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Mizuta K, Sato M. Multiphoton imaging of hippocampal neural circuits: techniques and biological insights into region-, cell-type-, and pathway-specific functions. Neurophotonics 2024; 11:033406. [PMID: 38464393 PMCID: PMC10923542 DOI: 10.1117/1.nph.11.3.033406] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/25/2023] [Revised: 01/31/2024] [Accepted: 02/06/2024] [Indexed: 03/12/2024]
Abstract
Significance The function of the hippocampus in behavior and cognition has long been studied primarily through electrophysiological recordings from freely moving rodents. However, the application of optical recording methods, particularly multiphoton fluorescence microscopy, in the last decade or two has dramatically advanced our understanding of hippocampal function. This article provides a comprehensive overview of techniques and biological findings obtained from multiphoton imaging of hippocampal neural circuits. Aim This review aims to summarize and discuss the recent technical advances in multiphoton imaging of hippocampal neural circuits and the accumulated biological knowledge gained through this technology. Approach First, we provide a brief overview of various techniques of multiphoton imaging of the hippocampus and discuss its advantages, drawbacks, and associated key innovations and practices. Then, we review a large body of findings obtained through multiphoton imaging by region (CA1 and dentate gyrus), cell type (pyramidal neurons, inhibitory interneurons, and glial cells), and cellular compartment (dendrite and axon). Results Multiphoton imaging of the hippocampus is primarily performed under head-fixed conditions and can reveal detailed mechanisms of circuit operation owing to its high spatial resolution and specificity. As the hippocampus lies deep below the cortex, its imaging requires elaborate methods. These include imaging cannula implantation, microendoscopy, and the use of long-wavelength light sources. Although many studies have focused on the dorsal CA1 pyramidal cells, studies of other local and inter-areal circuitry elements have also helped provide a more comprehensive picture of the information processing performed by the hippocampal circuits. Imaging of circuit function in mouse models of Alzheimer's disease and other brain disorders such as autism spectrum disorder has also contributed greatly to our understanding of their pathophysiology. Conclusions Multiphoton imaging has revealed much regarding region-, cell-type-, and pathway-specific mechanisms in hippocampal function and dysfunction in health and disease. Future technological advances will allow further illustration of the operating principle of the hippocampal circuits via the large-scale, high-resolution, multimodal, and minimally invasive imaging.
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Affiliation(s)
- Kotaro Mizuta
- RIKEN BDR, Kobe, Japan
- New York University Abu Dhabi, Department of Biology, Abu Dhabi, United Arab Emirates
| | - Masaaki Sato
- Hokkaido University Graduate School of Medicine, Department of Neuropharmacology, Sapporo, Japan
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2
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Manley J, Lu S, Barber K, Demas J, Kim H, Meyer D, Traub FM, Vaziri A. Simultaneous, cortex-wide dynamics of up to 1 million neurons reveal unbounded scaling of dimensionality with neuron number. Neuron 2024; 112:1694-1709.e5. [PMID: 38452763 PMCID: PMC11098699 DOI: 10.1016/j.neuron.2024.02.011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2022] [Revised: 05/18/2023] [Accepted: 02/14/2024] [Indexed: 03/09/2024]
Abstract
The brain's remarkable properties arise from the collective activity of millions of neurons. Widespread application of dimensionality reduction to multi-neuron recordings implies that neural dynamics can be approximated by low-dimensional "latent" signals reflecting neural computations. However, can such low-dimensional representations truly explain the vast range of brain activity, and if not, what is the appropriate resolution and scale of recording to capture them? Imaging neural activity at cellular resolution and near-simultaneously across the mouse cortex, we demonstrate an unbounded scaling of dimensionality with neuron number in populations up to 1 million neurons. Although half of the neural variance is contained within sixteen dimensions correlated with behavior, our discovered scaling of dimensionality corresponds to an ever-increasing number of neuronal ensembles without immediate behavioral or sensory correlates. The activity patterns underlying these higher dimensions are fine grained and cortex wide, highlighting that large-scale, cellular-resolution recording is required to uncover the full substrates of neuronal computations.
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Affiliation(s)
- Jason Manley
- Laboratory of Neurotechnology and Biophysics, The Rockefeller University, New York, NY 10065, USA; The Kavli Neural Systems Institute, The Rockefeller University, New York, NY 10065, USA
| | - Sihao Lu
- Laboratory of Neurotechnology and Biophysics, The Rockefeller University, New York, NY 10065, USA
| | - Kevin Barber
- Laboratory of Neurotechnology and Biophysics, The Rockefeller University, New York, NY 10065, USA
| | - Jeffrey Demas
- Laboratory of Neurotechnology and Biophysics, The Rockefeller University, New York, NY 10065, USA; The Kavli Neural Systems Institute, The Rockefeller University, New York, NY 10065, USA
| | - Hyewon Kim
- Laboratory of Neurotechnology and Biophysics, The Rockefeller University, New York, NY 10065, USA
| | - David Meyer
- Laboratory of Neurotechnology and Biophysics, The Rockefeller University, New York, NY 10065, USA
| | - Francisca Martínez Traub
- Laboratory of Neurotechnology and Biophysics, The Rockefeller University, New York, NY 10065, USA
| | - Alipasha Vaziri
- Laboratory of Neurotechnology and Biophysics, The Rockefeller University, New York, NY 10065, USA; The Kavli Neural Systems Institute, The Rockefeller University, New York, NY 10065, USA.
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3
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Singh Alvarado J, Lutas A, Madara JC, Isaac J, Lommer C, Massengill C, Andermann ML. Transient cAMP production drives rapid and sustained spiking in brainstem parabrachial neurons to suppress feeding. Neuron 2024; 112:1416-1425.e5. [PMID: 38417435 PMCID: PMC11065603 DOI: 10.1016/j.neuron.2024.02.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2023] [Revised: 12/01/2023] [Accepted: 02/01/2024] [Indexed: 03/01/2024]
Abstract
Brief stimuli can trigger longer-lasting brain states. G-protein-coupled receptors (GPCRs) could help sustain such states by coupling slow-timescale molecular signals to neuronal excitability. Brainstem parabrachial nucleus glutamatergic (PBNGlut) neurons regulate sustained brain states such as pain and express Gs-coupled GPCRs that increase cAMP signaling. We asked whether cAMP in PBNGlut neurons directly influences their excitability and effects on behavior. Both brief tail shocks and brief optogenetic stimulation of cAMP production in PBNGlut neurons drove minutes-long suppression of feeding. This suppression matched the duration of prolonged elevations in cAMP, protein kinase A (PKA) activity, and calcium activity in vivo and ex vivo, as well as sustained, PKA-dependent increases in action potential firing ex vivo. Shortening this elevation in cAMP reduced the duration of feeding suppression following tail shocks. Thus, molecular signaling in PBNGlut neurons helps prolong neural activity and behavioral states evoked by brief, salient bodily stimuli.
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Affiliation(s)
- Jonnathan Singh Alvarado
- Division of Endocrinology, Metabolism, and Diabetes, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02115, USA
| | - Andrew Lutas
- Division of Endocrinology, Metabolism, and Diabetes, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02115, USA; Diabetes, Endocrinology, and Obesity Branch, National Institutes of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892, USA.
| | - Joseph C Madara
- Division of Endocrinology, Metabolism, and Diabetes, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02115, USA
| | - Jeremiah Isaac
- Diabetes, Endocrinology, and Obesity Branch, National Institutes of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Caroline Lommer
- Division of Endocrinology, Metabolism, and Diabetes, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02115, USA
| | | | - Mark L Andermann
- Division of Endocrinology, Metabolism, and Diabetes, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02115, USA.
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4
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Deng J, Sun C, Zheng Y, Gao J, Cui X, Wang Y, Zhang L, Tang P. In vivo imaging of the neuronal response to spinal cord injury: a narrative review. Neural Regen Res 2024; 19:811-817. [PMID: 37843216 PMCID: PMC10664102 DOI: 10.4103/1673-5374.382225] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2023] [Revised: 05/15/2023] [Accepted: 07/07/2023] [Indexed: 10/17/2023] Open
Abstract
Deciphering the neuronal response to injury in the spinal cord is essential for exploring treatment strategies for spinal cord injury (SCI). However, this subject has been neglected in part because appropriate tools are lacking. Emerging in vivo imaging and labeling methods offer great potential for observing dynamic neural processes in the central nervous system in conditions of health and disease. This review first discusses in vivo imaging of the mouse spinal cord with a focus on the latest imaging techniques, and then analyzes the dynamic biological response of spinal cord sensory and motor neurons to SCI. We then summarize and compare the techniques behind these studies and clarify the advantages of in vivo imaging compared with traditional neuroscience examinations. Finally, we identify the challenges and possible solutions for spinal cord neuron imaging.
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Affiliation(s)
- Junhao Deng
- Department of Orthopedics, The Fourth Medical Center of Chinese PLA General Hospital, Beijing, China
- National Clinical Research Center for Orthopedics, Sports Medicine and Rehabilitation, Beijing, China
- School of Life Sciences, Tsinghua University, Beijing, China
| | - Chang Sun
- Department of Orthopedics, The Fourth Medical Center of Chinese PLA General Hospital, Beijing, China
- National Clinical Research Center for Orthopedics, Sports Medicine and Rehabilitation, Beijing, China
- Department of Orthopedics, Air Force Medical Center, PLA, Beijing, China
| | - Ying Zheng
- Medical School of Chinese PLA, Beijing, China
| | - Jianpeng Gao
- Department of Orthopedics, The Fourth Medical Center of Chinese PLA General Hospital, Beijing, China
- National Clinical Research Center for Orthopedics, Sports Medicine and Rehabilitation, Beijing, China
| | - Xiang Cui
- Department of Orthopedics, The Fourth Medical Center of Chinese PLA General Hospital, Beijing, China
- National Clinical Research Center for Orthopedics, Sports Medicine and Rehabilitation, Beijing, China
| | - Yu Wang
- Institute of Orthopedics, The First Medical Center, Chinese PLA General Hospital, Beijing, China
- Key Lab of Regenerative Medicine in Orthopedics, Key Laboratory of Musculoskeletal Trauma and War Injuries PLA, Beijing, China
| | - Licheng Zhang
- Department of Orthopedics, The Fourth Medical Center of Chinese PLA General Hospital, Beijing, China
- National Clinical Research Center for Orthopedics, Sports Medicine and Rehabilitation, Beijing, China
| | - Peifu Tang
- Department of Orthopedics, The Fourth Medical Center of Chinese PLA General Hospital, Beijing, China
- National Clinical Research Center for Orthopedics, Sports Medicine and Rehabilitation, Beijing, China
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5
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Tanaka M, Hirayoshi Y, Minatani S, Hasegawa I, Itoh Y. Diffusion Mediates Molecular Transport through the Perivascular Space in the Brain. Int J Mol Sci 2024; 25:2480. [PMID: 38473727 DOI: 10.3390/ijms25052480] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2024] [Revised: 02/13/2024] [Accepted: 02/19/2024] [Indexed: 03/14/2024] Open
Abstract
The perivascular space has been proposed as a clearance pathway for degradation products in the brain, including amyloid β, the accumulation of which may induce Alzheimer's disease. Live images were acquired using a two-photon microscope through a closed cranial window in mice. In topical application experiments, the dynamics of FITC-dextran were evaluated from 30 to 150 min after the application and closure of the window. In continuous injection experiments, image acquisition began before the continuous injection of FITC-dextran. The transport of dextran molecules of different sizes was evaluated. In topical application experiments, circumferential accumulation around the penetrating arteries, veins, and capillaries was observed, even at the beginning of the observation period. No further increases were detected. In continuous injection experiments, a time-dependent increase in the fluorescence intensity was observed around the penetrating arteries and veins. Lower-molecular-weight dextran was transported more rapidly than higher-molecular-weight dextran, especially around the arteries. The largest dextran molecules were not transported significantly during the observation period. The size-dependent transport of dextran observed in the present study strongly suggests that diffusion is the main mechanism mediating substance transport in the perivascular space.
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Affiliation(s)
- Marie Tanaka
- Department of Neurology, Osaka City University Graduate School of Medicine, Osaka 545-8585, Japan
| | - Yoko Hirayoshi
- Department of Neurology, Osaka City University Graduate School of Medicine, Osaka 545-8585, Japan
| | - Shinobu Minatani
- Department of Neurology, Osaka City University Graduate School of Medicine, Osaka 545-8585, Japan
| | - Itsuki Hasegawa
- Department of Neurology, Osaka City University Graduate School of Medicine, Osaka 545-8585, Japan
| | - Yoshiaki Itoh
- Department of Neurology, Osaka City University Graduate School of Medicine, Osaka 545-8585, Japan
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Lepekhina TB, Nikolaev VV, Darvin ME, Zuhayri H, Snegerev MS, Lozhkomoev AS, Senkina EI, Kokhanenko AP, Lozovoy KA, Kistenev YV. Two-Photon-Excited FLIM of NAD(P)H and FAD-Metabolic Activity of Fibroblasts for the Diagnostics of Osteoimplant Survival. Int J Mol Sci 2024; 25:2257. [PMID: 38396933 PMCID: PMC10889693 DOI: 10.3390/ijms25042257] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2023] [Revised: 02/04/2024] [Accepted: 02/11/2024] [Indexed: 02/25/2024] Open
Abstract
Bioinert materials such as the zirconium dioxide and aluminum oxide are widely used in surgery and dentistry due to the absence of cytotoxicity of the materials in relation to the surrounding cells of the body. However, little attention has been paid to the study of metabolic processes occurring at the implant-cell interface. The metabolic activity of mouse 3T3 fibroblasts incubated on yttrium-stabilized zirconium ceramics cured with aluminum oxide (ATZ) and stabilized zirconium ceramics (Y-TZP) was analyzed based on the ratio of the free/bound forms of cofactors NAD(P)H and FAD obtained using two-photon microscopy. The results show that fibroblasts incubated on ceramics demonstrate a shift towards the free form of NAD(P)H, which is observed during the glycolysis process, which, according to our assumptions, is related to the porosity of the surface of ceramic structures. Consequently, despite the high viability and good proliferation of fibroblasts assessed using an MTT test and a scanning electron microscope, the cells are in a state of hypoxia during incubation on ceramic structures. The FLIM results obtained in this work can be used as additional information for scientists who are interested in manufacturing osteoimplants.
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Affiliation(s)
- Tatiana B. Lepekhina
- Laboratory of Laser Molecular Imaging and Machine Learning, Tomsk State University, Lenin Ave. 36, 634050 Tomsk, Russia; (T.B.L.); (V.V.N.); (H.Z.); (M.S.S.); (E.I.S.); (Y.V.K.)
| | - Viktor V. Nikolaev
- Laboratory of Laser Molecular Imaging and Machine Learning, Tomsk State University, Lenin Ave. 36, 634050 Tomsk, Russia; (T.B.L.); (V.V.N.); (H.Z.); (M.S.S.); (E.I.S.); (Y.V.K.)
| | | | - Hala Zuhayri
- Laboratory of Laser Molecular Imaging and Machine Learning, Tomsk State University, Lenin Ave. 36, 634050 Tomsk, Russia; (T.B.L.); (V.V.N.); (H.Z.); (M.S.S.); (E.I.S.); (Y.V.K.)
| | - Mikhail S. Snegerev
- Laboratory of Laser Molecular Imaging and Machine Learning, Tomsk State University, Lenin Ave. 36, 634050 Tomsk, Russia; (T.B.L.); (V.V.N.); (H.Z.); (M.S.S.); (E.I.S.); (Y.V.K.)
| | - Aleksandr S. Lozhkomoev
- Institute of Strength Physics and Materials Science of the Siberian Branch of the Russian Academy of Sciences (ISPMS SB RAS), 634021 Tomsk, Russia;
| | - Elena I. Senkina
- Laboratory of Laser Molecular Imaging and Machine Learning, Tomsk State University, Lenin Ave. 36, 634050 Tomsk, Russia; (T.B.L.); (V.V.N.); (H.Z.); (M.S.S.); (E.I.S.); (Y.V.K.)
- Institute of Strength Physics and Materials Science of the Siberian Branch of the Russian Academy of Sciences (ISPMS SB RAS), 634021 Tomsk, Russia;
| | - Andrey P. Kokhanenko
- Department of Quantum Electronics and Photonics, Faculty of Radiophysics, National Research Tomsk State University, Lenin Av. 36, 634050 Tomsk, Russia;
| | - Kirill A. Lozovoy
- Department of Quantum Electronics and Photonics, Faculty of Radiophysics, National Research Tomsk State University, Lenin Av. 36, 634050 Tomsk, Russia;
| | - Yury V. Kistenev
- Laboratory of Laser Molecular Imaging and Machine Learning, Tomsk State University, Lenin Ave. 36, 634050 Tomsk, Russia; (T.B.L.); (V.V.N.); (H.Z.); (M.S.S.); (E.I.S.); (Y.V.K.)
