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Uhlířová H, Stibůrek M, Pikálek T, Gomes A, Turtaev S, Kolbábková P, Čižmár T. "There's plenty of room at the bottom": deep brain imaging with holographic endo-microscopy. NEUROPHOTONICS 2024; 11:S11504. [PMID: 38250297 PMCID: PMC10798506 DOI: 10.1117/1.nph.11.s1.s11504] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/14/2023] [Revised: 12/09/2023] [Accepted: 12/14/2023] [Indexed: 01/23/2024]
Abstract
Significance Over more than 300 years, microscopic imaging keeps providing fundamental insights into the mechanisms of living organisms. Seeing microscopic structures beyond the reach of free-space light-based microscopy, however, requires dissection of the tissue-an intervention seriously disturbing its physiological functions. The hunt for low-invasiveness tools has led a growing community of physicists and engineers into the realm of complex media photonics. One of its activities represents exploiting multimode optical fibers (MMFs) as ultra-thin endoscopic probes. Employing wavefront shaping, these tools only recently facilitated the first peeks at cells and their sub-cellular compartments at the bottom of the mouse brain with the impact of micro-scale tissue damage. Aim Here, we aim to highlight advances in MMF-based holographic endo-microscopy facilitating microscopic imaging throughout the whole depth of the mouse brain. Approach We summarize the important technical and methodological prerequisites for stabile high-resolution imaging in vivo. Results We showcase images of the microscopic building blocks of brain tissue, including neurons, neuronal processes, vessels, intracellular calcium signaling, and red blood cell velocity in individual vessels. Conclusions This perspective article helps to understand the complexity behind the technology of holographic endo-microscopy, summarizes its recent advances and challenges, and stimulates the mind of the reader for further exploitation of this tool in the neuroscience research.
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Affiliation(s)
- Hana Uhlířová
- Institute of Scientific Instruments of the Czech Academy of Sciences, Brno, Czech Republic
| | - Miroslav Stibůrek
- Institute of Scientific Instruments of the Czech Academy of Sciences, Brno, Czech Republic
| | - Tomáš Pikálek
- Institute of Scientific Instruments of the Czech Academy of Sciences, Brno, Czech Republic
| | - André Gomes
- Leibniz Institute of Photonic Technology, Jena, Germany
| | | | - Petra Kolbábková
- Institute of Scientific Instruments of the Czech Academy of Sciences, Brno, Czech Republic
| | - Tomáš Čižmár
- Institute of Scientific Instruments of the Czech Academy of Sciences, Brno, Czech Republic
- Leibniz Institute of Photonic Technology, Jena, Germany
- Friedrich Schiller University Jena, Institute of Applied Optics, Jena, Germany
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2
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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] [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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3
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Redman WT, Acosta-Mendoza S, Wei XX, Goard MJ. Robust variability of grid cell properties within individual grid modules enhances encoding of local space. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.02.27.582373. [PMID: 38915504 PMCID: PMC11195105 DOI: 10.1101/2024.02.27.582373] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/26/2024]
Abstract
Although grid cells are one of the most well studied functional classes of neurons in the mammalian brain, the assumption that there is a single grid orientation and spacing per grid module has not been carefully tested. We investigate and analyze a recent large-scale recording of medial entorhinal cortex to characterize the presence and degree of heterogeneity of grid properties within individual modules. We find evidence for small, but robust, variability and hypothesize that this property of the grid code could enhance the ability of encoding local spatial information. Performing analysis on synthetic populations of grid cells, where we have complete control over the amount heterogeneity in grid properties, we demonstrate that variability, of a similar magnitude to the analyzed data, leads to significantly decreased decoding error, even when restricted to activity from a single module. Our results highlight how the heterogeneity of the neural response properties may benefit coding and opens new directions for theoretical and experimental analysis of grid cells.
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Affiliation(s)
- William T Redman
- Interdepartmental Graduate Program in Dynamical Neuroscience, University of California, Santa Barbara
- Intelligent Systems Center, Johns Hopkins University Applied Physics Lab
| | - Santiago Acosta-Mendoza
- Interdepartmental Graduate Program in Dynamical Neuroscience, University of California, Santa Barbara
| | - Xue-Xin Wei
- Department of Neuroscience, The University of Texas at Austin
- Department of Psychology, The University of Texas at Austin
- Center for Perceptual Systems, The University of Texas at Austin
- Center for Theoretical and Computational Neuroscience, The University of Texas at Austin
| | - Michael J Goard
- Department of Psychological and Brain Sciences, University of California, Santa Barbara
- Department of Molecular, Cellular, and Developmental Biology, University of California, Santa Barbara
- Neuroscience Research Institute, University of California Santa Barbara
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4
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Linsley JW, Reisine T, Finkbeiner S. Three dimensional and four dimensional live imaging to study mechanisms of progressive neurodegeneration. J Biol Chem 2024; 300:107433. [PMID: 38825007 DOI: 10.1016/j.jbc.2024.107433] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2023] [Revised: 05/20/2024] [Accepted: 05/26/2024] [Indexed: 06/04/2024] Open
Abstract
Neurodegenerative diseases are complex and progressive, posing challenges to their study and understanding. Recent advances in microscopy imaging technologies have enabled the exploration of neurons in three spatial dimensions (3D) over time (4D). When applied to 3D cultures, tissues, or animals, these technologies can provide valuable insights into the dynamic and spatial nature of neurodegenerative diseases. This review focuses on the use of imaging techniques and neurodegenerative disease models to study neurodegeneration in 4D. Imaging techniques such as confocal microscopy, two-photon microscopy, miniscope imaging, light sheet microscopy, and robotic microscopy offer powerful tools to visualize and analyze neuronal changes over time in 3D tissue. Application of these technologies to in vitro models of neurodegeneration such as mouse organotypic culture systems and human organoid models provide versatile platforms to study neurodegeneration in a physiologically relevant context. Additionally, use of 4D imaging in vivo, including in mouse and zebrafish models of neurodegenerative diseases, allows for the investigation of early dysfunction and behavioral changes associated with neurodegeneration. We propose that these studies have the power to overcome the limitations of two-dimensional monolayer neuronal cultures and pave the way for improved understanding of the dynamics of neurodegenerative diseases and the development of effective therapeutic strategies.
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Affiliation(s)
- Jeremy W Linsley
- Center for Systems and Therapeutics, Gladstone Institutes, San Francisco, California, USA; Operant Biopharma, San Francisco, California, USA
| | - Terry Reisine
- Independent Scientific Consultant, Santa Cruz, California, USA
| | - Steven Finkbeiner
- Center for Systems and Therapeutics, Gladstone Institutes, San Francisco, California, USA; Operant Biopharma, San Francisco, California, USA; Taube/Koret Center for Neurodegenerative Disease, Gladstone Institutes, San Francisco, California, USA; Departments of Neurology and Physiology, University of California, San Francisco, California, USA; Neuroscience Graduate Program, University of California, San Francisco, California, USA; Biomedical Sciences Graduate Program, University of California, San Francisco, California, USA.
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5
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Bimbard C, Takács F, Catarino JA, Fabre JMJ, Gupta S, Lenzi SC, Melin MD, O’Neill N, Orsolic I, Robacha M, Street JS, Teixeira J, Townsend S, van Beest EH, Zhang AM, Churchland AK, Duan CA, Harris KD, Kullmann DM, Lignani G, Mainen ZF, Margrie TW, Rochefort N, Wikenheiser AM, Carandini M, Coen P. An adaptable, reusable, and light implant for chronic Neuropixels probes. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2023.08.03.551752. [PMID: 37577563 PMCID: PMC10418246 DOI: 10.1101/2023.08.03.551752] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/15/2023]
Abstract
Electrophysiology has proven invaluable to record neural activity, and the development of Neuropixels probes dramatically increased the number of recorded neurons. These probes are often implanted acutely, but acute recordings cannot be performed in freely moving animals and the recorded neurons cannot be tracked across days. To study key behaviors such as navigation, learning, and memory formation, the probes must be implanted chronically. An ideal chronic implant should (1) allow stable recordings of neurons for weeks; (2) allow reuse of the probes after explantation; (3) be light enough for use in mice. Here, we present the "Apollo Implant", an open-source and editable device that meets these criteria and accommodates up to two Neuropixels 1.0 or 2.0 probes. The implant comprises a "payload" module which is attached to the probe and is recoverable, and a "docking" module which is cemented to the skull. The design is adjustable, making it easy to change the distance between probes, the angle of insertion, and the depth of insertion. We tested the implant across eight labs in head-fixed mice, freely moving mice, and freely moving rats. The number of neurons recorded across days was stable, even after repeated implantations of the same probe. The Apollo implant provides an inexpensive, lightweight, and flexible solution for reusable chronic Neuropixels recordings.
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Affiliation(s)
- C. Bimbard
- UCL Institute of Ophthalmology, University College London, London, UK
| | - F. Takács
- Sainsbury Wellcome Centre for Neural Circuits and Behaviour, University College London, London, UK
| | - J. A. Catarino
- Champalimaud Research, Champalimaud Centre for the Unknown, Av. Brasilia, Lisbon, Portugal
| | - J. M. J. Fabre
- UCL Queen Square Institute of Neurology, University College London, London, UK
| | - S. Gupta
- Department of Psychology, University of California, Los Angeles, Los Angeles, California, USA
| | - S. C. Lenzi
- Sainsbury Wellcome Centre for Neural Circuits and Behaviour, University College London, London, UK
| | - M. D. Melin
- Department of Neurobiology, University of California Los Angeles, Los Angeles, California, USA
| | - N. O’Neill
- UCL Queen Square Institute of Neurology, University College London, London, UK
| | - I. Orsolic
- Sainsbury Wellcome Centre for Neural Circuits and Behaviour, University College London, London, UK
| | - M. Robacha
- UCL Institute of Ophthalmology, University College London, London, UK
| | - J. S. Street
- UCL Queen Square Institute of Neurology, University College London, London, UK
| | - J. Teixeira
- Champalimaud Research, Champalimaud Centre for the Unknown, Av. Brasilia, Lisbon, Portugal
| | - S. Townsend
- The FabLab, Sainsbury Wellcome Centre for Neural Circuits and Behaviour, University College London, UK
| | - E. H. van Beest
- UCL Institute of Ophthalmology, University College London, London, UK
| | - A. M. Zhang
- Centre for Discovery Brain Sciences, School of Biomedical Sciences, University of Edinburgh, UK
| | - A. K. Churchland
- Department of Neurobiology, University of California Los Angeles, Los Angeles, California, USA
| | - C. A. Duan
- Sainsbury Wellcome Centre for Neural Circuits and Behaviour, University College London, London, UK
| | - K. D. Harris
- UCL Queen Square Institute of Neurology, University College London, London, UK
| | - D. M. Kullmann
- UCL Queen Square Institute of Neurology, University College London, London, UK
| | - G. Lignani
- UCL Queen Square Institute of Neurology, University College London, London, UK
| | - Z. F. Mainen
- Champalimaud Research, Champalimaud Centre for the Unknown, Av. Brasilia, Lisbon, Portugal
| | - T. W. Margrie
- Sainsbury Wellcome Centre for Neural Circuits and Behaviour, University College London, London, UK
| | - N.L. Rochefort
- Centre for Discovery Brain Sciences, School of Biomedical Sciences, University of Edinburgh, UK
- Simons Initiative for the Developing Brain, University of Edinburgh, Edinburgh, UK
| | - A. M. Wikenheiser
- Department of Psychology, University of California, Los Angeles, Los Angeles, California, USA
| | - M. Carandini
- UCL Institute of Ophthalmology, University College London, London, UK
| | - P. Coen
- UCL Institute of Ophthalmology, University College London, London, UK
- Department of Cell and Developmental Biology, University College London, UK
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Bancelin S, Mercier L, Roos J, Belkadi M, Pfeiffer T, Kim SK, Nägerl UV. Imaging dendritic spines in the hippocampus of a living mouse by 3D-stimulated emission depletion microscopy. NEUROPHOTONICS 2023; 10:044402. [PMID: 37215638 PMCID: PMC10197143 DOI: 10.1117/1.nph.10.4.044402] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/07/2023] [Revised: 03/31/2023] [Accepted: 04/14/2023] [Indexed: 05/24/2023]
Abstract
Significance Stimulated emission depletion (STED) microscopy has been used to address a wide range of neurobiological questions in optically well-accessible samples, such as cell culture or brain slices. However, the application of STED to deeply embedded structures in the brain of living animals remains technically challenging. Aim In previous work, we established chronic STED imaging in the hippocampus in vivo but the gain in spatial resolution was restricted to the lateral plane. In our study, we report on extending the gain in STED resolution into the optical axis to visualize dendritic spines in the hippocampus in vivo. Approach Our approach is based on a spatial light modulator to shape the focal STED light intensity in all three dimensions and a conically shaped window that is compatible with an objective that has a long working distance and a high numerical aperture. We corrected distortions of the laser wavefront to optimize the shape of the bottle beam of the STED laser. Results We show how the new window design improves the STED point spread function and the spatial resolution using nanobeads. We then demonstrate the beneficial effects for 3D-STED microscopy of dendritic spines, visualized with an unprecedented level of detail in the hippocampus of a living mouse. Conclusions We present a methodology to improve the axial resolution for STED microscopy in the deeply embedded hippocampus in vivo, facilitating longitudinal studies of neuroanatomical plasticity at the nanoscale in a wide range of (patho-)physiological contexts.
