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Leong LM, Storace DA. Imaging different cell populations in the mouse olfactory bulb using the genetically encoded voltage indicator ArcLight. Neurophotonics 2024; 11:033402. [PMID: 38288247 PMCID: PMC10823906 DOI: 10.1117/1.nph.11.3.033402] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/01/2023] [Revised: 11/30/2023] [Accepted: 12/14/2023] [Indexed: 01/31/2024]
Abstract
Genetically encoded voltage indicators (GEVIs) are protein-based optical sensors that allow for measurements from genetically defined populations of neurons. Although in vivo imaging in the mammalian brain with early generation GEVIs was difficult due to poor membrane expression and low signal-to-noise ratio, newer and more sensitive GEVIs have begun to make them useful for answering fundamental questions in neuroscience. We discuss principles of imaging using GEVIs and genetically encoded calcium indicators, both useful tools for in vivo imaging of neuronal activity, and review some of the recent mechanistic advances that have led to GEVI improvements. We provide an overview of the mouse olfactory bulb (OB) and discuss recent studies using the GEVI ArcLight to study different cell types within the bulb using both widefield and two-photon microscopy. Specific emphasis is placed on using GEVIs to begin to study the principles of concentration coding in the OB, how to interpret the optical signals from population measurements in the in vivo brain, and future developments that will push the field forward.
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Affiliation(s)
- Lee Min Leong
- Florida State University, Department of Biological Science, Tallahassee, Florida, United States
| | - Douglas A. Storace
- Florida State University, Department of Biological Science, Tallahassee, Florida, United States
- Florida State University, Program in Neuroscience, Tallahassee, Florida, United States
- Florida State University, Institute of Molecular Biophysics, Tallahassee, Florida, United States
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2
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Yeon C, Im JM, Kim M, Kim YR, Chung E. Cranial and Spinal Window Preparation for in vivo Optical Neuroimaging in Rodents and Related Experimental Techniques. Exp Neurobiol 2022; 31:131-146. [PMID: 35786637 PMCID: PMC9272117 DOI: 10.5607/en22015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2022] [Revised: 06/03/2022] [Accepted: 06/15/2022] [Indexed: 11/19/2022] Open
Abstract
Optical neuroimaging provides an effective neuroscience tool for multi-scale investigation of the neural structures and functions, ranging from molecular, cellular activities to the inter-regional connectivity assessment. Amongst experimental preparations, the implementation of an artificial window to the central nervous system (CNS) is primarily required for optical visualization of the CNS and associated brain activities through the opaque skin and bone. Either thinning down or removing portions of the skull or spine is necessary for unobstructed long-term in vivo observations, for which types of the cranial and spinal window and applied materials vary depending on the study objectives. As diversely useful, a window can be designed to accommodate other experimental methods such as electrophysiology or optogenetics. Moreover, auxiliary apparatuses would allow the recording in synchrony with behavior of large-scale brain connectivity signals across the CNS, such as olfactory bulb, cerebral cortex, cerebellum, and spinal cord. Such advancements in the cranial and spinal window have resulted in a paradigm shift in neuroscience, enabling in vivo investigation of the brain function and dysfunction at the microscopic, cellular level. This Review addresses the types and classifications of windows used in optical neuroimaging while describing how to perform in vivo studies using rodent models in combination with other experimental modalities during behavioral tests. The cranial and spinal window has enabled longitudinal examination of evolving neural mechanisms via in situ visualization of the brain. We expect transformable and multi-functional cranial and spinal windows to become commonplace in neuroscience laboratories, further facilitating advances in optical neuroimaging systems.
