplane HiLo microscopy aided by NLM denoising provides a simple tool for fast optically sectioned volumetric imaging that can be of general utility for fluorescence imaging applications.
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Affiliation(s)
- Shuqi Zheng
- Boston University, Department of Electrical and Computer Engineering, Boston, Massachusetts, United States
| | - Minoru Koyama
- University of Toronto, Department of Cell and Systems Biology, Scarborough, Ontario, Canada
| | - Jerome Mertz
- Boston University, Department of Biomedical Engineering, Boston, Massachusetts, United States
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4
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Shi R, Li Y, Kong L. High-speed volumetric imaging in vivo based on structured illumination microscopy with interleaved reconstruction. JOURNAL OF BIOPHOTONICS 2021; 14:e202000513. [PMID: 33502121 DOI: 10.1002/jbio.202000513] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/29/2020] [Revised: 01/21/2021] [Accepted: 01/24/2021] [Indexed: 06/12/2023]
Abstract
Wide-field fluorescence microscopy (WFFM) is widely adopted in biomedical studies, due to its high imaging speed over large field-of-views. However, WFFM is susceptible to out-of-focus background. To overcome this problem, structured illumination microscopy (SIM) was proposed as a wide-field, optical-sectioning technique, which needs multiple raw images for image reconstruction and thus has a lower imaging speed. Here we propose SIM with interleaved reconstruction, to make SIM of lossless speed. We apply this method in volumetric imaging of neural network dynamics in brains of zebrafish larva in vivo.
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Affiliation(s)
- Ruheng Shi
- State Key Laboratory of Precision Measurement Technology and Instruments, Department of Precision Instrument, Tsinghua University, Beijing, China
| | - Yuting Li
- State Key Laboratory of Precision Measurement Technology and Instruments, Department of Precision Instrument, Tsinghua University, Beijing, China
| | - Lingjie Kong
- State Key Laboratory of Precision Measurement Technology and Instruments, Department of Precision Instrument, Tsinghua University, Beijing, China
- IDG/McGovern Institute for Brain Research, Tsinghua University, Beijing, China
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Malvaut S, Constantinescu VS, Dehez H, Doric S, Saghatelyan A. Deciphering Brain Function by Miniaturized Fluorescence Microscopy in Freely Behaving Animals. Front Neurosci 2020; 14:819. [PMID: 32848576 PMCID: PMC7432153 DOI: 10.3389/fnins.2020.00819] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2020] [Accepted: 07/14/2020] [Indexed: 11/19/2022] Open
Abstract
Animal behavior is regulated by environmental stimuli and is shaped by the activity of neural networks, underscoring the importance of assessing the morpho-functional properties of different populations of cells in freely behaving animals. In recent years, a number of optical tools have been developed to monitor and modulate neuronal and glial activity at the protein, cellular, or network level and have opened up new avenues for studying brain function in freely behaving animals. Tools such as genetically encoded sensors and actuators are now commonly used for studying brain activity and function through their expression in different neuronal ensembles. In parallel, microscopy has also made major progress over the last decades. The advent of miniature microscopes (mini-microscopes also called mini-endoscopes) has become a method of choice for studying brain activity at the cellular and network levels in different brain regions of freely behaving mice. This technique also allows for longitudinal investigations while animals carrying the microscope on their head are performing behavioral tasks. In this review, we will discuss mini-endoscopic imaging and the advantages that these devices offer to research. We will also discuss current limitations of and potential future improvements in mini-endoscopic imaging.