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Affiliation(s)
- Stéphane Bancelin
- University of Bordeaux, CNRS, Interdisciplinary Institute for Neuroscience, IINS, UMR 5297, Bordeaux, France
| | - Luc Mercier
- University of Bordeaux, CNRS, Interdisciplinary Institute for Neuroscience, IINS, UMR 5297, Bordeaux, France
| | - Johannes Roos
- University of Bordeaux, CNRS, Interdisciplinary Institute for Neuroscience, IINS, UMR 5297, Bordeaux, France
| | - Mohamed Belkadi
- University of Bordeaux, CNRS, Interdisciplinary Institute for Neuroscience, IINS, UMR 5297, Bordeaux, France
| | - Thomas Pfeiffer
- University of Bordeaux, CNRS, Interdisciplinary Institute for Neuroscience, IINS, UMR 5297, Bordeaux, France
| | - Sun Kwang Kim
- Kyung Hee University, Graduate School, Department of Science in Korean Medicine, Seoul, Republic of Korea
| | - U. Valentin Nägerl
- University of Bordeaux, CNRS, Interdisciplinary Institute for Neuroscience, IINS, UMR 5297, Bordeaux, France
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7
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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] [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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Komorowska-Müller JA, Gellner AK, Ravichandran KA, Bilkei-Gorzo A, Zimmer A, Stein V. Chronic low-dose Δ 9-tetrahydrocannabinol (THC) treatment stabilizes dendritic spines in 18-month-old mice. Sci Rep 2023; 13:1390. [PMID: 36697430 PMCID: PMC9877016 DOI: 10.1038/s41598-022-27146-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2022] [Accepted: 12/27/2022] [Indexed: 01/26/2023] Open
Abstract
Cognitive functions decline during aging. This decline could be caused by changes in dendritic spine stability and altered spine dynamics. Previously, we have shown that a low dose chronic THC treatment improves learning abilities in old whereas impairs learning abilities in young mice. The mechanism underlying this age-dependent effect is not known. Dendritic spine stability is a key for memory formation, therefore we hypothesized that THC affects spine dynamics in an age-dependent manner. We applied longitudinal 2-photon in vivo imaging to 3- and 18-month-old mice treated with 3 mg/kg/day of THC for 28 days via an osmotic pump. We imaged the same dendritic segments before, during and after the treatment and assessed changes in spine density and stability. We now show that in old mice THC improved spine stability resulting in a long-lasting increase in spine density. In contrast, in young mice THC transiently increased spine turnover and destabilized the spines.
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Affiliation(s)
| | - Anne-Kathrin Gellner
- Medical Faculty, Institute of Physiology II, University of Bonn, Bonn, Germany.,Department of Psychiatry and Psychotherapy, University Hospital Bonn, Bonn, Germany
| | - Kishore Aravind Ravichandran
- Medical Faculty, Institute of Molecular Psychiatry, University of Bonn, Bonn, Germany.,Medical Faculty, Institute of Physiology II, University of Bonn, Bonn, Germany
| | - Andras Bilkei-Gorzo
- Medical Faculty, Institute of Molecular Psychiatry, University of Bonn, Bonn, Germany
| | - Andreas Zimmer
- Medical Faculty, Institute of Molecular Psychiatry, University of Bonn, Bonn, Germany.
| | - Valentin Stein
- Medical Faculty, Institute of Physiology II, University of Bonn, Bonn, Germany.
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Heck N, Santos MD. Dendritic Spines in Learning and Memory: From First Discoveries to Current Insights. ADVANCES IN NEUROBIOLOGY 2023; 34:311-348. [PMID: 37962799 DOI: 10.1007/978-3-031-36159-3_7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/15/2023]
Abstract
The central nervous system is composed of neural ensembles, and their activity patterns are neural correlates of cognitive functions. Those ensembles are networks of neurons connected to each other by synapses. Most neurons integrate synaptic signal through a remarkable subcellular structure called spine. Dendritic spines are protrusions whose diverse shapes make them appear as a specific neuronal compartment, and they have been the focus of studies for more than a century. Soon after their first description by Ramón y Cajal, it has been hypothesized that spine morphological changes could modify neuronal connectivity and sustain cognitive abilities. Later studies demonstrated that changes in spine density and morphology occurred in experience-dependent plasticity during development, and in clinical cases of mental retardation. This gave ground for the assumption that dendritic spines are the particular locus of cerebral plasticity. With the discovery of synaptic long-term potentiation, a research program emerged with the aim to establish whether dendritic spine plasticity could explain learning and memory. The development of live imaging methods revealed on the one hand that dendritic spine remodeling is compatible with learning process and, on the other hand, that their long-term stability is compatible with lifelong memories. Furthermore, the study of the mechanisms of spine growth and maintenance shed new light on the rules of plasticity. In behavioral paradigms of memory, spine formation or elimination and morphological changes were found to correlate with learning. In a last critical step, recent experiments have provided evidence that dendritic spines play a causal role in learning and memory.
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Affiliation(s)
- Nicolas Heck
- Laboratory Neurosciences Paris Seine, Sorbonne Université, Paris, France.
| | - Marc Dos Santos
- Department of Neuroscience, Northwestern University Feinberg School of Medicine, Chicago, IL, USA
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10
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Nebeling FC, Poll S, Justus LC, Steffen J, Keppler K, Mittag M, Fuhrmann M. Microglial motility is modulated by neuronal activity and correlates with dendritic spine plasticity in the hippocampus of awake mice. eLife 2023; 12:83176. [PMID: 36749020 PMCID: PMC9946443 DOI: 10.7554/elife.83176] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2022] [Accepted: 02/03/2023] [Indexed: 02/08/2023] Open
Abstract
Microglia, the resident immune cells of the brain, play a complex role in health and disease. They actively survey the brain parenchyma by physically interacting with other cells and structurally shaping the brain. Yet, the mechanisms underlying microglial motility and significance for synapse stability, especially in the hippocampus during adulthood, remain widely unresolved. Here, we investigated the effect of neuronal activity on microglial motility and the implications for the formation and survival of dendritic spines on hippocampal CA1 neurons in vivo. We used repetitive two-photon in vivo imaging in the hippocampus of awake and anesthetized mice to simultaneously study the motility of microglia and their interaction with dendritic spines. We found that CA3 to CA1 input is sufficient to modulate microglial process motility. Simultaneously, more dendritic spines emerged in mice after awake compared to anesthetized imaging. Interestingly, the rate of microglial contacts with individual dendritic spines and dendrites was associated with the stability, removal, and emergence of dendritic spines. These results suggest that microglia might sense neuronal activity via neurotransmitter release and actively participate in synaptic rewiring of the hippocampal neural network during adulthood. Further, this study has profound relevance for hippocampal learning and memory processes.
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Affiliation(s)
| | - Stefanie Poll
- Neuroimmunology and Imaging Group, German Center for Neurodegenerative DiseasesBonnGermany
| | - Lena Christine Justus
- Neuroimmunology and Imaging Group, German Center for Neurodegenerative DiseasesBonnGermany
| | - Julia Steffen
- Neuroimmunology and Imaging Group, German Center for Neurodegenerative DiseasesBonnGermany
| | - Kevin Keppler
- Light Microscopy Facility, German Center for Neurodegenerative DiseasesBonnGermany
| | - Manuel Mittag
- Neuroimmunology and Imaging Group, German Center for Neurodegenerative DiseasesBonnGermany
| | - Martin Fuhrmann
- Neuroimmunology and Imaging Group, German Center for Neurodegenerative DiseasesBonnGermany
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11
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Grienberger C, Giovannucci A, Zeiger W, Portera-Cailliau C. Two-photon calcium imaging of neuronal activity. NATURE REVIEWS. METHODS PRIMERS 2022; 2:67. [PMID: 38124998 PMCID: PMC10732251 DOI: 10.1038/s43586-022-00147-1] [Citation(s) in RCA: 26] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 07/07/2022] [Indexed: 12/23/2023]
Abstract
In vivo two-photon calcium imaging (2PCI) is a technique used for recording neuronal activity in the intact brain. It is based on the principle that, when neurons fire action potentials, intracellular calcium levels rise, which can be detected using fluorescent molecules that bind to calcium. This Primer is designed for scientists who are considering embarking on experiments with 2PCI. We provide the reader with a background on the basic concepts behind calcium imaging and on the reasons why 2PCI is an increasingly powerful and versatile technique in neuroscience. The Primer explains the different steps involved in experiments with 2PCI, provides examples of what ideal preparations should look like and explains how data are analysed. We also discuss some of the current limitations of the technique, and the types of solutions to circumvent them. Finally, we conclude by anticipating what the future of 2PCI might look like, emphasizing some of the analysis pipelines that are being developed and international efforts for data sharing.
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Affiliation(s)
- Christine Grienberger
- Department of Biology and Volen National Center for Complex Systems, Brandeis University, Waltham, MA, USA
| | - Andrea Giovannucci
- Joint Department of Biomedical Engineering University of North Carolina at Chapel Hill and North Carolina State University, Chapel Hill, NC, USA
- UNC Neuroscience Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - William Zeiger
- Department of Neurology, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA
| | - Carlos Portera-Cailliau
- Department of Neurology, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA
- Department of Neurobiology, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA
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12
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Redman WT, Wolcott NS, Montelisciani L, Luna G, Marks TD, Sit KK, Yu CH, Smith S, Goard MJ. Long-term transverse imaging of the hippocampus with glass microperiscopes. eLife 2022; 11:75391. [PMID: 35775393 PMCID: PMC9249394 DOI: 10.7554/elife.75391] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2021] [Accepted: 06/12/2022] [Indexed: 11/19/2022] Open
Abstract
The hippocampus consists of a stereotyped neuronal circuit repeated along the septal-temporal axis. This transverse circuit contains distinct subfields with stereotyped connectivity that support crucial cognitive processes, including episodic and spatial memory. However, comprehensive measurements across the transverse hippocampal circuit in vivo are intractable with existing techniques. Here, we developed an approach for two-photon imaging of the transverse hippocampal plane in awake mice via implanted glass microperiscopes, allowing optical access to the major hippocampal subfields and to the dendritic arbor of pyramidal neurons. Using this approach, we tracked dendritic morphological dynamics on CA1 apical dendrites and characterized spine turnover. We then used calcium imaging to quantify the prevalence of place and speed cells across subfields. Finally, we measured the anatomical distribution of spatial information, finding a non-uniform distribution of spatial selectivity along the DG-to-CA1 axis. This approach extends the existing toolbox for structural and functional measurements of hippocampal circuitry.
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Affiliation(s)
- William T Redman
- Interdepartmental Graduate Program in Dynamical Neuroscience, University of California, Santa Barbara, United States
| | - Nora S Wolcott
- Department of Molecular, Cellular, and Developmental Biology, University of California, Santa Barbara, United States
| | - Luca Montelisciani
- Cognitive and Systems Neuroscience Group, University of Amsterdam, Amsterdam, Netherlands
| | - Gabriel Luna
- Neuroscience Research Institute, University of California, Santa Barbara, United States
| | - Tyler D Marks
- Neuroscience Research Institute, University of California, Santa Barbara, United States
| | - Kevin K Sit
- Department of Psychological and Brain Sciences, University of California, Santa Barbara, United States
| | - Che-Hang Yu
- Department of Electrical and Computer Engineering, University of California, Santa Barbara, Santa Barbara, United States
| | - Spencer Smith
- Neuroscience Research Institute, University of California, Santa Barbara, United States.,Department of Electrical and Computer Engineering, University of California, Santa Barbara, Santa Barbara, United States
| | - Michael J Goard
- Department of Molecular, Cellular, and Developmental Biology, University of California, Santa Barbara, United States.,Neuroscience Research Institute, University of California, Santa Barbara, United States.,Department of Psychological and Brain Sciences, University of California, Santa Barbara, United States
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13
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Graf J, Rahmati V, Majoros M, Witte OW, Geis C, Kiebel SJ, Holthoff K, Kirmse K. Network instability dynamics drive a transient bursting period in the developing hippocampus in vivo. eLife 2022; 11:82756. [PMID: 36534089 PMCID: PMC9762703 DOI: 10.7554/elife.82756] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2022] [Accepted: 12/05/2022] [Indexed: 12/23/2022] Open
Abstract
Spontaneous correlated activity is a universal hallmark of immature neural circuits. However, the cellular dynamics and intrinsic mechanisms underlying network burstiness in the intact developing brain are largely unknown. Here, we use two-photon Ca2+ imaging to comprehensively map the developmental trajectories of spontaneous network activity in the hippocampal area CA1 of mice in vivo. We unexpectedly find that network burstiness peaks after the developmental emergence of effective synaptic inhibition in the second postnatal week. We demonstrate that the enhanced network burstiness reflects an increased functional coupling of individual neurons to local population activity. However, pairwise neuronal correlations are low, and network bursts (NBs) recruit CA1 pyramidal cells in a virtually random manner. Using a dynamic systems modeling approach, we reconcile these experimental findings and identify network bi-stability as a potential regime underlying network burstiness at this age. Our analyses reveal an important role of synaptic input characteristics and network instability dynamics for NB generation. Collectively, our data suggest a mechanism, whereby developing CA1 performs extensive input-discrimination learning prior to the onset of environmental exploration.
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Affiliation(s)
- Jürgen Graf
- Department of Neurology, Jena University HospitalJenaGermany
| | - Vahid Rahmati
- Department of Neurology, Jena University HospitalJenaGermany,Section Translational Neuroimmunology, Jena University HospitalJenaGermany,Department of Psychology, Technical University DresdenDresdenGermany
| | - Myrtill Majoros
- Department of Neurology, Jena University HospitalJenaGermany
| | - Otto W Witte
- Department of Neurology, Jena University HospitalJenaGermany
| | - Christian Geis
- Department of Neurology, Jena University HospitalJenaGermany,Section Translational Neuroimmunology, Jena University HospitalJenaGermany
| | - Stefan J Kiebel
- Department of Psychology, Technical University DresdenDresdenGermany
| | - Knut Holthoff
- Department of Neurology, Jena University HospitalJenaGermany
| | - Knut Kirmse
- Department of Neurology, Jena University HospitalJenaGermany,Department of Neurophysiology, Institute of Physiology, University of WürzburgWürzburgGermany
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14
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Adesnik H, Abdeladim L. Probing neural codes with two-photon holographic optogenetics. Nat Neurosci 2021; 24:1356-1366. [PMID: 34400843 PMCID: PMC9793863 DOI: 10.1038/s41593-021-00902-9] [Citation(s) in RCA: 49] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2020] [Accepted: 06/30/2021] [Indexed: 02/07/2023]
Abstract
Optogenetics ushered in a revolution in how neuroscientists interrogate brain function. Because of technical limitations, the majority of optogenetic studies have used low spatial resolution activation schemes that limit the types of perturbations that can be made. However, neural activity manipulations at finer spatial scales are likely to be important to more fully understand neural computation. Spatially precise multiphoton holographic optogenetics promises to address this challenge and opens up many new classes of experiments that were not previously possible. More specifically, by offering the ability to recreate extremely specific neural activity patterns in both space and time in functionally defined ensembles of neurons, multiphoton holographic optogenetics could allow neuroscientists to reveal fundamental aspects of the neural codes for sensation, cognition and behavior that have been beyond reach. This Review summarizes recent advances in multiphoton holographic optogenetics that substantially expand its capabilities, highlights outstanding technical challenges and provides an overview of the classes of experiments it can execute to test and validate key theoretical models of brain function. Multiphoton holographic optogenetics could substantially accelerate the pace of neuroscience discovery by helping to close the loop between experimental and theoretical neuroscience, leading to fundamental new insights into nervous system function and disorder.
