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Astafiev AA, Shakhov AM, Osychenko AA, Martirosyan DY, Tochilo WA, Zalessky AD, Syrchina MS, Karmenyan AV, Cheng CL, Nadtochenko VA. Femtosecond Laser Microsurgery of Mouse Oocytes: Formation and Dynamics of Cavitation Bubbles Under the Action of Sharply Focused Laser Radiation on Various Oocyte Zones. RUSSIAN JOURNAL OF PHYSICAL CHEMISTRY B 2023. [DOI: 10.1134/s1990793123010189] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/07/2023]
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2
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Long-term in vivo imaging of mouse spinal cord through an optically cleared intervertebral window. Nat Commun 2022; 13:1959. [PMID: 35414131 PMCID: PMC9005710 DOI: 10.1038/s41467-022-29496-x] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2021] [Accepted: 03/17/2022] [Indexed: 11/08/2022] Open
Abstract
The spinal cord accounts for the main communication pathway between the brain and the peripheral nervous system. Spinal cord injury is a devastating and largely irreversible neurological trauma, and can result in lifelong disability and paralysis with no available cure. In vivo spinal cord imaging in mouse models without introducing immunological artifacts is critical to understand spinal cord pathology and discover effective treatments. We developed a minimally invasive intervertebral window by retaining the ligamentum flavum to protect the underlying spinal cord. By introducing an optical clearing method, we achieve repeated two-photon fluorescence and stimulated Raman scattering imaging at subcellular resolution with up to 15 imaging sessions over 6-167 days and observe no inflammatory response. Using this optically cleared intervertebral window, we study neuron-glia dynamics following laser axotomy and observe strengthened contact of microglia with the nodes of Ranvier during axonal degeneration. By enabling long-term, repetitive, stable, high-resolution and inflammation-free imaging of mouse spinal cord, our method provides a reliable platform in the research aiming at interpretation of spinal cord physiology and pathology.
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3
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In vivo two-photon microscopic observation and ablation in deeper brain regions realized by modifications of excitation beam diameter and immersion liquid. PLoS One 2020; 15:e0237230. [PMID: 32764808 PMCID: PMC7413496 DOI: 10.1371/journal.pone.0237230] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2020] [Accepted: 07/21/2020] [Indexed: 02/06/2023] Open
Abstract
In vivo two-photon microscopy utilizing a nonlinear optical process enables, in living mouse brains, not only the visualization of morphologies and functions of neural networks in deep regions but also their optical manipulation at targeted sites with high spatial precision. Because the two-photon excitation efficiency is proportional to the square of the photon density of the excitation laser light at the focal position, optical aberrations induced by specimens mainly limit the maximum depth of observations or that of manipulations in the microscopy. To increase the two-photon excitation efficiency, we developed a method for evaluating the focal volume in living mouse brains. With this method, we modified the beam diameter of the excitation laser light and the value of the refractive index in the immersion liquid to maximize the excitation photon density at the focal position. These two modifications allowed the successful visualization of the finer structures of hippocampal CA1 neurons, as well as the intracellular calcium dynamics in cortical layer V astrocytes, even with our conventional two-photon microscopy system. Furthermore, it enabled focal laser ablation dissection of both single apical and single basal dendrites of cortical layer V pyramidal neurons. These simple modifications would enable us to investigate the contributions of single cells or single dendrites to the functions of local cortical networks.
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4
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Eversole D, Subramanian K, Harrison RK, Bourgeois F, Yuksel A, Ben-Yakar A. Femtosecond Plasmonic Laser Nanosurgery (fs-PLN) mediated by molecularly targeted gold nanospheres at ultra-low pulse fluences. Sci Rep 2020; 10:12387. [PMID: 32709944 PMCID: PMC7382507 DOI: 10.1038/s41598-020-68512-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2018] [Accepted: 06/25/2020] [Indexed: 12/16/2022] Open
Abstract
Plasmonic Laser Nanosurgery (PLN) is a novel photomodification technique that exploits the near-field enhancement of femtosecond (fs) laser pulses in the vicinity of gold nanoparticles. While prior studies have shown the advantages of fs-PLN to modify cells, further reduction in the pulse fluence needed to initiate photomodification is crucial to facilitate deep–tissue treatments. This work presents an in-depth study of fs-PLN at ultra-low pulse fluences using 47 nm gold nanoparticles, conjugated to antibodies that target the epithelial growth factor receptor and excited off-resonance using 760 nm, 270 fs laser pulses at 80 MHz repetition rate. We find that fs-PLN can optoporate cellular membranes with pulse fluences as low as 1.3 mJ/cm2, up to two orders of magnitude lower than those used at lower repetition rates. Our results, corroborated by simulations of free-electron generation by particle photoemission and photoionization of the surrounding water, shed light on the off-resonance fs-PLN mechanism. We suggest that photo-chemical pathways likely drive cellular optoporation and cell damage at these off-resonance, low fluence, and high repetition rate fs-laser pulses, with clusters acting as local concentrators of ROS generation. We believe that the low fluence and highly localized ROS-mediated fs-PLN approach will enable targeted therapeutics and cancer treatment.
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Affiliation(s)
- Daniel Eversole
- Biomedical Engineering, The University of Texas At Austin, Austin, TX, 78712, USA
| | - Kaushik Subramanian
- Mechanical Engineering, The University of Texas At Austin, Austin, TX, 78712, USA
| | - Rick K Harrison
- Mechanical Engineering, The University of Texas At Austin, Austin, TX, 78712, USA
| | - Frederic Bourgeois
- Mechanical Engineering, The University of Texas At Austin, Austin, TX, 78712, USA
| | - Anil Yuksel
- Mechanical Engineering, The University of Texas At Austin, Austin, TX, 78712, USA
| | - Adela Ben-Yakar
- Biomedical Engineering, The University of Texas At Austin, Austin, TX, 78712, USA. .,Mechanical Engineering, The University of Texas At Austin, Austin, TX, 78712, USA.
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5
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Park J, Papoutsi A, Ash RT, Marin MA, Poirazi P, Smirnakis SM. Contribution of apical and basal dendrites to orientation encoding in mouse V1 L2/3 pyramidal neurons. Nat Commun 2019; 10:5372. [PMID: 31772192 PMCID: PMC6879601 DOI: 10.1038/s41467-019-13029-0] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2018] [Accepted: 09/23/2019] [Indexed: 11/08/2022] Open
Abstract
Pyramidal neurons integrate synaptic inputs from basal and apical dendrites to generate stimulus-specific responses. It has been proposed that feed-forward inputs to basal dendrites drive a neuron's stimulus preference, while feedback inputs to apical dendrites sharpen selectivity. However, how a neuron's dendritic domains relate to its functional selectivity has not been demonstrated experimentally. We performed 2-photon dendritic micro-dissection on layer-2/3 pyramidal neurons in mouse primary visual cortex. We found that removing the apical dendritic tuft did not alter orientation-tuning. Furthermore, orientation-tuning curves were remarkably robust to the removal of basal dendrites: ablation of 2 basal dendrites was needed to cause a small shift in orientation preference, without significantly altering tuning width. Computational modeling corroborated our results and put limits on how orientation preferences among basal dendrites differ in order to reproduce the post-ablation data. In conclusion, neuronal orientation-tuning appears remarkably robust to loss of dendritic input.
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Affiliation(s)
- Jiyoung Park
- Brigham and Women's Hospital and Jamaica Plain VA Hospital, Harvard Medical School, Boston, MA, USA.
- Program in Structural and Computational Biology and Molecular Biophysics, Baylor College of Medicine, Houston, TX, USA.
| | - Athanasia Papoutsi
- Institute of Molecular Biology and Biotechnology (IMBB), Foundation of Research and Technology Hellas (FORTH), Vassilika Vouton, Heraklion, Crete, Greece
| | - Ryan T Ash
- Brigham and Women's Hospital and Jamaica Plain VA Hospital, Harvard Medical School, Boston, MA, USA
- Department of Neuroscience, Baylor College of Medicine, Houston, TX, USA
- Department of Psychiatry and Behavioral Sciences, Stanford University, Stanford, USA
| | - Miguel A Marin
- Department of Neuroscience, Baylor College of Medicine, Houston, TX, USA
- Department of Neurology, University of California, Los Angeles, USA
| | - Panayiota Poirazi
- Institute of Molecular Biology and Biotechnology (IMBB), Foundation of Research and Technology Hellas (FORTH), Vassilika Vouton, Heraklion, Crete, Greece.
| | - Stelios M Smirnakis
- Brigham and Women's Hospital and Jamaica Plain VA Hospital, Harvard Medical School, Boston, MA, USA.