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7
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Ocana-Santero G, Packer AM, Sharp T, Butt SJB. In Vivo Two-Photon Microscopy Reveals Sensory-Evoked Serotonin (5-HT) Release in Adult Mammalian Neocortex. ACS Chem Neurosci 2024; 15:456-461. [PMID: 38251903 PMCID: PMC10853926 DOI: 10.1021/acschemneuro.3c00725] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2023] [Revised: 01/09/2024] [Accepted: 01/16/2024] [Indexed: 01/23/2024] Open
Abstract
The recent development of genetically encoded fluorescent neurotransmitter biosensors has opened the door to recording serotonin (5-hydroxytryptamine, 5-HT) signaling dynamics with high temporal and spatial resolution in vivo. While this represents a significant step forward for serotonin research, the utility of available 5-HT biosensors remains to be fully established under diverse in vivo conditions. Here, we used two-photon microscopy in awake mice to examine the effectiveness of specific 5-HT biosensors for monitoring 5-HT dynamics in somatosensory cortex. Initial experiments found that whisker stimulation evoked a striking change in 5-HT biosensor signal. However, similar changes were observed in controls expressing green fluorescent protein, suggesting a potential hemodynamic artifact. Subsequent use of a second control fluorophore with emission peaks separated from the 5-HT biosensor revealed a reproducible, stimulus-locked increase in 5-HT signal. Our data highlight the promise of 5-HT biosensors for in vivo application, provided measurements are carried out with appropriate optical controls.
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Affiliation(s)
- Gabriel Ocana-Santero
- Department
of Pharmacology, University of Oxford, Oxford OX1 3QT, U.K.
- Department
of Physiology, Anatomy & Genetics, University
of Oxford, Oxford OX1 3PT, U.K.
| | - Adam M. Packer
- Department
of Physiology, Anatomy & Genetics, University
of Oxford, Oxford OX1 3PT, U.K.
| | - Trevor Sharp
- Department
of Pharmacology, University of Oxford, Oxford OX1 3QT, U.K.
| | - Simon J. B. Butt
- Department
of Physiology, Anatomy & Genetics, University
of Oxford, Oxford OX1 3PT, U.K.
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8
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Hong M, Chong SZ, Goh YY, Tong L. Two-Photon and Multiphoton Microscopy in Anterior Segment Diseases of the Eye. Int J Mol Sci 2024; 25:1670. [PMID: 38338948 PMCID: PMC10855705 DOI: 10.3390/ijms25031670] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2023] [Revised: 01/19/2024] [Accepted: 01/23/2024] [Indexed: 02/12/2024] Open
Abstract
Two-photon excitation microscopy (TPM) and multiphoton fluorescence microscopy (MPM) are advanced forms of intravital high-resolution functional microscopy techniques that allow for the imaging of dynamic molecular processes and resolve features of the biological tissues of interest. Due to the cornea's optical properties and the uniquely accessible position of the globe, it is possible to image cells and tissues longitudinally to investigate ocular surface physiology and disease. MPM can also be used for the in vitro investigation of biological processes and drug kinetics in ocular tissues. In corneal immunology, performed via the use of TPM, cells thought to be intraepithelial dendritic cells are found to resemble tissue-resident memory T cells, and reporter mice with labeled plasmacytoid dendritic cells are imaged to understand the protective antiviral defenses of the eye. In mice with limbal progenitor cells labeled by reporters, the kinetics and localization of corneal epithelial replenishment are evaluated to advance stem cell biology. In studies of the conjunctiva and sclera, the use of such imaging together with second harmonic generation allows for the delineation of matrix wound healing, especially following glaucoma surgery. In conclusion, these imaging models play a pivotal role in the progress of ocular surface science and translational research.
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Affiliation(s)
- Merrelynn Hong
- Yong Loo Lin School of Medicine, National University of Singapore, Singapore 117597, Singapore;
- Training and Education Department, Singapore National Eye Centre, Singapore 168751, Singapore
| | - Shu Zhen Chong
- Singapore Immunology Network (SIgN), Agency for Science Technology and Research (A*STAR), Singapore 138632, Singapore;
| | - Yun Yao Goh
- Lee Kong Chian School of Medicine, National Technical University, Singapore 639798, Singapore;
| | - Louis Tong
- Corneal and External Diseases Department, Singapore National Eye Centre, Singapore 168751, Singapore
- Ocular Surface Group, Singapore Eye Research Institute, Singapore 169856, Singapore
- Eye Academic Clinical Program, Duke-NUS Medical School, Singapore 169857, Singapore
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9
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Uderhardt S, Neag G, Germain RN. Dynamic Multiplex Tissue Imaging in Inflammation Research. Annu Rev Pathol 2024; 19:43-67. [PMID: 37722698 DOI: 10.1146/annurev-pathmechdis-070323-124158] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/20/2023]
Abstract
Inflammation is a highly dynamic process with immune cells that continuously interact with each other and parenchymal components as they migrate through tissue. The dynamic cellular responses and interaction patterns are a function of the complex tissue environment that cannot be fully reconstructed ex vivo, making it necessary to assess cell dynamics and changing spatial patterning in vivo. These dynamics often play out deep within tissues, requiring the optical focus to be placed far below the surface of an opaque organ. With the emergence of commercially available two-photon excitation lasers that can be combined with existing imaging systems, new avenues for imaging deep tissues over long periods of time have become available. We discuss a selected subset of studies illustrating how two-photon microscopy (2PM) has helped to relate the dynamics of immune cells to their in situ function and to understand the molecular patterns that govern their behavior in vivo. We also review some key practical aspects of 2PM methods and point out issues that can confound the results, so that readers can better evaluate the reliability of conclusions drawn using this technology.
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Affiliation(s)
- Stefan Uderhardt
- Department of Medicine 3-Rheumatology and Immunology, Friedrich-Alexander-University Erlangen-Nürnberg and Universitätsklinikum Erlangen, Erlangen, Germany
- Deutsches Zentrum für Immuntherapie, Friedrich-Alexander-University Erlangen-Nürnberg, Erlangen, Germany
- Exploratory Research Unit, Optical Imaging Competence Centre, Friedrich-Alexander-University Erlangen-Nürnberg, Erlangen, Germany
| | - Georgiana Neag
- Department of Medicine 3-Rheumatology and Immunology, Friedrich-Alexander-University Erlangen-Nürnberg and Universitätsklinikum Erlangen, Erlangen, Germany
- Deutsches Zentrum für Immuntherapie, Friedrich-Alexander-University Erlangen-Nürnberg, Erlangen, Germany
- Exploratory Research Unit, Optical Imaging Competence Centre, Friedrich-Alexander-University Erlangen-Nürnberg, Erlangen, Germany
| | - Ronald N Germain
- Lymphocyte Biology Section, Laboratory of Immune System Biology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, USA
- Center for Advanced Tissue Imaging (CAT-I), National Institute of Allergy and Infectious Diseases and National Cancer Institute, National Institutes of Health, Bethesda, Maryland, USA;
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Werner MP, Kučikas V, Voß K, Abel D, Jockenhoevel S, van Zandvoort MAMJ, Schmitz-Rode T. Multiphoton Imaging of Maturation in Tissue Engineering. Tissue Eng Part C Methods 2024; 30:38-48. [PMID: 38115629 DOI: 10.1089/ten.tec.2023.0141] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2023] Open
Abstract
Donor cell-specific tissue-engineered (TE) implants are a promising therapy for personalized treatment of cardiovascular diseases, but current development protocols lack a stable longitudinal assessment of tissue development at subcellular resolution. As a first step toward such an assessment approach, in this study we establish a generalized labeling and imaging protocol to obtain quantified maturation parameters of TE constructs in three dimensions (3D) without the need of histological slicing, thus leaving the tissue intact. Focusing on intracellular matrix (ICM) and extracellular matrix (ECM) networks, multiphoton laser scanning microscopy (MPLSM) was used to investigate TE patches of different conditioning durations of up to 21 days. We show here that with a straightforward labeling procedure of whole-mount samples (so without slicing into thin histological sections), followed by an easy-to-use multiphoton imaging process, we obtained high-quality images of the tissue in 3D at various time points during development. The stacks of images could then be further analyzed to visualize and quantify the volume of cell coverage as well as the volume fraction and network of structural proteins. We showed that collagen and alpha-smooth muscle actin (α-SMA) volume fractions increased as normalized to full tissue volume and proportional to the cell count, with a converging trend to the final density of (4.0% ± 0.6%) and (7.6% ± 0.7%), respectively. The image analysis of ICM and ECM revealed a developing and widely branched interconnected matrix. We are currently working on the second step, that is, to integrate MPLSM endoscopy into a dynamic bioreactor system to monitor the maturation of intact TE constructs over time, thus without the need to take them out.
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Affiliation(s)
- Maximilian P Werner
- Department of Biohybrid & Medical Textiles (BioTex), Institute of Applied Medical Engineering (AME), Helmholtz Institute, RWTH Aachen University, Aachen, Germany
- Aachen-Maastricht-Institute for Biobased Materials (AMIBM), Maastricht University, Geleen, The Netherlands
| | - Vytautas Kučikas
- Institute of Molecular Cardiovascular Research (IMCAR), RWTH Aachen University, Aachen, Germany
| | - Kirsten Voß
- Institute of Automatic Control (IRT), RWTH Aachen University, Aachen, Germany
| | - Dirk Abel
- Institute of Automatic Control (IRT), RWTH Aachen University, Aachen, Germany
| | - Stefan Jockenhoevel
- Department of Biohybrid & Medical Textiles (BioTex), Institute of Applied Medical Engineering (AME), Helmholtz Institute, RWTH Aachen University, Aachen, Germany
- Aachen-Maastricht-Institute for Biobased Materials (AMIBM), Maastricht University, Geleen, The Netherlands
| | - Marc A M J van Zandvoort
- Institute of Molecular Cardiovascular Research (IMCAR), RWTH Aachen University, Aachen, Germany
- Department of Genetics and Cell Biology, Cardiovascular Research Institute Maastricht (CARIM), School for Oncology and Developmental Biology (GROW), Maastricht, The Netherlands
| | - Thomas Schmitz-Rode
- Department of Biohybrid & Medical Textiles (BioTex), Institute of Applied Medical Engineering (AME), Helmholtz Institute, RWTH Aachen University, Aachen, Germany
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11
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Lees RM, Pichler B, Packer AM. Contribution of optical resolution to the spatial precision of two-photon optogenetic photostimulation in vivo. Neurophotonics 2024; 11:015006. [PMID: 38322022 PMCID: PMC10846536 DOI: 10.1117/1.nph.11.1.015006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/11/2023] [Revised: 01/04/2024] [Accepted: 01/05/2024] [Indexed: 02/08/2024]
Abstract
Significance Two-photon optogenetics combines nonlinear excitation with noninvasive activation of neurons to enable the manipulation of neural circuits with a high degree of spatial precision. Combined with two-photon population calcium imaging, these approaches comprise a flexible platform for all-optical interrogation of neural circuits. However, a multitude of optical and biological factors dictate the exact precision of this approach in vivo, where it is most usefully applied. Aim We aimed to assess how the optical point spread function (OPSF) contributes to the spatial precision of two-photon photostimulation in neurobiology. Approach We altered the axial spread of the OPSF of the photostimulation beam using a spatial light modulator. Subsequently, calcium imaging was used to monitor the axial spatial precision of two-photon photostimulation of layer 2 neurons in the mouse neocortex. Results We found that optical resolution is not always the limiting factor of the spatial precision of two-photon optogenetic photostimulation and, by doing so, reveal the key factors that must be improved to achieve maximal precision. Conclusions Our results enable future work to focus on the optimal factors by providing key insight from controlled experiments in a manner not previously reported. This research can be applied to advance the state-of-the-art of all-optical interrogation, extending the toolkit for neuroscience research to achieve spatiotemporal precision at the crucial levels in which neural circuits operate.
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Affiliation(s)
- Robert M. Lees
- Science and Technology Facilities Council, Octopus Imaging Facility, Oxfordshire, United Kingdom
- University of Oxford, Department of Physiology, Anatomy, and Genetics, Oxford, United Kingdom
| | - Bruno Pichler
- Independent NeuroScience Services INSS Ltd., East Sussex, United Kingdom
| | - Adam M. Packer
- University of Oxford, Department of Physiology, Anatomy, and Genetics, Oxford, United Kingdom
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12
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Strohm AO, O'Connor TN, Oldfield S, Young S, Hammond C, McCall M, Dirksen RT, Majewska AK. Cortical microglia dynamics are conserved during voluntary wheel running. J Appl Physiol (1985) 2024; 136:89-108. [PMID: 37969082 DOI: 10.1152/japplphysiol.00311.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2023] [Revised: 11/13/2023] [Accepted: 11/14/2023] [Indexed: 11/17/2023] Open
Abstract
We present the first demonstration of chronic in vivo imaging of microglia in mice undergoing voluntary wheel running. We find that healthy mice undergoing voluntary wheel running have similar microglia dynamics, morphologies, and responses to injury when compared to sedentary mice. This suggests that exercise over a period of 1 mo does not grossly alter cortical microglial phenotypes and that exercise may exert its beneficial effects on the brain through other mechanisms. Future work examining how microglia dynamics may be altered during exercise in disease or injury models could provide further insights into the therapeutic benefit of exercise.NEW & NOTEWORTHY We demonstrate the first use of chronic in vivo imaging of microglia over time during physical exercise. We found that microglia movement, morphology, and process motility were remarkably stable during voluntary wheel running (VWR). Additionally, microglia in running mice respond similarly to laser ablation injury compared to sedentary mice. These findings indicate that VWR does not induce changes in microglia dynamics in healthy adults. Exercise may elicit positive effects on the brain through other mechanisms.
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Affiliation(s)
- Alexandra O Strohm
- Department of Environmental Medicine, University of Rochester Medical Center, Rochester, New York, United States
| | - Thomas N O'Connor
- Department of Biomedical Genetics, University of Rochester Medical Center, Rochester, New York, United States
- Department of Pharmacology and Physiology, University of Rochester Medical Center, Rochester, New York, United States
| | - Sadie Oldfield
- Department of Neuroscience, University of Rochester Medical Center, Rochester, New York, United States
| | - Sala Young
- Department of Neuroscience, University of Rochester Medical Center, Rochester, New York, United States
| | - Christian Hammond
- Department of Biostatistics and Computational Biology, University of Rochester Medical Center, Rochester, New York, United States
| | - Matthew McCall
- Department of Biostatistics and Computational Biology, University of Rochester Medical Center, Rochester, New York, United States
| | - Robert T Dirksen
- Department of Pharmacology and Physiology, University of Rochester Medical Center, Rochester, New York, United States
| | - Ania K Majewska
- Department of Neuroscience, University of Rochester Medical Center, Rochester, New York, United States
- Center for Visual Science, University of Rochester Medical Center, Rochester, New York, United States
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13
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Woeppel KM, Krahe DD, Robbins EM, Vazquez AL, Cui XT. Electrically Controlled Vasodilator Delivery from PEDOT/Silica Nanoparticle Modulates Vessel Diameter in Mouse Brain. Adv Healthc Mater 2024; 13:e2301221. [PMID: 37916912 PMCID: PMC10842908 DOI: 10.1002/adhm.202301221] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2023] [Revised: 10/16/2023] [Indexed: 11/03/2023]
Abstract
Vascular damage and reduced tissue perfusion are expected to majorly contribute to the loss of neurons or neural signals around implanted electrodes. However, there are limited methods of controlling the vascular dynamics in tissues surrounding these implants. This work utilizes conducting polymer poly(ethylenedioxythiophene) and sulfonated silica nanoparticle composite (PEDOT/SNP) to load and release a vasodilator, sodium nitroprusside, to controllably dilate the vasculature around carbon fiber electrodes (CFEs) implanted in the mouse cortex. The vasodilator release is triggered via electrical stimulation and the amount of release increases with increasing electrical pulses. The vascular dynamics are monitored in real-time using two-photon microscopy, with changes in vessel diameters quantified before, during, and after the release of the vasodilator into the tissues. This work observes significant increases in vessel diameters when the vasodilator is electrically triggered to release, and differential effects of the drug release on vessels of different sizes. In conclusion, the use of nanoparticle reservoirs in conducting polymer-based drug delivery platforms enables the controlled delivery of vasodilator into the implant environment, effectively altering the local vascular dynamics on demand. With further optimization, this technology could be a powerful tool to improve the neural electrode-tissue interface and study neurovascular coupling.
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Affiliation(s)
- Kevin M Woeppel
- Department of Bioengineering, University of Pittsburgh, United States
| | - Daniela D Krahe
- Department of Bioengineering, University of Pittsburgh, United States
| | - Elaine M Robbins
- Department of Bioengineering, University of Pittsburgh, United States
| | - Alberto L Vazquez
- Department of Bioengineering, University of Pittsburgh, United States
- Center for Neural Basis of Cognition, University of Pittsburgh and Carnegie Mellon University, United States
- Department of Radiology, University of Pittsburgh, United States
- McGowan Institute for Regenerative Medicine, University of Pittsburgh, United States
| | - Xinyan Tracy Cui
- Department of Bioengineering, University of Pittsburgh, United States
- Center for Neural Basis of Cognition, University of Pittsburgh and Carnegie Mellon University, United States
- McGowan Institute for Regenerative Medicine, University of Pittsburgh, United States
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14
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Krishnan S, Sheffield ME. Reward Expectation Reduces Representational Drift in the Hippocampus. bioRxiv 2023:2023.12.21.572809. [PMID: 38187677 PMCID: PMC10769341 DOI: 10.1101/2023.12.21.572809] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/09/2024]
Abstract
Spatial memory in the hippocampus involves dynamic neural patterns that change over days, termed representational drift. While drift may aid memory updating, excessive drift could impede retrieval. Memory retrieval is influenced by reward expectation during encoding, so we hypothesized that diminished reward expectation would exacerbate representational drift. We found that high reward expectation limited drift, with CA1 representations on one day gradually re-emerging over successive trials the following day. Conversely, the absence of reward expectation resulted in increased drift, as the gradual re-emergence of the previous day's representation did not occur. At the single cell level, lowering reward expectation caused an immediate increase in the proportion of place-fields with low trial-to-trial reliability. These place fields were less likely to be reinstated the following day, underlying increased drift in this condition. In conclusion, heightened reward expectation improves memory encoding and retrieval by maintaining reliable place fields that are gradually reinstated across days, thereby minimizing representational drift.