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Affiliation(s)
- Sarah Malvaut
- CERVO Brain Research Center, Quebec City, QC, Canada
- Department of Psychiatry and Neuroscience, Universite Laval, Quebec City, QC, Canada
| | - Vlad-Stefan Constantinescu
- CERVO Brain Research Center, Quebec City, QC, Canada
- Department of Psychiatry and Neuroscience, Universite Laval, Quebec City, QC, Canada
| | | | - Sead Doric
- Doric Lenses Inc., Quebec City, QC, Canada
| | - Armen Saghatelyan
- CERVO Brain Research Center, Quebec City, QC, Canada
- Department of Psychiatry and Neuroscience, Universite Laval, Quebec City, QC, Canada
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6
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Shi R, Jin C, Xie H, Zhang Y, Li X, Dai Q, Kong L. Multi-plane, wide-field fluorescent microscopy for biodynamic imaging in vivo. BIOMEDICAL OPTICS EXPRESS 2019; 10:6625-6635. [PMID: 31853421 PMCID: PMC6913411 DOI: 10.1364/boe.10.006625] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/14/2019] [Revised: 10/05/2019] [Accepted: 10/30/2019] [Indexed: 05/29/2023]
Abstract
Wide-field fluorescent microscopy (WFFM) is widely employed in biomedical studies, due to its inherent advantages in high-speed imaging of biological dynamics noninvasively and specifically. However, WFFM suffers from the loss of axial resolution and the poor resistance to light scattering in deep tissue imaging. Here we propose a novel WFFM which has the capability in optical sectioning and volumetric imaging. We perform speckle illumination with a digital-micromirror-device for optical sectioning and employ an electrically tunable lens for defocusing modulation so as to quickly switch the image planes. We demonstrate its applications in multi-plane, wide-field imaging of biological dynamics in both zebrafish brains and mouse brains in vivo.
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Affiliation(s)
- Ruheng Shi
- State Key Laboratory of Precision Measurement Technology and Instruments, Department of Precision Instrument, Tsinghua University, Beijing 100084, China
| | - Cheng Jin
- State Key Laboratory of Precision Measurement Technology and Instruments, Department of Precision Instrument, Tsinghua University, Beijing 100084, China
| | - Hao Xie
- Department of Automation, Tsinghua University, Beijing 100084, China
| | - Yuanlong Zhang
- Department of Automation, Tsinghua University, Beijing 100084, China
| | - Xinyang Li
- Department of Automation, Tsinghua University, Beijing 100084, China
- Graduate School at Shenzhen, Tsinghua University, Shenzhen 518055, China
| | - Qionghai Dai
- Department of Automation, Tsinghua University, Beijing 100084, China
| | - Lingjie Kong
- State Key Laboratory of Precision Measurement Technology and Instruments, Department of Precision Instrument, Tsinghua University, Beijing 100084, China
- IDG/McGovern Institute for Brain Research, Tsinghua University, Beijing 100084, China
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7
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Huang C, Tai CY, Yang KP, Chang WK, Hsu KJ, Hsiao CC, Wu SC, Lin YY, Chiang AS, Chu SW. All-Optical Volumetric Physiology for Connectomics in Dense Neuronal Structures. iScience 2019; 22:133-146. [PMID: 31765994 PMCID: PMC6883334 DOI: 10.1016/j.isci.2019.11.011] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2019] [Revised: 09/19/2019] [Accepted: 11/04/2019] [Indexed: 01/04/2023] Open
Abstract
All-optical physiology (AOP) manipulates and reports neuronal activities with light, allowing for interrogation of neuronal functional connections with high spatiotemporal resolution. However, contemporary high-speed AOP platforms are limited to single-depth or discrete multi-plane recordings that are not suitable for studying functional connections among densely packed small neurons, such as neurons in Drosophila brains. Here, we constructed a 3D AOP platform by incorporating single-photon point stimulation and two-photon high-speed volumetric recordings with a tunable acoustic gradient-index (TAG) lens. We demonstrated the platform effectiveness by studying the anterior visual pathway (AVP) of Drosophila. We achieved functional observation of spatiotemporal coding and the strengths of calcium-sensitive connections between anterior optic tubercle (AOTU) sub-compartments and >70 tightly assembled 2-μm bulb (BU) microglomeruli in 3D coordinates with a single trial. Our work aids the establishment of in vivo 3D functional connectomes in neuron-dense brain areas. All-optical volumetric physiology = precise stimulation + fast volumetric recording Precise single-photon point stimulation among genetically defined neurons 3D two-photon imaging by an acoustic gradient-index lens for dense neural structures Observation of 3D functional connectivity in Drosophila anterior visual pathway
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Affiliation(s)
- Chiao Huang
- Department of Physics, National Taiwan University, 1, Sec 4, Roosevelt Road, Taipei 10617, Taiwan
| | - Chu-Yi Tai
- Institute of Biotechnology, National Tsing Hua University, 101, Sec 2, Guangfu Road, Hsinchu 30013, Taiwan
| | - Kai-Ping Yang
- Department of Physics, National Taiwan University, 1, Sec 4, Roosevelt Road, Taipei 10617, Taiwan
| | - Wei-Kun Chang
- Brain Research Center, National Tsing Hua University, 101, Sec 2, Guangfu Road, Hsinchu 30013, Taiwan
| | - Kuo-Jen Hsu
- Department of Physics, National Taiwan University, 1, Sec 4, Roosevelt Road, Taipei 10617, Taiwan; Brain Research Center, National Tsing Hua University, 101, Sec 2, Guangfu Road, Hsinchu 30013, Taiwan
| | - Ching-Chun Hsiao
- Department of Engineering and System Science, National Tsing Hua University, 101, Sec 2, Guangfu Road, Hsinchu 30013, Taiwan
| | - Shun-Chi Wu
- Department of Engineering and System Science, National Tsing Hua University, 101, Sec 2, Guangfu Road, Hsinchu 30013, Taiwan
| | - Yen-Yin Lin
- Brain Research Center, National Tsing Hua University, 101, Sec 2, Guangfu Road, Hsinchu 30013, Taiwan.