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Affiliation(s)
- Chanmi Yeon
- Department of Biomedical Science and Engineering, Gwangju Institute of Science and Technology, Gwangju 61005, Korea
| | - Jeong Myo Im
- Department of Biomedical Science and Engineering, Gwangju Institute of Science and Technology, Gwangju 61005, Korea
| | - Minsung Kim
- Department of Biomedical Science and Engineering, Gwangju Institute of Science and Technology, Gwangju 61005, Korea
| | - Young Ro Kim
- Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, MA 02129, USA.,Department of Radiology, Harvard Medical School, Boston, MA 02115, USA
| | - Euiheon Chung
- Department of Biomedical Science and Engineering, Gwangju Institute of Science and Technology, Gwangju 61005, Korea.,AI Graduate School, Gwangju Institute of Science and Technology, Gwangju 61005, Korea.,Research Center for Photon Science Technology, Gwangju Institute of Science and Technology, Gwangju 61005, Korea
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3
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Soleimanzad H, Smekens F, Peyronnet J, Juchaux M, Lefebvre O, Bouville D, Magnan C, Gurden H, Pain F. Multiple speckle exposure imaging for the study of blood flow changes induced by functional activation of barrel cortex and olfactory bulb in mice. Neurophotonics 2019; 6:015008. [PMID: 30854406 PMCID: PMC6400140 DOI: 10.1117/1.nph.6.1.015008] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/05/2018] [Accepted: 02/13/2019] [Indexed: 06/09/2023]
Abstract
Speckle contrast imaging allows in vivo imaging of relative blood flow changes. Multiple exposure speckle imaging (MESI) is more accurate than the standard single-exposure method since it allows separating the contribution of the static and moving scatters of the recorded speckle patterns. MESI requires experimental validation on phantoms prior to in vivo experiments to ensure the proper calibration of the system and the robustness of the model. The data analysis relies on the calculation of the speckle contrast for each exposure and a subsequent nonlinear fit to the MESI model to extract the scatterers correlation time and the relative contribution of moving scatters. We have designed two multichannel polydimethylsiloxane chips to study the influence of multiple and static scattering on the accuracy of MESI quantitation. We also propose a method based on standard C++ libraries to implement a computationally efficient analysis of the MESI data. Finally, the system was used to obtain in vivo hemodynamic data on two distinct sensory areas of the mice brain: the barrel cortex and the olfactory bulb.
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Affiliation(s)
- Haleh Soleimanzad
- IMNC, CNRS, Université Paris-Sud, Université Paris-Saclay, Orsay, France
- BFA, CNRS, Université Paris Diderot, Paris, France
| | - François Smekens
- IMNC, CNRS, Université Paris-Sud, Université Paris-Saclay, Orsay, France
| | - Juliette Peyronnet
- IMNC, CNRS, Université Paris-Sud, Université Paris-Saclay, Orsay, France
| | - Marjorie Juchaux
- IMNC, CNRS, Université Paris-Sud, Université Paris-Saclay, Orsay, France
- C2N, CNRS, Université Paris-Sud, Université Paris-Saclay, Palaiseau, France
| | - Olivier Lefebvre
- IMNC, CNRS, Université Paris-Sud, Université Paris-Saclay, Orsay, France
| | - David Bouville
- C2N, CNRS, Université Paris-Sud, Université Paris-Saclay, Palaiseau, France
| | | | - Hirac Gurden
- BFA, CNRS, Université Paris Diderot, Paris, France
| | - Frederic Pain
- IMNC, CNRS, Université Paris-Sud, Université Paris-Saclay, Orsay, France
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Uytingco CR, Puche AC, Munger SD. Using Intrinsic Flavoprotein and NAD(P)H Imaging to Map Functional Circuitry in the Main Olfactory Bulb. PLoS One 2016; 11:e0165342. [PMID: 27902689 PMCID: PMC5130181 DOI: 10.1371/journal.pone.0165342] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2016] [Accepted: 10/10/2016] [Indexed: 12/02/2022] Open
Abstract
Neurons exhibit strong coupling of electrochemical and metabolic activity. Increases in intrinsic fluorescence from either oxidized flavoproteins or reduced nicotinamide adenine dinucleotide (phosphate) [NAD(P)H] in the mitochondria have been used as an indicator of neuronal activity for the functional mapping of neural circuits. However, this technique has not been used to investigate the flow of olfactory information within the circuitry of the main olfactory bulb (MOB). We found that intrinsic flavoprotein fluorescence signals induced by electrical stimulation of single glomeruli displayed biphasic responses within both the glomerular (GL) and external plexiform layers (EPL) of the MOB. Pharmacological blockers of mitochondrial activity, voltage-gated Na+ channels, or ionotropic glutamate receptors abolished stimulus-dependent flavoprotein responses. Blockade of GABAA receptors enhanced the amplitude and spatiotemporal spread of the flavoprotein signals, indicating an important role for inhibitory neurotransmission in shaping the spread of neural activity in the MOB. Stimulus-dependent spread of fluorescence across the GL and EPL displayed a spatial distribution consistent with that of individual glomerular microcircuits mapped by neuroanatomic tract tracing. These findings demonstrated the feasibility of intrinsic fluorescence imaging in the olfactory systems and provided a new tool to examine the functional circuitry of the MOB.