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15
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Jordan JT, McDermott KD, Frechou MA, Shtrahman M, Gonçalves JT. Treadmill-based task for assessing spatial memory in head-fixed mice. STAR Protoc 2021; 2:100770. [PMID: 34471907 PMCID: PMC8387801 DOI: 10.1016/j.xpro.2021.100770] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Several mouse in vivo neuronal recording techniques require head fixation. Head-fixed treadmill walking can be used to design tasks that enable the study of neural activity in the context of behavior. Here, we provide a detailed protocol for constructing a treadmill with tactile spatial cues, training mice on a rewarded behavioral task, and analyzing behavioral data. We discuss common problems and solutions we have developed to optimize training. Finally, we demonstrate how to test spatial memory performance using this task.
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Affiliation(s)
- Jake T. Jordan
- Dominick P. Purpura Department of Neuroscience and Gottesman Institute for Stem Cell Biology and Regenerative Medicine, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Kelsey D. McDermott
- Dominick P. Purpura Department of Neuroscience and Gottesman Institute for Stem Cell Biology and Regenerative Medicine, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - M. Agustina Frechou
- Dominick P. Purpura Department of Neuroscience and Gottesman Institute for Stem Cell Biology and Regenerative Medicine, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Matthew Shtrahman
- Department of Neurosciences, University of California San Diego, La Jolla, CA 92093, USA
| | - J. Tiago Gonçalves
- Dominick P. Purpura Department of Neuroscience and Gottesman Institute for Stem Cell Biology and Regenerative Medicine, Albert Einstein College of Medicine, Bronx, NY 10461, USA
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16
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Bi X, Beck C, Gong Y. Genetically Encoded Fluorescent Indicators for Imaging Brain Chemistry. BIOSENSORS 2021; 11:116. [PMID: 33920418 PMCID: PMC8069469 DOI: 10.3390/bios11040116] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/08/2021] [Revised: 04/06/2021] [Accepted: 04/09/2021] [Indexed: 12/17/2022]
Abstract
Genetically encoded fluorescent indicators, combined with optical imaging, enable the detection of physiologically or behaviorally relevant neural activity with high spatiotemporal resolution. Recent developments in protein engineering and screening strategies have improved the dynamic range, kinetics, and spectral properties of genetically encoded fluorescence indicators of brain chemistry. Such indicators have detected neurotransmitter and calcium dynamics with high signal-to-noise ratio at multiple temporal and spatial scales in vitro and in vivo. This review summarizes the current trends in these genetically encoded fluorescent indicators of neurotransmitters and calcium, focusing on their key metrics and in vivo applications.
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Affiliation(s)
| | | | - Yiyang Gong
- Department of Biomedical Engineering, Duke University, Durham, NC 27708, USA; (X.B.); (C.B.)
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17
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A limited role of NKCC1 in telencephalic glutamatergic neurons for developing hippocampal network dynamics and behavior. Proc Natl Acad Sci U S A 2021; 118:2014784118. [PMID: 33782119 DOI: 10.1073/pnas.2014784118] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
NKCC1 is the primary transporter mediating chloride uptake in immature principal neurons, but its role in the development of in vivo network dynamics and cognitive abilities remains unknown. Here, we address the function of NKCC1 in developing mice using electrophysiological, optical, and behavioral approaches. We report that NKCC1 deletion from telencephalic glutamatergic neurons decreases in vitro excitatory actions of γ-aminobutyric acid (GABA) and impairs neuronal synchrony in neonatal hippocampal brain slices. In vivo, it has a minor impact on correlated spontaneous activity in the hippocampus and does not affect network activity in the intact visual cortex. Moreover, long-term effects of the developmental NKCC1 deletion on synaptic maturation, network dynamics, and behavioral performance are subtle. Our data reveal a neural network function of NKCC1 in hippocampal glutamatergic neurons in vivo, but challenge the hypothesis that NKCC1 is essential for major aspects of hippocampal development.
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18
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Sosulina L, Mittag M, Geis HR, Hoffmann K, Klyubin I, Qi Y, Steffen J, Friedrichs D, Henneberg N, Fuhrmann F, Justus D, Keppler K, Cuello AC, Rowan MJ, Fuhrmann M, Remy S. Hippocampal hyperactivity in a rat model of Alzheimer's disease. J Neurochem 2021; 157:2128-2144. [PMID: 33583024 DOI: 10.1111/jnc.15323] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2020] [Revised: 01/19/2021] [Accepted: 01/31/2021] [Indexed: 12/21/2022]
Abstract
Neuronal network dysfunction is a hallmark of Alzheimer's disease (AD). However, the underlying pathomechanisms remain unknown. We analyzed the hippocampal micronetwork in transgenic McGill-R-Thy1-APP rats (APPtg) at the beginning of extracellular amyloid beta (Aβ) deposition. We established two-photon Ca2+ -imaging in vivo in the hippocampus of rats and found hyperactivity of CA1 neurons. Patch-clamp recordings in brain slices in vitro revealed increased neuronal input resistance and prolonged action potential width in CA1 pyramidal neurons. We did neither observe changes in synaptic inhibition, nor in excitation. Our data support the view that increased intrinsic excitability of CA1 neurons may precede inhibitory dysfunction at an early stage of Aβ-deposition and disease progression.
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Affiliation(s)
- Liudmila Sosulina
- Neuronal Networks Group, German Center for Neurodegenerative Diseases (DZNE), Bonn, Germany.,Department of Cellular Neuroscience, Leibniz Institute for Neurobiology, Magdeburg, Germany
| | - Manuel Mittag
- Neuroimmunology and Imaging Group, German Center for Neurodegenerative Diseases (DZNE), Bonn, Germany
| | - Hans-Rüdiger Geis
- Neuronal Networks Group, German Center for Neurodegenerative Diseases (DZNE), Bonn, Germany
| | - Kerstin Hoffmann
- Neuroimmunology and Imaging Group, German Center for Neurodegenerative Diseases (DZNE), Bonn, Germany
| | - Igor Klyubin
- Department of Pharmacology and Therapeutics, Trinity College, Dublin, Ireland
| | - Yingjie Qi
- Department of Pharmacology and Therapeutics, Trinity College, Dublin, Ireland
| | - Julia Steffen
- Neuroimmunology and Imaging Group, German Center for Neurodegenerative Diseases (DZNE), Bonn, Germany
| | - Detlef Friedrichs
- Neuronal Networks Group, German Center for Neurodegenerative Diseases (DZNE), Bonn, Germany
| | - Niklas Henneberg
- Neuronal Networks Group, German Center for Neurodegenerative Diseases (DZNE), Bonn, Germany
| | - Falko Fuhrmann
- Neuronal Networks Group, German Center for Neurodegenerative Diseases (DZNE), Bonn, Germany
| | - Daniel Justus
- Neuronal Networks Group, German Center for Neurodegenerative Diseases (DZNE), Bonn, Germany
| | - Kevin Keppler
- Light Microscopy Facility, German Center for Neurodegenerative Diseases (DZNE), Bonn, Germany
| | - A Claudio Cuello
- Department of Pharmacology and Therapeutics, McGill University, Montreal, QC, Canada
| | - Michael J Rowan
- Department of Pharmacology and Therapeutics, Trinity College, Dublin, Ireland
| | - Martin Fuhrmann
- Neuroimmunology and Imaging Group, German Center for Neurodegenerative Diseases (DZNE), Bonn, Germany
| | - Stefan Remy
- Neuronal Networks Group, German Center for Neurodegenerative Diseases (DZNE), Bonn, Germany.,Department of Cellular Neuroscience, Leibniz Institute for Neurobiology, Magdeburg, Germany
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19
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Flores-Soto M, Romero-Guerrero C, Vázquez-Hernández N, Tejeda-Martínez A, Martín-Amaya-Barajas FL, Orozco-Suárez S, González-Burgos I. Pentylenetetrazol-induced seizures in adult rats are associated with plastic changes to the dendritic spines on hippocampal CA1 pyramidal neurons. Behav Brain Res 2021; 406:113198. [PMID: 33657439 DOI: 10.1016/j.bbr.2021.113198] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2020] [Revised: 02/17/2021] [Accepted: 02/18/2021] [Indexed: 12/29/2022]
Abstract
Epilepsy is a chronic neurobehavioral disorder whereby an imbalance between neurochemical excitation and inhibition at the synaptic level provokes seizures. Various experimental models have been used to study epilepsy, including that based on acute or chronic administration of Pentylenetetrazol (PTZ). In this study, a single PTZ dose (60 mg/kg) was administered to adult male rats and 30 min later, various neurobiological parameters were studied related to the transmission and modulation of excitatory impulses in pyramidal neurons of the hippocampal CA1 field. Rats experienced generalized seizures 1-3 min after PTZ administration, accompanied by elevated levels of Synaptophysin and Glutaminase. This response suggests presynaptic glutamate release is exacerbated to toxic levels, which eventually provokes neuronal death as witnessed by the higher levels of Caspase-3, TUNEL and GFAP. Similarly, the increase in PSD-95 suggests that viable dendritic spines are functional. Indeed, the increase in stubby and wide spines is likely related to de novo spinogenesis, and the regulation of neuronal excitability, which could represent a plastic response to the synaptic over-excitation. Furthermore, the increase in mushroom spines could be associated with the storage of cognitive information and the potentiation of thin spines until they are transformed into mushroom spines. However, the reduction in BDNF suggests that the activity of these spines would be down-regulated, may in part be responsible for the cognitive decline related to hippocampal function in patients with epilepsy.
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Affiliation(s)
- Mario Flores-Soto
- División de Neurociencias, Centro de Investigación Biomédica de Occidente, IMSS, Guadalajara, Jal., Mexico
| | - Christian Romero-Guerrero
- División de Neurociencias, Centro de Investigación Biomédica de Occidente, IMSS, Guadalajara, Jal., Mexico
| | - Nallely Vázquez-Hernández
- División de Neurociencias, Centro de Investigación Biomédica de Occidente, IMSS, Guadalajara, Jal., Mexico
| | - Aldo Tejeda-Martínez
- División de Neurociencias, Centro de Investigación Biomédica de Occidente, IMSS, Guadalajara, Jal., Mexico
| | | | - Sandra Orozco-Suárez
- Unidad de Investigación Médica en Enfermedades Neurológicas, Hospital de Especialidades, CMN S-XXI, IMSS, Guadalajara, Jal., Mexico
| | - Ignacio González-Burgos
- División de Neurociencias, Centro de Investigación Biomédica de Occidente, IMSS, Guadalajara, Jal., Mexico.
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20
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Roth RH, Ding JB. From Neurons to Cognition: Technologies for Precise Recording of Neural Activity Underlying Behavior. BME FRONTIERS 2020; 2020:7190517. [PMID: 37849967 PMCID: PMC10521756 DOI: 10.34133/2020/7190517] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2020] [Accepted: 10/27/2020] [Indexed: 10/19/2023] Open
Abstract
Understanding how brain activity encodes information and controls behavior is a long-standing question in neuroscience. This complex problem requires converging efforts from neuroscience and engineering, including technological solutions to perform high-precision and large-scale recordings of neuronal activity in vivo as well as unbiased methods to reliably measure and quantify behavior. Thanks to advances in genetics, molecular biology, engineering, and neuroscience, in recent decades, a variety of optical imaging and electrophysiological approaches for recording neuronal activity in awake animals have been developed and widely applied in the field. Moreover, sophisticated computer vision and machine learning algorithms have been developed to analyze animal behavior. In this review, we provide an overview of the current state of technology for neuronal recordings with a focus on optical and electrophysiological methods in rodents. In addition, we discuss areas that future technological development will need to cover in order to further our understanding of the neural activity underlying behavior.
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Affiliation(s)
- Richard H Roth
- Department of Neurosurgery, Stanford University, Stanford, CA 94305, USA
| | - Jun B Ding
- Department of Neurosurgery, Stanford University, Stanford, CA 94305, USA
- Department of Neurology and Neurological Sciences, Stanford University, Stanford, CA 94305, USA
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21
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Subramanian J, Savage JC, Tremblay MÈ. Synaptic Loss in Alzheimer's Disease: Mechanistic Insights Provided by Two-Photon in vivo Imaging of Transgenic Mouse Models. Front Cell Neurosci 2020; 14:592607. [PMID: 33408613 PMCID: PMC7780885 DOI: 10.3389/fncel.2020.592607] [Citation(s) in RCA: 42] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2020] [Accepted: 11/25/2020] [Indexed: 01/05/2023] Open
Abstract
Synapse loss is the strongest correlate for cognitive decline in Alzheimer's disease. The mechanisms underlying synapse loss have been extensively investigated using mouse models expressing genes with human familial Alzheimer's disease mutations. In this review, we summarize how multiphoton in vivo imaging has improved our understanding of synapse loss mechanisms associated with excessive amyloid in the living animal brain. We also discuss evidence obtained from these imaging studies for the role of cell-intrinsic calcium dyshomeostasis and cell-extrinsic activities of microglia, which are the immune cells of the brain, in mediating synapse loss.
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Affiliation(s)
- Jaichandar Subramanian
- Department of Pharmacology & Toxicology, University of Kansas, Lawrence, KS, United States
| | - Julie C Savage
- Axe Neurosciences, Centre de Recherche du CHU de Québec, Université Laval, Québec City, QC, Canada
| | - Marie-Ève Tremblay
- Neurology and Neurosurgery Department, McGill University, Montreal, QC, Canada.,Department of Molecular Medicine, Université Laval, Québec City, QC, Canada.,Division of Medical Sciences, University of Victoria, Victoria, BC, Canada.,Department of Biochemistry and Molecular Biology, The University of British Columbia, Vancouver, BC, Canada
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22
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Liang Y, Walczak P. Long term intravital single cell tracking under multiphoton microscopy. J Neurosci Methods 2020; 349:109042. [PMID: 33340557 DOI: 10.1016/j.jneumeth.2020.109042] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2020] [Revised: 12/07/2020] [Accepted: 12/11/2020] [Indexed: 12/13/2022]
Abstract
Visualizing and tracking cells over time in a living organism has been a much-coveted dream before the invention of intravital microscopy. The opaque nature of tissue was a major hurdle that was remedied by the multiphoton microscopy. With the advancement of optical imaging and fluorescent labeling tools, intravital high resolution imaging has become increasingly accessible over the past few years. Long-term intravital tracking of single cells (LIST) under multiphoton microscopy provides a unique opportunity to gain insight into the longitudinal changes in the morphology, migration, or function of cells or subcellular structures. It is particularly suitable for studying slow-evolving cellular and molecular events during normal development or disease progression, without losing the opportunity of catching fast events such as calcium signals. Here, we review the application of LIST under 2-photon microscopy in various fields of neurobiology and discuss challenges and new directions in labeling and imaging methods for LIST. Overall, this review provides an overview of current applications of LIST in mammals, which is an emerging field that will contribute to a better understanding of essential molecular and cellular events in health and disease.