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15
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Pinke D, Issa JB, Dara GA, Dobos G, Dombeck DA. Full field-of-view virtual reality goggles for mice. Neuron 2023; 111:3941-3952.e6. [PMID: 38070501 PMCID: PMC10841834 DOI: 10.1016/j.neuron.2023.11.019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2023] [Revised: 10/03/2023] [Accepted: 11/15/2023] [Indexed: 12/23/2023]
Abstract
Visual virtual reality (VR) systems for head-fixed mice offer advantages over real-world studies for investigating the neural circuitry underlying behavior. However, current VR approaches do not fully cover the visual field of view of mice, do not stereoscopically illuminate the binocular zone, and leave the lab frame visible. To overcome these limitations, we developed iMRSIV (Miniature Rodent Stereo Illumination VR)-VR goggles for mice. Our system is compact, separately illuminates each eye for stereo vision, and provides each eye with an ∼180° field of view, thus excluding the lab frame while accommodating saccades. Mice using iMRSIV while navigating engaged in virtual behaviors more quickly than in a current monitor-based system and displayed freezing and fleeing reactions to overhead looming stimulation. Using iMRSIV with two-photon functional imaging, we found large populations of hippocampal place cells during virtual navigation, global remapping during environment changes, and unique responses of place cell ensembles to overhead looming stimulation.
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Affiliation(s)
- Domonkos Pinke
- Department of Neurobiology, Northwestern University, Evanston, IL 60208, USA
| | - John B Issa
- Department of Neurobiology, Northwestern University, Evanston, IL 60208, USA
| | - Gabriel A Dara
- Department of Neurobiology, Northwestern University, Evanston, IL 60208, USA
| | - Gergely Dobos
- 360world Ltd, Sümegvár köz 9, 1118 Budapest, Hungary
| | - Daniel A Dombeck
- Department of Neurobiology, Northwestern University, Evanston, IL 60208, USA.
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16
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Blanc H, Kaddour G, David NB, Supatto W, Livet J, Beaurepaire E, Mahou P. Chromatically Corrected Multicolor Multiphoton Microscopy. ACS Photonics 2023; 10:4104-4111. [PMID: 38145164 PMCID: PMC10739991 DOI: 10.1021/acsphotonics.3c01104] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/02/2023] [Indexed: 12/26/2023]
Abstract
Simultaneous imaging of multiple labels in tissues is key to studying complex biological processes. Although strategies for color multiphoton excitation have been established, chromatic aberration remains a major problem when multiple excitation wavelengths are used in a scanning microscope. Chromatic aberration introduces a spatial shift between the foci of beams of different wavelengths that varies across the field of view, severely degrading the performance of color imaging. In this work, we propose an adaptive correction strategy that solves this problem in two-beam microscopy techniques. Axial chromatic aberration is corrected by a refractive phase mask that introduces pure defocus into one beam, while lateral chromatic aberration is corrected by a piezoelectric mirror that dynamically compensates for lateral shifts during scanning. We show that this light-efficient approach allows seamless chromatic correction over the entire field of view of different multiphoton objectives without compromising spatial and temporal resolution and that the effective area for beam-mixing processes can be increased by more than 1 order of magnitude. We illustrate this approach with simultaneous three-color, two-photon imaging of developing zebrafish embryos and fixed Brainbow mouse brain slices over large areas. These results establish a robust and efficient method for chromatically corrected multiphoton imaging.
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Affiliation(s)
- Hugo Blanc
- Laboratoire
d’Optique et Biosciences, Ecole Polytechnique, CNRS,
INSERM, Institut Polytechnique de Paris, 91128 Palaiseau, France
| | - Gabriel Kaddour
- Sorbonne
Université, INSERM, CNRS, Institut
de la Vision, 75012 Paris, France
| | - Nicolas B. David
- Laboratoire
d’Optique et Biosciences, Ecole Polytechnique, CNRS,
INSERM, Institut Polytechnique de Paris, 91128 Palaiseau, France
| | - Willy Supatto
- Laboratoire
d’Optique et Biosciences, Ecole Polytechnique, CNRS,
INSERM, Institut Polytechnique de Paris, 91128 Palaiseau, France
| | - Jean Livet
- Sorbonne
Université, INSERM, CNRS, Institut
de la Vision, 75012 Paris, France
| | - Emmanuel Beaurepaire
- Laboratoire
d’Optique et Biosciences, Ecole Polytechnique, CNRS,
INSERM, Institut Polytechnique de Paris, 91128 Palaiseau, France
| | - Pierre Mahou
- Laboratoire
d’Optique et Biosciences, Ecole Polytechnique, CNRS,
INSERM, Institut Polytechnique de Paris, 91128 Palaiseau, France
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17
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Blochet B, Akemann W, Gigan S, Bourdieu L. Fast wavefront shaping for two-photon brain imaging with multipatch correction. Proc Natl Acad Sci U S A 2023; 120:e2305593120. [PMID: 38100413 PMCID: PMC10743372 DOI: 10.1073/pnas.2305593120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2023] [Accepted: 10/19/2023] [Indexed: 12/17/2023] Open
Abstract
Nonlinear fluorescence microscopy promotes in-vivo optical imaging of cellular structure at diffraction-limited resolution deep inside scattering biological tissues. Active compensation of tissue-induced aberrations and light scattering through adaptive wavefront correction further extends the accessible depth by restoring high resolution at large depth. However, those corrections are only valid over a very limited field of view within the angular memory effect. To overcome this limitation, we introduce an acousto-optic light modulation technique for fluorescence imaging with simultaneous wavefront correction at pixel scan speed. Biaxial wavefront corrections are first learned by adaptive optimization at multiple locations in the image field. During image acquisition, the learned corrections are then switched on the fly according to the position of the excitation focus during the raster scan. The proposed microscope is applied to in vivo transcranial neuron imaging and demonstrates multi-patch correction of thinned skull-induced aberrations and scattering at 40-kHz data acquisition speed.
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Affiliation(s)
- Baptiste Blochet
- Institut de Biologie de l’École Normale Supérieure, École Normale Supérieure, CNRS, INSERM, Université Paris Sciences et Lettres, Paris75005, France
- Laboratoire Kastler Brossel, École Normale Supérieure-Université Paris Sciences et Lettres, CNRS, Sorbonne Université, Collège de France, Paris75005, France
| | - Walther Akemann
- Institut de Biologie de l’École Normale Supérieure, École Normale Supérieure, CNRS, INSERM, Université Paris Sciences et Lettres, Paris75005, France
- Laboratoire Kastler Brossel, École Normale Supérieure-Université Paris Sciences et Lettres, CNRS, Sorbonne Université, Collège de France, Paris75005, France
| | - Sylvain Gigan
- Laboratoire Kastler Brossel, École Normale Supérieure-Université Paris Sciences et Lettres, CNRS, Sorbonne Université, Collège de France, Paris75005, France
| | - Laurent Bourdieu
- Institut de Biologie de l’École Normale Supérieure, École Normale Supérieure, CNRS, INSERM, Université Paris Sciences et Lettres, Paris75005, France
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18
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Lande AS, Garvert AC, Ebbesen NC, Jordbræk SV, Vervaeke K. Representations of tactile object location in the retrosplenial cortex. Curr Biol 2023; 33:4599-4610.e7. [PMID: 37774708 DOI: 10.1016/j.cub.2023.09.019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2022] [Revised: 07/23/2023] [Accepted: 09/06/2023] [Indexed: 10/01/2023]
Abstract
How animals use tactile sensation to detect important objects and remember their location in a world-based coordinate system is unclear. Here, we hypothesized that the retrosplenial cortex (RSC), a key network for contextual memory and spatial navigation, represents the location of objects based on tactile sensation. We studied mice palpating objects with their whiskers while navigating in a tactile virtual reality in darkness. Using two-photon Ca2+ imaging, we discovered that a population of neurons in the agranular RSC signal the location of objects. Responses to objects do not simply reflect the sensory stimulus. Instead, they are highly position, task, and context dependent and often predict the upcoming object before it is within reach. In addition, a large fraction of neurons encoding object location maintain a memory trace of the object's location. These data show that the RSC encodes the location and arrangement of tactile objects in a spatial reference frame.
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Affiliation(s)
- Andreas Sigstad Lande
- Institute of Basic Medical Sciences, Section of Physiology, University of Oslo, Sognsvannsveien 9, 0372 Oslo, Norway
| | - Anna Christina Garvert
- Institute of Basic Medical Sciences, Section of Physiology, University of Oslo, Sognsvannsveien 9, 0372 Oslo, Norway
| | - Nora Cecilie Ebbesen
- Institute of Basic Medical Sciences, Section of Physiology, University of Oslo, Sognsvannsveien 9, 0372 Oslo, Norway
| | - Sondre Valentin Jordbræk
- Institute of Basic Medical Sciences, Section of Physiology, University of Oslo, Sognsvannsveien 9, 0372 Oslo, Norway
| | - Koen Vervaeke
- Institute of Basic Medical Sciences, Section of Physiology, University of Oslo, Sognsvannsveien 9, 0372 Oslo, Norway.
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19
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Bonnar O, Shaw K, Anderle S, Grijseels DM, Clarke D, Bell L, King SL, Hall CN. APOE4 expression confers a mild, persistent reduction in neurovascular function in the visual cortex and hippocampus of awake mice. J Cereb Blood Flow Metab 2023; 43:1826-1841. [PMID: 37350319 PMCID: PMC10676141 DOI: 10.1177/0271678x231172842] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/14/2022] [Revised: 03/23/2023] [Accepted: 03/27/2023] [Indexed: 06/24/2023]
Abstract
Vascular factors are known to be early and important players in Alzheimer's disease (AD) development, however the role of the ε4 allele of the Apolipoprotein (APOE) gene (a risk factor for developing AD) remains unclear. APOE4 genotype is associated with early and severe neocortical vascular deficits in anaesthetised mice, but in humans, vascular and cognitive dysfunction are focused on the hippocampal formation and appear later. How APOE4 might interact with the vasculature to confer AD risk during the preclinical phase represents a gap in existing knowledge. To avoid potential confounds of anaesthesia and to explore regions most relevant for human disease, we studied the visual cortex and hippocampus of awake APOE3 and APOE4-TR mice using 2-photon microscopy of neurons and blood vessels. We found mild vascular deficits: vascular density and functional hyperaemia were unaffected in APOE4 mice, and neuronal or vascular function did not decrease up to late middle-age. Instead, vascular responsiveness was lower, arteriole vasomotion was reduced and neuronal calcium signals during visual stimulation were increased. This suggests that, alone, APOE4 expression is not catastrophic but stably alters neurovascular physiology. We suggest this state makes APOE4 carriers more sensitive to subsequent insults such as injury or beta amyloid accumulation.
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Affiliation(s)
| | | | - Silvia Anderle
- School of Psychology and Sussex Neuroscience, University of Sussex, Falmer, Brighton, East Sussex, UK
| | - Dori M Grijseels
- School of Psychology and Sussex Neuroscience, University of Sussex, Falmer, Brighton, East Sussex, UK
| | - Devin Clarke
- School of Psychology and Sussex Neuroscience, University of Sussex, Falmer, Brighton, East Sussex, UK
| | - Laura Bell
- School of Psychology and Sussex Neuroscience, University of Sussex, Falmer, Brighton, East Sussex, UK
| | - Sarah L King
- School of Psychology and Sussex Neuroscience, University of Sussex, Falmer, Brighton, East Sussex, UK
| | - Catherine N Hall
- School of Psychology and Sussex Neuroscience, University of Sussex, Falmer, Brighton, East Sussex, UK
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20
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Funamizu A, Marbach F, Zador AM. Stable sound decoding despite modulated sound representation in the auditory cortex. Curr Biol 2023; 33:4470-4483.e7. [PMID: 37802051 PMCID: PMC10665086 DOI: 10.1016/j.cub.2023.09.031] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2023] [Revised: 07/27/2023] [Accepted: 09/13/2023] [Indexed: 10/08/2023]
Abstract
The activity of neurons in the auditory cortex is driven by both sounds and non-sensory context. To investigate the neuronal correlates of non-sensory context, we trained head-fixed mice to perform a two-alternative-choice auditory task in which either reward or stimulus expectation (prior) was manipulated in blocks. Using two-photon calcium imaging to record populations of single neurons in the auditory cortex, we found that both stimulus and reward expectation modulated the activity of these neurons. A linear decoder trained on this population activity could decode stimuli as well or better than predicted by the animal's performance. Interestingly, the optimal decoder was stable even in the face of variable sensory representations. Neither the context nor the mouse's choice could be reliably decoded from the recorded neural activity. Our findings suggest that, in spite of modulation of auditory cortical activity by task priors, the auditory cortex does not represent sufficient information about these priors to exploit them optimally. Thus, the combination of rapidly changing sensory information with more slowly varying task information required for decisions in this task might be represented in brain regions other than the auditory cortex.
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Affiliation(s)
- Akihiro Funamizu
- Cold Spring Harbor Laboratory, 1 Bungtown Rd, Cold Spring Harbor, NY 11724, USA.
| | - Fred Marbach
- Cold Spring Harbor Laboratory, 1 Bungtown Rd, Cold Spring Harbor, NY 11724, USA
| | - Anthony M Zador
- Cold Spring Harbor Laboratory, 1 Bungtown Rd, Cold Spring Harbor, NY 11724, USA
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21
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Wang Y, You L, Tan K, Li M, Zou J, Zhao Z, Hu W, Li T, Xie F, Li C, Yuan R, Ding K, Cao L, Xin F, Shang C, Liu M, Gao Y, Wei L, You Z, Gao X, Xiong W, Cao P, Luo M, Chen F, Li K, Wu J, Hong B, Yuan K. A common thalamic hub for general and defensive arousal control. Neuron 2023; 111:3270-3287.e8. [PMID: 37557180 DOI: 10.1016/j.neuron.2023.07.007] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2022] [Revised: 05/25/2023] [Accepted: 07/11/2023] [Indexed: 08/11/2023]
Abstract
The expression of defensive responses to alerting sensory cues requires both general arousal and a specific arousal state associated with defensive emotions. However, it remains unclear whether these two forms of arousal can be regulated by common brain regions. We discovered that the medial sector of the auditory thalamus (ATm) in mice is a thalamic hub controlling both general and defensive arousal. The spontaneous activity of VGluT2-expressing ATm (ATmVGluT2+) neurons was correlated with and causally contributed to wakefulness. In sleeping mice, sustained ATmVGluT2+ population responses were predictive of sensory-induced arousal, the likelihood of which was markedly decreased by inhibiting ATmVGluT2+ neurons or multiple downstream pathways. In awake mice, ATmVGluT2+ activation led to heightened arousal accompanied by excessive anxiety and avoidance behavior. Notably, blocking their neurotransmission abolished alerting stimuli-induced defensive behaviors. These findings may shed light on the comorbidity of sleep disturbances and abnormal sensory sensitivity in specific brain disorders.