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6
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Astrocytic endfeet re-cover blood vessels after removal by laser ablation. Sci Rep 2019; 9:1263. [PMID: 30718555 PMCID: PMC6362239 DOI: 10.1038/s41598-018-37419-4] [Citation(s) in RCA: 66] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2018] [Accepted: 12/03/2018] [Indexed: 11/08/2022] Open
Abstract
The astrocyte, one of the glial cells, plays many functional roles. These include provision of nutrients from blood vessels to neurons, supply of neurotransmitters and support of blood-brain barrier (BBB) integrity. Astrocytes are known to support the integrity of BBB through maintenance of the tight junction between endothelial cells of blood vessels. However, evidence of its direct contribution to BBB is lacking owing to technical limitations. In this study, astrocytic endfeet covering blood vessels were removed by the laser ablation method with two photon laser scanning microscopy in in vivo mouse brain, and the re-covering of blood vessels with the astrocytic endfeet was observed in about half of the cases. Blood vessels kept their integrity without astrocytic endfoot covers: leakage of plasma marker dyes, Evans Blue or dextran-conjugated fluorescein, was not observed from stripped blood vessels, while ablation of vascular walls induced extravasation of Evans Blue. These results suggest that the astrocytic endfeet covering blood vessels do not contribute to the immediate BBB barrier.
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7
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Functional imaging of visual cortical layers and subplate in awake mice with optimized three-photon microscopy. Nat Commun 2019; 10:177. [PMID: 30635577 PMCID: PMC6329792 DOI: 10.1038/s41467-018-08179-6] [Citation(s) in RCA: 90] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2018] [Accepted: 12/13/2018] [Indexed: 01/02/2023] Open
Abstract
Two-photon microscopy is used to image neuronal activity, but has severe limitations for studying deeper cortical layers. Here, we developed a custom three-photon microscope optimized to image a vertical column of the cerebral cortex > 1 mm in depth in awake mice with low (<20 mW) average laser power. Our measurements of physiological responses and tissue-damage thresholds define pulse parameters and safety limits for damage-free three-photon imaging. We image functional visual responses of neurons expressing GCaMP6s across all layers of the primary visual cortex (V1) and in the subplate. These recordings reveal diverse visual selectivity in deep layers: layer 5 neurons are more broadly tuned to visual stimuli, whereas mean orientation selectivity of layer 6 neurons is slightly sharper, compared to neurons in other layers. Subplate neurons, located in the white matter below cortical layer 6 and characterized here for the first time, show low visual responsivity and broad orientation selectivity. Two-photon microscopy is a powerful tool for studying neuronal activity but cannot easily image deeper cortical layers. Here, the authors design a custom microscope for three-photon microscopy and use it to reveal response properties of layer 5, 6, and subplate visual cortical neurons.
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8
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Siegerist F, Endlich K, Endlich N. Novel Microscopic Techniques for Podocyte Research. Front Endocrinol (Lausanne) 2018; 9:379. [PMID: 30050501 PMCID: PMC6050355 DOI: 10.3389/fendo.2018.00379] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/20/2018] [Accepted: 06/22/2018] [Indexed: 01/16/2023] Open
Abstract
Together with endothelial cells and the glomerular basement membrane, podocytes form the size-specific filtration barrier of the glomerulus with their interdigitating foot processes. Since glomerulopathies are associated with so-called foot process effacement-a severe change of well-formed foot processes into flat and broadened processes-visualization of the three-dimensional podocyte morphology is a crucial part for diagnosis of nephrotic diseases. However, interdigitating podocyte foot processes are too narrow to be resolved by classic light microscopy due to Ernst Abbe's law making electron microscopy necessary. Although three dimensional electron microscopy approaches like serial block face and focused ion beam scanning electron microscopy and electron tomography allow volumetric reconstruction of podocytes, these techniques are very time-consuming and too specialized for routine use or screening purposes. During the last few years, different super-resolution microscopic techniques were developed to overcome the optical resolution limit enabling new insights into podocyte morphology. Super-resolution microscopy approaches like three dimensional structured illumination microscopy (3D-SIM), stimulated emission depletion microscopy (STED) and localization microscopy [stochastic optical reconstruction microscopy (STORM), photoactivated localization microscopy (PALM)] reach resolutions down to 80-20 nm and can be used to image and further quantify podocyte foot process morphology. Furthermore, in vivo imaging of podocytes is essential to study the behavior of these cells in situ. Therefore, multiphoton laser microscopy was a breakthrough for in vivo studies of podocytes in transgenic animal models like rodents and zebrafish larvae because it allows imaging structures up to several hundred micrometer in depth within the tissue. Additionally, along with multiphoton microscopy, lightsheet microscopy is currently used to visualize larger tissue volumes and therefore image complete glomeruli in their native tissue context. Alongside plain visualization of cellular structures, atomic force microscopy has been used to study the change of mechanical properties of podocytes in diseased states which has been shown to be a culprit in podocyte maintenance. This review discusses recent advances in the field of microscopic imaging and demonstrates their currently used and other possible applications for podocyte research.
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Affiliation(s)
| | | | - Nicole Endlich
- Institute for Anatomy and Cell Biology, University Medicine Greifswald, Greifswald, Germany
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9
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Thompson-Peer KL, DeVault L, Li T, Jan LY, Jan YN. In vivo dendrite regeneration after injury is different from dendrite development. Genes Dev 2017; 30:1776-89. [PMID: 27542831 PMCID: PMC5002981 DOI: 10.1101/gad.282848.116] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2016] [Accepted: 07/25/2016] [Indexed: 12/22/2022]
Abstract
Thompson-Peer et al. show that, in intact Drosophila larvae, a discrete injury that removes all dendrites induces robust dendritic growth that recreates many features of uninjured dendrites. However, the growth and patterning of injury-induced dendrites is significantly different from uninjured dendrites. Neurons receive information along dendrites and send signals along axons to synaptic contacts. The factors that control axon regeneration have been examined in many systems, but dendrite regeneration has been largely unexplored. Here we report that, in intact Drosophila larvae, a discrete injury that removes all dendrites induces robust dendritic growth that recreates many features of uninjured dendrites, including the number of dendrite branches that regenerate and responsiveness to sensory stimuli. However, the growth and patterning of injury-induced dendrites is significantly different from uninjured dendrites. We found that regenerated arbors cover much less territory than uninjured neurons, fail to avoid crossing over other branches from the same neuron, respond less strongly to mechanical stimuli, and are pruned precociously. Finally, silencing the electrical activity of the neurons specifically blocks injury-induced, but not developmental, dendrite growth. By elucidating the essential features of dendrites grown in response to acute injury, our work builds a framework for exploring dendrite regeneration in physiological and pathological conditions.
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Affiliation(s)
- Katherine L Thompson-Peer
- Howard Hughes Medical Institute, Department of Physiology, Department of Biochemistry and Biophysics, University of California at San Francisco, San Francisco, California 94158, USA
| | - Laura DeVault
- Howard Hughes Medical Institute, Department of Physiology, Department of Biochemistry and Biophysics, University of California at San Francisco, San Francisco, California 94158, USA
| | - Tun Li
- Howard Hughes Medical Institute, Department of Physiology, Department of Biochemistry and Biophysics, University of California at San Francisco, San Francisco, California 94158, USA
| | - Lily Yeh Jan
- Howard Hughes Medical Institute, Department of Physiology, Department of Biochemistry and Biophysics, University of California at San Francisco, San Francisco, California 94158, USA
| | - Yuh Nung Jan
- Howard Hughes Medical Institute, Department of Physiology, Department of Biochemistry and Biophysics, University of California at San Francisco, San Francisco, California 94158, USA
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10
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Zhao Z, Chen S, Luo Y, Li J, Badea S, Ren C, Wu W. Time-lapse changes of in vivo injured neuronal substructures in the central nervous system after low energy two-photon nanosurgery. Neural Regen Res 2017; 12:751-756. [PMID: 28616030 PMCID: PMC5461611 DOI: 10.4103/1673-5374.206644] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
There is currently very little research regarding the dynamics of the subcellular degenerative events that occur in the central nervous system in response to injury. To date, multi-photon excitation has been primarily used for imaging applications; however, it has been recently used to selectively disrupt neural structures in living animals. However, understanding the complicated processes and the essential underlying molecular pathways involved in these dynamic events is necessary for studying the underlying process that promotes neuronal regeneration. In this study, we introduced a novel method allowing in vivo use of low energy (less than 30 mW) two-photon nanosurgery to selectively disrupt individual dendrites, axons, and dendritic spines in the murine brain and spinal cord to accurately monitor the time-lapse changes in the injured neuronal structures. Individual axons, dendrites, and dendritic spines in the brain and spinal cord were successfully ablated and in vivo imaging revealed the time-lapse alterations in these structures in response to the two-photon nanosurgery induced lesion. The energy (less than 30 mW) used in this study was very low and caused no observable additional damage in the neuronal sub-structures that occur frequently, especially in dendritic spines, with current commonly used methods using high energy levels. In addition, our approach includes the option of monitoring the time-varying dynamics to control the degree of lesion. The method presented here may be used to provide new insight into the growth of axons and dendrites in response to acute injury.