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Affiliation(s)
- Yajie Liang
- Department of Diagnostic Radiology and Nuclear Medicine, University of Maryland School of Medicine, Baltimore, MD, USA.
| | - Piotr Walczak
- Department of Diagnostic Radiology and Nuclear Medicine, University of Maryland School of Medicine, Baltimore, MD, USA
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23
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Qin Z, Chen C, He S, Wang Y, Tam KF, Ip NY, Qu JY. Adaptive optics two-photon endomicroscopy enables deep-brain imaging at synaptic resolution over large volumes. SCIENCE ADVANCES 2020; 6:6/40/eabc6521. [PMID: 32998883 PMCID: PMC7527232 DOI: 10.1126/sciadv.abc6521] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/06/2020] [Accepted: 08/11/2020] [Indexed: 05/02/2023]
Abstract
Optical deep-brain imaging in vivo at high resolution has remained a great challenge over the decades. Two-photon endomicroscopy provides a minimally invasive approach to image buried brain structures, once it is integrated with a gradient refractive index (GRIN) lens embedded in the brain. However, its imaging resolution and field of view are compromised by the intrinsic aberrations of the GRIN lens. Here, we develop a two-photon endomicroscopy by adding adaptive optics based on direct wavefront sensing, which enables recovery of diffraction-limited resolution in deep-brain imaging. A new precompensation strategy plays a critical role to correct aberrations over large volumes and achieve rapid random-access multiplane imaging. We investigate the neuronal plasticity in the hippocampus, a critical deep brain structure, and reveal the relationship between the somatic and dendritic activity of pyramidal neurons.
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Affiliation(s)
- Zhongya Qin
- Department of Electronic and Computer Engineering, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, P. R. China
- State Key Laboratory of Molecular Neuroscience, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, P. R. China
- Center of Systems Biology and Human Health, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, P. R. China
| | - Congping Chen
- Department of Electronic and Computer Engineering, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, P. R. China
- State Key Laboratory of Molecular Neuroscience, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, P. R. China
- Center of Systems Biology and Human Health, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, P. R. China
| | - Sicong He
- Department of Electronic and Computer Engineering, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, P. R. China
- State Key Laboratory of Molecular Neuroscience, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, P. R. China
- Center of Systems Biology and Human Health, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, P. R. China
| | - Ye Wang
- State Key Laboratory of Molecular Neuroscience, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, P. R. China
- Division of Life Science, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, P. R. China
- Molecular Neuroscience Center, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, P.R. China
| | - Kam Fai Tam
- State Key Laboratory of Molecular Neuroscience, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, P. R. China
- Division of Life Science, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, P. R. China
- Molecular Neuroscience Center, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, P.R. China
| | - Nancy Y Ip
- State Key Laboratory of Molecular Neuroscience, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, P. R. China.
- Division of Life Science, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, P. R. China
- Molecular Neuroscience Center, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, P.R. China
| | - Jianan Y Qu
- Department of Electronic and Computer Engineering, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, P. R. China.
- State Key Laboratory of Molecular Neuroscience, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, P. R. China
- Center of Systems Biology and Human Health, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, P. R. China
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24
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Xie L, Li T, Song X, Sun H, Liu J, Yang J, Zhao W, Cheng L, Chen H, Liu B, Han W, Yang C, Jiang L. Dynamic alteration of dendrites and dendritic spines in the hippocampus and microglia in mouse brain tissues after kainate-induced status epilepticus. Int J Neurosci 2020; 131:1045-1057. [PMID: 32448031 DOI: 10.1080/00207454.2020.1770246] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Affiliation(s)
- Lingling Xie
- Department of Neurology, Children’s Hospital of Chongqing Medical University, Chongqing, China
- Pediatric Research Institute, Children’s Hospital of Chongqing Medical University, Chongqing, China
- National Clinical Research Center for Child Health and Disorders, Chongqing, China
- Ministry of Education Key Laboratory of Child Development and Disorders, Chongqing, China
- China International Science and Technology Cooperation Base of Child Development and Critical Disorders, Children's Hospital of Chongqing Medical University, Chongqing, China
| | - Tianyi Li
- Department of Neurology, Children’s Hospital of Chongqing Medical University, Chongqing, China
- National Clinical Research Center for Child Health and Disorders, Chongqing, China
- Ministry of Education Key Laboratory of Child Development and Disorders, Chongqing, China
- China International Science and Technology Cooperation Base of Child Development and Critical Disorders, Children's Hospital of Chongqing Medical University, Chongqing, China
- Chongqing Key Laboratory of Pediatrics, Chongqing, China
| | - Xiaojie Song
- Department of Neurology, Children’s Hospital of Chongqing Medical University, Chongqing, China
- National Clinical Research Center for Child Health and Disorders, Chongqing, China
- Ministry of Education Key Laboratory of Child Development and Disorders, Chongqing, China
- China International Science and Technology Cooperation Base of Child Development and Critical Disorders, Children's Hospital of Chongqing Medical University, Chongqing, China
- Chongqing Key Laboratory of Pediatrics, Chongqing, China
| | - Hong Sun
- Department of Neurology, Children’s Hospital of Chongqing Medical University, Chongqing, China
- National Clinical Research Center for Child Health and Disorders, Chongqing, China
- Ministry of Education Key Laboratory of Child Development and Disorders, Chongqing, China
- China International Science and Technology Cooperation Base of Child Development and Critical Disorders, Children's Hospital of Chongqing Medical University, Chongqing, China
- Chongqing Key Laboratory of Pediatrics, Chongqing, China
| | - Jie Liu
- Department of Neurology, Children’s Hospital of Chongqing Medical University, Chongqing, China
- National Clinical Research Center for Child Health and Disorders, Chongqing, China
- Ministry of Education Key Laboratory of Child Development and Disorders, Chongqing, China
- China International Science and Technology Cooperation Base of Child Development and Critical Disorders, Children's Hospital of Chongqing Medical University, Chongqing, China
- Chongqing Key Laboratory of Pediatrics, Chongqing, China
| | - Jing Yang
- Department of Neurology, Children’s Hospital of Chongqing Medical University, Chongqing, China
- National Clinical Research Center for Child Health and Disorders, Chongqing, China
- Ministry of Education Key Laboratory of Child Development and Disorders, Chongqing, China
- China International Science and Technology Cooperation Base of Child Development and Critical Disorders, Children's Hospital of Chongqing Medical University, Chongqing, China
- Chongqing Key Laboratory of Pediatrics, Chongqing, China
| | - Wenjie Zhao
- Department of Neurology, Children’s Hospital of Chongqing Medical University, Chongqing, China
- National Clinical Research Center for Child Health and Disorders, Chongqing, China
- Ministry of Education Key Laboratory of Child Development and Disorders, Chongqing, China
- China International Science and Technology Cooperation Base of Child Development and Critical Disorders, Children's Hospital of Chongqing Medical University, Chongqing, China
- Chongqing Key Laboratory of Pediatrics, Chongqing, China
| | - Li Cheng
- Pediatric Research Institute, Children’s Hospital of Chongqing Medical University, Chongqing, China
- National Clinical Research Center for Child Health and Disorders, Chongqing, China
- Ministry of Education Key Laboratory of Child Development and Disorders, Chongqing, China
- China International Science and Technology Cooperation Base of Child Development and Critical Disorders, Children's Hospital of Chongqing Medical University, Chongqing, China
- Chongqing Key Laboratory of Pediatrics, Chongqing, China
| | - Hengsheng Chen
- Pediatric Research Institute, Children’s Hospital of Chongqing Medical University, Chongqing, China
- National Clinical Research Center for Child Health and Disorders, Chongqing, China
- Ministry of Education Key Laboratory of Child Development and Disorders, Chongqing, China
- China International Science and Technology Cooperation Base of Child Development and Critical Disorders, Children's Hospital of Chongqing Medical University, Chongqing, China
- Chongqing Key Laboratory of Pediatrics, Chongqing, China
| | - Benke Liu
- Department of Neurology, Children’s Hospital of Chongqing Medical University, Chongqing, China
- National Clinical Research Center for Child Health and Disorders, Chongqing, China
- Ministry of Education Key Laboratory of Child Development and Disorders, Chongqing, China
- China International Science and Technology Cooperation Base of Child Development and Critical Disorders, Children's Hospital of Chongqing Medical University, Chongqing, China
- Chongqing Key Laboratory of Pediatrics, Chongqing, China
| | - Wei Han
- Department of Neurology, Children’s Hospital of Chongqing Medical University, Chongqing, China
- National Clinical Research Center for Child Health and Disorders, Chongqing, China
- Ministry of Education Key Laboratory of Child Development and Disorders, Chongqing, China
- China International Science and Technology Cooperation Base of Child Development and Critical Disorders, Children's Hospital of Chongqing Medical University, Chongqing, China
- Chongqing Key Laboratory of Pediatrics, Chongqing, China
| | - Chen Yang
- Department of Neurology, Children’s Hospital of Chongqing Medical University, Chongqing, China
- National Clinical Research Center for Child Health and Disorders, Chongqing, China
- Ministry of Education Key Laboratory of Child Development and Disorders, Chongqing, China
- China International Science and Technology Cooperation Base of Child Development and Critical Disorders, Children's Hospital of Chongqing Medical University, Chongqing, China
- Chongqing Key Laboratory of Pediatrics, Chongqing, China
| | - Li Jiang
- Department of Neurology, Children’s Hospital of Chongqing Medical University, Chongqing, China
- Pediatric Research Institute, Children’s Hospital of Chongqing Medical University, Chongqing, China
- National Clinical Research Center for Child Health and Disorders, Chongqing, China
- Ministry of Education Key Laboratory of Child Development and Disorders, Chongqing, China
- China International Science and Technology Cooperation Base of Child Development and Critical Disorders, Children's Hospital of Chongqing Medical University, Chongqing, China
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25
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Soulet D, Lamontagne-Proulx J, Aubé B, Davalos D. Multiphoton intravital microscopy in small animals: motion artefact challenges and technical solutions. J Microsc 2020; 278:3-17. [PMID: 32072642 PMCID: PMC7187339 DOI: 10.1111/jmi.12880] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2019] [Revised: 02/06/2020] [Accepted: 02/14/2020] [Indexed: 12/28/2022]
Abstract
Since its invention 29 years ago, two‐photon laser‐scanning microscopy has evolved from a promising imaging technique, to an established widely available imaging modality used throughout the biomedical research community. The establishment of two‐photon microscopy as the preferred method for imaging fluorescently labelled cells and structures in living animals can be attributed to the biophysical mechanism by which the generation of fluorescence is accomplished. The use of powerful lasers capable of delivering infrared light pulses within femtosecond intervals, facilitates the nonlinear excitation of fluorescent molecules only at the focal plane and determines by objective lens position. This offers numerous benefits for studies of biological samples at high spatial and temporal resolutions with limited photo‐damage and superior tissue penetration. Indeed, these attributes have established two‐photon microscopy as the ideal method for live‐animal imaging in several areas of biology and have led to a whole new field of study dedicated to imaging biological phenomena in intact tissues and living organisms. However, despite its appealing features, two‐photon intravital microscopy is inherently limited by tissue motion from heartbeat, respiratory cycles, peristalsis, muscle/vascular tone and physiological functions that change tissue geometry. Because these movements impede temporal and spatial resolution, they must be properly addressed to harness the full potential of two‐photon intravital microscopy and enable accurate data analysis and interpretation. In addition, the sources and features of these motion artefacts are varied, sometimes unpredictable and unique to specific organs and multiple complex strategies have previously been devised to address them. This review will discuss these motion artefacts requirement and technical solutions for their correction and after intravital two‐photon microscopy.
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Affiliation(s)
- D Soulet
- Centre de recherche du CHUL, Department of Neurosciences, Quebec, Canada.,Faculty of Pharmacy, Université Laval, Quebec, Canada
| | - J Lamontagne-Proulx
- Centre de recherche du CHUL, Department of Neurosciences, Quebec, Canada.,Faculty of Pharmacy, Université Laval, Quebec, Canada
| | - B Aubé
- Centre de recherche du CHUL, Department of Neurosciences, Quebec, Canada
| | - D Davalos
- Department of Neurosciences, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio, U.S.A
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26
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Obaid A, Hanna ME, Wu YW, Kollo M, Racz R, Angle MR, Müller J, Brackbill N, Wray W, Franke F, Chichilnisky EJ, Hierlemann A, Ding JB, Schaefer AT, Melosh NA. Massively parallel microwire arrays integrated with CMOS chips for neural recording. SCIENCE ADVANCES 2020; 6:eaay2789. [PMID: 32219158 PMCID: PMC7083623 DOI: 10.1126/sciadv.aay2789] [Citation(s) in RCA: 73] [Impact Index Per Article: 18.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/05/2019] [Accepted: 12/26/2019] [Indexed: 05/21/2023]
Abstract
Multi-channel electrical recordings of neural activity in the brain is an increasingly powerful method revealing new aspects of neural communication, computation, and prosthetics. However, while planar silicon-based CMOS devices in conventional electronics scale rapidly, neural interface devices have not kept pace. Here, we present a new strategy to interface silicon-based chips with three-dimensional microwire arrays, providing the link between rapidly-developing electronics and high density neural interfaces. The system consists of a bundle of microwires mated to large-scale microelectrode arrays, such as camera chips. This system has excellent recording performance, demonstrated via single unit and local-field potential recordings in isolated retina and in the motor cortex or striatum of awake moving mice. The modular design enables a variety of microwire types and sizes to be integrated with different types of pixel arrays, connecting the rapid progress of commercial multiplexing, digitisation and data acquisition hardware together with a three-dimensional neural interface.