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Affiliation(s)
- Cedric R Uytingco
- Department of Anatomy and Neurobiology, University of Maryland School of Medicine, Baltimore, Maryland, United States of America.,Program in Neuroscience, University of Maryland School of Medicine, Baltimore, Maryland, United States of America
| | - Adam C Puche
- Department of Anatomy and Neurobiology, University of Maryland School of Medicine, Baltimore, Maryland, United States of America.,Program in Neuroscience, University of Maryland School of Medicine, Baltimore, Maryland, United States of America
| | - Steven D Munger
- Center for Smell and Taste, University of Florida, Gainesville, Florida, United States of America.,Department of Pharmacology and Therapeutics, University of Florida, Gainesville, Florida, United States of America.,Department of Medicine, Division of Endocrinology, Diabetes and Metabolism, University of Florida, Gainesville, Florida, United States of America
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Gaffield MA, Amat SB, Bito H, Christie JM. Chronic imaging of movement-related Purkinje cell calcium activity in awake behaving mice. J Neurophysiol 2015; 115:413-22. [PMID: 26561609 DOI: 10.1152/jn.00834.2015] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2015] [Accepted: 11/05/2015] [Indexed: 01/28/2023] Open
Abstract
Purkinje cells (PCs) are a major site of information integration and plasticity in the cerebellum, a brain region involved in motor task refinement. Thus PCs provide an ideal location for studying the mechanisms necessary for cerebellum-dependent motor learning. Increasingly, sophisticated behavior tasks, used in combination with genetic reporters and effectors of activity, have opened up the possibility of studying cerebellar circuits during voluntary movement at an unprecedented level of quantitation. However, current methods used to monitor PC activity do not take full advantage of these advances. For example, single-unit or multiunit electrode recordings, which provide excellent temporal information regarding electrical activity, only monitor a small population of cells and can be quite invasive. Bolus loading of cell-permeant calcium (Ca(2+)) indicators is short-lived, requiring same-day imaging immediately after surgery and/or indicator injection. Genetically encoded Ca(2+) indicators (GECIs) overcome many of these limits and have garnered considerable use in many neuron types but only limited use in PCs. Here we employed these indicators to monitor Ca(2+) activity in PCs over several weeks. We could repeatedly image from the same cerebellar regions across multiple days and observed stable activity. We used chronic imaging to monitor PC activity in crus II, an area previously linked to licking behavior, and identified a region of increased activity at the onset of licking. We then monitored this same region after training tasks to initiate voluntary licking behavior in response to different sensory stimuli. In all cases, PC Ca(2+) activity increased at the onset of rhythmic licking.