| | - Ann-Shyn Chiang
- Institute of Biotechnology, National Tsing Hua University, 101, Sec 2, Guangfu Road, Hsinchu 30013, Taiwan; Brain Research Center, National Tsing Hua University, 101, Sec 2, Guangfu Road, Hsinchu 30013, Taiwan; Institute of Systems Neuroscience, National Tsing Hua University, 101, Sec 2, Guangfu Road, Hsinchu 30013, Taiwan; Department of Biomedical Science and Environmental Biology, Kaohsiung Medical University, Kaohsiung 80780, Taiwan; Graduate Institute of Clinical Medical Science, China Medical University, Taichung 40402, Taiwan; Institute of Molecular and Genomic Medicine, National Health Research Institutes, Zhunan, Miaoli 35053, Taiwan; Kavli Institute for Brain and Mind, University of California, San Diego, CA 92161, USA.
| | - Shi-Wei Chu
- Department of Physics, National Taiwan University, 1, Sec 4, Roosevelt Road, Taipei 10617, Taiwan; Molecular Imaging Center, National Taiwan University, 1, Sec 4, Roosevelt Road, Taipei 10617, Taiwan.
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Macias-Romero C, Teulon C, Didier M, Roke S. Endogenous SHG and 2PEF coherence imaging of substructures in neurons in 3D. OPTICS EXPRESS 2019; 27:2235-2247. [PMID: 30732263 DOI: 10.1364/oe.27.002235] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
Neuronal morphology, long-distance transport and signalling critically depend on the organization of microtubules in the cytoskeleton. Second harmonic generation (SHG) imaging has been recognized as a potentially powerful tool for in situ label-free neuroimaging with specific sensitivity to microtubules. We study here the structural organization of microtubules in living neurons using a wide-field multiphoton microscope that performs 3D imaging using a structured illumination. This microscope allows label-free high throughput imaging of living mammalian neurons. We show that we can image structural correlations by taking advantage of the structured illumination and the coherence of the emitted light. The result allows us to study the microtubule organization throughout the development of the neuron and to differentiate between the regions of the cytoskeleton in the matured neuron.
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9
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The State of the NIH BRAIN Initiative. J Neurosci 2018; 38:6427-6438. [PMID: 29921715 DOI: 10.1523/jneurosci.3174-17.2018] [Citation(s) in RCA: 51] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2018] [Revised: 06/01/2018] [Accepted: 06/04/2018] [Indexed: 12/30/2022] Open
Abstract
The BRAIN Initiative arose from a grand challenge to "accelerate the development and application of new technologies that will enable researchers to produce dynamic pictures of the brain that show how individual brain cells and complex neural circuits interact at the speed of thought." The BRAIN Initiative is a public-private effort focused on the development and use of powerful tools for acquiring fundamental insights about how information processing occurs in the central nervous system (CNS). As the Initiative enters its fifth year, NIH has supported >500 principal investigators, who have answered the Initiative's challenge via hundreds of publications describing novel tools, methods, and discoveries that address the Initiative's seven scientific priorities. We describe scientific advances produced by individual laboratories, multi-investigator teams, and entire consortia that, over the coming decades, will produce more comprehensive and dynamic maps of the brain, deepen our understanding of how circuit activity can produce a rich tapestry of behaviors, and lay the foundation for understanding how its circuitry is disrupted in brain disorders. Much more work remains to bring this vision to fruition, and the National Institutes of Health continues to look to the diverse scientific community, from mathematics, to physics, chemistry, engineering, neuroethics, and neuroscience, to ensure that the greatest scientific benefit arises from this unique research Initiative.