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Affiliation(s)
- Yiwei Wang
- Department of Biomedical Engineering, School of Medicine, Tsinghua University, Beijing 100084, China; IDG/McGovern Institute for Brain Research at Tsinghua, Beijing 100084, China
| | - Ling You
- Department of Biomedical Engineering, School of Medicine, Tsinghua University, Beijing 100084, China; IDG/McGovern Institute for Brain Research at Tsinghua, Beijing 100084, China
| | - KaMun Tan
- Department of Biomedical Engineering, School of Medicine, Tsinghua University, Beijing 100084, China; IDG/McGovern Institute for Brain Research at Tsinghua, Beijing 100084, China
| | - Meijie Li
- Department of Biomedical Engineering, School of Medicine, Tsinghua University, Beijing 100084, China; IDG/McGovern Institute for Brain Research at Tsinghua, Beijing 100084, China
| | - Jingshan Zou
- Hospital of Chengdu University of Traditional Chinese Medicine, Traditional Chinese Medicine Hospital of Sichuan Province, Chengdu 610036, China
| | - Zhifeng Zhao
- IDG/McGovern Institute for Brain Research at Tsinghua, Beijing 100084, China; Department of Automation, Tsinghua University, Beijing 100084, China
| | - Wenxin Hu
- School of Aerospace Engineering, Tsinghua University, Beijing 100084, China
| | - Tianyu Li
- Department of Biomedical Engineering, School of Medicine, Tsinghua University, Beijing 100084, China; IDG/McGovern Institute for Brain Research at Tsinghua, Beijing 100084, China
| | - Fenghua Xie
- Department of Biomedical Engineering, School of Medicine, Tsinghua University, Beijing 100084, China; Tsinghua Laboratory of Brain and Intelligence (THBI), Beijing 100084, China
| | - Caiqin Li
- Department of Biomedical Engineering, School of Medicine, Tsinghua University, Beijing 100084, China; IDG/McGovern Institute for Brain Research at Tsinghua, Beijing 100084, China
| | - Ruizhi Yuan
- Department of Biomedical Engineering, School of Medicine, Tsinghua University, Beijing 100084, China
| | - Kai Ding
- Department of Chemical Engineering, Tsinghua University, Beijing 100084, China
| | - Lingwei Cao
- Zhili College, Tsinghua University, Beijing 100084, China
| | - Fengyuan Xin
- Department of Biomedical Engineering, School of Medicine, Tsinghua University, Beijing 100084, China; IDG/McGovern Institute for Brain Research at Tsinghua, Beijing 100084, China
| | - Congping Shang
- National Institute of Biological Sciences (NIBS), Beijing 102206, China
| | - Miaomiao Liu
- Department of Biomedical Engineering, School of Medicine, Tsinghua University, Beijing 100084, China; Laboratory Animal Resources Center, Tsinghua University, Beijing 100084, China
| | - Yixiao Gao
- IDG/McGovern Institute for Brain Research at Tsinghua, Beijing 100084, China; Department of Basic Medical Sciences, School of Medicine, Tsinghua University, Beijing 100084, China; Tsinghua-Peking Joint Center for Life Sciences, Beijing 100084, China
| | - Liqiang Wei
- IDG/McGovern Institute for Brain Research at Tsinghua, Beijing 100084, China; School of Life Sciences, Tsinghua University, Beijing 100084, China; Tsinghua-Peking Joint Center for Life Sciences, Beijing 100084, China
| | - Zhiwei You
- Department of Basic Medical Sciences, School of Medicine, Tsinghua University, Beijing 100084, China; Tsinghua-Peking Joint Center for Life Sciences, Beijing 100084, China; Laboratory of Dynamic Immunobiology, Institute for Immunology, Tsinghua University, Beijing 100084, China
| | - Xiaorong Gao
- Department of Biomedical Engineering, School of Medicine, Tsinghua University, Beijing 100084, China; IDG/McGovern Institute for Brain Research at Tsinghua, Beijing 100084, China; Tsinghua Laboratory of Brain and Intelligence (THBI), Beijing 100084, China
| | - Wei Xiong
- IDG/McGovern Institute for Brain Research at Tsinghua, Beijing 100084, China; School of Life Sciences, Tsinghua University, Beijing 100084, China; Chinese Institute for Brain Research, Beijing 102206, China
| | - Peng Cao
- National Institute of Biological Sciences (NIBS), Beijing 102206, China
| | - Minmin Luo
- National Institute of Biological Sciences (NIBS), Beijing 102206, China; Chinese Institute for Brain Research, Beijing 102206, China
| | - Feng Chen
- Department of Automation, Tsinghua University, Beijing 100084, China
| | - Kun Li
- IDG/McGovern Institute for Brain Research at Tsinghua, Beijing 100084, China; School of Life Sciences, Tsinghua University, Beijing 100084, China; Tsinghua-Peking Joint Center for Life Sciences, Beijing 100084, China
| | - Jiamin Wu
- IDG/McGovern Institute for Brain Research at Tsinghua, Beijing 100084, China; Department of Automation, Tsinghua University, Beijing 100084, China
| | - Bo Hong
- Department of Biomedical Engineering, School of Medicine, Tsinghua University, Beijing 100084, China; Tsinghua Laboratory of Brain and Intelligence (THBI), Beijing 100084, China.
| | - Kexin Yuan
- Department of Biomedical Engineering, School of Medicine, Tsinghua University, Beijing 100084, China; IDG/McGovern Institute for Brain Research at Tsinghua, Beijing 100084, China; Tsinghua Laboratory of Brain and Intelligence (THBI), Beijing 100084, China.
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22
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Navarro P, Oweiss K. Compressive sensing of functional connectivity maps from patterned optogenetic stimulation of neuronal ensembles. Patterns (N Y) 2023; 4:100845. [PMID: 37876895 PMCID: PMC10591201 DOI: 10.1016/j.patter.2023.100845] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/26/2022] [Revised: 04/04/2023] [Accepted: 08/25/2023] [Indexed: 10/26/2023]
Abstract
Mapping functional connectivity between neurons is an essential step toward probing the neural computations mediating behavior. Accurately determining synaptic connectivity maps in populations of neurons is challenging in terms of yield, accuracy, and experimental time. Here, we developed a compressive sensing approach to reconstruct synaptic connectivity maps based on random two-photon cell-targeted optogenetic stimulation and membrane voltage readout of many putative postsynaptic neurons. Using a biophysical network model of interconnected populations of excitatory and inhibitory neurons, we characterized mapping recall and precision as a function of network observability, sparsity, number of neurons stimulated, off-target stimulation, synaptic reliability, propagation latency, and network topology. We found that mapping can be achieved with far fewer measurements than the standard pairwise sequential approach, with network sparsity and synaptic reliability serving as primary determinants of the performance. Our results suggest a rapid and efficient method to reconstruct functional connectivity of sparsely connected neuronal networks.
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Affiliation(s)
- Phillip Navarro
- Electrical and Computer Engineering Department, University of Florida, Gainesville, FL 32611, USA
| | - Karim Oweiss
- Electrical and Computer Engineering Department, University of Florida, Gainesville, FL 32611, USA
- Department of Biomedical Engineering, University of Florida, Gainesville, FL 32611, USA
- Department of Neurology, University of Florida, Gainesville, FL 32611, USA
- Department of Neuroscience, McKnight Brain Institute, University of Florida, Gainesville, FL 32611, USA
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23
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Tsutsumi M, Takahashi T, Kobayashi K, Nemoto T. Fluorescence radial fluctuation enables two-photon super-resolution microscopy. Front Cell Neurosci 2023; 17:1243633. [PMID: 37881492 PMCID: PMC10595032 DOI: 10.3389/fncel.2023.1243633] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2023] [Accepted: 09/26/2023] [Indexed: 10/27/2023] Open
Abstract
Despite recent improvements in microscopy, it is still difficult to apply super-resolution microscopy for deep imaging due to the deterioration of light convergence properties in thick specimens. As a strategy to avoid such optical limitations for deep super-resolution imaging, we focused on super-resolution radial fluctuation (SRRF), a super-resolution technique based on image analysis. In this study, we applied SRRF to two-photon microscopy (2P-SRRF) and characterized its spatial resolution, suitability for deep observation, and morphological reproducibility in real brain tissue. By the comparison with structured illumination microscopy (SIM), it was confirmed that 2P-SRRF exhibited two-point resolution and morphological reproducibility comparable to that of SIM. The improvement in spatial resolution was also demonstrated at depths of more than several hundred micrometers in a brain-mimetic environment. After optimizing SRRF processing parameters, we successfully demonstrated in vivo high-resolution imaging of the fifth layer of the cerebral cortex using 2P-SRRF. This is the first report on the application of SRRF to in vivo two-photon imaging. This method can be easily applied to existing two-photon microscopes and can expand the visualization range of super-resolution imaging studies.
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Affiliation(s)
- Motosuke Tsutsumi
- Biophotonics Research Group, Exploratory Research Center on Life and Living Systems, National Institutes of Natural Sciences, Okazaki, Japan
- Research Division of Biophotonics, National Institute for Physiological Sciences, National Institutes of Natural Sciences, Okazaki, Japan
| | - Taiga Takahashi
- Biophotonics Research Group, Exploratory Research Center on Life and Living Systems, National Institutes of Natural Sciences, Okazaki, Japan
- Research Division of Biophotonics, National Institute for Physiological Sciences, National Institutes of Natural Sciences, Okazaki, Japan
| | - Kentaro Kobayashi
- Nikon Imaging Center, Research Institute for Electronic Science, Hokkaido University, Sapporo, Japan
| | - Tomomi Nemoto
- Biophotonics Research Group, Exploratory Research Center on Life and Living Systems, National Institutes of Natural Sciences, Okazaki, Japan
- Research Division of Biophotonics, National Institute for Physiological Sciences, National Institutes of Natural Sciences, Okazaki, Japan
- Nikon Imaging Center, Research Institute for Electronic Science, Hokkaido University, Sapporo, Japan
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24
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Tanguay E, Bouchard SJ, Lévesque M, De Koninck P, Breton-Provencher V. Shining light on the noradrenergic system. Neurophotonics 2023; 10:044406. [PMID: 37766924 PMCID: PMC10519836 DOI: 10.1117/1.nph.10.4.044406] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/12/2023] [Revised: 08/08/2023] [Accepted: 08/30/2023] [Indexed: 09/29/2023]
Abstract
Despite decades of research on the noradrenergic system, our understanding of its impact on brain function and behavior remains incomplete. Traditional recording techniques are challenging to implement for investigating in vivo noradrenergic activity, due to the relatively small size and the position in the brain of the locus coeruleus (LC), the primary location for noradrenergic neurons. However, recent advances in optical and fluorescent methods have enabled researchers to study the LC more effectively. Use of genetically encoded calcium indicators to image the activity of noradrenergic neurons and biosensors that monitor noradrenaline release with fluorescence can be an indispensable tool for studying noradrenergic activity. In this review, we examine how these methods are being applied to record the noradrenergic system in the rodent brain during behavior.
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Affiliation(s)
| | | | - Martin Lévesque
- CERVO Brain Research Centre, Quebec, Quebec, Canada
- Université Laval, Department of Psychiatry and Neuroscience, Faculty of Medicine, Quebec, Quebec, Canada
| | - Paul De Koninck
- CERVO Brain Research Centre, Quebec, Quebec, Canada
- Université Laval, Department of Biochemistry, Microbiology, and Bioinformatics, Faculty of Science and Engineering, Quebec, Quebec, Canada
| | - Vincent Breton-Provencher
- CERVO Brain Research Centre, Quebec, Quebec, Canada
- Université Laval, Department of Psychiatry and Neuroscience, Faculty of Medicine, Quebec, Quebec, Canada
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25
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Saidi S, Shtrahman M. Evaluation of compact pulsed lasers for two-photon microscopy using a simple method for measuring two-photon excitation efficiency. Neurophotonics 2023; 10:044303. [PMID: 38076726 PMCID: PMC10704185 DOI: 10.1117/1.nph.10.4.044303] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/01/2023] [Revised: 09/26/2023] [Accepted: 10/17/2023] [Indexed: 02/12/2024]
Abstract
Significance Two-photon (2p) microscopy has historically relied on titanium sapphire pulsed lasers that are expensive and have a large footprint. Recently, several manufacturers have developed less expensive compact pulsed lasers optimized for 2p excitation of green fluorophores. However, quantitative evaluation of their quality is lacking. Aim We describe a simple approach to systematically evaluate 2p excitation efficiency, an empiric measure of the quality of a pulsed laser and its ability to elicit 2p induced fluorescence. Approach By measuring pulse width, repetition rate, and fluorescence output, we calculated a measure of 2p excitation efficiency η , which we compared for four commercially available compact pulsed lasers in the 920 to 930 nm wavelength range. Results 2p excitation efficiency varied substantially among tested lasers. The Coherent Axon exhibited the best 2p excitation efficiency (1.09 ± 0.03 ), exceeding that of a titanium sapphire reference laser (defined to have efficiency = 1). However, its measured fluorescence was modest due to its long pulse width. Of the compact lasers, the Toptica Femtofiber Ultra exhibited the best combination of measured fluorescence (0.75 ± 0.01 ) and 2p excitation efficiency (0.86 ± 0.01 ). Conclusions We describe a simple method that both laser developers and end users can use to benchmark the 2p excitation efficiency of lasers used for 2p microscopy.
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Affiliation(s)
- Samir Saidi
- University of California, San Diego, Shu Chien-Gene Lay Department of Bioengineering, La Jolla, California, United States
| | - Matthew Shtrahman
- University of California, San Diego, Department of Neurosciences, La Jolla, California, United States
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26
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Delafontaine-Martel P, Zhang C, Lu X, Damseh R, Lesage F, Marchand PJ. Targeted capillary photothrombosis via multiphoton excitation of Rose Bengal. J Cereb Blood Flow Metab 2023; 43:1713-1725. [PMID: 36647768 PMCID: PMC10581236 DOI: 10.1177/0271678x231151560] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/01/2021] [Revised: 12/12/2022] [Accepted: 12/19/2022] [Indexed: 01/18/2023]
Abstract
Microvascular stalling, the process occurring when a capillary temporarily loses perfusion, has gained increasing interest in recent years through its demonstrated presence in various neuropathologies. Studying the impact of such stalls on the surrounding brain tissue is of paramount importance to understand their role in such diseases. Despite efforts trying to study the stalling events, investigations are hampered by their elusiveness and scarcity. In an attempt to alleviate these hurdles, we present here a novel methodology enabling transient occlusions of targeted microvascular segments through multiphoton excitation of Rose Bengal, an established photothrombotic agent. With n = 7 mice C57BL/6 J (5 males and 2 females) and 95 photothrombosis trials, we demonstrate the ability of triggering reversible blockages by illuminating a capillary segment during ∼300 s at 1000 nm, using a standard Ti:Sapphire femtosecond laser. Furthermore, we performed concurrent Optical Coherence Microscopy (OCM) angiography imaging of the microvascular network to highlight the specificity of the targeted occlusion and its duration. Through comparison with a control group, we conclude that blood flow cessation is indeed created by the photothrombotic agent via multiphoton excitation and is temporary, followed by a flow recovery in less than 24 h. Moreover, Immunohistology points toward a stalling mechanism driven by adherence of the neutrophil in the vascular lumen. This observation seems to be promoted by the inflammation locally created via multiphoton activation of Rose Bengal.
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Affiliation(s)
- Patrick Delafontaine-Martel
- Department of Electrical Engineering, Polytechnique Montreal, Montreal, Canada
- Research Center, Montreal Heart Institute, Montreal, Canada
| | - Cong Zhang
- Department of Electrical Engineering, Polytechnique Montreal, Montreal, Canada
- Research Center, Montreal Heart Institute, Montreal, Canada
| | - Xuecong Lu
- Research Center, Montreal Heart Institute, Montreal, Canada
- DeGroote School of Business – McMaster University, Ontario, Canada
| | - Rafat Damseh
- Research Center, Montreal Heart Institute, Montreal, Canada
- College of Information Technology, United Arab Emirates University, Al Ain, United Arab Emirates
| | - Frédéric Lesage
- Department of Electrical Engineering, Polytechnique Montreal, Montreal, Canada
- Research Center, Montreal Heart Institute, Montreal, Canada
| | - Paul J Marchand
- Department of Electrical Engineering, Polytechnique Montreal, Montreal, Canada
- Research Center, Montreal Heart Institute, Montreal, Canada
- École polytechnique fédérale de Lausanne- EPFL, Lausanne, Switzerland
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27
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Engelmann SA, Tomar A, Woods AL, Dunn AK. Pulse train gating to improve signal generation for in vivo two-photon fluorescence microscopy. Neurophotonics 2023; 10:045006. [PMID: 37937198 PMCID: PMC10627479 DOI: 10.1117/1.nph.10.4.045006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/06/2023] [Revised: 09/27/2023] [Accepted: 10/10/2023] [Indexed: 11/09/2023]
Abstract
Significance Two-photon microscopy is used routinely for in vivo imaging of neural and vascular structures and functions in rodents with a high resolution. Image quality, however, often degrades in deeper portions of the cerebral cortex. Strategies to improve deep imaging are therefore needed. We introduce such a strategy using the gating of high repetition rate ultrafast pulse trains to increase the signal level. Aim We investigate how the signal generation, signal-to-noise ratio (SNR), and signal-to-background ratio (SBR) improve with pulse gating while imaging in vivo mouse cerebral vasculature. Approach An electro-optic modulator with a high-power (6 W) 80 MHz repetition rate ytterbium fiber amplifier is used to create gates of pulses at a 1 MHz repetition rate. We first measure signal generation from a Texas Red solution in a cuvette to characterize the system with no gating and at a 50%, 25%, and 12.5% duty cycle. We then compare the signal generation, SNR, and SBR when imaging Texas Red-labeled vasculature using these conditions. Results We find up to a 6.73-fold increase in fluorescent signal from a cuvette when using a 12.5% duty cycle pulse gating excitation pattern as opposed to a constant 80 MHz pulse train at the same average power. We verify similar increases for in vivo imaging to that observed in cuvette testing. For deep imaging, we find that pulse gating results in a 2.95-fold increase in the SNR and a 1.37-fold increase in the SBR on average when imaging mouse cortical vasculature at depths ranging from 950 to 1050 μ m . Conclusions We demonstrate that a pulse gating strategy can either be used to limit heating when imaging superficial brain regions or used to increase signal generation in deep regions. These findings should encourage others to adopt similar pulse gating excitation schemes for imaging neural structures through two-photon microscopy.
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Affiliation(s)
- Shaun A. Engelmann
- University of Texas at Austin, Department of Biomedical Engineering, Austin, Texas, United States
| | - Alankrit Tomar
- University of Texas at Austin, Department of Biomedical Engineering, Austin, Texas, United States
| | - Aaron L. Woods
- University of Texas at Austin, Department of Biomedical Engineering, Austin, Texas, United States
| | - Andrew K. Dunn
- University of Texas at Austin, Department of Biomedical Engineering, Austin, Texas, United States
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28
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Funamizu A, Marbach F, Zador AM. Stable sound decoding despite modulated sound representation in the auditory cortex. bioRxiv 2023:2023.01.31.526457. [PMID: 37745428 PMCID: PMC10515783 DOI: 10.1101/2023.01.31.526457] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/26/2023]
Abstract
The activity of neurons in the auditory cortex is driven by both sounds and non-sensory context. To investigate the neuronal correlates of non-sensory context, we trained head-fixed mice to perform a two-alternative choice auditory task in which either reward or stimulus expectation (prior) was manipulated in blocks. Using two-photon calcium imaging to record populations of single neurons in auditory cortex, we found that both stimulus and reward expectation modulated the activity of these neurons. A linear decoder trained on this population activity could decode stimuli as well or better than predicted by the animal's performance. Interestingly, the optimal decoder was stable even in the face of variable sensory representations. Neither the context nor the mouse's choice could be reliably decoded from the recorded neural activity. Our findings suggest that in spite of modulation of auditory cortical activity by task priors, auditory cortex does not represent sufficient information about these priors to exploit them optimally and that decisions in this task require that rapidly changing sensory information be combined with more slowly varying task information extracted and represented in brain regions other than auditory cortex.