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Affiliation(s)
- Abdulmalik Obaid
- Department of Materials Science and Engineering, Stanford University, Stanford, CA, USA
| | - Mina-Elraheb Hanna
- Department of Materials Science and Engineering, Stanford University, Stanford, CA, USA
- Paradromics Inc., Austin, TX, USA
| | - Yu-Wei Wu
- Department of Neurosurgery, Stanford University School of Medicine, Stanford, CA, USA
| | - Mihaly Kollo
- Neurophysiology of Behaviour Laboratory, Francis Crick Institute, London, UK
- Department of Neuroscience, Physiology and Pharmacology, University College London, London, UK
| | - Romeo Racz
- Neurophysiology of Behaviour Laboratory, Francis Crick Institute, London, UK
| | | | - Jan Müller
- Department of Biosystems Science and Engineering, ETH Zurich, Basel, Switzerland
| | - Nora Brackbill
- Department of Physics, Stanford University, Stanford, CA, USA
| | - William Wray
- Neurophysiology of Behaviour Laboratory, Francis Crick Institute, London, UK
| | - Felix Franke
- Department of Biosystems Science and Engineering, ETH Zurich, Basel, Switzerland
| | - E. J. Chichilnisky
- Departments of Neurosurgery and Ophthalmology, Stanford University, Stanford, CA, USA
| | - Andreas Hierlemann
- Department of Biosystems Science and Engineering, ETH Zurich, Basel, Switzerland
| | - Jun B. Ding
- Department of Neurosurgery, Stanford University School of Medicine, Stanford, CA, USA
| | - Andreas T. Schaefer
- Neurophysiology of Behaviour Laboratory, Francis Crick Institute, London, UK
- Department of Neuroscience, Physiology and Pharmacology, University College London, London, UK
| | - Nicholas A. Melosh
- Department of Materials Science and Engineering, Stanford University, Stanford, CA, USA
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27
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Chidambaram SB, Rathipriya AG, Bolla SR, Bhat A, Ray B, Mahalakshmi AM, Manivasagam T, Thenmozhi AJ, Essa MM, Guillemin GJ, Chandra R, Sakharkar MK. Dendritic spines: Revisiting the physiological role. Prog Neuropsychopharmacol Biol Psychiatry 2019; 92:161-193. [PMID: 30654089 DOI: 10.1016/j.pnpbp.2019.01.005] [Citation(s) in RCA: 150] [Impact Index Per Article: 30.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/22/2018] [Revised: 01/04/2019] [Accepted: 01/12/2019] [Indexed: 12/11/2022]
Abstract
Dendritic spines are small, thin, specialized protrusions from neuronal dendrites, primarily localized in the excitatory synapses. Sophisticated imaging techniques revealed that dendritic spines are complex structures consisting of a dense network of cytoskeletal, transmembrane and scaffolding molecules, and numerous surface receptors. Molecular signaling pathways, mainly Rho and Ras family small GTPases pathways that converge on actin cytoskeleton, regulate the spine morphology and dynamics bi-directionally during synaptic activity. During synaptic plasticity the number and shapes of dendritic spines undergo radical reorganizations. Long-term potentiation (LTP) induction promote spine head enlargement and the formation and stabilization of new spines. Long-term depression (LTD) results in their shrinkage and retraction. Reports indicate increased spine density in the pyramidal neurons of autism and Fragile X syndrome patients and reduced density in the temporal gyrus loci of schizophrenic patients. Post-mortem reports of Alzheimer's brains showed reduced spine number in the hippocampus and cortex. This review highlights the spine morphogenesis process, the activity-dependent structural plasticity and mechanisms by which synaptic activity sculpts the dendritic spines, the structural and functional changes in spines during learning and memory using LTP and LTD processes. It also discusses on spine status in neurodegenerative diseases and the impact of nootropics and neuroprotective agents on the functional restoration of dendritic spines.
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Affiliation(s)
- Saravana Babu Chidambaram
- Department of Pharmacology, JSS College of Pharmacy, JSS Academy of Higher Education & Research (JSSAHER), Mysuru, Karnataka 570015, India.
| | - A G Rathipriya
- Food and Brain Research Foundation, Chennai, Tamil Nadu, India
| | - Srinivasa Rao Bolla
- Department of Anatomy, College of Medicine, Imam Abdulrahman Bin Faisal University, Damam, Saudi Arabia
| | - Abid Bhat
- Department of Pharmacology, JSS College of Pharmacy, JSS Academy of Higher Education & Research (JSSAHER), Mysuru, Karnataka 570015, India
| | - Bipul Ray
- Department of Pharmacology, JSS College of Pharmacy, JSS Academy of Higher Education & Research (JSSAHER), Mysuru, Karnataka 570015, India
| | - Arehally Marappa Mahalakshmi
- Department of Pharmacology, JSS College of Pharmacy, JSS Academy of Higher Education & Research (JSSAHER), Mysuru, Karnataka 570015, India
| | - Thamilarasan Manivasagam
- Department of Biochemistry and Biotechnology, Faculty of Science, Annamalai University, Annamalainagar, Tamilnadu, India
| | - Arokiasamy Justin Thenmozhi
- Department of Biochemistry and Biotechnology, Faculty of Science, Annamalai University, Annamalainagar, Tamilnadu, India
| | - Musthafa Mohamed Essa
- Department of Food Science and Nutrition, CAMS, Sultan Qaboos University, Muscat, Oman
| | - Gilles J Guillemin
- Neuropharmacology Group, Faculty of Medicine and Health Sciences, Deb Bailey MND Research Laboratory, Macquarie University, Sydney, NSW 2109, Australia
| | - Ramesh Chandra
- Department of Chemistry, Ambedkar Centre for BioMedical Research, Delhi University, Delhi 110007, India
| | - Meena Kishore Sakharkar
- College of Pharmacy and Nutrition, University of Saskatchewan, 107, Wiggins Road, Saskatoon, SK S7N 5C9, Canada.
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28
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Pernici CD, Kemp BS, Murray TA. Time course images of cellular injury and recovery in murine brain with high-resolution GRIN lens system. Sci Rep 2019; 9:7946. [PMID: 31138885 PMCID: PMC6538613 DOI: 10.1038/s41598-019-44174-7] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2018] [Accepted: 05/10/2019] [Indexed: 12/20/2022] Open
Abstract
Time course, in vivo imaging of brain cells is crucial to fully understand the progression of secondary cellular damage and recovery in murine models of injury. We have combined high-resolution gradient index lens technology with a model of diffuse axonal injury in rodents to enable repeated visualization of fine features of individual cells in three-dimensional space over several weeks. For example, we recorded changes in morphology in the same axons in the external capsule numerous times over 30 to 60 days, before and after induced traumatic brain injury. We observed the expansion of secondary injury and limited recovery of individual axons in this subcortical white matter tract over time. In another application, changes in microglial activation state were visualized in the penumbra region of mice before and after ischemia induced by middle carotid artery occlusion. The ability to collect a series of high-resolution images of cellular features of the same cells pre- and post-injury enables a unique opportunity to study the progression of damage, spontaneous healing, and effects of therapeutics in mouse models of neurodegenerative disease and brain injury.
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Affiliation(s)
- Chelsea D Pernici
- Center for Biomedical Engineering and Rehabilitation Sciences, Louisiana Tech University, Ruston, Louisiana, USA
| | - Benjamin S Kemp
- Center for Biomedical Engineering and Rehabilitation Sciences, Louisiana Tech University, Ruston, Louisiana, USA
| | - Teresa A Murray
- Center for Biomedical Engineering and Rehabilitation Sciences, Louisiana Tech University, Ruston, Louisiana, USA.
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29
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Abstract
Understanding the mechanisms by which long-term synaptic plasticity is expressed remains an important objective in neuroscience. From a physiological perspective, the strength of a synapse can be considered a consequence of several parameters including the probability that a presynaptic action potential (AP) evokes the release of neurotransmitter, the mean number of quanta of transmitter released when release is evoked, and the mean amplitude of a postsynaptic response to a single quantum. Various methods have been employed to estimate these quantal parameters from electrophysiological recordings; such "quantal analysis" has been used to support competing accounts of mechanisms of expression of long-term plasticity. Because electrophysiological recordings, even with minimal presynaptic stimulation, can reflect responses arising at multiple synaptic sites, these methods are open to alternative interpretations. By combining intracellular electrical recording with optical detection of transmission at individual synapses, however, it is possible to eliminate such ambiguity. Here, we describe methods for such combined optical and electrical monitoring of synaptic transmission in brain slice preparations and illustrate how quantal analyses thereby obtained permit more definitive conclusions about the physiological changes that underlie long-term synaptic plasticity.
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Affiliation(s)
| | - Alan Fine
- Department of Physiology and Biophysics, Faculty of Medicine, Dalhousie University, Halifax, NS, Canada
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30
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Meng G, Liang Y, Sarsfield S, Jiang WC, Lu R, Dudman JT, Aponte Y, Ji N. High-throughput synapse-resolving two-photon fluorescence microendoscopy for deep-brain volumetric imaging in vivo. eLife 2019; 8:40805. [PMID: 30604680 PMCID: PMC6338462 DOI: 10.7554/elife.40805] [Citation(s) in RCA: 60] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2018] [Accepted: 12/20/2018] [Indexed: 01/02/2023] Open
Abstract
Optical imaging has become a powerful tool for studying brains in vivo. The opacity of adult brains makes microendoscopy, with an optical probe such as a gradient index (GRIN) lens embedded into brain tissue to provide optical relay, the method of choice for imaging neurons and neural activity in deeply buried brain structures. Incorporating a Bessel focus scanning module into two-photon fluorescence microendoscopy, we extended the excitation focus axially and improved its lateral resolution. Scanning the Bessel focus in 2D, we imaged volumes of neurons at high-throughput while resolving fine structures such as synaptic terminals. We applied this approach to the volumetric anatomical imaging of dendritic spines and axonal boutons in the mouse hippocampus, and functional imaging of GABAergic neurons in the mouse lateral hypothalamus in vivo.
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Affiliation(s)
- Guanghan Meng
- Department of Molecular and Cell Biology, University of California, Berkeley, United States.,Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, United States.,Solomon H Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, United States.,Department of Physics, University of California, Berkeley, United States.,Helen Wills Neuroscience Institute, University of California, Berkeley, United States
| | - Yajie Liang
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, United States
| | - Sarah Sarsfield
- Intramural Research Program, Neuronal Circuits and Behavior Unit, National Institute on Drug Abuse, National Institutes of Health, Baltimore, United States
| | - Wan-Chen Jiang
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, United States
| | - Rongwen Lu
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, United States
| | - Joshua Tate Dudman
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, United States
| | - Yeka Aponte
- Solomon H Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, United States.,Intramural Research Program, Neuronal Circuits and Behavior Unit, National Institute on Drug Abuse, National Institutes of Health, Baltimore, United States
| | - Na Ji
- Department of Molecular and Cell Biology, University of California, Berkeley, United States.,Department of Physics, University of California, Berkeley, United States.,Helen Wills Neuroscience Institute, University of California, Berkeley, United States.,Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, United States
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31
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Attardo A, Lu J, Kawashima T, Okuno H, Fitzgerald JE, Bito H, Schnitzer MJ. Long-Term Consolidation of Ensemble Neural Plasticity Patterns in Hippocampal Area CA1. Cell Rep 2018; 25:640-650.e2. [DOI: 10.1016/j.celrep.2018.09.064] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2017] [Revised: 06/27/2018] [Accepted: 09/19/2018] [Indexed: 12/20/2022] Open
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32
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Pfeiffer T, Poll S, Bancelin S, Angibaud J, Inavalli VK, Keppler K, Mittag M, Fuhrmann M, Nägerl UV. Chronic 2P-STED imaging reveals high turnover of dendritic spines in the hippocampus in vivo. eLife 2018; 7:34700. [PMID: 29932052 PMCID: PMC6014725 DOI: 10.7554/elife.34700] [Citation(s) in RCA: 95] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2017] [Accepted: 06/05/2018] [Indexed: 11/13/2022] Open
Abstract
Rewiring neural circuits by the formation and elimination of synapses is thought to be a key cellular mechanism of learning and memory in the mammalian brain. Dendritic spines are the postsynaptic structural component of excitatory synapses, and their experience-dependent plasticity has been extensively studied in mouse superficial cortex using two-photon microscopy in vivo. By contrast, very little is known about spine plasticity in the hippocampus, which is the archetypical memory center of the brain, mostly because it is difficult to visualize dendritic spines in this deeply embedded structure with sufficient spatial resolution. We developed chronic 2P-STED microscopy in mouse hippocampus, using a ‘hippocampal window’ based on resection of cortical tissue and a long working distance objective for optical access. We observed a two-fold higher spine density than previous studies and measured a spine turnover of ~40% within 4 days, which depended on spine size. We thus provide direct evidence for a high level of structural rewiring of synaptic circuits and new insights into the structure-dynamics relationship of hippocampal spines. Having established chronic super-resolution microscopy in the hippocampus in vivo, our study enables longitudinal and correlative analyses of nanoscale neuroanatomical structures with genetic, molecular and behavioral experiments.
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Affiliation(s)
- Thomas Pfeiffer
- Interdisciplinary Institute for Neuroscience, CNRS UMR 5297, Bordeaux, France.,Interdisciplinary Institute for Neuroscience, University of Bordeaux, Bordeaux, France
| | - Stefanie Poll
- Neuroimmunology and Imaging Group, German Center for Neurodegenerative Diseases, Bonn, Germany
| | - Stephane Bancelin
- Interdisciplinary Institute for Neuroscience, CNRS UMR 5297, Bordeaux, France.,Interdisciplinary Institute for Neuroscience, University of Bordeaux, Bordeaux, France
| | - Julie Angibaud
- Interdisciplinary Institute for Neuroscience, CNRS UMR 5297, Bordeaux, France.,Interdisciplinary Institute for Neuroscience, University of Bordeaux, Bordeaux, France
| | - Vvg Krishna Inavalli
- Interdisciplinary Institute for Neuroscience, CNRS UMR 5297, Bordeaux, France.,Interdisciplinary Institute for Neuroscience, University of Bordeaux, Bordeaux, France
| | - Kevin Keppler
- Light Microscope Facility, German Center for Neurodegenerative Diseases, Bonn, Germany
| | - Manuel Mittag
- Neuroimmunology and Imaging Group, German Center for Neurodegenerative Diseases, Bonn, Germany
| | - Martin Fuhrmann
- Neuroimmunology and Imaging Group, German Center for Neurodegenerative Diseases, Bonn, Germany
| | - U Valentin Nägerl
- Interdisciplinary Institute for Neuroscience, CNRS UMR 5297, Bordeaux, France.,Interdisciplinary Institute for Neuroscience, University of Bordeaux, Bordeaux, France
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33
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Bloem B, Huda R, Sur M, Graybiel AM. Two-photon imaging in mice shows striosomes and matrix have overlapping but differential reinforcement-related responses. eLife 2017; 6:32353. [PMID: 29251596 PMCID: PMC5764569 DOI: 10.7554/elife.32353] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2017] [Accepted: 12/16/2017] [Indexed: 12/14/2022] Open
Abstract
Striosomes were discovered several decades ago as neurochemically identified zones in the striatum, yet technical hurdles have hampered the study of the functions of these striatal compartments. Here we used 2-photon calcium imaging in neuronal birthdate-labeled Mash1-CreER;Ai14 mice to image simultaneously the activity of striosomal and matrix neurons as mice performed an auditory conditioning task. With this method, we identified circumscribed zones of tdTomato-labeled neuropil that correspond to striosomes as verified immunohistochemically. Neurons in both striosomes and matrix responded to reward-predicting cues and were active during or after consummatory licking. However, we found quantitative differences in response strength: striosomal neurons fired more to reward-predicting cues and encoded more information about expected outcome as mice learned the task, whereas matrix neurons were more strongly modulated by recent reward history. These findings open the possibility of harnessing in vivo imaging to determine the contributions of striosomes and matrix to striatal circuit function.