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Affiliation(s)
- Zhikai Zhao
- Guangdong-Hong Kong-Macau Institute of CNS Regeneration, Jinan University, Guangzhou, Guangdong Province, China
| | - Shuangxi Chen
- Guangdong-Hong Kong-Macau Institute of CNS Regeneration, Jinan University, Guangzhou, Guangdong Province, China
| | - Yunhao Luo
- School of Biomedical Sciences, Division of Anatomy, The University of Hong Kong, Pokfulam, Hong Kong Special Administrative Region, China
| | - Jing Li
- Guangdong-Hong Kong-Macau Institute of CNS Regeneration, Jinan University, Guangzhou, Guangdong Province, China
| | - Smaranda Badea
- School of Biomedical Sciences, Division of Anatomy, The University of Hong Kong, Pokfulam, Hong Kong Special Administrative Region, China
| | - Chaoran Ren
- Guangdong-Hong Kong-Macau Institute of CNS Regeneration, Jinan University, Guangzhou, Guangdong Province, China
| | - Wutian Wu
- Guangdong-Hong Kong-Macau Institute of CNS Regeneration, Jinan University, Guangzhou, Guangdong Province, China.,School of Biomedical Sciences, Division of Anatomy, The University of Hong Kong, Pokfulam, Hong Kong Special Administrative Region, China.,Guangdong Engineering Research Center of Stem Cell Storage and Clinical Application, Saliai Stem Cell Science and Technology, Guangzhou, Guangdong Province, China.,State Key Laboratory of Brain and Cognitive Sciences, The University of Hong Kong, Pokfulam, Hong Kong Special Administrative Region, China
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11
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Lefort C, O'Connor RP, Blanquet V, Magnol L, Kano H, Tombelaine V, Lévêque P, Couderc V, Leproux P. Multicolor multiphoton microscopy based on a nanosecond supercontinuum laser source. JOURNAL OF BIOPHOTONICS 2016; 9:709-14. [PMID: 26872004 DOI: 10.1002/jbio.201500283] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/23/2015] [Revised: 12/19/2015] [Accepted: 01/06/2016] [Indexed: 05/24/2023]
Abstract
Multicolor multiphoton microscopy is experimentally demonstrated for the first time on a spectral bandwidth of excitation of 300 nm (full width half maximum) thanks to the implementation a nanosecond supercontinuum (SC) source compact and simple with a low repetition rate. The interest of such a wide spectral bandwidth, never demonstrated until now, is highlighted in vivo: images of glioma tumor cells stably expressing eGFP grafted on the brain of a mouse and its blood vessels network labelled with Texas Red(®) are obtained. These two fluorophores have a spectral bandwidth covering the whole 300 nm available. In parallel, a similar image quality is obtained on a sample of mouse muscle in vitro when excited with this nanosecond SC source or with a classical high rate, femtosecond and quasi monochromatic laser. This opens the way for (i) a simple and very complete biological characterization never performed to date with multiphoton processes, (ii) multiple means of contrast in nonlinear imaging allowed by the use of numerous fluorophores and (iii) other multiphoton processes like three-photon ones.
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Affiliation(s)
- Claire Lefort
- Université de Limoges, CNRS UMR 7252, Labex "Sigma-Lim", INRA UMR 1061, F-87000, Limoges, France.
| | - Rodney P O'Connor
- Université de Limoges, CNRS UMR 7252, Labex "Sigma-Lim", INRA UMR 1061, F-87000, Limoges, France
| | - Véronique Blanquet
- Université de Limoges, CNRS UMR 7252, Labex "Sigma-Lim", INRA UMR 1061, F-87000, Limoges, France
| | - Laetitia Magnol
- Université de Limoges, CNRS UMR 7252, Labex "Sigma-Lim", INRA UMR 1061, F-87000, Limoges, France
| | - Hideaki Kano
- Institute of Applied Physics, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki, 305-8573, Japan
| | - Vincent Tombelaine
- LEUKOS Innovative Optical Systems, 37 rue Henri Giffard, Z.I. Nord, 87280, Limoges, France
| | - Philippe Lévêque
- Université de Limoges, CNRS UMR 7252, Labex "Sigma-Lim", INRA UMR 1061, F-87000, Limoges, France
| | - Vincent Couderc
- Université de Limoges, CNRS UMR 7252, Labex "Sigma-Lim", INRA UMR 1061, F-87000, Limoges, France
| | - Philippe Leproux
- Université de Limoges, CNRS UMR 7252, Labex "Sigma-Lim", INRA UMR 1061, F-87000, Limoges, France
- LEUKOS Innovative Optical Systems, 37 rue Henri Giffard, Z.I. Nord, 87280, Limoges, France
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12
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Targeted pruning of a neuron's dendritic tree via femtosecond laser dendrotomy. Sci Rep 2016; 6:19078. [PMID: 26739126 PMCID: PMC4703956 DOI: 10.1038/srep19078] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2015] [Accepted: 12/04/2015] [Indexed: 12/25/2022] Open
Abstract
Neurons are classified according to action potential firing in response to current injection. While such firing patterns are shaped by the composition and distribution of ion channels, modelling studies suggest that the geometry of dendritic branches also influences temporal firing patterns. Verifying this link is crucial to understanding how neurons transform their inputs to output but has so far been technically challenging. Here, we investigate branching-dependent firing by pruning the dendritic tree of pyramidal neurons. We use a focused ultrafast laser to achieve highly localized and minimally invasive cutting of dendrites, thus keeping the rest of the dendritic tree intact and the neuron functional. We verify successful dendrotomy via two-photon uncaging of neurotransmitters before and after dendrotomy at sites around the cut region and via biocytin staining. Our results show that significantly altering the dendritic arborisation, such as by severing the apical trunk, enhances excitability in layer V cortical pyramidal neurons as predicted by simulations. This method may be applied to the analysis of specific relationships between dendritic structure and neuronal function. The capacity to dynamically manipulate dendritic topology or isolate inputs from various dendritic domains can provide a fresh perspective on the roles they play in shaping neuronal output.
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13
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Jackson J, Canty AJ, Huang L, De Paola V. Laser-Mediated Microlesions in Mouse Neocortex to Investigate Neuronal Degeneration and Regeneration. ACTA ACUST UNITED AC 2015; 73:2.24.1-2.24.17. [PMID: 26426385 DOI: 10.1002/0471142301.ns0224s73] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
In vivo two-photon (2P) imaging enables neural circuitry to be repeatedly visualized in both normal conditions and following trauma. This protocol describes how laser-mediated neuronal microlesions can be created in the cerebral cortex using an ultrafast laser without causing a significant inflammatory reaction or compromising the blood-brain barrier. Furthermore, directives are provided for the acute and chronic in vivo imaging of the lesion site, as well as for post-hoc analysis of the lesion site in fixed tissue, which can be correlated with the live imaging phase.