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Meng Y, Lin W, Li C, Chen SC. Fast two-snapshot structured illumination for temporal focusing microscopy with enhanced axial resolution. OPTICS EXPRESS 2017; 25:23109-23121. [PMID: 29041614 DOI: 10.1364/oe.25.023109] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/31/2017] [Accepted: 09/08/2017] [Indexed: 06/07/2023]
Abstract
We present a new two-snapshot structured light illumination (SLI) reconstruction algorithm for fast image acquisition. The new algorithm, which only requires two mutually π phase-shifted raw structured images, is implemented on a custom-built temporal focusing fluorescence microscope (TFFM) to enhance its axial resolution via a digital micromirror device (DMD). First, the orientation of the modulated sinusoidal fringe patterns is automatically identified via spatial frequency vector detection. Subsequently, the modulated in-focal-plane images are obtained via rotation and subtraction. Lastly, a parallel amplitude demodulation method, derived based on Hilbert transform, is applied to complete the decoding processes. To demonstrate the new SLI algorithm, a TFFM is custom-constructed, where a DMD replaces the generic blazed grating in the system and simultaneously functions as a diffraction grating and a programmable binary mask, generating arbitrary fringe patterns. The experimental results show promising depth-discrimination capability with an axial resolution enhancement factor of 1.25, which matches well with the theoretical estimation, i.e, 1.27. Imaging experiments on pollen grain and mouse kidney samples have been performed. The results indicate that the two-snapshot algorithm presents comparable contrast reconstruction and optical cross-sectioning capability than those adopting the conventional root-mean-square (RMS) reconstruction method. The two-snapshot method can be readily applied to any sinusoidally modulated illumination systems to realize high-speed 3D imaging as less frames are required for each in-focal-plane image restoration, i.e., the image acquisition speed is improved by 2.5 times for any two-photon systems.
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11
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Optimization of a Neurotoxin to Investigate the Contribution of Excitatory Interneurons to Speed Modulation In Vivo. Curr Biol 2016; 26:2319-28. [PMID: 27524486 DOI: 10.1016/j.cub.2016.06.037] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2016] [Revised: 05/24/2016] [Accepted: 06/17/2016] [Indexed: 01/06/2023]
Abstract
Precise control of speed during locomotion is essential for adaptation of behavior in different environmental contexts [1-4]. A central question in locomotion lies in understanding which neural populations set locomotor frequency during slow and fast regimes. Tackling this question in vivo requires additional non-invasive tools to silence large populations of neurons during active locomotion. Here we generated a stable transgenic line encoding a zebrafish-optimized botulinum neurotoxin light chain fused to GFP (BoTxBLC-GFP) to silence synaptic output over large populations of motor neurons or interneurons while monitoring active locomotion. By combining calcium imaging, electrophysiology, optogenetics, and behavior, we show that expression of BoTxBLC-GFP abolished synaptic release while maintaining characterized activity patterns and without triggering off-target effects. As chx10(+) V2a interneurons (V2as) are well characterized as the main population driving the frequency-dependent recruitment of motor neurons during fictive locomotion [5-14], we validated our silencing method by testing the effect of silencing chx10(+) V2as during active and fictive locomotion. Silencing of V2as selectively abolished fast locomotor frequencies during escape responses. In addition, spontaneous slow locomotion occurred less often and at frequencies lower than in controls. Overall, this silencing approach confirms that V2a excitation is critical for the production of fast stimulus-evoked swimming and also reveals a role for V2a excitation in the production of slower spontaneous locomotor behavior. Altogether, these results establish BoTxBLC-GFP as an ideal tool for in vivo silencing for probing the development and function of neural circuits from the synaptic to the behavioral level.