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Affiliation(s)
- Bernard Bloem
- McGovern Institute for Brain Research, Massachusetts Institute of Technology, Cambridge, United States.,Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, United States
| | - Rafiq Huda
- Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, United States.,Picower Institute for Learning and Memory, Massachusetts Institute of Technology, Cambridge, United States
| | - Mriganka Sur
- Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, United States.,Picower Institute for Learning and Memory, Massachusetts Institute of Technology, Cambridge, United States
| | - Ann M Graybiel
- McGovern Institute for Brain Research, Massachusetts Institute of Technology, Cambridge, United States.,Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, United States
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34
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Busche MA, Konnerth A. Impairments of neural circuit function in Alzheimer's disease. Philos Trans R Soc Lond B Biol Sci 2017; 371:rstb.2015.0429. [PMID: 27377723 DOI: 10.1098/rstb.2015.0429] [Citation(s) in RCA: 201] [Impact Index Per Article: 28.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/31/2016] [Indexed: 11/12/2022] Open
Abstract
An essential feature of Alzheimer's disease (AD) is the accumulation of amyloid-β (Aβ) peptides in the brain, many years to decades before the onset of overt cognitive symptoms. We suggest that during this very extended early phase of the disease, soluble Aβ oligomers and amyloid plaques alter the function of local neuronal circuits and large-scale networks by disrupting the balance of synaptic excitation and inhibition (E/I balance) in the brain. The analysis of mouse models of AD revealed that an Aβ-induced change of the E/I balance caused hyperactivity in cortical and hippocampal neurons, a breakdown of slow-wave oscillations, as well as network hypersynchrony. Remarkably, hyperactivity of hippocampal neurons precedes amyloid plaque formation, suggesting that hyperactivity is one of the earliest dysfunctions in the pathophysiological cascade initiated by abnormal Aβ accumulation. Therapeutics that correct the E/I balance in early AD may prevent neuronal dysfunction, widespread cell loss and cognitive impairments associated with later stages of the disease.This article is part of the themed issue 'Evolution brings Ca(2+) and ATP together to control life and death'.
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Affiliation(s)
- Marc Aurel Busche
- Institute of Neuroscience, Technical University of Munich, Munich, Germany Department of Psychiatry and Psychotherapy, Technical University of Munich, Munich, Germany Munich Cluster for Systems Neurology (SyNergy), Munich, Germany Center of Integrated Protein Science Munich (CIPSM), Munich, Germany
| | - Arthur Konnerth
- Institute of Neuroscience, Technical University of Munich, Munich, Germany Munich Cluster for Systems Neurology (SyNergy), Munich, Germany Center of Integrated Protein Science Munich (CIPSM), Munich, Germany
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35
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Sato M, Motegi Y, Yagi S, Gengyo-Ando K, Ohkura M, Nakai J. Fast varifocal two-photon microendoscope for imaging neuronal activity in the deep brain. BIOMEDICAL OPTICS EXPRESS 2017; 8:4049-4060. [PMID: 28966846 PMCID: PMC5611922 DOI: 10.1364/boe.8.004049] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/01/2017] [Revised: 07/31/2017] [Accepted: 08/01/2017] [Indexed: 05/04/2023]
Abstract
Fluorescence microendoscopy is becoming a promising approach for deep brain imaging, but the current technology for visualizing neurons on a single focal plane limits the experimental efficiency and the pursuit of three-dimensional functional neural circuit architectures. Here we present a novel fast varifocal two-photon microendoscope system equipped with a gradient refractive index (GRIN) lens and an electrically tunable lens (ETL). This microendoscope enables quasi-simultaneous imaging of the neuronal network activity of deep brain areas at multiple focal planes separated by 85-120 µm at a fast scan rate of 7.5-15 frames per second per plane, as demonstrated in calcium imaging of the mouse dorsal CA1 hippocampus and amygdala in vivo.
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Affiliation(s)
- Masaaki Sato
- Graduate School of Science and Engineering, Saitama University, Saitama 338-8570, Japan
- Brain and Body System Science Institute, Saitama University, Saitama 338-8570, Japan
- RIKEN Brain Science Institute, Wako, Saitama 351-0198, Japan
| | - Yuki Motegi
- Graduate School of Science and Engineering, Saitama University, Saitama 338-8570, Japan
- Brain and Body System Science Institute, Saitama University, Saitama 338-8570, Japan
| | - Shogo Yagi
- NTT Advanced Technology Corporation, Atsugi, Kanagawa, 243-0198, Japan
| | - Keiko Gengyo-Ando
- Graduate School of Science and Engineering, Saitama University, Saitama 338-8570, Japan
- Brain and Body System Science Institute, Saitama University, Saitama 338-8570, Japan
- RIKEN Brain Science Institute, Wako, Saitama 351-0198, Japan
| | - Masamichi Ohkura
- Graduate School of Science and Engineering, Saitama University, Saitama 338-8570, Japan
- Brain and Body System Science Institute, Saitama University, Saitama 338-8570, Japan
| | - Junichi Nakai
- Graduate School of Science and Engineering, Saitama University, Saitama 338-8570, Japan
- Brain and Body System Science Institute, Saitama University, Saitama 338-8570, Japan
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36
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Functional Imaging of Dentate Granule Cells in the Adult Mouse Hippocampus. J Neurosci 2017; 36:7407-14. [PMID: 27413151 DOI: 10.1523/jneurosci.3065-15.2016] [Citation(s) in RCA: 66] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2015] [Accepted: 05/24/2016] [Indexed: 11/21/2022] Open
Abstract
UNLABELLED The hippocampal dentate gyrus is critically involved in learning and memory. However, methods for imaging the activity of its principal neurons, the dentate gyrus granule cells, are missing. Here we demonstrate chronic two-photon imaging of granule cell population activity in awake mice using a cortical window implant that leaves the hippocampal formation intact and does not lead to obvious alteration of animal behavior. Using virus delivery, we targeted expression of genetically encoded calcium indicators specifically to dentate gyrus granule cells. Calcium imaging of granule cell activity 600-800 μm below the hippocampal surface was facilitated by using 1040 nm excitation of the red indicator R-CaMP1.07, but was also achieved using the green indicator GCaMP6s. We found that the rate of calcium transients was increased during wakefulness relative to an extremely low rate during anesthesia; however, activity still remained sparse with, on average, approximately one event per 2-5 min per cell across the granule cell population. Comparing periods of running on a ladder wheel and periods of resting, we furthermore identified state-dependent differences in the active granule cell population, with some cells displaying highest activity level during running and others during resting. Typically, cells did not maintain a clear state preference in their activity pattern across days. Our approach opens new avenues to elucidate granule cell function, plasticity mechanisms, and network computation in the adult dentate gyrus. SIGNIFICANCE STATEMENT We describe a technique that allows for chronic, functional imaging of dentate gyrus granule cells in awake, behaving mice in an intact hippocampal circuitry using genetically encoded calcium indicators. This novel approach enables the analyses of individual granule cell activity over time and provides a powerful tool to elucidate the mechanisms underlying structural and functional plasticity of the adult dentate gyrus.
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37
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Kanda T, Ohyama K, Muramoto H, Kitajima N, Sekiya H. Promising techniques to illuminate neuromodulatory control of the cerebral cortex in sleeping and waking states. Neurosci Res 2017; 118:92-103. [PMID: 28434992 DOI: 10.1016/j.neures.2017.04.009] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2017] [Revised: 03/27/2017] [Accepted: 04/05/2017] [Indexed: 01/31/2023]
Abstract
Sleep, a common event in daily life, has clear benefits for brain function, but what goes on in the brain when we sleep remains unclear. Sleep was long regarded as a silent state of the brain because the brain seemingly lacks interaction with the surroundings during sleep. Since the discovery of electrical activities in the brain at rest, electrophysiological methods have revealed novel concepts in sleep research. During sleep, the brain generates oscillatory activities that represent characteristic states of sleep. In addition to electrophysiology, opto/chemogenetics and two-photon Ca2+ imaging methods have clarified that the sleep/wake states organized by neuronal and glial ensembles in the cerebral cortex are transitioned by neuromodulators. Even with these methods, however, it is extremely difficult to elucidate how and when neuromodulators spread, accumulate, and disappear in the extracellular space of the cortex. Thus, real-time monitoring of neuromodulator dynamics at high spatiotemporal resolution is required for further understanding of sleep. Toward direct detection of neuromodulator behavior during sleep and wakefulness, in this review, we discuss developing imaging techniques based on the activation of G-protein-coupled receptors that allow for visualization of neuromodulator dynamics.
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Affiliation(s)
- Takeshi Kanda
- International Institute for Integrative Sleep Medicine, University of Tsukuba, Ibaraki 305-8575, Japan.
| | - Kaoru Ohyama
- International Institute for Integrative Sleep Medicine, University of Tsukuba, Ibaraki 305-8575, Japan
| | - Hiroki Muramoto
- International Institute for Integrative Sleep Medicine, University of Tsukuba, Ibaraki 305-8575, Japan
| | - Nami Kitajima
- Department of Pharmacology, Graduate School of Medicine, The University of Tokyo, Bunkyo, Tokyo 113-0033, Japan
| | - Hiroshi Sekiya
- Department of Pharmacology, Graduate School of Medicine, The University of Tokyo, Bunkyo, Tokyo 113-0033, Japan.
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38
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Yang MH, Abashin M, Saisan PA, Tian P, Ferri CGL, Devor A, Fainman Y. Non-degenerate 2-photon excitation in scattering medium for fluorescence microscopy. OPTICS EXPRESS 2016; 24:30173-30187. [PMID: 28059294 PMCID: PMC5234507 DOI: 10.1364/oe.24.030173] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/18/2016] [Revised: 12/01/2016] [Accepted: 12/03/2016] [Indexed: 05/22/2023]
Abstract
Non-degenerate 2-photon excitation (ND-2PE) of a fluorophore with two laser beams of different photon energies offers an independent degree of freedom in tuning of the photon flux for each beam. This feature takes advantage of the infrared wavelengths used in degenerate 3-photon excitation (D-3PE) microscopy to achieve increased penetration depths, while preserving a relatively high 2-photon excitation cross section in comparison to that of D-3PE. Here, using spatially and temporally aligned Ti:Sapphire laser and optical parametric oscillator beams operating at near infrared (NIR) and short-wavelength infrared (SWIR) optical frequencies, we employ ND-2PE and provide a practical demonstration that a constant fluorophore emission intensity is achievable deeper into a scattering medium using ND-2PE as compared to the commonly used degenerate 2-photon excitation (D-2PE).
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Affiliation(s)
- Mu-Han Yang
- Department of Electrical and Computer Engineering, University of California, San Diego, CA 92093, USA
| | - Maxim Abashin
- Department of Electrical and Computer Engineering, University of California, San Diego, CA 92093, USA
| | - Payam A. Saisan
- Department of Neurosciences, University of California, San Diego, CA 92093, USA
| | - Peifang Tian
- Department of Neurosciences, University of California, San Diego, CA 92093, USA
- Department of Physics, John Carroll University, University Heights, OH 44118, USA
| | | | - Anna Devor
- Department of Neurosciences, University of California, San Diego, CA 92093, USA
- Department of Radiology, University of California, San Diego, CA 92093, USA
- Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, MA 02129, USA
| | - Yeshaiahu Fainman
- Department of Electrical and Computer Engineering, University of California, San Diego, CA 92093, USA
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39
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Sato M, Kawano M, Yanagawa Y, Hayashi Y. In vivo two-photon imaging of striatal neuronal circuits in mice. Neurobiol Learn Mem 2016; 135:146-151. [PMID: 27400866 DOI: 10.1016/j.nlm.2016.07.006] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2016] [Revised: 07/06/2016] [Accepted: 07/07/2016] [Indexed: 10/21/2022]
Abstract
Imaging studies of the subcortical striatum in vivo have been technically challenging despite its functional importance in movement control and procedural learning. Here, we report a method for imaging striatal neuronal circuits in mice in vivo using two-photon microscopy. Cell bodies and intermingled dendrites of GABAergic neurons labeled with fluorescent proteins were imaged in the dorsal striatum through an imaging window implanted in the overlying cortex. This technique could be highly useful for studying the structure and function of striatal networks at cellular and subcellular resolutions in normal mice, as well as in mouse models of neurological disorders.
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Affiliation(s)
- Masaaki Sato
- RIKEN Brain Science Institute, Wako, Saitama, Japan; PRESTO, Japan Science and Technology Agency, Kawaguchi, Saitama, Japan.
| | | | - Yuchio Yanagawa
- Department of Genetic and Behavioral Neuroscience, Gunma University Graduate School of Medicine, Maebashi, Gunma, Japan
| | - Yasunori Hayashi
- RIKEN Brain Science Institute, Wako, Saitama, Japan; Brain Science Institute, Saitama University, Saitama, Japan; School of Life Science, South China Normal University, Guangzhou, China; Department of Pharmacology, Kyoto University Graduate School of Medicine, Kyoto, Japan
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40
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Fauth M, Tetzlaff C. Opposing Effects of Neuronal Activity on Structural Plasticity. Front Neuroanat 2016; 10:75. [PMID: 27445713 PMCID: PMC4923203 DOI: 10.3389/fnana.2016.00075] [Citation(s) in RCA: 52] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2015] [Accepted: 06/16/2016] [Indexed: 12/21/2022] Open
Abstract
The connectivity of the brain is continuously adjusted to new environmental influences by several activity-dependent adaptive processes. The most investigated adaptive mechanism is activity-dependent functional or synaptic plasticity regulating the transmission efficacy of existing synapses. Another important but less prominently discussed adaptive process is structural plasticity, which changes the connectivity by the formation and deletion of synapses. In this review, we show, based on experimental evidence, that structural plasticity can be classified similar to synaptic plasticity into two categories: (i) Hebbian structural plasticity, which leads to an increase (decrease) of the number of synapses during phases of high (low) neuronal activity and (ii) homeostatic structural plasticity, which balances these changes by removing and adding synapses. Furthermore, based on experimental and theoretical insights, we argue that each type of structural plasticity fulfills a different function. While Hebbian structural changes enhance memory lifetime, storage capacity, and memory robustness, homeostatic structural plasticity self-organizes the connectivity of the neural network to assure stability. However, the link between functional synaptic and structural plasticity as well as the detailed interactions between Hebbian and homeostatic structural plasticity are more complex. This implies even richer dynamics requiring further experimental and theoretical investigations.