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Affiliation(s)
- Akihiro Funamizu
- Cold Spring Harbor Laboratory, 1 Bungtown Rd, Cold Spring Harbor, NY 11724, USA
- Present address: Institute for Quantitative Biosciences, the University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo, 1130032, Japan
- Present address: Department of Life Sciences, Graduate School of Arts and Sciences, the University of Tokyo, 3-8-1 Komaba, Meguro-ku, Tokyo, 1538902, Japan
| | - Fred Marbach
- Cold Spring Harbor Laboratory, 1 Bungtown Rd, Cold Spring Harbor, NY 11724, USA
- Present address: The Francis Crick Institute, 1 Midland Rd, NW1 4AT London, UK
| | - Anthony M Zador
- Cold Spring Harbor Laboratory, 1 Bungtown Rd, Cold Spring Harbor, NY 11724, USA
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29
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Delledonne A, Guazzelli E, Pescina S, Bianchera A, Galli G, Martinelli E, Sissa C. Amphiphilic Fluorinated Unimer Micelles as Nanocarriers of Fluorescent Probes for Bioimaging. ACS Appl Nano Mater 2023; 6:15551-15562. [PMID: 37706068 PMCID: PMC10496108 DOI: 10.1021/acsanm.3c02300] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/23/2023] [Accepted: 08/07/2023] [Indexed: 09/15/2023]
Abstract
The unique self-assembly properties of unimer micelles are exploited for the preparation of fluorescent nanocarriers embedding hydrophobic fluorophores. Unimer micelles are constituted by a (meth)acrylate copolymer with oligoethyleneglycol and perflurohexylethyl side chains (PEGMA90-co-FA10) in which the hydrophilic and hydrophobic comonomers are statistically distributed along the polymeric backbone. Thanks to hydrophobic interactions in water, the amphiphilic copolymer forms small nanoparticles (<10 nm), with tunable properties and functionality. An easy procedure for the encapsulation of a small hydrophobic molecule (C153 fluorophore) within unimer micelles is presented. UV-vis, fluorescence, and fluorescence anisotropy spectroscopic experimental data demonstrate that the fluorophore is effectively embedded in the nanocarriers. Moreover, the nanocarrier positively contributes to preserve the good emissive properties of the fluorophore in water. The efficacy of the dye-loaded nanocarrier as a fluorescent probe is tested in two-photon imaging of thick ex vivo porcine scleral tissue.
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Affiliation(s)
- Andrea Delledonne
- Dipartimento
di Scienze Chimiche, della Vita e della Sostenibilità Ambientale, Università di Parma, Parco Area delle Scienze 17A, 43124 Parma, Italy
| | - Elisa Guazzelli
- Dipartimento
di Chimica e Chimica Industriale, Università
di Pisa, 56124 Pisa, Italy
| | - Silvia Pescina
- ADDRes
Lab, Dipartimento di Scienze degli Alimenti e del Farmaco, Università di Parma, Parco Area delle Scienze 27A, 43124 Parma, Italy
| | - Annalisa Bianchera
- ADDRes
Lab, Dipartimento di Scienze degli Alimenti e del Farmaco, Università di Parma, Parco Area delle Scienze 27A, 43124 Parma, Italy
| | - Giancarlo Galli
- Dipartimento
di Chimica e Chimica Industriale, Università
di Pisa, 56124 Pisa, Italy
| | - Elisa Martinelli
- Dipartimento
di Chimica e Chimica Industriale, Università
di Pisa, 56124 Pisa, Italy
- Centro
per la Integrazione Della Strumentazione Dell’Università
di Pisa (CISUP), Lungarno
Pacinotti 43/44, 56126 Pisa, Italy
| | - Cristina Sissa
- Dipartimento
di Scienze Chimiche, della Vita e della Sostenibilità Ambientale, Università di Parma, Parco Area delle Scienze 17A, 43124 Parma, Italy
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30
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Slomp M, Koekkoek LL, Mutersbaugh M, Linville I, Luquet SH, la Fleur SE. Free-choice high-fat diet consumption reduces lateral hypothalamic GABAergic activity, without disturbing neural response to sucrose drinking in mice. Front Neurosci 2023; 17:1219569. [PMID: 37600007 PMCID: PMC10434857 DOI: 10.3389/fnins.2023.1219569] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2023] [Accepted: 07/21/2023] [Indexed: 08/22/2023] Open
Abstract
Nutrition can influence the brain and affect its regulation of food intake, especially that of high-palatable foods. We hypothesize that fat and sugar have interacting effects on the brain, and the lateral hypothalamus (LH) is a prime candidate to be involved in this interaction. The LH is a heterogeneous area, crucial for regulating consummatory behaviors, and integrating homeostatic and hedonic needs. GABAergic LH neurons stimulate feeding when activated, and are responsive to consummatory behavior while encoding sucrose palatability. Previously, we have shown that glutamatergic LH neurons reduce their activity in response to sugar drinking and that this response is disturbed by a free-choice high-fat diet (fcHFD). Whether GABAergic LH neurons, and their response to sugar, is affected by a fcHFD is yet unknown. Using head-fixed two-photon microscopy, we analyzed activity changes in LHVgat neuronal activity in chow or fcHFD-fed mice in response to water or sucrose drinking. A fcHFD decreased overall LHVgat neuronal activity, without disrupting the sucrose-induced increase. When focusing on the response per unique neuron, a vast majority of neurons respond inconsistently over time. Thus, a fcHFD dampens overall LH GABAergic activity, while it does not disturb the response to sucrose. The inconsistent responding over time suggests that it is not one specific subpopulation of LH GABAergic neurons that is driving these behaviors, but rather a result of the integrative properties of a complex neural network. Further research should focus on determining how this dampening of LH GABAergic activity contributes to hyperphagia and the development of obesity.
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Affiliation(s)
- Margo Slomp
- Endocrinology Laboratory, Department of Laboratory Medicine, Amsterdam UMC, Location University of Amsterdam, Amsterdam, Netherlands
- Amsterdam Neuroscience, Cellular and Molecular Mechanisms, Amsterdam, Netherlands
- Amsterdam Gastroenterology Endocrinology and Metabolism, Amsterdam, Netherlands
- Metabolism and Reward Group, Royal Netherlands Academy of Arts and Sciences, Netherlands Institute of Neuroscience, Amsterdam, Netherlands
| | - Laura L. Koekkoek
- Endocrinology Laboratory, Department of Laboratory Medicine, Amsterdam UMC, Location University of Amsterdam, Amsterdam, Netherlands
- Amsterdam Neuroscience, Cellular and Molecular Mechanisms, Amsterdam, Netherlands
- Amsterdam Gastroenterology Endocrinology and Metabolism, Amsterdam, Netherlands
- Metabolism and Reward Group, Royal Netherlands Academy of Arts and Sciences, Netherlands Institute of Neuroscience, Amsterdam, Netherlands
| | - Michael Mutersbaugh
- Department of Biomedical Engineering, University of Virginia, Charlottesville, VA, United States
| | - Ian Linville
- Department of Biomedical Engineering, University of Virginia, Charlottesville, VA, United States
| | - Serge H. Luquet
- Université Paris Cité, CNRS, Unité de Biologie Fonctionnelle et Adaptative, Paris, France
| | - Susanne E. la Fleur
- Endocrinology Laboratory, Department of Laboratory Medicine, Amsterdam UMC, Location University of Amsterdam, Amsterdam, Netherlands
- Amsterdam Neuroscience, Cellular and Molecular Mechanisms, Amsterdam, Netherlands
- Amsterdam Gastroenterology Endocrinology and Metabolism, Amsterdam, Netherlands
- Metabolism and Reward Group, Royal Netherlands Academy of Arts and Sciences, Netherlands Institute of Neuroscience, Amsterdam, Netherlands
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31
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Shin P, Pian Q, Ishikawa H, Hamanaka G, Mandeville ET, Guo S, Fu B, Alfadhel M, Allu SR, Şencan-Eğilmez I, Li B, Ran C, Vinogradov SA, Ayata C, Lo E, Arai K, Devor A, Sakadžić S. Aerobic exercise reverses aging-induced depth-dependent decline in cerebral microcirculation. eLife 2023; 12:e86329. [PMID: 37402178 PMCID: PMC10319437 DOI: 10.7554/elife.86329] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2023] [Accepted: 06/16/2023] [Indexed: 07/06/2023] Open
Abstract
Aging is a major risk factor for cognitive impairment. Aerobic exercise benefits brain function and may promote cognitive health in older adults. However, underlying biological mechanisms across cerebral gray and white matter are poorly understood. Selective vulnerability of the white matter to small vessel disease and a link between white matter health and cognitive function suggests a potential role for responses in deep cerebral microcirculation. Here, we tested whether aerobic exercise modulates cerebral microcirculatory changes induced by aging. To this end, we carried out a comprehensive quantitative examination of changes in cerebral microvascular physiology in cortical gray and subcortical white matter in mice (3-6 vs. 19-21 months old), and asked whether and how exercise may rescue age-induced deficits. In the sedentary group, aging caused a more severe decline in cerebral microvascular perfusion and oxygenation in deep (infragranular) cortical layers and subcortical white matter compared with superficial (supragranular) cortical layers. Five months of voluntary aerobic exercise partly renormalized microvascular perfusion and oxygenation in aged mice in a depth-dependent manner, and brought these spatial distributions closer to those of young adult sedentary mice. These microcirculatory effects were accompanied by an improvement in cognitive function. Our work demonstrates the selective vulnerability of the deep cortex and subcortical white matter to aging-induced decline in microcirculation, as well as the responsiveness of these regions to aerobic exercise.
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Affiliation(s)
- Paul Shin
- Athinoula A Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Charlestown, United States
| | - Qi Pian
- Athinoula A Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Charlestown, United States
| | - Hidehiro Ishikawa
- Neuroprotection Research Laboratory, Departments of Radiology and Neurology, Massachusetts General Hospital, Harvard Medical School, Charlestown, United States
| | - Gen Hamanaka
- Neuroprotection Research Laboratory, Departments of Radiology and Neurology, Massachusetts General Hospital, Harvard Medical School, Charlestown, United States
| | - Emiri T Mandeville
- Neuroprotection Research Laboratory, Departments of Radiology and Neurology, Massachusetts General Hospital, Harvard Medical School, Charlestown, United States
| | - Shuzhen Guo
- Neuroprotection Research Laboratory, Departments of Radiology and Neurology, Massachusetts General Hospital, Harvard Medical School, Charlestown, United States
| | - Buyin Fu
- Athinoula A Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Charlestown, United States
| | - Mohammed Alfadhel
- Athinoula A Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Charlestown, United States
- Department of Bioengineering, Northeastern University, Boston, United States
| | - Srinivasa Rao Allu
- Department of Biochemistry and Biophysics, University of Pennsylvania, Philadelphia, United States
- Department of Chemistry, University of Pennsylvania, Philadelphia, United States
| | - Ikbal Şencan-Eğilmez
- Athinoula A Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Charlestown, United States
- Biophotonics Research Center, Mallinckrodt Institute of Radiology, Department of Radiology, Washington University School of Medicine, St. Louis, United States
| | - Baoqiang Li
- Athinoula A Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Charlestown, United States
- Brain Cognition and Brain Disease Institute, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China
| | - Chongzhao Ran
- Athinoula A Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Charlestown, United States
| | - Sergei A Vinogradov
- Department of Biochemistry and Biophysics, University of Pennsylvania, Philadelphia, United States
- Department of Chemistry, University of Pennsylvania, Philadelphia, United States
| | - Cenk Ayata
- Neurovascular Research Laboratory, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Charlestown, United States
- Stroke Service, Department of Neurology, Massachusetts General Hospital, Harvard Medical School, Charlestown, United States
| | - Eng Lo
- Neuroprotection Research Laboratory, Departments of Radiology and Neurology, Massachusetts General Hospital, Harvard Medical School, Charlestown, United States
| | - Ken Arai
- Neuroprotection Research Laboratory, Departments of Radiology and Neurology, Massachusetts General Hospital, Harvard Medical School, Charlestown, United States
| | - Anna Devor
- Athinoula A Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Charlestown, United States
- Department of Biomedical Engineering, Boston University, Boston, United States
| | - Sava Sakadžić
- Athinoula A Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Charlestown, United States
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32
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Pian Q, Alfadhel M, Tang J, Lee GV, Li B, Fu B, Ayata Y, Yaseen MA, Boas DA, Secomb TW, Sakadzic S. Cortical microvascular blood flow velocity mapping by combining dynamic light scattering optical coherence tomography and two-photon microscopy. J Biomed Opt 2023; 28:076003. [PMID: 37484973 PMCID: PMC10362155 DOI: 10.1117/1.jbo.28.7.076003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/12/2023] [Revised: 05/30/2023] [Accepted: 06/05/2023] [Indexed: 07/25/2023]
Abstract
Significance The accurate large-scale mapping of cerebral microvascular blood flow velocity is crucial for a better understanding of cerebral blood flow (CBF) regulation. Although optical imaging techniques enable both high-resolution microvascular angiography and fast absolute CBF velocity measurements in the mouse cortex, they usually require different imaging techniques with independent system configurations to maximize their performances. Consequently, it is still a challenge to accurately combine functional and morphological measurements to co-register CBF speed distribution from hundreds of microvessels with high-resolution microvascular angiograms. Aim We propose a data acquisition and processing framework to co-register a large set of microvascular blood flow velocity measurements from dynamic light scattering optical coherence tomography (DLS-OCT) with the corresponding microvascular angiogram obtained using two-photon microscopy (2PM). Approach We used DLS-OCT to first rapidly acquire a large set of microvascular velocities through a sealed cranial window in mice and then to acquire high-resolution microvascular angiograms using 2PM. The acquired data were processed in three steps: (i) 2PM angiogram coregistration with the DLS-OCT angiogram, (ii) 2PM angiogram segmentation and graphing, and (iii) mapping of the CBF velocities to the graph representation of the 2PM angiogram. Results We implemented the developed framework on the three datasets acquired from the mice cortices to facilitate the coregistration of the large sets of DLS-OCT flow velocity measurements with 2PM angiograms. We retrieved the distributions of red blood cell velocities in arterioles, venules, and capillaries as a function of the branching order from precapillary arterioles and postcapillary venules from more than 1000 microvascular segments. Conclusions The proposed framework may serve as a useful tool for quantitative analysis of large microvascular datasets obtained by OCT and 2PM in studies involving normal brain functioning, progression of various diseases, and numerical modeling of the oxygen advection and diffusion in the realistic microvascular networks.
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Affiliation(s)
- Qi Pian
- Massachusetts General Hospital, Harvard Medical School, Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Charlestown, Massachusetts, United States
| | - Mohammed Alfadhel
- Massachusetts General Hospital, Harvard Medical School, Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Charlestown, Massachusetts, United States
- Northeastern University, Department of Bioengineering, Boston, Massachusetts, United States
| | - Jianbo Tang
- Southern University of Science and Technology, Department of Biomedical Engineering, Shenzhen, China
| | - Grace V. Lee
- University of Arizona, Program in Applied Mathematics, Tucson, Arizona, United States
| | - Baoqiang Li
- Massachusetts General Hospital, Harvard Medical School, Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Charlestown, Massachusetts, United States
- Chinese Academy of Sciences, Shenzhen Institute of Advanced Technology, Brain Cognition and Brain Disease Institute; Shenzhen Fundamental Research Institutions, Shenzhen–Hong Kong Institute of Brain Science, Shenzhen, Guangdong, China
| | - Buyin Fu
- Massachusetts General Hospital, Harvard Medical School, Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Charlestown, Massachusetts, United States
| | - Yagmur Ayata
- Massachusetts General Hospital, Harvard Medical School, Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Charlestown, Massachusetts, United States
| | - Mohammad Abbas Yaseen
- Massachusetts General Hospital, Harvard Medical School, Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Charlestown, Massachusetts, United States
- Northeastern University, Department of Bioengineering, Boston, Massachusetts, United States
| | - David A. Boas
- Boston University, Department of Biomedical Engineering, Boston, Massachusetts, United States
| | - Timothy W. Secomb
- University of Arizona, Program in Applied Mathematics, Tucson, Arizona, United States
- University of Arizona, Department of Mathematics, Tucson, Arizona, United States
- University of Arizona, Department of Physiology, Tucson, Arizona, United States
| | - Sava Sakadzic
- Massachusetts General Hospital, Harvard Medical School, Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Charlestown, Massachusetts, United States
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Li B, Leng J, Şencan-Eğilmez I, Takase H, Alfadhel MAH, Fu B, Shahidi M, Lo EH, Arai K, Sakadžić S. Differential reductions in the capillary red-blood-cell flux between retina and brain under chronic global hypoperfusion. Neurophotonics 2023; 10:035001. [PMID: 37323511 PMCID: PMC10266089 DOI: 10.1117/1.nph.10.3.035001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/09/2023] [Revised: 04/13/2023] [Accepted: 04/26/2023] [Indexed: 06/17/2023]
Abstract
Significance It has been hypothesized that abnormal microcirculation in the retina might predict the risk of ischemic damages in the brain. Direct comparison between the retinal and the cerebral microcirculation using similar animal preparation and under similar experimental conditions would help test this hypothesis. Aim We investigated capillary red-blood-cell (RBC) flux changes under controlled conditions and bilateral-carotid-artery-stenosis (BCAS)-induced hypoperfusion, and then compared them with our previous measurements performed in the brain. Approach We measured capillary RBC flux in mouse retina with two-photon microscopy using a fluorescence-labeled RBC-passage approach. Key physiological parameters were monitored during experiments to ensure stable physiology. Results We found that under the controlled conditions, capillary RBC flux in the retina was much higher than in the brain (i.e., cerebral cortical gray matter and subcortical white matter), and that BCAS induced a much larger decrease in capillary RBC flux in the retina than in the brain. Conclusions We demonstrated a two-photon microscopy-based technique to efficiently measure capillary RBC flux in the retina. Since cerebral subcortical white matter often exhibits early pathological developments due to global hypoperfusion, our results suggest that retinal microcirculation may be utilized as an early marker of brain diseases involving global hypoperfusion.