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Philipp K, Smolarski A, Koukourakis N, Fischer A, Stürmer M, Wallrabe U, Czarske JW. Volumetric HiLo microscopy employing an electrically tunable lens. OPTICS EXPRESS 2016; 24:15029-41. [PMID: 27410654 DOI: 10.1364/oe.24.015029] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
Electrically tunable lenses exhibit strong potential for fast motion-free axial scanning in a variety of microscopes. However, they also lead to a degradation of the achievable resolution because of aberrations and misalignment between illumination and detection optics that are induced by the scan itself. Additionally, the typically nonlinear relation between actuation voltage and axial displacement leads to over- or under-sampled frame acquisition in most microscopic techniques because of their static depth-of-field. To overcome these limitations, we present an Adaptive-Lens-High-and-Low-frequency (AL-HiLo) microscope that enables volumetric measurements employing an electrically tunable lens. By using speckle-patterned illumination, we ensure stability against aberrations of the electrically tunable lens. Its depth-of-field can be adjusted a-posteriori and hence enables to create flexible scans, which compensates for irregular axial measurement positions. The adaptive HiLo microscope provides an axial scanning range of 1 mm with an axial resolution of about 4 μm and sub-micron lateral resolution over the full scanning range. Proof of concept measurements at home-built specimens as well as zebrafish embryos with reporter gene-driven fluorescence in the thyroid gland are shown.
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13
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Hernandez O, Papagiakoumou E, Tanese D, Fidelin K, Wyart C, Emiliani V. Three-dimensional spatiotemporal focusing of holographic patterns. Nat Commun 2016; 7:11928. [PMID: 27306044 PMCID: PMC4912686 DOI: 10.1038/ncomms11928] [Citation(s) in RCA: 76] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2015] [Accepted: 05/12/2016] [Indexed: 12/11/2022] Open
Abstract
Two-photon excitation with temporally focused pulses can be combined with phase-modulation approaches, such as computer-generated holography and generalized phase contrast, to efficiently distribute light into two-dimensional, axially confined, user-defined shapes. Adding lens-phase modulations to 2D-phase holograms enables remote axial pattern displacement as well as simultaneous pattern generation in multiple distinct planes. However, the axial confinement linearly degrades with lateral shape area in previous reports where axially shifted holographic shapes were not temporally focused. Here we report an optical system using two spatial light modulators to independently control transverse- and axial-target light distribution. This approach enables simultaneous axial translation of single or multiple spatiotemporally focused patterns across the sample volume while achieving the axial confinement of temporal focusing. We use the system's capability to photoconvert tens of Kaede-expressing neurons with single-cell resolution in live zebrafish larvae. Three-dimensional computer-generated holography cannot be implemented with temporal focusing. Here, Hernandez et al. use two spatial light modulators to control transverse- and axial-target light distribution, generating spatiotemporally focused patterns with uniform light distribution throughout the entire volume.
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Affiliation(s)
- Oscar Hernandez
- Wavefront-Engineering Microscopy Group, Neurophotonics Laboratory, CNRS UMR 8250, Paris Descartes University, UFR Biomédicale, 45 rue des Saints-Pères, 75270 Paris Cedex 06, France
| | - Eirini Papagiakoumou
- Wavefront-Engineering Microscopy Group, Neurophotonics Laboratory, CNRS UMR 8250, Paris Descartes University, UFR Biomédicale, 45 rue des Saints-Pères, 75270 Paris Cedex 06, France.,Institut national de la santé et de la recherche médicale (Inserm), France
| | - Dimitrii Tanese
- Wavefront-Engineering Microscopy Group, Neurophotonics Laboratory, CNRS UMR 8250, Paris Descartes University, UFR Biomédicale, 45 rue des Saints-Pères, 75270 Paris Cedex 06, France
| | - Kevin Fidelin
- Institut du Cerveau et de la Moelle Épinière, UPMC, Inserm UMR S975, CNRS UMR 7225, Campus Hospitalier Pitié Salpêtrière, 47 building de l'Hôpital, 75013 Paris, France
| | - Claire Wyart
- Institut du Cerveau et de la Moelle Épinière, UPMC, Inserm UMR S975, CNRS UMR 7225, Campus Hospitalier Pitié Salpêtrière, 47 building de l'Hôpital, 75013 Paris, France
| | - Valentina Emiliani
- Wavefront-Engineering Microscopy Group, Neurophotonics Laboratory, CNRS UMR 8250, Paris Descartes University, UFR Biomédicale, 45 rue des Saints-Pères, 75270 Paris Cedex 06, France
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