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Affiliation(s)
- Michael Fauth
- Department of Computational Neuroscience, Third Institute of Physics - Biophysics, Georg-August UniversityGöttingen, Germany; Bernstein Center for Computational NeuroscienceGöttingen, Germany
| | - Christian Tetzlaff
- Bernstein Center for Computational NeuroscienceGöttingen, Germany; Max Planck Institute for Dynamics and Self-OrganizationGöttingen, Germany
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41
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Gonçalves JT, Bloyd CW, Shtrahman M, Johnston ST, Schafer ST, Parylak SL, Tran T, Chang T, Gage FH. In vivo imaging of dendritic pruning in dentate granule cells. Nat Neurosci 2016; 19:788-91. [PMID: 27135217 PMCID: PMC4941946 DOI: 10.1038/nn.4301] [Citation(s) in RCA: 67] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2016] [Accepted: 04/05/2016] [Indexed: 12/28/2022]
Abstract
We longitudinally imaged the developing dendrites of adult-born mouse dentate granule cells (DGCs) in vivo and found that they underwent over-branching and pruning. Exposure to an enriched environment (EE) and constraining dendritic growth by disrupting Wnt signaling led to increased branch addition and accelerated growth, which were, however, counteracted by earlier and more extensive pruning. Our results indicate that pruning is regulated in a homeostatic fashion to oppose excessive branching and promote a similar dendrite structure in DGCs.
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Affiliation(s)
- J Tiago Gonçalves
- Laboratory of Genetics, Salk Institute for Biological Sciences, La Jolla, California, USA
| | - Cooper W Bloyd
- Laboratory of Genetics, Salk Institute for Biological Sciences, La Jolla, California, USA
| | - Matthew Shtrahman
- Laboratory of Genetics, Salk Institute for Biological Sciences, La Jolla, California, USA
| | - Stephen T Johnston
- Laboratory of Genetics, Salk Institute for Biological Sciences, La Jolla, California, USA
| | - Simon T Schafer
- Laboratory of Genetics, Salk Institute for Biological Sciences, La Jolla, California, USA
| | - Sarah L Parylak
- Laboratory of Genetics, Salk Institute for Biological Sciences, La Jolla, California, USA
| | - Thanh Tran
- Laboratory of Genetics, Salk Institute for Biological Sciences, La Jolla, California, USA
| | - Tina Chang
- Laboratory of Genetics, Salk Institute for Biological Sciences, La Jolla, California, USA
| | - Fred H Gage
- Laboratory of Genetics, Salk Institute for Biological Sciences, La Jolla, California, USA
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42
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Berdyyeva TK, Frady EP, Nassi JJ, Aluisio L, Cherkas Y, Otte S, Wyatt RM, Dugovic C, Ghosh KK, Schnitzer MJ, Lovenberg T, Bonaventure P. Direct Imaging of Hippocampal Epileptiform Calcium Motifs Following Kainic Acid Administration in Freely Behaving Mice. Front Neurosci 2016; 10:53. [PMID: 26973444 PMCID: PMC4770289 DOI: 10.3389/fnins.2016.00053] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2015] [Accepted: 02/05/2016] [Indexed: 12/24/2022] Open
Abstract
Prolonged exposure to abnormally high calcium concentrations is thought to be a core mechanism underlying hippocampal damage in epileptic patients; however, no prior study has characterized calcium activity during seizures in the live, intact hippocampus. We have directly investigated this possibility by combining whole-brain electroencephalographic (EEG) measurements with microendoscopic calcium imaging of pyramidal cells in the CA1 hippocampal region of freely behaving mice treated with the pro-convulsant kainic acid (KA). We observed that KA administration led to systematic patterns of epileptiform calcium activity: a series of large-scale, intensifying flashes of increased calcium fluorescence concurrent with a cluster of low-amplitude EEG waveforms. This was accompanied by a steady increase in cellular calcium levels (>5 fold increase relative to the baseline), followed by an intense spreading calcium wave characterized by a 218% increase in global mean intensity of calcium fluorescence (n = 8, range [114–349%], p < 10−4; t-test). The wave had no consistent EEG phenotype and occurred before the onset of motor convulsions. Similar changes in calcium activity were also observed in animals treated with 2 different proconvulsant agents, N-methyl-D-aspartate (NMDA) and pentylenetetrazol (PTZ), suggesting the measured changes in calcium dynamics are a signature of seizure activity rather than a KA-specific pathology. Additionally, despite reducing the behavioral severity of KA-induced seizures, the anticonvulsant drug valproate (VA, 300 mg/kg) did not modify the observed abnormalities in calcium dynamics. These results confirm the presence of pathological calcium activity preceding convulsive motor seizures and support calcium as a candidate signaling molecule in a pathway connecting seizures to subsequent cellular damage. Integrating in vivo calcium imaging with traditional assessment of seizures could potentially increase translatability of pharmacological intervention, leading to novel drug screening paradigms and therapeutics designed to target and abolish abnormal patterns of both electrical and calcium excitation.
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Affiliation(s)
| | - E Paxon Frady
- InscopixPalo Alto, CA, USA; Redwood Center for Theoretical Neuroscience, University of California, BerkeleyBerkeley, CA, USA
| | | | - Leah Aluisio
- Janssen Research & Development, LLC San Diego, CA, USA
| | | | | | - Ryan M Wyatt
- Janssen Research & Development, LLC San Diego, CA, USA
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43
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Jeanneret V, Yepes M. The Plasminogen Activation System Promotes Dendritic Spine Recovery and Improvement in Neurological Function After an Ischemic Stroke. Transl Stroke Res 2016. [PMID: 26846991 DOI: 10.1007/s12975-016-0454-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
Advances in neurocritical care and interventional neuroradiology have led to a significant decrease in acute ischemic stroke (AIS) mortality. In contrast, due to the lack of an effective therapeutic strategy to promote neuronal recovery among AIS survivors, cerebral ischemia is still a leading cause of disability in the world. Ischemic stroke has a harmful impact on synaptic structure and function, and plasticity-mediated synaptic recovery is associated with neurological improvement following an AIS. Dendritic spines (DSs) are specialized dendritic protrusions that receive most of the excitatory input in the brain. The deleterious effect of cerebral ischemia on DSs morphology and function has been associated with impaired synaptic transmission and neurological deterioration. However, these changes are reversible if cerebral blood flow is restored on time, and this recovery has been associated with neurological improvement following an AIS. Tissue-type plasminogen activator (tPA) and urokinase-type plasminogen activator (uPA) are two serine proteases that, besides catalyzing the conversion of plasminogen into plasmin in the intravascular and pericellular environment, respectively, are also efficient inductors of synaptic plasticity. Accordingly, recent evidence indicates that both, tPA and uPA, protect DSs from the metabolic stress associated with the ischemic injury, and promote their morphological and functional recovery during the recovery phase from an AIS. Here, we will review data indicating that plasticity-induced changes in DSs and the associated post-synaptic density play a pivotal role in the recovery process from AIS, making special emphasis on the role of tPA and uPA in this process.
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Affiliation(s)
- Valerie Jeanneret
- Department of Neurology & Center for Neurodegenerative Disease, Emory University School of Medicine, Whitehead Biomedical Research Building, 615 Michael Street, Suite 505J, Atlanta, GA, 30322, USA
| | - Manuel Yepes
- Department of Neurology & Center for Neurodegenerative Disease, Emory University School of Medicine, Whitehead Biomedical Research Building, 615 Michael Street, Suite 505J, Atlanta, GA, 30322, USA. .,Department of Neurology, Veterans Affairs Medical Center, Atlanta, GA, USA.
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44
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Jeanneret V, Yepes M. The Plasminogen Activation System Promotes Dendritic Spine Recovery and Improvement in Neurological Function After an Ischemic Stroke. Transl Stroke Res 2016:10.1007/s12975-016-0454-x. [PMID: 26846991 PMCID: PMC4974155] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2015] [Revised: 01/21/2016] [Accepted: 01/26/2016] [Indexed: 02/28/2024]
Abstract
Advances in neurocritical care and interventional neuroradiology have led to a significant decrease in acute ischemic stroke (AIS) mortality. In contrast, due to the lack of an effective therapeutic strategy to promote neuronal recovery among AIS survivors, cerebral ischemia is still a leading cause of disability in the world. Ischemic stroke has a harmful impact on synaptic structure and function, and plasticity-mediated synaptic recovery is associated with neurological improvement following an AIS. Dendritic spines (DSs) are specialized dendritic protrusions that receive most of the excitatory input in the brain. The deleterious effect of cerebral ischemia on DSs morphology and function has been associated with impaired synaptic transmission and neurological deterioration. However, these changes are reversible if cerebral blood flow is restored on time, and this recovery has been associated with neurological improvement following an AIS. Tissue-type plasminogen activator (tPA) and urokinase-type plasminogen activator (uPA) are two serine proteases that, besides catalyzing the conversion of plasminogen into plasmin in the intravascular and pericellular environment, respectively, are also efficient inductors of synaptic plasticity. Accordingly, recent evidence indicates that both, tPA and uPA, protect DSs from the metabolic stress associated with the ischemic injury, and promote their morphological and functional recovery during the recovery phase from an AIS. Here, we will review data indicating that plasticity-induced changes in DSs and the associated post-synaptic density play a pivotal role in the recovery process from AIS, making special emphasis on the role of tPA and uPA in this process.
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Affiliation(s)
- Valerie Jeanneret
- Department of Neurology & Center for Neurodegenerative Disease, Emory University School of Medicine, Whitehead Biomedical Research Building, 615 Michael Street, Suite 505J, Atlanta, GA, 30322, USA
| | - Manuel Yepes
- Department of Neurology & Center for Neurodegenerative Disease, Emory University School of Medicine, Whitehead Biomedical Research Building, 615 Michael Street, Suite 505J, Atlanta, GA, 30322, USA.
- Department of Neurology, Veterans Affairs Medical Center, Atlanta, GA, USA.
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45
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Bocarsly ME, Jiang WC, Wang C, Dudman JT, Ji N, Aponte Y. Minimally invasive microendoscopy system for in vivo functional imaging of deep nuclei in the mouse brain. BIOMEDICAL OPTICS EXPRESS 2015; 6:4546-56. [PMID: 26601017 PMCID: PMC4646561 DOI: 10.1364/boe.6.004546] [Citation(s) in RCA: 61] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/31/2015] [Revised: 10/16/2015] [Accepted: 10/16/2015] [Indexed: 05/18/2023]
Abstract
The ability to image neurons anywhere in the mammalian brain is a major goal of optical microscopy. Here we describe a minimally invasive microendoscopy system for studying the morphology and function of neurons at depth. Utilizing a guide cannula with an ultrathin wall, we demonstrated in vivo two-photon fluorescence imaging of deeply buried nuclei such as the striatum (2.5 mm depth), substantia nigra (4.4 mm depth) and lateral hypothalamus (5.0 mm depth) in mouse brain. We reported, for the first time, the observation of neuronal activity with subcellular resolution in the lateral hypothalamus and substantia nigra of head-fixed awake mice.
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Affiliation(s)
- Miriam E Bocarsly
- Intramural Research Program, Neuronal Circuits and Behavior Unit, National Institute on Drug Abuse, Baltimore, MD 21224, USA ; Janelia Research Campus, Howard Hughes Medical Institute, 19700 Helix Drive, Ashburn, VA 20147, USA ; These authors contributed equally to this work ; Current address: Section on Neuronal Structure, National Institute on Alcohol Abuse and Alcoholism, National Institute of Health, Bethesda, MD 20892, USA
| | - Wan-Chen Jiang
- Janelia Research Campus, Howard Hughes Medical Institute, 19700 Helix Drive, Ashburn, VA 20147, USA ; These authors contributed equally to this work
| | - Chen Wang
- Janelia Research Campus, Howard Hughes Medical Institute, 19700 Helix Drive, Ashburn, VA 20147, USA
| | - Joshua T Dudman
- Janelia Research Campus, Howard Hughes Medical Institute, 19700 Helix Drive, Ashburn, VA 20147, USA
| | - Na Ji
- Janelia Research Campus, Howard Hughes Medical Institute, 19700 Helix Drive, Ashburn, VA 20147, USA ;
| | - Yeka Aponte
- Intramural Research Program, Neuronal Circuits and Behavior Unit, National Institute on Drug Abuse, Baltimore, MD 21224, USA ; Janelia Research Campus, Howard Hughes Medical Institute, 19700 Helix Drive, Ashburn, VA 20147, USA ;
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46
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Willem M, Tahirovic S, Busche MA, Ovsepian SV, Chafai M, Kootar S, Hornburg D, Evans LDB, Moore S, Daria A, Hampel H, Müller V, Giudici C, Nuscher B, Wenninger-Weinzierl A, Kremmer E, Heneka MT, Thal DR, Giedraitis V, Lannfelt L, Müller U, Livesey FJ, Meissner F, Herms J, Konnerth A, Marie H, Haass C. η-Secretase processing of APP inhibits neuronal activity in the hippocampus. Nature 2015; 526:443-7. [PMID: 26322584 DOI: 10.1038/nature14864] [Citation(s) in RCA: 272] [Impact Index Per Article: 30.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2015] [Accepted: 06/25/2015] [Indexed: 12/24/2022]
Abstract
Alzheimer disease (AD) is characterized by the accumulation of amyloid plaques, which are predominantly composed of amyloid-β peptide. Two principal physiological pathways either prevent or promote amyloid-β generation from its precursor, β-amyloid precursor protein (APP), in a competitive manner. Although APP processing has been studied in great detail, unknown proteolytic events seem to hinder stoichiometric analyses of APP metabolism in vivo. Here we describe a new physiological APP processing pathway, which generates proteolytic fragments capable of inhibiting neuronal activity within the hippocampus. We identify higher molecular mass carboxy-terminal fragments (CTFs) of APP, termed CTF-η, in addition to the long-known CTF-α and CTF-β fragments generated by the α- and β-secretases ADAM10 (a disintegrin and metalloproteinase 10) and BACE1 (β-site APP cleaving enzyme 1), respectively. CTF-η generation is mediated in part by membrane-bound matrix metalloproteinases such as MT5-MMP, referred to as η-secretase activity. η-Secretase cleavage occurs primarily at amino acids 504-505 of APP695, releasing a truncated ectodomain. After shedding of this ectodomain, CTF-η is further processed by ADAM10 and BACE1 to release long and short Aη peptides (termed Aη-α and Aη-β). CTFs produced by η-secretase are enriched in dystrophic neurites in an AD mouse model and in human AD brains. Genetic and pharmacological inhibition of BACE1 activity results in robust accumulation of CTF-η and Aη-α. In mice treated with a potent BACE1 inhibitor, hippocampal long-term potentiation was reduced. Notably, when recombinant or synthetic Aη-α was applied on hippocampal slices ex vivo, long-term potentiation was lowered. Furthermore, in vivo single-cell two-photon calcium imaging showed that hippocampal neuronal activity was attenuated by Aη-α. These findings not only demonstrate a major functionally relevant APP processing pathway, but may also indicate potential translational relevance for therapeutic strategies targeting APP processing.