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Affiliation(s)
- Johanna Jackson
- Lilly UK, Windlesham, United Kingdom.,These authors contributed equally to this work
| | - Alison J Canty
- Wicking Dementia Research and Education Centre, University of Tasmania, Hobart, Australia.,These authors contributed equally to this work
| | - Lieven Huang
- Australian Regenerative Medicine Institute, Monash University, Clayton, Australia
| | - Vincenzo De Paola
- MRC Clinical Sciences Centre, Imperial College London, London, United Kingdom
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14
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Lin CY, Li PK, Cheng LC, Li YC, Chang CY, Chiang AS, Dong CY, Chen SJ. High-throughput multiphoton-induced three-dimensional ablation and imaging for biotissues. BIOMEDICAL OPTICS EXPRESS 2015; 6:491-9. [PMID: 25780739 PMCID: PMC4354595 DOI: 10.1364/boe.6.000491] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/05/2014] [Revised: 12/22/2014] [Accepted: 12/22/2014] [Indexed: 05/23/2023]
Abstract
In this study, a temporal focusing-based high-throughput multiphoton-induced ablation system with axially-resolved widefield multiphoton excitation has been successfully applied to rapidly disrupt biotissues. Experimental results demonstrate that this technique features high efficiency for achieving large-area laser ablation without causing serious photothermal damage in non-ablated regions. Furthermore, the rate of tissue processing can reach around 1.6 × 10(6) μm(3)/s in chicken tendon. Moreover, the temporal focusing-based multiphoton system can be efficiently utilized in optical imaging through iterating high-throughput multiphoton-induced ablation machining followed by widefield optical sectioning; hence, it has the potential to obtain molecular images for a whole bio-specimen.
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Affiliation(s)
- Chun-Yu Lin
- Department of Engineering Science, National Cheng Kung University, Tainan 701,
Taiwan
| | - Pei-Kao Li
- Department of Engineering Science, National Cheng Kung University, Tainan 701,
Taiwan
| | - Li-Chung Cheng
- Department of Photonics, National Cheng Kung University, Tainan 701,
Taiwan
| | - Yi-Cheng Li
- Department of Photonics, National Cheng Kung University, Tainan 701,
Taiwan
| | - Chia-Yuan Chang
- Department of Photonics, National Cheng Kung University, Tainan 701,
Taiwan
| | - Ann-Shyn Chiang
- Brain Research Center, National Tsing Hua University, Hsinchu 300,
Taiwan
- Institute of Biotechnology and Department of Life Science, National Tsing Hua University, Hsinchu 300,
Taiwan
| | - Chen Yuan Dong
- Department of Physics, National Taiwan University, Taipei 106,
Taiwan
| | - Shean-Jen Chen
- Department of Engineering Science, National Cheng Kung University, Tainan 701,
Taiwan
- Center for Micro/Nano Science and Technology, National Cheng Kung University, Tainan 701,
Taiwan
- Advanced Optoelectronic Technology Center, National Cheng Kung University, Tainan 701,
Taiwan
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15
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Orzekowsky-Schroeder R, Klinger A, Freidank S, Linz N, Eckert S, Hüttmann G, Gebert A, Vogel A. Probing the immune and healing response of murine intestinal mucosa by time-lapse 2-photon microscopy of laser-induced lesions with real-time dosimetry. BIOMEDICAL OPTICS EXPRESS 2014; 5:3521-40. [PMID: 25360369 PMCID: PMC4206321 DOI: 10.1364/boe.5.003521] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/23/2014] [Revised: 09/02/2014] [Accepted: 09/02/2014] [Indexed: 05/13/2023]
Abstract
Gut mucosa is an important interface between body and environment. Immune response and healing processes of murine small intestinal mucosa were investigated by intravital time-lapse two-photon excited autofluorescence microscopy of the response to localized laser-induced damage. Epithelial lesions were created by 355-nm, 500-ps pulses from a microchip laser that produced minute cavitation bubbles. Size and dynamics of these bubbles were monitored using a novel interferometric backscattering technique with 80 nm resolution. Small bubbles (< 2.5 µm maximum radius) merely resulted in autofluorescence loss of the target cell. Larger bubbles (7-25 µm) affected several cells and provoked immigration of immune cells (polymorphonuclear leucocytes). Damaged cells were expelled into the lumen, and the epithelium healed within 2 hours by stretching and migration of adjacent epithelial cells.
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Affiliation(s)
- Regina Orzekowsky-Schroeder
- University of Lübeck, Institute of Biomedical Optics, Peter-Monnik-Weg 4, 23562 Lübeck, Germany
- Authors have contributed equally
| | - Antje Klinger
- University of Lübeck, Institute of Anatomy, Ratzeburger Allee 160, 23538 Lübeck, Germany
- Authors have contributed equally
| | - Sebastian Freidank
- University of Lübeck, Institute of Biomedical Optics, Peter-Monnik-Weg 4, 23562 Lübeck, Germany
| | - Norbert Linz
- University of Lübeck, Institute of Biomedical Optics, Peter-Monnik-Weg 4, 23562 Lübeck, Germany
| | - Sebastian Eckert
- University of Lübeck, Institute of Biomedical Optics, Peter-Monnik-Weg 4, 23562 Lübeck, Germany
| | - Gereon Hüttmann
- University of Lübeck, Institute of Biomedical Optics, Peter-Monnik-Weg 4, 23562 Lübeck, Germany
| | - Andreas Gebert
- University of Lübeck, Institute of Anatomy, Ratzeburger Allee 160, 23538 Lübeck, Germany
- present address: University of Jena, Institute of Anatomy II, 07740 Jena, Germany
| | - Alfred Vogel
- University of Lübeck, Institute of Biomedical Optics, Peter-Monnik-Weg 4, 23562 Lübeck, Germany
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16
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Yuryev M, Molotkov D, Khiroug L. In vivo two-photon microscopy of single nerve endings in skin. J Vis Exp 2014. [PMID: 25178088 DOI: 10.3791/51045] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
Nerve endings in skin are involved in physiological processes such as sensing(1) as well as in pathological processes such as neuropathic pain(2). Their close-to-surface positioning facilitates microscopic imaging of skin nerve endings in living intact animal. Using multiphoton microscopy, it is possible to obtain fine images overcoming the problem of strong light scattering of the skin tissue. Reporter transgenic mice that express EYFP under the control of Thy-1 promoter in neurons (including periphery sensory neurons) are well suited for the longitudinal studies of individual nerve endings over extended periods of time up to several months or even life-long. Furthermore, using the same femtosecond laser as for the imaging, it is possible to produce highly selective lesions of nerve fibers for the studies of the nerve fiber restructuring. Here, we present a simple and reliable protocol for longitudinal multiphoton in vivo imaging and laser-based microsurgery on mouse skin nerve endings.
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17
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Abstract
Only a few neuronal populations in the central nervous system (CNS) of adult mammals show local regrowth upon dissection of their axon. In order to understand the mechanism that promotes neuronal regeneration, an in-depth analysis of the neuronal types that can remodel after injury is needed. Several studies showed that damaged climbing fibers are capable of regrowing also in adult animals. The investigation of the time-lapse dynamics of degeneration and regeneration of these axons within their complex environment can be performed by time-lapse two-photon fluorescence (TPF) imaging in vivo. This technique is here combined with laser surgery, which proved to be a highly selective tool to disrupt fluorescent structures in the intact mouse cortex. This protocol describes how to perform TPF time-lapse imaging and laser nanosurgery of single axonal branches in the cerebellum in vivo. Olivocerebellar neurons are labeled by anterograde tracing with a dextran-conjugated dye and then monitored by TPF imaging through a cranial window. The terminal portion of their axons are then dissected by irradiation with a Ti:Sapphire laser at high power. The degeneration and potential regrowth of the damaged neuron are monitored by TPF in vivo imaging during the days following the injury.
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Affiliation(s)
| | - Leonardo Sacconi
- European Laboratory for Non-Linear Spectroscopy, University of Florence; National Institute of Optics, National Research Council
| | - Francesco Saverio Pavone
- European Laboratory for Non-Linear Spectroscopy, University of Florence; National Institute of Optics, National Research Council; Department of Physics and Astronomy, University of Florence; International Center for Computational Neurophotonics (ICON Foundation)
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18
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Holtmaat A, Randall J, Cane M. Optical imaging of structural and functional synaptic plasticity in vivo. Eur J Pharmacol 2013; 719:128-136. [DOI: 10.1016/j.ejphar.2013.07.020] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2013] [Accepted: 07/11/2013] [Indexed: 12/13/2022]
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19
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Silvestri L, Allegra Mascaro AL, Costantini I, Sacconi L, Pavone FS. Correlative two-photon and light sheet microscopy. Methods 2013; 66:268-72. [PMID: 23806642 DOI: 10.1016/j.ymeth.2013.06.013] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2013] [Revised: 06/13/2013] [Accepted: 06/14/2013] [Indexed: 10/26/2022] Open
Abstract
Information processing inside the central nervous system takes place on multiple scales in both space and time. A single imaging technique can reveal only a small part of this complex machinery. To obtain a more comprehensive view of brain functionality, complementary approaches should be combined into a correlative framework. Here, we describe a method to integrate data from in vivo two-photon fluorescence imaging and ex vivo light sheet microscopy, taking advantage of blood vessels as reference chart. We show how the apical dendritic arbor of a single cortical pyramidal neuron imaged in living thy1-GFP-M mice can be found in the large-scale brain reconstruction obtained with light sheet microscopy. Starting from the apical portion, the whole pyramidal neuron can then be segmented. The correlative approach presented here allows contextualizing within a three-dimensional anatomic framework the neurons whose dynamics have been observed with high detail in vivo.