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Affiliation(s)
- Baoqiang Li
- Chinese Academy of Sciences, Shenzhen Institute of Advanced Technology, Brain Cognition and Brain Disease Institute; Shenzhen Fundamental Research Institutions, Shenzhen–Hong Kong Institute of Brain Science, Shenzhen, Guangdong, China
- Harvard Medical School, Massachusetts General Hospital, Athinoula A. Martinos Center for Biomedical Imaging, Charlestown, Massachusetts, United States
| | - Ji Leng
- Chinese Academy of Sciences, Shenzhen Institute of Advanced Technology, Brain Cognition and Brain Disease Institute; Shenzhen Fundamental Research Institutions, Shenzhen–Hong Kong Institute of Brain Science, Shenzhen, Guangdong, China
| | - Ikbal Şencan-Eğilmez
- Harvard Medical School, Massachusetts General Hospital, Athinoula A. Martinos Center for Biomedical Imaging, Charlestown, Massachusetts, United States
| | - Hajime Takase
- Harvard Medical School, Massachusetts General Hospital, Department of Radiology, Charlestown, Massachusetts, United States
- Harvard Medical School, Massachusetts General Hospital, Department of Neurology, Charlestown, Massachusetts, United States
| | - Mohammed Ali H. Alfadhel
- Harvard Medical School, Massachusetts General Hospital, Athinoula A. Martinos Center for Biomedical Imaging, Charlestown, Massachusetts, United States
| | - Buyin Fu
- Harvard Medical School, Massachusetts General Hospital, Athinoula A. Martinos Center for Biomedical Imaging, Charlestown, Massachusetts, United States
| | - Mahnaz Shahidi
- University of Southern California, Department of Ophthalmology, Los Angeles, California, United States
| | - Eng H. Lo
- Harvard Medical School, Massachusetts General Hospital, Department of Radiology, Charlestown, Massachusetts, United States
- Harvard Medical School, Massachusetts General Hospital, Department of Neurology, Charlestown, Massachusetts, United States
| | - Ken Arai
- Harvard Medical School, Massachusetts General Hospital, Department of Radiology, Charlestown, Massachusetts, United States
- Harvard Medical School, Massachusetts General Hospital, Department of Neurology, Charlestown, Massachusetts, United States
| | - Sava Sakadžić
- Harvard Medical School, Massachusetts General Hospital, Athinoula A. Martinos Center for Biomedical Imaging, Charlestown, Massachusetts, United States
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Giblin J, Kura S, Nunuez JLU, Zhang J, Kureli G, Jiang J, Boas DA, Chen IA. High throughput detection of capillary stalling events with Bessel beam two-photon microscopy. Neurophotonics 2023; 10:035009. [PMID: 37705938 PMCID: PMC10495839 DOI: 10.1117/1.nph.10.3.035009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/02/2023] [Revised: 08/09/2023] [Accepted: 08/17/2023] [Indexed: 09/15/2023]
Abstract
Significance Brief disruptions in capillary flow, commonly referred to as capillary "stalling," have gained interest recently for their potential role in disrupting cerebral blood flow and oxygen delivery. Approaches to studying this phenomenon have been hindered by limited volumetric imaging rates and cumbersome manual analysis. The ability to precisely and efficiently quantify the dynamics of these events will be key in understanding their potential role in stroke and neurodegenerative diseases, such as Alzheimer's disease. Aim Our study aimed to demonstrate that the fast volumetric imaging rates offered by Bessel beam two-photon microscopy combined with improved data analysis throughput allows for faster and more precise measurement of capillary stall dynamics. Results We found that while our analysis approach was unable to achieve full automation, we were able to cut analysis time in half while also finding stalling events that were missed in traditional blind manual analysis. The resulting data showed that our Bessel beam system was captured more stalling events compared to optical coherence tomography, particularly shorter stalling events. We then compare differences in stall dynamics between a young and old group of mice as well as a demonstrate changes in stalling before and after photothrombotic model of stroke. Finally, we also demonstrate the ability to monitor arteriole dynamics alongside stall dynamics. Conclusions Bessel beam two-photon microscopy combined with high throughput analysis is a powerful tool for studying capillary stalling due to its ability to monitor hundreds of capillaries simultaneously at high frame rates.
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Affiliation(s)
- John Giblin
- Boston University, Department of Biomedical Engineering, Boston, Massachusetts, United States
- Boston University, Neurophotonics Center, Boston, Massachusetts, United States
| | - Sreekanth Kura
- Boston University, Department of Biomedical Engineering, Boston, Massachusetts, United States
- Boston University, Neurophotonics Center, Boston, Massachusetts, United States
| | - Juan Luis Ugarte Nunuez
- Boston University, Department of Biomedical Engineering, Boston, Massachusetts, United States
- Boston University, Neurophotonics Center, Boston, Massachusetts, United States
| | - Juncheng Zhang
- Boston University, Department of Biomedical Engineering, Boston, Massachusetts, United States
- Boston University, Neurophotonics Center, Boston, Massachusetts, United States
| | - Gulce Kureli
- Boston University, Department of Biomedical Engineering, Boston, Massachusetts, United States
- Boston University, Neurophotonics Center, Boston, Massachusetts, United States
| | - John Jiang
- Boston University, Department of Biomedical Engineering, Boston, Massachusetts, United States
- Boston University, Neurophotonics Center, Boston, Massachusetts, United States
| | - David A. Boas
- Boston University, Department of Biomedical Engineering, Boston, Massachusetts, United States
- Boston University, Neurophotonics Center, Boston, Massachusetts, United States
| | - Ichun A. Chen
- Boston University, Department of Biomedical Engineering, Boston, Massachusetts, United States
- Boston University, Neurophotonics Center, Boston, Massachusetts, United States
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Benkowska-Biernacka D, Mucha SG, Firlej L, Formalik F, Bantignies JL, Anglaret E, Samoć M, Matczyszyn K. Strongly Emitting Folic Acid-Derived Carbon Nanodots for One- and Two-Photon Imaging of Lyotropic Myelin Figures. ACS Appl Mater Interfaces 2023. [PMID: 37366586 DOI: 10.1021/acsami.3c05656] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/28/2023]
Abstract
Non-invasive imaging of morphological changes in biologically relevant lipidic mesophases is essential for the understanding of membrane-mediated processes. However, its methodological aspects need to be further explored, with particular attention paid to the design of new excellent fluorescent probes. Here, we have demonstrated that bright and biocompatible folic acid-derived carbon nanodots (FA CNDs) may be successfully applied as fluorescent markers in one- and two-photon imaging of bioinspired myelin figures (MFs). Structural and optical properties of these new FA CNDs were first extensively characterized; they revealed remarkable fluorescence performance in linear and non-linear excitation regimes, justifying further applications. Then, confocal fluorescence microscopy and two-photon excited fluorescence microscopy were used to investigate a three-dimensional distribution of FA CNDs within the phospholipid-based MFs. Our results showed that FA CNDs are effective markers for imaging various forms and parts of multilamellar microstructures.
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Affiliation(s)
- Dominika Benkowska-Biernacka
- Institute of Advanced Materials, Faculty of Chemistry, Wroclaw University of Science and Technology, 50-370 Wroclaw, Poland
| | - Sebastian G Mucha
- Laboratoire Charles Coulomb (L2C), UMR5221, Université de Montpellier (CNRS), 34095 Montpellier, France
| | - Lucyna Firlej
- Laboratoire Charles Coulomb (L2C), UMR5221, Université de Montpellier (CNRS), 34095 Montpellier, France
- Department of Physics and Astronomy, University of Missouri, Columbia, Missouri 65211, United States
| | - Filip Formalik
- Department of Chemical and Biological Engineering, Northwestern University, Evanston, Illinois 60208, United States
- Department of Micro, Nano, and Bioprocess Engineering, Faculty of Chemistry, Wroclaw University of Science and Technology, 50-370 Wroclaw, Poland
| | - Jean-Louis Bantignies
- Laboratoire Charles Coulomb (L2C), UMR5221, Université de Montpellier (CNRS), 34095 Montpellier, France
| | - Eric Anglaret
- Laboratoire Charles Coulomb (L2C), UMR5221, Université de Montpellier (CNRS), 34095 Montpellier, France
| | - Marek Samoć
- Institute of Advanced Materials, Faculty of Chemistry, Wroclaw University of Science and Technology, 50-370 Wroclaw, Poland
| | - Katarzyna Matczyszyn
- Institute of Advanced Materials, Faculty of Chemistry, Wroclaw University of Science and Technology, 50-370 Wroclaw, Poland
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Paoli M, Antonacci Y, Albi A, Faes L, Haase A. Granger Causality Analysis of Transient Calcium Dynamics in the Honey Bee Antennal Lobe Network. Insects 2023; 14:539. [PMID: 37367355 DOI: 10.3390/insects14060539] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/28/2023] [Revised: 05/28/2023] [Accepted: 06/08/2023] [Indexed: 06/28/2023]
Abstract
Odorant processing presents multiple parallels across animal species, and insects became relevant models for the study of olfactory coding because of the tractability of the underlying neural circuits. Within the insect brain, odorants are received by olfactory sensory neurons and processed by the antennal lobe network. Such a network comprises multiple nodes, named glomeruli, that receive sensory information and are interconnected by local interneurons participating in shaping the neural representation of an odorant. The study of functional connectivity between the nodes of a sensory network in vivo is a challenging task that requires simultaneous recording from multiple nodes at high temporal resolutions. Here, we followed the calcium dynamics of antennal lobe glomeruli and applied Granger causality analysis to assess the functional connectivity among network nodes in the presence and absence of an odorous stimulus. This approach revealed the existence of causal connectivity links between antennal lobe glomeruli in the absence of olfactory stimulation, while at odor arrival, the connectivity network's density increased and became stimulus-specific. Thus, such an analytical approach may provide a new tool for the investigation of neural network plasticity in vivo.
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Affiliation(s)
- Marco Paoli
- Research Center of Animal Cognition, Center for Integrative Biology, CNRS, University of Toulouse, 31400 Toulouse, France
| | - Yuri Antonacci
- Dipartimento di Ingegneria, Università di Palermo, 90128 Palermo, Italy
| | - Angela Albi
- Department of Collective Behavior, Max Planck Institute of Animal Behavior, 78457 Konstanz, Germany
- Department of Biology, University of Konstanz, 78457 Konstanz, Germany
| | - Luca Faes
- Dipartimento di Ingegneria, Università di Palermo, 90128 Palermo, Italy
| | - Albrecht Haase
- Center for Mind/Brain Science (CIMeC), University of Trento, 38068 Rovereto, Italy
- Department of Physics, University of Trento, 38123 Povo, Italy
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37
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Leikvoll A, Kara P. High fidelity sensory-evoked responses in neocortex after intravenous injection of genetically encoded calcium sensors. Front Neurosci 2023; 17:1181828. [PMID: 37250396 PMCID: PMC10213453 DOI: 10.3389/fnins.2023.1181828] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2023] [Accepted: 04/12/2023] [Indexed: 05/31/2023] Open
Abstract
Two-photon imaging of genetically-encoded calcium indicators (GECIs) has traditionally relied on intracranial injections of adeno-associated virus (AAV) or transgenic animals to achieve expression. Intracranial injections require an invasive surgery and result in a relatively small volume of tissue labeling. Transgenic animals, although they can have brain-wide GECI expression, often express GECIs in only a small subset of neurons, may have abnormal behavioral phenotypes, and are currently limited to older generations of GECIs. Inspired by recent developments in the synthesis of AAVs that readily cross the blood brain barrier, we tested whether an alternative strategy of intravenously injecting AAV-PHP.eB is suitable for two-photon calcium imaging of neurons over many months after injection. We injected C57BL/6 J mice with AAV-PHP.eB-Synapsin-jGCaMP7s via the retro-orbital sinus. After allowing 5 to 34 weeks for expression, we performed conventional and widefield two-photon imaging of layers 2/3, 4 and 5 of the primary visual cortex. We found reproducible trial-by-trial neural responses and tuning properties consistent with known feature selectivity in the visual cortex. Thus, intravenous injection of AAV-PHP.eB does not interfere with the normal processing in neural circuits. In vivo and histological images show no nuclear expression of jGCaMP7s for at least 34 weeks post-injection.
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Affiliation(s)
| | - Prakash Kara
- Department of Neuroscience, University of Minnesota, Minneapolis, MN, United States
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Zhukov O, He C, Soylu-Kucharz R, Cai C, Lauritzen AD, Aldana BI, Björkqvist M, Lauritzen M, Kucharz K. Preserved blood-brain barrier and neurovascular coupling in female 5xFAD model of Alzheimer's disease. Front Aging Neurosci 2023; 15:1089005. [PMID: 37261266 PMCID: PMC10228387 DOI: 10.3389/fnagi.2023.1089005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2022] [Accepted: 04/17/2023] [Indexed: 06/02/2023] Open
Abstract
Introduction Dysfunction of the cerebral vasculature is considered one of the key components of Alzheimer's disease (AD), but the mechanisms affecting individual brain vessels are poorly understood. Methods Here, using in vivo two-photon microscopy in superficial cortical layers and ex vivo imaging across brain regions, we characterized blood-brain barrier (BBB) function and neurovascular coupling (NVC) at the level of individual brain vessels in adult female 5xFAD mice, an aggressive amyloid-β (Aβ) model of AD. Results We report a lack of abnormal increase in adsorptive-mediated transcytosis of albumin and preserved paracellular barrier for fibrinogen and small molecules despite an extensive load of Aβ. Likewise, the NVC responses to somatosensory stimulation were preserved at all regulatory segments of the microvasculature: penetrating arterioles, precapillary sphincters, and capillaries. Lastly, the Aβ plaques did not affect the density of capillary pericytes. Conclusion Our findings provide direct evidence of preserved microvascular function in the 5xFAD mice and highlight the critical dependence of the experimental outcomes on the choice of preclinical models of AD. We propose that the presence of parenchymal Aβ does not warrant BBB and NVC dysfunction and that the generalized view that microvascular impairment is inherent to Aβ aggregation may need to be revised.
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Affiliation(s)
- Oleg Zhukov
- Department of Neuroscience, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Chen He
- Department of Neuroscience, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Rana Soylu-Kucharz
- Biomarkers in Brain Disease, Department of Experimental Medical Sciences, Lund University, Lund, Sweden
| | - Changsi Cai
- Department of Neuroscience, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | | | - Blanca Irene Aldana
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Maria Björkqvist
- Biomarkers in Brain Disease, Department of Experimental Medical Sciences, Lund University, Lund, Sweden
| | - Martin Lauritzen
- Department of Neuroscience, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
- Department of Clinical Neurophysiology, Rigshospitalet, Copenhagen, Denmark
| | - Krzysztof Kucharz
- Department of Neuroscience, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
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Zhao Z, Zhou Y, Liu B, He J, Zhao J, Cai Y, Fan J, Li X, Wang Z, Lu Z, Wu J, Qi H, Dai Q. Two-photon synthetic aperture microscopy for minimally invasive fast 3D imaging of native subcellular behaviors in deep tissue. Cell 2023; 186:2475-2491.e22. [PMID: 37178688 DOI: 10.1016/j.cell.2023.04.016] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2022] [Revised: 02/21/2023] [Accepted: 04/10/2023] [Indexed: 05/15/2023]
Abstract
Holistic understanding of physio-pathological processes requires noninvasive 3D imaging in deep tissue across multiple spatial and temporal scales to link diverse transient subcellular behaviors with long-term physiogenesis. Despite broad applications of two-photon microscopy (TPM), there remains an inevitable tradeoff among spatiotemporal resolution, imaging volumes, and durations due to the point-scanning scheme, accumulated phototoxicity, and optical aberrations. Here, we harnessed the concept of synthetic aperture radar in TPM to achieve aberration-corrected 3D imaging of subcellular dynamics at a millisecond scale for over 100,000 large volumes in deep tissue, with three orders of magnitude reduction in photobleaching. With its advantages, we identified direct intercellular communications through migrasome generation following traumatic brain injury, visualized the formation process of germinal center in the mouse lymph node, and characterized heterogeneous cellular states in the mouse visual cortex, opening up a horizon for intravital imaging to understand the organizations and functions of biological systems at a holistic level.