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Affiliation(s)
| | - Samantha B Amat
- Max Planck Florida Institute for Neuroscience, Jupiter, Florida; and
| | - Haruhiko Bito
- Department of Neurochemistry, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
| | - Jason M Christie
- Max Planck Florida Institute for Neuroscience, Jupiter, Florida; and
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Jotty K, Shuttleworth CW, Valenzuela CF. Characterization of activity-dependent changes in flavoprotein fluorescence in cerebellar slices from juvenile rats. Neurosci Lett 2015; 584:17-22. [PMID: 25301569 DOI: 10.1016/j.neulet.2014.09.052] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2014] [Revised: 09/17/2014] [Accepted: 09/29/2014] [Indexed: 01/30/2023]
Abstract
Flavoprotein autofluorescence signals attributed to neuronal metabolism have been used to assess synaptic function. Here, we characterized flavoprotein autofluorescence responses in the molecular layer of rat cerebellar slices. High frequency stimulation elicited a transient fluorescence increase (peak phase) that was followed by a longer-lasting fluorescence decrease (valley phase). The peak phase was restricted to the molecular layer, whereas the valley phase extended into the Purkinje cell layer and a portion of the granule cell layer. Responses were abolished by either the Na(+) channel antagonist, tetrodotoxin, or a combination of the AMPA receptor antagonists, NBQX and GIKI-53655, and were also reduced by a flavoprotein inhibitor (diphenyleneiodonium). These findings are consistent with responses being mediated by an increase in mitochondrial activity triggered by increased energy demands evoked by AMPA receptor-mediated synaptic transmission. The GABAA receptor antagonist picrotoxin did not significantly influence evoked responses. Likewise, exogenous application of ethanol, at concentrations known to increase GABAA receptor-mediated synaptic transmission at Purkinje cells, did not modify peak responses. These observations indicate that flavoprotein autofluorescence imaging could be useful to assess the coupling between glutamatergic synaptic transmission and neuronal metabolism in cerebellar slices.
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Abstract
Within the last few decades, optical imaging methods have yielded revolutionary results when applied to all parts of the central nervous system. The purpose of this review is to analyze research possibilities and limitations of several novel imaging techniques and show some of the most interesting achievements obtained by these methods. Here we covered intrinsic optical imaging, voltage-sensitive dye, photoacoustic, optical coherence tomography, near-infrared spectroscopy and some other techniques. All of them are mainly applicable for experimental neuroscience but some of them also suitable for the clinical studies.
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Affiliation(s)
- Vassiliy Tsytsarev
- Department of Anatomy and Neurobiology, University of Maryland School of Medicine, HSF II Room S251, 20 Penn Street, Baltimore, MD 21201-1075, USA
| | - Chad Bernardelli
- Department of Anatomy and Neurobiology, University of Maryland School of Medicine, HSF II Room S251, 20 Penn Street, Baltimore, MD 21201-1075, USA
| | - Konstantin I Maslov
- Department of Biomedical Engineering, Washington University in St. Louis, One Brookings Drive, St. Louis, Missouri 63130, USA
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Renaud R, Martin C, Gurden H, Pain F. Multispectral reflectance imaging of brain activation in rodents: methodological study of the differential path length estimations and first in vivo recordings in the rat olfactory bulb. J Biomed Opt 2012; 17:016012. [PMID: 22352662 DOI: 10.1117/1.jbo.17.1.016012] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Dynamic maps of relative changes in blood volume and oxygenation following brain activation are obtained using multispectral reflectance imaging. The technique relies on optical absorption modifications linked to hemodynamic changes. The relative variation of hemodynamic parameters can be quantified using the modified Beer-Lambert Law if changes in reflected light intensities are recorded at two wavelengths or more and the differential path length (DP) is known. The DP is the mean path length in tissues of backscattered photons and varies with wavelength. It is usually estimated using Monte Carlo simulations in simplified semi-infinite homogeneous geometries. Here we consider the use of multilayered models of the somatosensory cortex (SsC) and olfactory bulb (OB), which are common physiological models of brain activation. Simulations demonstrate that specific DP estimation is required for SsC and OB, specifically for wavelengths above 600 nm. They validate the hypothesis of a constant path length during activation and show the need for specific DP if imaging is performed in a thinned-skull preparation. The first multispectral reflectance imaging data recorded in vivo during OB activation are presented, and the influence of DP on the hemodynamic parameters and the pattern of oxymetric changes in the activated OB are discussed.
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Affiliation(s)
- Rémi Renaud
- Université Paris-Sud, CNRS UMR8165, Orsay F-91405, France
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