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Affiliation(s)
- Ludovico Silvestri
- European Laboratory for Non-Linear Spectroscopy, University of Florence, Italy
| | | | - Irene Costantini
- European Laboratory for Non-Linear Spectroscopy, University of Florence, Italy
| | - Leonardo Sacconi
- National Institute of Optics, National Research Council, Sesto Fiorentino, Italy; European Laboratory for Non-Linear Spectroscopy, University of Florence, Italy
| | - Francesco Saverio Pavone
- European Laboratory for Non-Linear Spectroscopy, University of Florence, Italy; National Institute of Optics, National Research Council, Sesto Fiorentino, Italy; Department of Physics and Astronomy, University of Florence, Italy; International Center for Computational Neurophotonics (ICON Foundation), Sesto Fiorentino, Italy.
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20
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In vivo single branch axotomy induces GAP-43-dependent sprouting and synaptic remodeling in cerebellar cortex. Proc Natl Acad Sci U S A 2013; 110:10824-9. [PMID: 23754371 DOI: 10.1073/pnas.1219256110] [Citation(s) in RCA: 86] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Plasticity in the central nervous system in response to injury is a complex process involving axonal remodeling regulated by specific molecular pathways. Here, we dissected the role of growth-associated protein 43 (GAP-43; also known as neuromodulin and B-50) in axonal structural plasticity by using, as a model, climbing fibers. Single axonal branches were dissected by laser axotomy, avoiding collateral damage to the adjacent dendrite and the formation of a persistent glial scar. Despite the very small denervated area, the injured axons consistently reshape the connectivity with surrounding neurons. At the same time, adult climbing fibers react by sprouting new branches through the intact surroundings. Newly formed branches presented varicosities, suggesting that new axons were more than just exploratory sprouts. Correlative light and electron microscopy reveals that the sprouted branch contains large numbers of vesicles, with varicosities in the close vicinity of Purkinje dendrites. By using an RNA interference approach, we found that downregulating GAP-43 causes a significant increase in the turnover of presynaptic boutons. In addition, silencing hampers the generation of reactive sprouts. Our findings show the requirement of GAP-43 in sustaining synaptic stability and promoting the initiation of axonal regrowth.
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21
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Cell signaling experiments driven by optical manipulation. Int J Mol Sci 2013; 14:8963-84. [PMID: 23698758 PMCID: PMC3676767 DOI: 10.3390/ijms14058963] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2013] [Revised: 04/08/2013] [Accepted: 04/14/2013] [Indexed: 01/09/2023] Open
Abstract
Cell signaling involves complex transduction mechanisms in which information released by nearby cells or extracellular cues are transmitted to the cell, regulating fundamental cellular activities. Understanding such mechanisms requires cell stimulation with precise control of low numbers of active molecules at high spatial and temporal resolution under physiological conditions. Optical manipulation techniques, such as optical tweezing, mechanical stress probing or nano-ablation, allow handling of probes and sub-cellular elements with nanometric and millisecond resolution. PicoNewton forces, such as those involved in cell motility or intracellular activity, can be measured with femtoNewton sensitivity while controlling the biochemical environment. Recent technical achievements in optical manipulation have new potentials, such as exploring the actions of individual molecules within living cells. Here, we review the progress in optical manipulation techniques for single-cell experiments, with a focus on force probing, cell mechanical stimulation and the local delivery of active molecules using optically manipulated micro-vectors and laser dissection.
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22
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Laperchia C, Allegra Mascaro AL, Sacconi L, Andrioli A, Mattè A, De Franceschi L, Grassi-Zucconi G, Bentivoglio M, Buffelli M, Pavone FS. Two-photon microscopy imaging of thy1GFP-M transgenic mice: a novel animal model to investigate brain dendritic cell subsets in vivo. PLoS One 2013; 8:e56144. [PMID: 23409142 PMCID: PMC3567047 DOI: 10.1371/journal.pone.0056144] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2012] [Accepted: 01/07/2013] [Indexed: 12/23/2022] Open
Abstract
Transgenic mice expressing fluorescent proteins in specific cell populations are widely used for in vivo brain studies with two-photon fluorescence (TPF) microscopy. Mice of the thy1GFP-M line have been engineered for selective expression of green fluorescent protein (GFP) in neuronal populations. Here, we report that TPF microscopy reveals, at the brain surface of these mice, also motile non-neuronal GFP+ cells. We have analyzed the behavior of these cells in vivo and characterized in brain sections their immunophenotype. With TPF imaging, motile GFP+ cells were found in the meninges, subarachnoid space and upper cortical layers. The striking feature of these cells was their ability to move across the brain parenchyma, exhibiting evident shape changes during their scanning-like motion. In brain sections, GFP+ cells were immunonegative to antigens recognizing motile cells such as migratory neuroblasts, neuronal and glial precursors, mast cells, and fibroblasts. GFP+ non-neuronal cells exhibited instead the characteristic features and immunophenotype (CD11c and major histocompatibility complex molecule class II immunopositivity) of dendritic cells (DCs), and were immunonegative to the microglial marker Iba-1. GFP+ cells were also identified in lymph nodes and blood of thy1GFP-M mice, supporting their identity as DCs. Thus, TPF microscopy has here allowed the visualization for the first time of the motile behavior of brain DCs in situ. The results indicate that the thy1GFP-M mouse line provides a novel animal model for the study of subsets of these professional antigen-presenting cells in the brain. Information on brain DCs is still very limited and imaging in thy1GFP-M mice has a great potential for analyses of DC-neuron interaction in normal and pathological conditions.
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Affiliation(s)
- Claudia Laperchia
- Department of Neurological Sciences, University of Verona, Verona, Italy
- National Institute of Neuroscience, Verona, Italy
| | - Anna L. Allegra Mascaro
- European Laboratory of Non-Linear Spectroscopy, University of Florence, Sesto Fiorentino, Italy
| | - Leonardo Sacconi
- European Laboratory of Non-Linear Spectroscopy, University of Florence, Sesto Fiorentino, Italy
- National Institute of Optics, National Research Council, Florence, Italy
| | - Anna Andrioli
- Department of Neurological Sciences, University of Verona, Verona, Italy
- National Institute of Neuroscience, Verona, Italy
| | | | | | - Gigliola Grassi-Zucconi
- Department of Neurological Sciences, University of Verona, Verona, Italy
- National Institute of Neuroscience, Verona, Italy
| | - Marina Bentivoglio
- Department of Neurological Sciences, University of Verona, Verona, Italy
- National Institute of Neuroscience, Verona, Italy
| | - Mario Buffelli
- Department of Neurological Sciences, University of Verona, Verona, Italy
- National Institute of Neuroscience, Verona, Italy
- Center for Biomedical Computing, University of Verona, Verona, Italy
- * E-mail:
| | - Francesco S. Pavone
- European Laboratory of Non-Linear Spectroscopy, University of Florence, Sesto Fiorentino, Italy
- National Institute of Optics, National Research Council, Florence, Italy
- Department of Physics, University of Florence, Sesto Fiorentino, Italy
- International Center of Computational Neurophotonics, Sesto Fiorentino, Italy
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23
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Uchugonova A, Lessel M, Nietzsche S, Zeitz C, Jacobs K, Lemke C, König K. Nanosurgery of cells and chromosomes using near-infrared twelve-femtosecond laser pulses. JOURNAL OF BIOMEDICAL OPTICS 2012; 17:101502. [PMID: 23223978 DOI: 10.1117/1.jbo.17.10.101502] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
ABSTRACT. Laser-assisted surgery based on multiphoton absorption of near-infrared laser light has great potential for high precision surgery at various depths within the cells and tissues. Clinical applications include refractive surgery (fs-LASIK). The non-contact laser method also supports contamination-free cell nanosurgery. In this paper we describe usage of an ultrashort femtosecond laser scanning microscope for sub-100 nm surgery of human cells and metaphase chromosomes. A mode-locked 85 MHz Ti:Sapphire laser with an M-shaped ultrabroad band spectrum (maxima: 770 nm/830 nm) and an in situ pulse duration at the target ranging from 12 fs up to 3 ps was employed. The effects of laser nanoprocessing in cells and chromosomes have been quantified by atomic force microscopy. These studies demonstrate the potential of extreme ultrashort femtosecond laser pulses at low mean milliwatt powers for sub-100 nm surgery of cells and cellular organelles.