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Affiliation(s)
- Zhifeng Zhao
- Department of Automation, Tsinghua University, Beijing 100084, China; Institute for Brain and Cognitive Sciences, Tsinghua University, Beijing 100084, China; Beijing Key Laboratory of Multi-dimension & Multi-scale Computational Photography (MMCP), Tsinghua University, Beijing 100084, China; IDG/McGovern Institute for Brain Research, Tsinghua University, Beijing 100084, China; Hangzhou Zhuoxi Institute of Brain and Intelligence, Hangzhou 311100, China
| | - Yiliang Zhou
- Department of Automation, Tsinghua University, Beijing 100084, China; Institute for Brain and Cognitive Sciences, Tsinghua University, Beijing 100084, China; Beijing Key Laboratory of Multi-dimension & Multi-scale Computational Photography (MMCP), Tsinghua University, Beijing 100084, China; IDG/McGovern Institute for Brain Research, Tsinghua University, Beijing 100084, China; Hangzhou Zhuoxi Institute of Brain and Intelligence, Hangzhou 311100, China
| | - Bo Liu
- Tsinghua-Peking Center for Life Sciences, Beijing 100084, China; Laboratory of Dynamic Immunobiology, Institute for Immunology, Tsinghua University, Beijing 100084, China; Department of Basic Medical Sciences, School of Medicine, Tsinghua University, Beijing 100084, China
| | - Jing He
- Department of Automation, Tsinghua University, Beijing 100084, China; Institute for Brain and Cognitive Sciences, Tsinghua University, Beijing 100084, China; Beijing Key Laboratory of Multi-dimension & Multi-scale Computational Photography (MMCP), Tsinghua University, Beijing 100084, China; IDG/McGovern Institute for Brain Research, Tsinghua University, Beijing 100084, China
| | - Jiayin Zhao
- Department of Automation, Tsinghua University, Beijing 100084, China; Institute for Brain and Cognitive Sciences, Tsinghua University, Beijing 100084, China; Beijing Key Laboratory of Multi-dimension & Multi-scale Computational Photography (MMCP), Tsinghua University, Beijing 100084, China; Tsinghua Shenzhen International Graduate School, Tsinghua University, Shenzhen 518071, China
| | - Yeyi Cai
- Department of Automation, Tsinghua University, Beijing 100084, China; Institute for Brain and Cognitive Sciences, Tsinghua University, Beijing 100084, China; Beijing Key Laboratory of Multi-dimension & Multi-scale Computational Photography (MMCP), Tsinghua University, Beijing 100084, China; IDG/McGovern Institute for Brain Research, Tsinghua University, Beijing 100084, China
| | - Jingtao Fan
- Department of Automation, Tsinghua University, Beijing 100084, China; Institute for Brain and Cognitive Sciences, Tsinghua University, Beijing 100084, China; Beijing Key Laboratory of Multi-dimension & Multi-scale Computational Photography (MMCP), Tsinghua University, Beijing 100084, China
| | - Xinyang Li
- Department of Automation, Tsinghua University, Beijing 100084, China; Institute for Brain and Cognitive Sciences, Tsinghua University, Beijing 100084, China; Beijing Key Laboratory of Multi-dimension & Multi-scale Computational Photography (MMCP), Tsinghua University, Beijing 100084, China; Hangzhou Zhuoxi Institute of Brain and Intelligence, Hangzhou 311100, China; Tsinghua Shenzhen International Graduate School, Tsinghua University, Shenzhen 518071, China
| | - Zilin Wang
- Institute for Brain and Cognitive Sciences, Tsinghua University, Beijing 100084, China; Department of Anesthesiology, the First Medical Center, Chinese PLA General Hospital, Beijing 100853, China
| | - Zhi Lu
- Department of Automation, Tsinghua University, Beijing 100084, China; Institute for Brain and Cognitive Sciences, Tsinghua University, Beijing 100084, China; Beijing Key Laboratory of Multi-dimension & Multi-scale Computational Photography (MMCP), Tsinghua University, Beijing 100084, China; IDG/McGovern Institute for Brain Research, Tsinghua University, Beijing 100084, China; Hangzhou Zhuoxi Institute of Brain and Intelligence, Hangzhou 311100, China
| | - Jiamin Wu
- Department of Automation, Tsinghua University, Beijing 100084, China; Institute for Brain and Cognitive Sciences, Tsinghua University, Beijing 100084, China; Beijing Key Laboratory of Multi-dimension & Multi-scale Computational Photography (MMCP), Tsinghua University, Beijing 100084, China; IDG/McGovern Institute for Brain Research, Tsinghua University, Beijing 100084, China.
| | - Hai Qi
- Tsinghua-Peking Center for Life Sciences, Beijing 100084, China; Laboratory of Dynamic Immunobiology, Institute for Immunology, Tsinghua University, Beijing 100084, China; Department of Basic Medical Sciences, School of Medicine, Tsinghua University, Beijing 100084, China; Beijing Key Laboratory for Immunological Research on Chronic Diseases, Tsinghua University, Beijing 100084, China; Beijing Frontier Research Center for Biological Structure, Tsinghua University, Beijing 100084, China.
| | - Qionghai Dai
- Department of Automation, Tsinghua University, Beijing 100084, China; Institute for Brain and Cognitive Sciences, Tsinghua University, Beijing 100084, China; Beijing Key Laboratory of Multi-dimension & Multi-scale Computational Photography (MMCP), Tsinghua University, Beijing 100084, China; IDG/McGovern Institute for Brain Research, Tsinghua University, Beijing 100084, China.
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Xiong H, Tang F, Guo Y, Xu R, Lei P. Neural Circuit Changes in Neurological Disorders: Evidence from in vivo Two-photon Imaging. Ageing Res Rev 2023; 87:101933. [PMID: 37061201 DOI: 10.1016/j.arr.2023.101933] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2022] [Accepted: 04/11/2023] [Indexed: 04/17/2023]
Abstract
Neural circuits, such as synaptic plasticity and neural activity, are critical components of healthy brain function. The consequent dynamic remodeling of neural circuits is an ongoing procedure affecting neuronal activities. Disruption of this essential process results in diseases. Advanced microscopic applications such as two-photon laser scanning microscopy have recently been applied to understand neural circuit changes during disease since it can visualize fine structural and functional cellular activation in living animals. In this review, we have summarized the latest work assessing the dynamic rewiring of postsynaptic dendritic spines and modulation of calcium transients in neurons of the intact living brain, focusing on their potential roles in neurological disorders (e.g. Alzheimer's disease, stroke, and epilepsy). Understanding the fine changes that occurred in the brain during disease is crucial for future clinical intervention developments.
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Affiliation(s)
- Huan Xiong
- Department of Neurosurgery, Sichuan Provincial People's Hospital, University of Electronic Science and Technology of China, Chengdu, 610072, China; Chinese Academy of Sciences Sichuan Translational Medicine Research Hospital, Chengdu, 610072, China; Department of Neurology and State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Sichuan, Chengdu, 610041, China
| | - Fei Tang
- Department of Neurology and State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Sichuan, Chengdu, 610041, China
| | - Yujie Guo
- Department of Neurology and State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Sichuan, Chengdu, 610041, China
| | - Ruxiang Xu
- Department of Neurosurgery, Sichuan Provincial People's Hospital, University of Electronic Science and Technology of China, Chengdu, 610072, China; Chinese Academy of Sciences Sichuan Translational Medicine Research Hospital, Chengdu, 610072, China
| | - Peng Lei
- Department of Neurology and State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Sichuan, Chengdu, 610041, China.
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Engelmann SA, Tomar A, Woods AL, Dunn AK. Pulse train gating to improve signal generation for in vivo two-photon fluorescence microscopy. bioRxiv 2023:2023.04.03.535393. [PMID: 37066310 PMCID: PMC10103994 DOI: 10.1101/2023.04.03.535393] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/18/2023]
Abstract
Significance Two-photon microscopy is used routinely for in vivo imaging of neural and vascular structure and function in rodents with a high resolution. Image quality, however, often degrades in deeper portions of the cerebral cortex. Strategies to improve deep imaging are therefore needed. We introduce such a strategy using gates of high repetition rate ultrafast pulse trains to increase signal level. Aim We investigate how signal generation, signal-to-noise ratio (SNR), and signal-to-background ratio (SBR) improve with pulse gating while imaging in vivo mouse cerebral vasculature. Approach An electro-optic modulator is used with a high-power (6 W) 80 MHz repetition rate ytterbium fiber amplifier to create gates of pulses at a 1 MHz repetition rate. We first measure signal generation from a Texas Red solution in a cuvette to characterize the system with no gating and at a 50%, 25%, and 12.5% duty cycle. We then compare signal generation, SNR, and SBR when imaging Texas Red-labeled vasculature using these conditions. Results We find up to a 6.73-fold increase in fluorescent signal from a cuvette when using a 12.5% duty cycle pulse gating excitation pattern as opposed to a constant 80 MHz pulse train. We verify similar increases for in vivo imaging to that observed in cuvette testing. For deep imaging we find pulse gating to result in a 2.95-fold increase in SNR and a 1.37-fold increase in SBR on average when imaging mouse cortical vasculature at depths ranging from 950 μm to 1050 μm. Conclusions We demonstrate that a pulse gating strategy can either be used to limit heating when imaging superficial brain regions or used to increase signal generation in deep regions. These findings should encourage others to adopt similar pulse gating excitation schemes for imaging neural structure through two-photon microscopy.
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Affiliation(s)
- Shaun A. Engelmann
- University of Texas at Austin, Department of Biomedical Engineering, Austin Texas, United States
| | - Alankrit Tomar
- University of Texas at Austin, Department of Biomedical Engineering, Austin Texas, United States
| | - Aaron L. Woods
- University of Texas at Austin, Department of Biomedical Engineering, Austin Texas, United States
| | - Andrew K. Dunn
- University of Texas at Austin, Department of Biomedical Engineering, Austin Texas, United States
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Li R, Wang S, Lyu J, Chen K, Sun X, Huang J, Sun P, Liang S, Li M, Yang M, Liu H, Zeng S, Chen X, Li L, Jia H, Zhou Z. Ten-kilohertz two-photon microscopy imaging of single-cell dendritic activity and hemodynamics in vivo. Neurophotonics 2023; 10:025006. [PMID: 37152357 PMCID: PMC10156610 DOI: 10.1117/1.nph.10.2.025006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/03/2023] [Accepted: 04/03/2023] [Indexed: 05/09/2023]
Abstract
Significance The studying of rapid neuronal signaling across large spatial scales in intact, living brains requires both high temporal resolution and versatility of the measurement device. Aim We introduce a high-speed two-photon microscope based on a custom-built acousto-optic deflector (AOD). This microscope has a maximum line scan frequency of 400 kHz and a maximum frame rate of 10,000 frames per second (fps) at 250 × 40 pixels . For stepwise magnification from population view to subcellular view with high spatial and temporal resolution, we combined the AOD with resonance-galvo (RS) scanning. Approach With this combinatorial device that supports both large-view navigation and small-view high-speed imaging, we measured dendritic calcium propagation velocity and the velocity of single red blood cells (RBCs). Results We measured dendritic calcium propagation velocity ( 80 / 62.5 - 116.7 μ m / ms ) in OGB-1-labeled single cortical neurons in mice in vivo. To benchmark the spatial precision and detection sensitivity of measurement in vivo, we also visualized the trajectories of single RBCs and found that their movement speed follows Poiseuille's law of laminar flow. Conclusions This proof-of-concept methodological development shows that the combination of AOD and RS scanning two-photon microscopy provides both versatility and precision for quantitative analysis of single neuronal activities and hemodynamics in vivo.
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Affiliation(s)
- Ruijie Li
- Guangxi University, Advanced Institute for Brain and Intelligence, School of Physical Science and Technology, Nanning, China
- Third Military Medical University, Brain Research Center, State Key Laboratory of Trauma, Burns, and Combined Injury, Chongqing, China
| | - Sibo Wang
- Chinese Academy of Sciences, Suzhou Institute of Biomedical Engineering and Technology, Brain Research Instrument Innovation Center, Suzhou, China
| | - Jing Lyu
- Chinese Academy of Sciences, Suzhou Institute of Biomedical Engineering and Technology, Brain Research Instrument Innovation Center, Suzhou, China
| | - Ke Chen
- Sichuan Provincial People’s Hospital, University of Electronic Science and Technology of China, Medical School, Chengdu, China
| | - Xiaxin Sun
- Sichuan Provincial People’s Hospital, University of Electronic Science and Technology of China, Medical School, Chengdu, China
| | - Junjie Huang
- Chongqing University, School of Medicine, Center for Neurointelligence, Chongqing, China
| | - Pei Sun
- Third Military Medical University, Brain Research Center, State Key Laboratory of Trauma, Burns, and Combined Injury, Chongqing, China
| | - Susu Liang
- Chongqing University, School of Medicine, Center for Neurointelligence, Chongqing, China
| | - Min Li
- Chinese Academy of Sciences, Suzhou Institute of Biomedical Engineering and Technology, Brain Research Instrument Innovation Center, Suzhou, China
| | - Mengke Yang
- Chinese Academy of Sciences, Suzhou Institute of Biomedical Engineering and Technology, Brain Research Instrument Innovation Center, Suzhou, China
| | - Hongbang Liu
- Guangxi University, Advanced Institute for Brain and Intelligence, School of Physical Science and Technology, Nanning, China
| | - Shaoqun Zeng
- Huazhong University of Science and Technology, Britton Chance Center for Biomedical Photonics, Wuhan National Laboratory for Optoelectronics, Wuhan, China
| | - Xiaowei Chen
- Third Military Medical University, Brain Research Center, State Key Laboratory of Trauma, Burns, and Combined Injury, Chongqing, China
- Chongqing Institute for Brain and Intelligence, Guangyang Bay Laboratory, Chongqing, China
| | - Longhui Li
- Chongqing University, School of Medicine, Center for Neurointelligence, Chongqing, China
- Address all correspondence to Zhenqiao Zhou, ; Hongbo Jia, ; Longhui Li,
| | - Hongbo Jia
- Guangxi University, Advanced Institute for Brain and Intelligence, School of Physical Science and Technology, Nanning, China
- Chinese Academy of Sciences, Suzhou Institute of Biomedical Engineering and Technology, Brain Research Instrument Innovation Center, Suzhou, China
- Leibniz Institute for Neurobiology, Magdeburg, Germany
- Technical University Munich, Institute of Neuroscience and the SyNergy Cluster, Munich, Germany
- Address all correspondence to Zhenqiao Zhou, ; Hongbo Jia, ; Longhui Li,
| | - Zhenqiao Zhou
- Chinese Academy of Sciences, Suzhou Institute of Biomedical Engineering and Technology, Brain Research Instrument Innovation Center, Suzhou, China
- Address all correspondence to Zhenqiao Zhou, ; Hongbo Jia, ; Longhui Li,
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43
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Giblin JT, Park SW, Jiang J, Kılıç K, Kura S, Tang J, Boas DA, Chen IA. Measuring capillary flow dynamics using interlaced two-photon volumetric scanning. J Cereb Blood Flow Metab 2023; 43:595-609. [PMID: 36495178 PMCID: PMC10063827 DOI: 10.1177/0271678x221145091] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Two photon microscopy and optical coherence tomography (OCT) are two standard methods for measuring flow speeds of red blood cells in microvessels, particularly in animal models. However, traditional two photon microscopy lacks the depth of field to adequately capture the full volumetric complexity of the cerebral microvasculature and OCT lacks the specificity offered by fluorescent labeling. In addition, the traditional raster scanning technique utilized in both modalities requires a balance of image frame rate and field of view, which severely limits the study of RBC velocities in the microvascular network. Here, we overcome this by using a custom two photon system with an axicon based Bessel beam to obtain volumetric images of the microvascular network with fluorescent specificity. We combine this with a novel scan pattern that generates pairs of frames with short time delay sufficient for tracking red blood cell flow in capillaries. We track RBC flow speeds in 10 or more capillaries simultaneously at 1 Hz in a 237 µm × 237 µm × 120 µm volume and quantified both their spatial and temporal variability in speed. We also demonstrate the ability to track flow speed changes around stalls in capillary flow and measure to 300 µm in depth.
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Affiliation(s)
- John T Giblin
- Neurophotonics Center, Department of Biomedical Engineering, Boston University, Boston, MA, USA
| | - Seong-Wook Park
- Neurophotonics Center, Department of Biomedical Engineering, Boston University, Boston, MA, USA
| | - John Jiang
- Neurophotonics Center, Department of Biomedical Engineering, Boston University, Boston, MA, USA
| | - Kıvılcım Kılıç
- Neurophotonics Center, Department of Biomedical Engineering, Boston University, Boston, MA, USA
| | - Sreekanth Kura
- Neurophotonics Center, Department of Biomedical Engineering, Boston University, Boston, MA, USA
| | - Jianbo Tang
- Department of Biomedical Engineering, Southern University of Science and Technology, Shenzhen, China
| | - David A Boas
- Neurophotonics Center, Department of Biomedical Engineering, Boston University, Boston, MA, USA
| | - Ichun A Chen
- Neurophotonics Center, Department of Biomedical Engineering, Boston University, Boston, MA, USA
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Hattori Y, Kato D, Murayama F, Koike S, Asai H, Yamasaki A, Naito Y, Kawaguchi A, Konishi H, Prinz M, Masuda T, Wake H, Miyata T. CD206 + macrophages transventricularly infiltrate the early embryonic cerebral wall to differentiate into microglia. Cell Rep 2023; 42:112092. [PMID: 36753421 DOI: 10.1016/j.celrep.2023.112092] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2022] [Revised: 12/05/2022] [Accepted: 01/26/2023] [Indexed: 02/09/2023] Open
Abstract
The relationships between tissue-resident microglia and early macrophages, especially their lineage segregation outside the yolk sac, have been recently explored, providing a model in which a conversion from macrophages seeds microglia during brain development. However, spatiotemporal evidence to support such microglial seeding in situ and to explain how it occurs has not been obtained. By cell tracking via slice culture, intravital imaging, and Flash tag-mediated or genetic labeling, we find that intraventricular CD206+ macrophages, which are abundantly observed along the inner surface of the mouse cerebral wall, frequently enter the pallium at embryonic day 12. Immunofluorescence of the tracked cells show that postinfiltrative macrophages in the pallium acquire microglial properties while losing the CD206+ macrophage phenotype. We also find that intraventricular macrophages are supplied transepithelially from the roof plate. This study demonstrates that the "roof plate→ventricle→pallium" route is an essential path for microglial colonization into the embryonic mouse brain.