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Affiliation(s)
- Michael Willem
- Biomedical Center (BMC), Ludwig-Maximilians-University Munich, 81377 Munich, Germany
| | - Sabina Tahirovic
- German Center for Neurodegenerative Diseases (DZNE) Munich, 81377 Munich, Germany
| | - Marc Aurel Busche
- Department of Psychiatry and Psychotherapy, Technische Universität München, 81675 Munich, Germany.,Institute of Neuroscience, Technische Universität München, 80802 Munich, Germany.,Munich Cluster for Systems Neurology (SyNergy), Ludwig-Maximilians-University Munich, 81377 Munich, Germany
| | - Saak V Ovsepian
- German Center for Neurodegenerative Diseases (DZNE) Munich, 81377 Munich, Germany
| | - Magda Chafai
- Institut de Pharmacologie Moléculaire et Cellulaire (IPMC), Centre National de la Recherche Scientifique (CNRS), Université de Nice Sophia Antipolis, UMR 7275, 06560 Valbonne, France
| | - Scherazad Kootar
- Institut de Pharmacologie Moléculaire et Cellulaire (IPMC), Centre National de la Recherche Scientifique (CNRS), Université de Nice Sophia Antipolis, UMR 7275, 06560 Valbonne, France
| | - Daniel Hornburg
- Max Planck Institute of Biochemistry, Martinsried 82152, Germany
| | - Lewis D B Evans
- Gurdon Institute, Cambridge Stem Cell Institute &Department of Biochemistry, University of Cambridge, Cambridge CB2 1QN, UK
| | - Steven Moore
- Gurdon Institute, Cambridge Stem Cell Institute &Department of Biochemistry, University of Cambridge, Cambridge CB2 1QN, UK
| | - Anna Daria
- Biomedical Center (BMC), Ludwig-Maximilians-University Munich, 81377 Munich, Germany
| | - Heike Hampel
- Biomedical Center (BMC), Ludwig-Maximilians-University Munich, 81377 Munich, Germany
| | - Veronika Müller
- Biomedical Center (BMC), Ludwig-Maximilians-University Munich, 81377 Munich, Germany
| | - Camilla Giudici
- Biomedical Center (BMC), Ludwig-Maximilians-University Munich, 81377 Munich, Germany
| | - Brigitte Nuscher
- Biomedical Center (BMC), Ludwig-Maximilians-University Munich, 81377 Munich, Germany
| | | | - Elisabeth Kremmer
- German Center for Neurodegenerative Diseases (DZNE) Munich, 81377 Munich, Germany.,Munich Cluster for Systems Neurology (SyNergy), Ludwig-Maximilians-University Munich, 81377 Munich, Germany.,Institute of Molecular Immunology, German Research Center for Environmental Health, 81377 Munich, Germany
| | - Michael T Heneka
- Department of Neurology, Clinical Neuroscience Unit, University of Bonn, 53127 Bonn, Germany.,German Center for Neurodegenerative Diseases (DZNE) Bonn, 53175 Bonn, Germany
| | - Dietmar R Thal
- Institute of Pathology - Laboratory for Neuropathology, University of Ulm, 89081 Ulm, Germany
| | - Vilmantas Giedraitis
- Department of Public Health/Geriatrics, Uppsala University, 751 85 Uppsala, Sweden
| | - Lars Lannfelt
- Department of Public Health/Geriatrics, Uppsala University, 751 85 Uppsala, Sweden
| | - Ulrike Müller
- Institute for Pharmacy and Molecular Biotechnology IPMB, Functional Genomics, University of Heidelberg, 69120 Heidelberg, Germany
| | - Frederick J Livesey
- Gurdon Institute, Cambridge Stem Cell Institute &Department of Biochemistry, University of Cambridge, Cambridge CB2 1QN, UK
| | - Felix Meissner
- Max Planck Institute of Biochemistry, Martinsried 82152, Germany
| | - Jochen Herms
- German Center for Neurodegenerative Diseases (DZNE) Munich, 81377 Munich, Germany
| | - Arthur Konnerth
- Institute of Neuroscience, Technische Universität München, 80802 Munich, Germany.,Munich Cluster for Systems Neurology (SyNergy), Ludwig-Maximilians-University Munich, 81377 Munich, Germany
| | - Hélène Marie
- Institut de Pharmacologie Moléculaire et Cellulaire (IPMC), Centre National de la Recherche Scientifique (CNRS), Université de Nice Sophia Antipolis, UMR 7275, 06560 Valbonne, France
| | - Christian Haass
- Biomedical Center (BMC), Ludwig-Maximilians-University Munich, 81377 Munich, Germany.,German Center for Neurodegenerative Diseases (DZNE) Munich, 81377 Munich, Germany.,Munich Cluster for Systems Neurology (SyNergy), Ludwig-Maximilians-University Munich, 81377 Munich, Germany
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Attardo A, Fitzgerald JE, Schnitzer MJ. Impermanence of dendritic spines in live adult CA1 hippocampus. Nature 2015; 523:592-6. [PMID: 26098371 PMCID: PMC4648621 DOI: 10.1038/nature14467] [Citation(s) in RCA: 217] [Impact Index Per Article: 24.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2014] [Accepted: 04/10/2015] [Indexed: 01/26/2023]
Abstract
The mammalian hippocampus is crucial for episodic memory formation and transiently retains information for about 3-4 weeks in adult mice and longer in humans. Although neuroscientists widely believe that neural synapses are elemental sites of information storage, there has been no direct evidence that hippocampal synapses persist for time intervals commensurate with the duration of hippocampal-dependent memory. Here we tested the prediction that the lifetimes of hippocampal synapses match the longevity of hippocampal memory. By using time-lapse two-photon microendoscopy in the CA1 hippocampal area of live mice, we monitored the turnover dynamics of the pyramidal neurons' basal dendritic spines, postsynaptic structures whose turnover dynamics are thought to reflect those of excitatory synaptic connections. Strikingly, CA1 spine turnover dynamics differed sharply from those seen previously in the neocortex. Mathematical modelling revealed that the data best matched kinetic models with a single population of spines with a mean lifetime of approximately 1-2 weeks. This implies ∼100% turnover in ∼2-3 times this interval, a near full erasure of the synaptic connectivity pattern. Although N-methyl-d-aspartate (NMDA) receptor blockade stabilizes spines in the neocortex, in CA1 it transiently increased the rate of spine loss and thus lowered spine density. These results reveal that adult neocortical and hippocampal pyramidal neurons have divergent patterns of spine regulation and quantitatively support the idea that the transience of hippocampal-dependent memory directly reflects the turnover dynamics of hippocampal synapses.
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Affiliation(s)
- Alessio Attardo
- 1] James H. Clark Center for Biomedical Engineering &Sciences, Stanford University, Stanford, California 94305, USA [2] Howard Hughes Medical Institute, Stanford University, Stanford, California 94305, USA
| | - James E Fitzgerald
- James H. Clark Center for Biomedical Engineering &Sciences, Stanford University, Stanford, California 94305, USA
| | - Mark J Schnitzer
- 1] James H. Clark Center for Biomedical Engineering &Sciences, Stanford University, Stanford, California 94305, USA [2] Howard Hughes Medical Institute, Stanford University, Stanford, California 94305, USA [3] CNC Program, Stanford University, Stanford, California 94305, USA
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Peron S, Chen TW, Svoboda K. Comprehensive imaging of cortical networks. Curr Opin Neurobiol 2015; 32:115-23. [PMID: 25880117 DOI: 10.1016/j.conb.2015.03.016] [Citation(s) in RCA: 84] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2014] [Revised: 03/06/2015] [Accepted: 03/23/2015] [Indexed: 12/14/2022]
Abstract
Neural computations are implemented by activity in spatially distributed neural circuits. Cellular imaging fills a unique niche in linking activity of specific types of neurons to behavior, over spatial scales spanning single neurons to entire brain regions, and temporal scales from milliseconds to months. Imaging may soon make it possible to track activity of all neurons in a brain region, such as a cortical column. We review recent methodological advances that facilitate optical imaging of neuronal populations in vivo, with an emphasis on calcium imaging using protein indicators in mice. We point out areas that are particularly ripe for future developments.
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Affiliation(s)
- Simon Peron
- Janelia Research Campus, HHMI, Ashburn VA 20147, United States
| | - Tsai-Wen Chen
- Janelia Research Campus, HHMI, Ashburn VA 20147, United States
| | - Karel Svoboda
- Janelia Research Campus, HHMI, Ashburn VA 20147, United States.
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49
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Zhvania MG, Ksovreli M, Japaridze NJ, Lordkipanidze TG. Ultrastructural changes to rat hippocampus in pentylenetetrazol- and kainic acid-induced status epilepticus: A study using electron microscopy. Micron 2015; 74:22-9. [PMID: 25978010 DOI: 10.1016/j.micron.2015.03.015] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2015] [Revised: 03/30/2015] [Accepted: 03/31/2015] [Indexed: 02/06/2023]
Abstract
A pentylenetetrazol (PTZ)-induced status epilepticus model in rats was used in the study. The brains were studied one month after treatment. Ultrastructural observations using electron microscopy performed on the neurons, glial cells, and synapses, in the hippocampal CA1 region of epileptic brains, demonstrated the following major changes over normal control brain tissue. (i) There is ultrastructural alterations in some neurons, glial cells and synapses in the hippocampal CA1 region. (ii) The destruction of cellular organelles and peripheral, partial or even total chromatolysis in some pyramidal cells and in interneurons are observed. Several astrocytes are proliferated or activated. Presynaptic terminals with granular vesicles and degenerated presynaptic profiles are rarely observed. (iii) The alterations observed are found to be dependent on the frequency of seizure activities following the PTZ treatment. It was observed that if seizure episodes are frequent and severe, the ultrastructure of hippocampal area is significantly changed. Interestingly, the ultrastructure of CA1 area is found to be only moderately altered if seizure episodes following the status epilepticus are rare and more superficial; (iv) alterations in mitochondria and dendrites are among the most common ultrastructural changes seen, suggesting cell stress and changes to cellular metabolism. These morphological changes, observed in brain neurons in status epilepticus, are a reflection of epileptic pathophysiology. Further studies at the chemical and molecular level of neurotransmitter release, such as at the level of porosomes (secretory portals) at the presynaptic membrane, will further reveal molecular details of these changes.
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Affiliation(s)
- Mzia G Zhvania
- Institute of Chemical Biology, Ilia State University, 3/5 K. Cholokhashvili Avenue, 0162 Tbilisi, Georgia; Department of Brain Ultrastructure and Nanoarchitecture, I. Beriitashvili Center of Experimental BioMedicine, 14, Gotua Street, 0160 Tbilisi, Georgia.
| | - Mariam Ksovreli
- Institute of Chemical Biology, Ilia State University, 3/5 K. Cholokhashvili Avenue, 0162 Tbilisi, Georgia.
| | - Nadezhda J Japaridze
- Department of Brain Ultrastructure and Nanoarchitecture, I. Beriitashvili Center of Experimental BioMedicine, 14, Gotua Street, 0160 Tbilisi, Georgia; New Vision University, 1A Evgeni Mikeladze Street, 0158 Tbilisi, Georgia.
| | - Tamar G Lordkipanidze
- Institute of Chemical Biology, Ilia State University, 3/5 K. Cholokhashvili Avenue, 0162 Tbilisi, Georgia; Department of Brain Ultrastructure and Nanoarchitecture, I. Beriitashvili Center of Experimental BioMedicine, 14, Gotua Street, 0160 Tbilisi, Georgia.
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Long-term in vivo imaging of dendritic spines in the hippocampus reveals structural plasticity. J Neurosci 2015; 34:13948-53. [PMID: 25319691 DOI: 10.1523/jneurosci.1464-14.2014] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Hippocampal function is important for learning and memory. During memory processing, hippocampal CA1 neurons play a crucial role by integrating excitatory synaptic input from CA3 and the entorhinal cortex. These neurons receive excitatory input almost exclusively on dendritic spines. The formation and elimination--structural plasticity--of dendritic spines reflect wiring changes within the hippocampal network. Despite the relevance of the hippocampus in learning and memory, most in vivo data on structural plasticity derive from cortical regions. We established a chronic hippocampal window approach using two-photon microscopy to visualize dendritic spines throughout all CA1 hippocampal layers and over a time course of weeks. Moreover, even granule cells in dentate gyrus could be reliably detected. We found that the spine density in stratum radiatum (∼1.1 per micrometer) remained stable over weeks. However, a small fraction (3.4%) of spines were formed and eliminated between imaging sessions, which demonstrated that spines of CA1 neurons exhibit structural plasticity in adult mice. In addition, we tested for possible inflammatory or behavioral side effects of hippocampal window implantation. Mice exhibited a transient increase in microgliosis and astrogliosis, which declined within a few weeks. We did not detect any difference in behavioral performance in an open-field and contextual fear-conditioning paradigm. In conclusion, hippocampal long-term two-photon imaging revealed structural plasticity of dendritic spines in CA1 pyramidal neurons. This approach may provide a powerful tool to analyze changes in neuronal network rewiring during hippocampal learning and memory processes in health and disease.
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