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Affiliation(s)
- Aisada Uchugonova
- Department of Biophotonics and Laser Technology, Saarland University, Campus A51, 66123 Saarbruecken, Germany.
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24
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Yuryev M, Khiroug L. Dynamic longitudinal investigation of individual nerve endings in the skin of anesthetized mice using in vivo two-photon microscopy. JOURNAL OF BIOMEDICAL OPTICS 2012; 17:046007. [PMID: 22559685 DOI: 10.1117/1.jbo.17.4.046007] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Visualization of individual cutaneous nerve endings has previously relied on laborious procedures of tissue excision, fixation, sectioning and staining for light or electron microscopy. We present a method for non-invasive, longitudinal two-photon microscopy of single nerve endings within the skin of anesthetized transgenic mice. Besides excellent signal-to-background ratio and nanometer-scale spatial resolution, this method offers time-lapse "movies" of pathophysiological changes in nerve fine structure over minutes, hours, days or weeks. Structure of keratinocytes and dermal matrix is visualized simultaneously with nerve endings, providing clear landmarks for longitudinal analysis. We further demonstrate feasibility of dissecting individual nerve fibers with infra-red laser and monitoring their degradation and regeneration. In summary, our excision-free optical biopsy technique is ideal for longitudinal microscopic analysis of animal skin and skin innervations in vivo and can be applied widely in preclinical models of chronic pain, allergies, skin cancers and a variety of dermatological disorders.
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Affiliation(s)
- Mikhail Yuryev
- University of Helsinki, Neuroscience Center, Viikinkaari 4, 00790 Helsinki, Finland
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25
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Yavaş S, Erdogan M, Gürel K, Ilday FÖ, Eldeniz YB, Tazebay UH. Fiber laser-microscope system for femtosecond photodisruption of biological samples. BIOMEDICAL OPTICS EXPRESS 2012; 3:605-11. [PMID: 22435105 PMCID: PMC3296545 DOI: 10.1364/boe.3.000605] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/24/2012] [Revised: 02/14/2012] [Accepted: 02/14/2012] [Indexed: 05/17/2023]
Abstract
We report on the development of a ultrafast fiber laser-microscope system for femtosecond photodisruption of biological targets. A mode-locked Yb-fiber laser oscillator generates few-nJ pulses at 32.7 MHz repetition rate, amplified up to ∼125 nJ at 1030 nm. Following dechirping in a grating compressor, ∼240 fs-long pulses are delivered to the sample through a diffraction-limited microscope, which allows real-time imaging and control. The laser can generate arbitrary pulse patterns, formed by two acousto-optic modulators (AOM) controlled by a custom-developed field-programmable gate array (FPGA) controller. This capability opens the route to fine optimization of the ablation processes and management of thermal effects. Sample position, exposure time and imaging are all computerized. The capability of the system to perform femtosecond photodisruption is demonstrated through experiments on tissue and individual cells.
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Affiliation(s)
- Seydi Yavaş
- Institute of Materials Science and Nanotechnology, Bilkent University, Ankara,
Turkey 06800
| | - Mutlu Erdogan
- Institute of Materials Science and Nanotechnology, Bilkent University, Ankara,
Turkey 06800
| | - Kutan Gürel
- Department of Physics, Bilkent University, Ankara,
Turkey 06800
| | - F. Ömer Ilday
- Department of Physics, Bilkent University, Ankara,
Turkey 06800
| | - Y. Burak Eldeniz
- Electronics Engineering Department, Ankara University, Ankara,
Turkey 06100
| | - Uygar H. Tazebay
- Department of Molecular Biology and Genetics, Bilkent University, Ankara,
Turkey 06800
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26
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Jeong D, Tsai PS, Kleinfeld D. Prospect for feedback guided surgery with ultra-short pulsed laser light. Curr Opin Neurobiol 2012; 22:24-33. [PMID: 22088392 PMCID: PMC3763077 DOI: 10.1016/j.conb.2011.10.020] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2011] [Revised: 10/20/2011] [Accepted: 10/24/2011] [Indexed: 11/29/2022]
Abstract
The controlled cutting of tissue with laser light is a natural technology to combine with automated stereotaxic surgery. A central challenge is to cut hard tissue, such as bone, without inducing damage to juxtaposed soft tissue, such as nerve and dura. We review past work that demonstrates the feasibility of such control through the use of ultrafast laser light to both cut and generate optical feedback signals via second harmonic generation and laser induced plasma spectra.
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Affiliation(s)
- Diana Jeong
- Department of Physics, University of California at San Diego, La Jolla, CA
| | - Philbert S. Tsai
- Department of Physics, University of California at San Diego, La Jolla, CA
| | - David Kleinfeld
- Department of Physics, University of California at San Diego, La Jolla, CA
- Section of Neurobiology, University of California at San Diego, La Jolla, CA
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27
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Nguyen J, Ferdman J, Zhao M, Huland D, Saqqa S, Ma J, Nishimura N, Schwartz TH, Schaffer CB. Sub-surface, micrometer-scale incisions produced in rodent cortex using tightly-focused femtosecond laser pulses. Lasers Surg Med 2012; 43:382-91. [PMID: 21674543 DOI: 10.1002/lsm.21054] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
BACKGROUND AND OBJECTIVE Techniques that allow targeted, micrometer-scale disruption in the depths of biological tissue, without affecting overlying structures or causing significant collateral damage, could potentially lead to new surgical procedures. We describe an optical technique to make sub-surface incisions in in vivo rodent brain and characterize the relationship between the cut width and maximum depth of these optical transections as a function of laser energy. MATERIALS AND METHODS To produce cuts, high intensity, femtosecond laser pulses were tightly focused into and translated within the cortex, through a craniotomy, in anesthetized rodents. Imaging of stained brain slices was used to characterize cut width and maximum cutting depth. RESULTS Cut width decreased exponentially as a function of depth and increased as the cube root of laser energy, but showed about 50% variation at fixed depth and laser energy. For example, at a laser energy of 13 µJ, cut width decreased from 158 ± 43.1 µm (mean ± standard deviation) to 56 ± 33 µm over depths of approximately 200-800 µm, respectively. Maximal cut depth increased logarithmically with laser energy, with cut depths of up to 1 mm achieved with 13 µJ pulses. We further showcased this technique by selectively cutting sub-surface cortical dendrites in a live, anesthetized transgenic mouse. CONCLUSIONS Femtosecond laser pulses provide the novel capacity for precise, sub-surface, cellular-scale cuts for surgical applications in optically scattering tissues.
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Affiliation(s)
- John Nguyen
- Department of Biomedical Engineering, Cornell University, Ithaca, New York 14853, USA
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28
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Maghelli N, Tolić-Nørrelykke IM. Laser ablation of the microtubule cytoskeleton: setting up and working with an ablation system. Methods Mol Biol 2011; 777:261-71. [PMID: 21773935 DOI: 10.1007/978-1-61779-252-6_19] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Laser ablation is a powerful tool that can be used to study a variety of biological mechanisms. Microscopes with high optical performances are nowadays available, and lasers that could be used to perform ablations have become accessible to every laboratory. Setting up a laser ablation system is a relatively straightforward task; however, it requires some basic knowledge of optics. We illustrate the fundamental components of the experimental setup and describe the most common pitfalls and difficulties encountered when designing, setting up, and working with a laser ablation system.
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Affiliation(s)
- Nicola Maghelli
- Max Planck Institute of Molecular Cell Biology and Genetics, Dresden, Germany.