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Affiliation(s)
- Yuki Hattori
- Department of Anatomy and Cell Biology, Nagoya University Graduate School of Medicine, Nagoya 466-8550, Japan.
| | - Daisuke Kato
- Department of Anatomy and Molecular Cell Biology, Nagoya University Graduate School of Medicine, Nagoya 466-8550, Japan
| | - Futoshi Murayama
- Department of Anatomy and Cell Biology, Nagoya University Graduate School of Medicine, Nagoya 466-8550, Japan
| | - Sota Koike
- Department of Anatomy and Cell Biology, Nagoya University Graduate School of Medicine, Nagoya 466-8550, Japan
| | - Hisa Asai
- Department of Anatomy and Cell Biology, Nagoya University Graduate School of Medicine, Nagoya 466-8550, Japan
| | - Ayato Yamasaki
- Department of Molecular and System Pharmacology, Graduate School of Pharmaceutical Sciences, Kyushu University, Fukuoka 812-8582, Japan
| | - Yu Naito
- Department of Anatomy and Cell Biology, Nagoya University Graduate School of Medicine, Nagoya 466-8550, Japan; Department of Pathology, Tokyo Metropolitan Cancer and Infectious Diseases Center, Komagome Hospital, Tokyo 113-8677, Japan
| | - Ayano Kawaguchi
- Department of Anatomy and Cell Biology, Nagoya University Graduate School of Medicine, Nagoya 466-8550, Japan; Department of Human Morphology, Okayama University Graduate School of Medicine, Density and Pharmaceutical Sciences, Okayama 700-8558, Japan
| | - Hiroyuki Konishi
- Department of Functional Anatomy and Neuroscience, Nagoya University Graduate School of Medicine, Nagoya 466-8550, Japan
| | - Marco Prinz
- Institute of Neuropathology, Faculty of Medicine, University of Freiburg, 79106 Freiburg, Germany; Center for Basics in NeuroModulation (NeuroModulBasics), Faculty of Medicine, University of Freiburg, 79106 Freiburg, Germany; Signalling Research Centres BIOSS and CIBSS, University of Freiburg, 79106 Freiburg, Germany
| | - Takahiro Masuda
- Department of Molecular and System Pharmacology, Graduate School of Pharmaceutical Sciences, Kyushu University, Fukuoka 812-8582, Japan
| | - Hiroaki Wake
- Department of Anatomy and Molecular Cell Biology, Nagoya University Graduate School of Medicine, Nagoya 466-8550, Japan; Department of Physiological Sciences, The Graduate School for Advanced Study, Okazaki 444-0864, Japan; Division of Multicellular Circuit Dynamics, National Institute for Physiological Sciences, National Institute of Natural Sciences, Okazaki 444-8585, Japan; Center of Optical Scattering Image Science, Kobe University, Kobe 657-8501, Japan
| | - Takaki Miyata
- Department of Anatomy and Cell Biology, Nagoya University Graduate School of Medicine, Nagoya 466-8550, Japan
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45
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Hazart D, Delhomme B, Oheim M, Ricard C. Label-free, fast, 2-photon volume imaging of the organization of neurons and glia in the enteric nervous system. Front Neuroanat 2023; 16:1070062. [PMID: 36844894 PMCID: PMC9948619 DOI: 10.3389/fnana.2022.1070062] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2022] [Accepted: 12/19/2022] [Indexed: 02/11/2023] Open
Abstract
The enteric nervous system (ENS), sometimes referred to as a "second brain" is a quasi-autonomous nervous system, made up of interconnected plexuses organized in a mesh-like network lining the gastrointestinal tract. Originally described as an actor in the regulation of digestion, bowel contraction, and intestinal secretion, the implications of the ENS in various central neuropathologies has recently been demonstrated. However, with a few exceptions, the morphology and pathologic alterations of the ENS have mostly been studied on thin sections of the intestinal wall or, alternatively, in dissected explants. Precious information on the three-dimensional (3-D) architecture and connectivity is hence lost. Here, we propose the fast, label-free 3-D imaging of the ENS, based on intrinsic signals. We used a custom, fast tissue-clearing protocol based on a high refractive-index aqueous solution to increase the imaging depth and allow us the detection of faint signals and we characterized the autofluorescence (AF) from the various cellular and sub-cellular components of the ENS. Validation by immunofluorescence and spectral recordings complete this groundwork. Then, we demonstrate the rapid acquisition of detailed 3-D image stacks from unlabeled mouse ileum and colon, across the whole intestinal wall and including both the myenteric and submucosal enteric nervous plexuses using a new spinning-disk two-photon (2P) microscope. The combination of fast clearing (less than 15 min for 73% transparency), AF detection and rapid volume imaging [less than 1 min for the acquisition of a z-stack of 100 planes (150*150 μm) at sub-300-nm spatial resolution] opens up the possibility for new applications in fundamental and clinical research.
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Affiliation(s)
- Doriane Hazart
- Université Paris Cité, CNRS, Saints-Pères Paris Institute for the Neurosciences, Paris, France
| | - Brigitte Delhomme
- Université Paris Cité, CNRS, Saints-Pères Paris Institute for the Neurosciences, Paris, France
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46
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Guo C, Wang A, Cheng H, Chen L. New imaging instrument in animal models: Two-photon miniature microscope and large field of view miniature microscope for freely behaving animals. J Neurochem 2023; 164:270-283. [PMID: 36281555 DOI: 10.1111/jnc.15711] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2022] [Revised: 09/19/2022] [Accepted: 10/12/2022] [Indexed: 11/30/2022]
Abstract
Over the past decade, novel optical imaging tools have been developed for imaging neuronal activities along with the evolution of fluorescence indicators with brighter expression and higher sensitivity. Miniature microscopes, as revolutionary approaches, enable the imaging of large populations of neuron ensembles in freely behaving rodents and mammals, which allows exploring the neural basis of behaviors. Recent progress in two-photon miniature microscopes and mesoscale single-photon miniature microscopes further expand those affordable methods to navigate neural activities during naturalistic behaviors. In this review article, two-photon miniature microscopy techniques are summarized historically from the first documented attempt to the latest ones, and comparisons are made. The driving force behind and their potential for neuroscientific inquiries are also discussed. Current progress in terms of the mesoscale, i.e., the large field-of-view miniature microscopy technique, is addressed as well. Then, pipelines for registering single cells from the data of two-photon and large field-of-view miniature microscopes are discussed. Finally, we present the potential evolution of the techniques.
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Affiliation(s)
- Changliang Guo
- Beijing Institute of Collaborative Innovation, Beijing, China.,State Key Laboratory of Membrane Biology, Institute of Molecular Medicine, Peking-Tsinghua Center for Life Sciences, College of Future Technology, Peking University, Beijing, China
| | - Aimin Wang
- School of Electronics, Peking University, Beijing, China.,State Key Laboratory of Advanced Optical Communication System and Networks, Peking University, Beijing, China
| | - Heping Cheng
- State Key Laboratory of Membrane Biology, Institute of Molecular Medicine, Peking-Tsinghua Center for Life Sciences, College of Future Technology, Peking University, Beijing, China.,Research Unit of Mitochondria in Brain Diseases, Chinese Academy of Medical Sciences, PKU-Nanjing Institute of Translational Medicine, Nanjing, China
| | - Liangyi Chen
- State Key Laboratory of Membrane Biology, Institute of Molecular Medicine, Peking-Tsinghua Center for Life Sciences, College of Future Technology, Peking University, Beijing, China.,PKU-IDG/McGovern Institute for Brain Research, Beijing, China.,Beijing Academy of Artificial Intelligence, Beijing, China
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47
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Zhuo GY, Chen MC, Lin TY, Lin ST, Chen DT, Lee CW. Opioid-Modulated Receptor Localization and Erk1/2 Phosphorylation in Cells Coexpressing μ-Opioid and Nociceptin Receptors. Int J Mol Sci 2023; 24. [PMID: 36674576 DOI: 10.3390/ijms24021048] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2022] [Revised: 12/30/2022] [Accepted: 01/03/2023] [Indexed: 01/09/2023] Open
Abstract
We attempted to examine the alterations elicited by opioids via coexpressed μ-opioid (MOP) and nociceptin/orphanin FQ (NOP) receptors for receptor localization and Erk1/2 (p44/42 MAPK) in human embryonic kidney (HEK) 293 cells. Through two-photon microscopy, the proximity of MOP and NOP receptors was verified by fluorescence resonance energy transfer (FRET), and morphine but not buprenorphine facilitated the process of MOP-NOP heterodimerization. Single-particle tracking (SPT) further revealed that morphine or buprenorphine hindered the movement of the MOP-NOP heterodimers. After exposure to morphine or buprenorphine, receptor localization on lipid rafts was detected by immunocytochemistry, and phosphorylation of Erk1/2 was determined by immunoblotting in HEK 293 cells expressing MOP, NOP, or MOP+NOP receptors. Colocalization of MOP and NOP on lipid rafts was enhanced by morphine but not buprenorphine. Morphine stimulated the phosphorylation of Erk1/2 with a similar potency in HEK 293 cells expressing MOP and MOP+NOP receptors, but buprenorphine appeared to activate Erk1/2 solely through NOP receptors. Our results suggest that opioids can fine-tune the cellular localization of opioid receptors and phosphorylation of Erk1/2 in MOP+NOP-expressing cells.
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Abstract
In this series of papers on light microscopy imaging, we have covered the fundamentals of microscopy, super-resolution microscopy, and lightsheet microscopy. This last review covers multi-photon microscopy with a brief reference to intravital imaging and Brainbow labeling. Multi-photon microscopy is often referred to as two-photon microscopy. Indeed, using two-photon microscopy is by far the most common way of imaging thick tissues; however, it is theoretically possible to use a higher number of photons, and three-photon microscopy is possible. Therefore, this review is titled "multi-photon microscopy." Another term for describing multi-photon microscopy is "non-linear" microscopy because fluorescence intensity at the focal spot depends upon the average squared intensity rather than the squared average intensity; hence, non-linear optics (NLO) is an alternative name for multi-photon microscopy. It is this non-linear relationship (or third exponential power in the case of three-photon excitation) that determines the axial optical sectioning capability of multi-photon imaging. In this paper, the necessity for two-photon or multi-photon imaging is explained, and the method of optical sectioning by multi-photon microscopy is described. Advice is also given on what fluorescent markers to use and other practical aspects of imaging thick tissues. The technique of Brainbow imaging is discussed. The review concludes with a description of intravital imaging of the mouse. © 2023 Wiley Periodicals LLC.
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49
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Fantini A, Giulio L, Delledonne A, Pescina S, Sissa C, Nicoli S, Santi P, Padula C. Buccal Permeation of Polysaccharide High Molecular Weight Compounds: Effect of Chemical Permeation Enhancers. Pharmaceutics 2022; 15:pharmaceutics15010129. [PMID: 36678758 PMCID: PMC9864332 DOI: 10.3390/pharmaceutics15010129] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2022] [Revised: 12/15/2022] [Accepted: 12/20/2022] [Indexed: 01/04/2023] Open
Abstract
The greatest achievement in the advanced drug delivery field should be the optimization of non-invasive formulations for the delivery of high molecular weight compounds. Peptides, proteins, and other macromolecules can have poor membrane permeation, principally due to their large molecular weight. The aim of this work was to explore the possibility of administering fluorescently labeled dextrans (molecular weight 4-150 kDa) across the buccal mucosa. Permeation experiments across pig esophageal mucosa were carried out using fatty acids and bile salts as penetration enhancers. The data obtained show that it is possible to increase or promote the mucosa permeation of high molecular weight dextrans by using caprylic acid or sodium taurocholate as the chemical enhancers. With these enhancers, dextrans with molecular weight of 70 and 150 kDa, that in passive conditions did not permeate, could cross the mucosa in detectable amounts. FD-70 and FD-150 showed comparable permeability values, despite the molecular weight difference. The results obtained in the present work suggest that the buccal administration of high molecular weight compounds is feasible.
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Affiliation(s)
- Adriana Fantini
- ADDRes Lab, Department of Food and Drug, University of Parma, Parco Area delle Scienze 27/a, 43124 Parma, Italy
| | - Luca Giulio
- ADDRes Lab, Department of Food and Drug, University of Parma, Parco Area delle Scienze 27/a, 43124 Parma, Italy
| | - Andrea Delledonne
- Department of Chemistry, Life Science and Environmental Sustainability, University of Parma, Parco Area delle Scienze 17/a, 43124 Parma, Italy
| | - Silvia Pescina
- ADDRes Lab, Department of Food and Drug, University of Parma, Parco Area delle Scienze 27/a, 43124 Parma, Italy
| | - Cristina Sissa
- Department of Chemistry, Life Science and Environmental Sustainability, University of Parma, Parco Area delle Scienze 17/a, 43124 Parma, Italy
| | - Sara Nicoli
- ADDRes Lab, Department of Food and Drug, University of Parma, Parco Area delle Scienze 27/a, 43124 Parma, Italy
| | - Patrizia Santi
- ADDRes Lab, Department of Food and Drug, University of Parma, Parco Area delle Scienze 27/a, 43124 Parma, Italy
| | - Cristina Padula
- ADDRes Lab, Department of Food and Drug, University of Parma, Parco Area delle Scienze 27/a, 43124 Parma, Italy
- Correspondence: ; Tel.: +39-0521-905078
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50
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Grimaud B, Frétaud M, Terras F, Bénassy A, Duroure K, Bercier V, Trippé-Allard G, Mohammedi R, Gacoin T, Del Bene F, Marquier F, Langevin C, Treussart F. In Vivo Fast Nonlinear Microscopy Reveals Impairment of Fast Axonal Transport Induced by Molecular Motor Imbalances in the Brain of Zebrafish Larvae. ACS Nano 2022; 16:20470-20487. [PMID: 36459488 DOI: 10.1021/acsnano.2c06799] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
Cargo transport by molecular motors along microtubules is essential for the function of eukaryotic cells, in particular neurons in which axonal transport defects constitute the early pathological features of neurodegenerative diseases. Mainly studied in motor and sensory neurons, axonal transport is still difficult to characterize in neurons of the brain in absence of appropriate in vivo tools. Here, we measured fast axonal transport by tracing the second harmonic generation (SHG) signal of potassium titanyl phosphate (KTP) nanocrystals (nanoKTP) endocytosed by brain neurons of zebrafish (Zf) larvae. Thanks to the optical translucency of Zf larvae and to the perfect photostability of nanoKTP SHG, we achieved a high scanning speed of 20 frames (of ≈90 μm × 60 μm size) per second in Zf brain. We focused our study on endolysosomal vesicle transport in axons of known polarization, separately analyzing kinesin and dynein motor-driven displacements. To validate our assay, we used either loss-of-function mutations of dynein or kinesin 1 or the dynein inhibitor dynapyrazole and quantified several transport parameters. We successfully demonstrated that dynapyrazole reduces the nanoKTP mobile fraction and retrograde run length consistently, while the retrograde run length increased in kinesin 1 mutants. Taking advantage of nanoKTP SHG directional emission, we also quantified fluctuations of vesicle orientation. Thus, by combining endocytosis of nanocrystals having a nonlinear response, fast two-photon microscopy, and high-throughput analysis, we are able to finely monitor fast axonal transport in vivo in the brain of a vertebrate and reveal subtle axonal transport alterations. The high spatiotemporal resolution achieved in our model may be relevant to precisely investigate axonal transport impairment associated with disease models.
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Affiliation(s)
- Baptiste Grimaud
- ENS Paris-Saclay, CNRS, CentraleSupélec, LuMIn, Université Paris-Saclay, 91190Gif-sur-Yvette, France
| | - Maxence Frétaud
- INRAE, IERP, Université Paris-Saclay, 78350Jouy-ens-Josas, France
- INRAE, VIM, Université Paris-Saclay, 78350Jouy-en-Josas, France
| | - Feriel Terras
- ENS Paris-Saclay, CNRS, CentraleSupélec, LuMIn, Université Paris-Saclay, 91190Gif-sur-Yvette, France
| | - Antoine Bénassy
- ENS Paris-Saclay, CNRS, CentraleSupélec, LuMIn, Université Paris-Saclay, 91190Gif-sur-Yvette, France
| | - Karine Duroure
- INSERM, CNRS, Institut de la Vision, Sorbonne Université, 75012Paris, France
| | - Valérie Bercier
- Center for Brain and Disease Research, Laboratory of Neurobiology, VIB, 3000Leuven, Belgium
| | - Gaëlle Trippé-Allard
- ENS Paris-Saclay, CNRS, CentraleSupélec, LuMIn, Université Paris-Saclay, 91190Gif-sur-Yvette, France
| | - Rabei Mohammedi
- Laboratory of Condensed Matter Physics, Ecole Polytechnique, CNRS, Institut Polytechnique de Paris, 91128Palaiseau Cedex, France
| | - Thierry Gacoin
- Laboratory of Condensed Matter Physics, Ecole Polytechnique, CNRS, Institut Polytechnique de Paris, 91128Palaiseau Cedex, France
| | - Filippo Del Bene
- INSERM, CNRS, Institut de la Vision, Sorbonne Université, 75012Paris, France
| | - François Marquier
- ENS Paris-Saclay, CNRS, CentraleSupélec, LuMIn, Université Paris-Saclay, 91190Gif-sur-Yvette, France
| | | | - François Treussart
- ENS Paris-Saclay, CNRS, CentraleSupélec, LuMIn, Université Paris-Saclay, 91190Gif-sur-Yvette, France
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