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29
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Kuetemeyer K, Rezgui R, Lubatschowski H, Heisterkamp A. Influence of laser parameters and staining on femtosecond laser-based intracellular nanosurgery. BIOMEDICAL OPTICS EXPRESS 2010; 1:587-597. [PMID: 21258492 PMCID: PMC3017989 DOI: 10.1364/boe.1.000587] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/22/2010] [Revised: 08/05/2010] [Accepted: 08/05/2010] [Indexed: 05/19/2023]
Abstract
Femtosecond (fs) laser-based intracellular nanosurgery has become an important tool in cell biology, albeit the mechanisms in the so-called low-density plasma regime are largely unknown. Previous calculations of free-electron densities for intracellular surgery used water as a model substance for biological media and neglected the presence of dye and biomolecules. In addition, it is still unclear on which time scales free-electron and free-radical induced chemical effects take place in a cellular environment. Here, we present our experimental study on the influence of laser parameters and staining on the intracellular ablation threshold in the low-density plasma regime. We found that the ablation effect of fs laser pulse trains resulted from the accumulation of single-shot multiphoton-induced photochemical effects finished within a few nanoseconds. At the threshold, the number of applied pulses was inversely proportional to a higher order of the irradiance, depending on the laser repetition rate and wavelength. Furthermore, fluorescence staining of subcellular structures before surgery significantly decreased the ablation threshold. Based on our findings, we propose that dye molecules are the major source for providing seed electrons for the ionization cascade. Consequently, future calculations of free-electron densities for intracellular nanosurgery have to take them into account, especially in the calculations of multiphoton ionization rates.
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Affiliation(s)
| | - R. Rezgui
- Laser Zentrum Hannover e.V., Hollerithallee 8, 30419
Hannover, Germany
| | - H. Lubatschowski
- Laser Zentrum Hannover e.V., Hollerithallee 8, 30419
Hannover, Germany
| | - A. Heisterkamp
- Laser Zentrum Hannover e.V., Hollerithallee 8, 30419
Hannover, Germany
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30
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Zarbin MA, Montemagno C, Leary JF, Ritch R. Nanomedicine in ophthalmology: the new frontier. Am J Ophthalmol 2010; 150:144-162.e2. [PMID: 20670739 DOI: 10.1016/j.ajo.2010.03.019] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2009] [Revised: 03/09/2010] [Accepted: 03/10/2010] [Indexed: 12/23/2022]
Abstract
PURPOSE To review the fields of nanotechnology and nanomedicine as they relate to the development of treatments for vision-threatening disorders. DESIGN Perspective following literature review. METHODS Analysis of relevant publications in the peer-reviewed scientific literature. RESULTS Nanotechnology involves the creation and use of materials and devices at the size scale of intracellular structures and molecules and involves systems and constructs on the order of <100 nm. The aim of nanomedicine is the comprehensive monitoring, control, construction, repair, defense, and improvement of human biological systems at the molecular level, using engineered nanodevices and nanostructures, operating massively in parallel at the single cell level, ultimately to achieve medical benefit. The earliest impact of nanomedicine is likely to involve the areas of biopharmaceuticals (eg, drug delivery, drug discovery), implantable materials (eg, tissue regeneration scaffolds, bioresorbable materials), implantable devices (eg, intraocular pressure monitors, glaucoma drainage valves), and diagnostic tools (eg, genetic testing, imaging, intraocular pressure monitoring). Nanotechnology will bring about the development of regenerative medicine (ie, replacement and improvement of cells, tissues, and organs), ultrahigh-resolution in vivo imaging, microsensors and feedback devices, and artificial vision. "Regenerative nanomedicine," a new subfield of nanomedicine, uses nanoparticles containing gene transcription factors and other modulating molecules that allow for the reprogramming of cells in vivo. CONCLUSIONS Nanotechnology already has been applied to the measurement and treatment of different disease states in ophthalmology (including early- and late-stage disease), and many additional innovations will occur during the next century.
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31
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Allegra Mascaro AL, Sacconi L, Pavone FS. Multi-photon nanosurgery in live brain. FRONTIERS IN NEUROENERGETICS 2010; 2. [PMID: 20725602 PMCID: PMC2922942 DOI: 10.3389/fnene.2010.00021] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/26/2010] [Accepted: 07/05/2010] [Indexed: 11/13/2022]
Abstract
In the last few years two-photon microscopy has been used to perform in vivo high spatial resolution imaging of neurons, glial cells and vascular structures in the intact neocortex. Recently, in parallel to its applications in imaging, multi-photon absorption has been used as a tool for the selective disruption of neural processes and blood vessels in living animals. In this review we present some basic features of multi-photon nanosurgery and we illustrate the advantages offered by this novel methodology in neuroscience research. We show how the spatial localization of multi-photon excitation can be exploited to perform selective lesions on cortical neurons in living mice expressing fluorescent proteins. This methodology is applied to disrupt a single neuron without causing any visible collateral damage to the surrounding structures. The spatial precision of this method allows to dissect single processes as well as individual dendritic spines, preserving the structural integrity of the main neuronal arbor. The same approach can be used to breach the blood-brain barrier through a targeted photo-disruption of blood vessels walls. We show how the vascular system can be perturbed through laser ablation leading toward two different models of stroke: intravascular clot and extravasation. Following the temporal evolution of the injured system (either a neuron or a blood vessel) through time lapse in vivo imaging, the physiological response of the target structure and the rearrangement of the surrounding area can be characterized. Multi-photon nanosurgery in live brain represents a useful tool to produce different models of neurodegenerative disease.
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Mapping of fluorescent protein-expressing neurons and axon pathways in adult and developing Thy1-eYFP-H transgenic mice. Brain Res 2010; 1345:59-72. [DOI: 10.1016/j.brainres.2010.05.061] [Citation(s) in RCA: 131] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2010] [Revised: 05/19/2010] [Accepted: 05/19/2010] [Indexed: 11/21/2022]
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Zhao Y, Zhang Y, Zhou W, Liu X, Zeng S, Luo Q. Characteristics of calcium signaling in astrocytes induced by photostimulation with femtosecond laser. JOURNAL OF BIOMEDICAL OPTICS 2010; 15:035001. [PMID: 20615001 DOI: 10.1117/1.3454390] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
Astrocytes have been identified to actively contribute to brain functions through Ca(2+) signaling, serving as a bridge to communicate with neurons and other brain cells. However, conventional stimulation techniques are hard to apply to delicate investigations on astrocytes. Our group previously reported photostimulation with a femtosecond laser to evoke astrocytic calcium (Ca(2+)) waves, providing a noninvasive and efficient approach with highly precise targeting. In this work, detailed characteristics of astrocytic Ca(2+) signaling induced by photostimulation are presented. In a purified astrocytic culture, after the illumination of a femtosecond laser onto one cell, a Ca(2+) wave throughout the network with reduced speed is induced, and intracellular Ca(2+) oscillations are observed. The intercellular propagation is pharmacologically confirmed to be mainly mediated by ATP through P(2)Y receptors. Different patterns of Ca(2+) elevations with increased amplitude in the stimulated astrocyte are discovered by varying the femtosecond laser power, which is correspondingly followed by broader intercellular waves. These indicate that the strength of photogenerated Ca(2+) signaling in astrocytes has a positive relationship with the stimulating laser power. Therefore, distinct Ca(2+) signaling is feasibly available for specific studies on astrocytes by employing precisely controlled photostimulation.
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Affiliation(s)
- Yuan Zhao
- Huazhong University of Science and Technology, Wuhan National Laboratory for Optoelectronics, Britton Chance Center for Biomedical Photonics, Wuhan 430074, China
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Maghelli N, Tolić-Nørrelykke IM. Optical trapping and laser ablation of microtubules in fission yeast. Methods Cell Biol 2010; 97:173-83. [PMID: 20719271 DOI: 10.1016/s0091-679x(10)97010-6] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Manipulation has been used as a powerful investigation technique since the early history of biology. Every technical advance resulted in more refined instruments that led to the discovery of new phenomena and to the solution of old problems. The invention of laser in 1960 gave birth to what is now called optical manipulation: the use of light to interact with matter. Since then, the tremendous progress of laser technology made optical manipulation not only an affordable, reliable alternative to traditional manipulation techniques but disclosed also new, intriguing applications that were previously impossible, such as contact-free manipulation. Currently, optical manipulation is used in many fields, yet has the potential of becoming an everyday technique in a broader variety of contexts. Here, we focus on two main optical manipulation techniques: optical trapping and laser ablation. We illustrate with selected applications in fission yeast how in vivo optical manipulation can be used to study organelle positioning and the force balance in the microtubule cytoskeleton.
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Affiliation(s)
- Nicola Maghelli
- Max Planck Institute of Molecular Cell Biology and Genetics (MPI-CBG), 01307 Dresden, Germany
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35
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Ben-Yakar A, Bourgeois F. Ultrafast laser nanosurgery in microfluidics for genome-wide screenings. Curr Opin Biotechnol 2009; 20:100-5. [PMID: 19278850 DOI: 10.1016/j.copbio.2009.01.008] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2008] [Revised: 01/29/2009] [Accepted: 01/29/2009] [Indexed: 10/21/2022]
Abstract
The use of ultrafast laser pulses in surgery has allowed for unprecedented precision with minimal collateral damage to surrounding tissues. For these reasons, ultrafast laser nanosurgery, as an injury model, has gained tremendous momentum in experimental biology ranging from in vitro manipulations of subcellular structures to in vivo studies in whole living organisms. For example, femtosecond laser nanosurgery on such model organism as the nematode Caenorhabditis elegans has opened new opportunities for in vivo nerve regeneration studies. Meanwhile, the development of novel microfluidic devices has brought the control in experimental environment to the level required for precise nanosurgery in various animal models. Merging microfluidics and laser nanosurgery has recently improved the specificities and increased the speed of laser surgeries enabling fast genome-wide screenings that can more readily decode the genetic map of various biological processes.
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Affiliation(s)
- Adela Ben-Yakar
- Department of Mechanical Engineering, The University of Texas at Austin, Austin, TX 78712, USA.
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O'Brien GS, Rieger S, Martin SM, Cavanaugh AM, Portera-Cailliau C, Sagasti A. Two-photon axotomy and time-lapse confocal imaging in live zebrafish embryos. J Vis Exp 2009:1129. [PMID: 19229185 PMCID: PMC2726581 DOI: 10.3791/1129] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022] Open
Abstract
Zebrafish have long been utilized to study the cellular and molecular mechanisms of development by time-lapse imaging of the living transparent embryo. Here we describe a method to mount zebrafish embryos for long-term imaging and demonstrate how to automate the capture of time-lapse images using a confocal microscope. We also describe a method to create controlled, precise damage to individual branches of peripheral sensory axons in zebrafish using the focused power of a femtosecond laser mounted on a two-photon microscope. The parameters for successful two-photon axotomy must be optimized for each microscope. We will demonstrate two-photon axotomy on both a custom built two-photon microscope and a Zeiss 510 confocal/two-photon to provide two examples. Zebrafish trigeminal sensory neurons can be visualized in a transgenic line expressing GFP driven by a sensory neuron specific promoter (1). We have adapted this zebrafish trigeminal model to directly observe sensory axon regeneration in living zebrafish embryos. Embryos are anesthetized with tricaine and positioned within a drop of agarose as it solidifies. Immobilized embryos are sealed within an imaging chamber filled with phenylthiourea (PTU) Ringers. We have found that embryos can be continuously imaged in these chambers for 12-48 hours. A single confocal image is then captured to determine the desired site of axotomy. The region of interest is located on the two-photon microscope by imaging the sensory axons under low, non-damaging power. After zooming in on the desired site of axotomy, the power is increased and a single scan of that defined region is sufficient to sever the axon. Multiple location time-lapse imaging is then set up on a confocal microscope to directly observe axonal recovery from injury.
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Affiliation(s)
- Georgeann S O'Brien
- Department of Molecular Cell and Developmental Biology, University of California, Los Angeles, USA.
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37
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Zhao Y, Zhang Y, Liu X, Lv X, Zhou W, Luo Q, Zeng S. Photostimulation of astrocytes with femtosecond laser pulses. OPTICS EXPRESS 2009; 17:1291-1298. [PMID: 19188957 DOI: 10.1364/oe.17.001291] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
The involvement of astrocytes in brain functions rather than support has been identified and widely concerned. However the lack of an effective stimulation of astrocytes hampers our understanding of their essential roles. Here, we employed 800-nm near infrared (NIR) femtosecond laser to induce Ca2+ wave in astrocytes. It was demonstrated that photostimulation of astrocytes with femtosecond laser pulses is efficient with the advantages of non-contact, non-disruptiveness, reproducibility, and high spatiotemporal precision. Photostimulation of astrocytes would facilitate investigations on information processing in neuronal circuits by providing effective way to excite astrocytes.
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Affiliation(s)
- Yuan Zhao
- Britton Chance Center for Biomedical Photonics, Wuhan National Laboratory for Optoelectronics, Department of Biomedical Engineering, Huazhong University of Science & Technology, Wuhan, China
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Tsai PS, Blinder P, Migliori BJ, Neev J, Jin Y, Squier JA, Kleinfeld D. Plasma-mediated ablation: an optical tool for submicrometer surgery on neuronal and vascular systems. Curr Opin Biotechnol 2009; 20:90-9. [PMID: 19269159 PMCID: PMC3123732 DOI: 10.1016/j.copbio.2009.02.003] [Citation(s) in RCA: 66] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2008] [Accepted: 02/05/2009] [Indexed: 02/08/2023]
Abstract
Plasma-mediated ablation makes use of high energy laser pulses to ionize molecules within the first few femtoseconds of the pulse. This process leads to a submicrometer-sized bubble of plasma that can ablate tissue with negligible heat transfer and collateral damage to neighboring tissue. We review the physics of plasma-mediated ablation and its use as a tool to generate targeted insults at the subcellular level to neurons and blood vessels deep within nervous tissue. Illustrative examples from axon regeneration and microvascular research highlight the utility of this tool. We further discuss the use of ablation as an integral part of automated histology.
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Affiliation(s)
- Philbert S. Tsai
- Department of Physics, University of California at San Diego, 9500 Gilman Drive 0374, La Jolla, CA 92093-0374
| | - Pablo Blinder
- Department of Physics, University of California at San Diego, 9500 Gilman Drive 0374, La Jolla, CA 92093-0374
| | - Benjamin J. Migliori
- Department of Physics, University of California at San Diego, 9500 Gilman Drive 0374, La Jolla, CA 92093-0374
| | - Joseph Neev
- FemtoSec Tech, Inc., 27068 South La Paz Road, Aliso Viejo, CA 92656
| | - Yishi Jin
- Division of Biological Sciences, Howard Hughes Medical Institute, University of California at San Diego, 9500 Gilman Drive 0368, La Jolla, CA 92093-0368
- Graduate Program in Neurosciences, University of California at San Diego, 9500 Gilman Drive 0662, La Jolla, CA 92093-0662
| | - Jeffrey A. Squier
- Department of Physics, Colorado School of Mines, 1523 Illinois Street, Golden, CO 80401
| | - David Kleinfeld
- Department of Physics, University of California at San Diego, 9500 Gilman Drive 0374, La Jolla, CA 92093-0374
- Graduate Program in Neurosciences, University of California at San Diego, 9500 Gilman Drive 0662, La Jolla, CA 92093-0662
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Maghelli N, Tolić-Nørrelykke IM. Versatile laser-based cell manipulator. JOURNAL OF BIOPHOTONICS 2008; 1:299-309. [PMID: 19343653 DOI: 10.1002/jbio.200810026] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Here we describe a two-photon microscope and laser ablation setup combined with optical tweezers. We tested the setup on the fission yeast Schizosaccharomyces pombe, a commonly used model organism. We show that long-term imaging can be achieved without significant photo-bleaching or damage of the sample. The setup can precisely ablate sub-micrometer structures, such as microtubules and mitotic spindles, inside living cells, which remain viable after the manipulation. Longer exposure times lead to ablation, while shorter exposures lead to photo-bleaching of the target structure. We used optical tweezers to trap intracellular particles and to displace the cell nucleus. Two-photon fluorescence imaging of the manipulated cell can be performed simultaneously with trapping. The combination of techniques described here may help to solve a variety of problems in cell biology, such as positioning of organelles and the forces exerted by the cytoskeleton.
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Affiliation(s)
- Nicola Maghelli
- Max-Planck-Institute of Molecular Cell Biology and Genetics, 01307 Dresden, Germany.
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