101
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Hedrick NG, Lu Z, Bushong E, Singhi S, Nguyen P, Magaña Y, Jilani S, Lim BK, Ellisman M, Komiyama T. Learning binds new inputs into functional synaptic clusters via spinogenesis. Nat Neurosci 2022; 25:726-737. [PMID: 35654957 DOI: 10.1038/s41593-022-01086-6] [Citation(s) in RCA: 29] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2021] [Accepted: 04/26/2022] [Indexed: 11/08/2022]
Abstract
Learning induces the formation of new excitatory synapses in the form of dendritic spines, but their functional properties remain unknown. Here, using longitudinal in vivo two-photon imaging and correlated electron microscopy of dendritic spines in the motor cortex of mice during motor learning, we describe a framework for the formation, survival and resulting function of new, learning-related spines. Specifically, our data indicate that the formation of new spines during learning is guided by the potentiation of functionally clustered preexisting spines exhibiting task-related activity during earlier sessions of learning. We present evidence that this clustered potentiation induces the local outgrowth of multiple filopodia from the nearby dendrite, locally sampling the adjacent neuropil for potential axonal partners, likely via targeting preexisting presynaptic boutons. Successful connections are then selected for survival based on co-activity with nearby task-related spines, ensuring that the new spine preserves functional clustering. The resulting locally coherent activity of new spines signals the learned movement. Furthermore, we found that a majority of new spines synapse with axons previously unrepresented in these dendritic domains. Thus, learning involves the binding of new information streams into functional synaptic clusters to subserve learned behaviors.
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Affiliation(s)
- Nathan G Hedrick
- Neurobiology Section, Division of Biological Sciences, University of California, San Diego, La Jolla, CA, USA.
- Center for Neural Circuits and Behavior, University of California, San Diego, La Jolla, CA, USA.
- Department of Neurosciences, University of California, San Diego, School of Medicine, La Jolla, CA, USA.
- Halıcıoğlu Data Science Institute, University of California, San Diego, La Jolla, CA, USA.
| | - Zhongmin Lu
- Neurobiology Section, Division of Biological Sciences, University of California, San Diego, La Jolla, CA, USA
- Center for Neural Circuits and Behavior, University of California, San Diego, La Jolla, CA, USA
- Department of Neurosciences, University of California, San Diego, School of Medicine, La Jolla, CA, USA
- Halıcıoğlu Data Science Institute, University of California, San Diego, La Jolla, CA, USA
| | - Eric Bushong
- Department of Neurosciences, University of California, San Diego, School of Medicine, La Jolla, CA, USA
- Center for Research in Biological Systems, University of California, San Diego, School of Medicine, La Jolla, CA, USA
- National Center for Microscopy and Imaging Research, University of California, San Diego, La Jolla, CA, USA
| | - Surbhi Singhi
- Neurobiology Section, Division of Biological Sciences, University of California, San Diego, La Jolla, CA, USA
- Center for Neural Circuits and Behavior, University of California, San Diego, La Jolla, CA, USA
- Department of Neurosciences, University of California, San Diego, School of Medicine, La Jolla, CA, USA
- Halıcıoğlu Data Science Institute, University of California, San Diego, La Jolla, CA, USA
| | - Peter Nguyen
- Neurobiology Section, Division of Biological Sciences, University of California, San Diego, La Jolla, CA, USA
- Center for Neural Circuits and Behavior, University of California, San Diego, La Jolla, CA, USA
- Department of Neurosciences, University of California, San Diego, School of Medicine, La Jolla, CA, USA
- Halıcıoğlu Data Science Institute, University of California, San Diego, La Jolla, CA, USA
| | - Yessenia Magaña
- Neurobiology Section, Division of Biological Sciences, University of California, San Diego, La Jolla, CA, USA
- Center for Neural Circuits and Behavior, University of California, San Diego, La Jolla, CA, USA
- Department of Neurosciences, University of California, San Diego, School of Medicine, La Jolla, CA, USA
- Halıcıoğlu Data Science Institute, University of California, San Diego, La Jolla, CA, USA
| | - Sayyed Jilani
- Neurobiology Section, Division of Biological Sciences, University of California, San Diego, La Jolla, CA, USA
- Center for Neural Circuits and Behavior, University of California, San Diego, La Jolla, CA, USA
- Department of Neurosciences, University of California, San Diego, School of Medicine, La Jolla, CA, USA
- Halıcıoğlu Data Science Institute, University of California, San Diego, La Jolla, CA, USA
| | - Byung Kook Lim
- Neurobiology Section, Division of Biological Sciences, University of California, San Diego, La Jolla, CA, USA
- Center for Neural Circuits and Behavior, University of California, San Diego, La Jolla, CA, USA
| | - Mark Ellisman
- Department of Neurosciences, University of California, San Diego, School of Medicine, La Jolla, CA, USA
- Center for Research in Biological Systems, University of California, San Diego, School of Medicine, La Jolla, CA, USA
- National Center for Microscopy and Imaging Research, University of California, San Diego, La Jolla, CA, USA
| | - Takaki Komiyama
- Neurobiology Section, Division of Biological Sciences, University of California, San Diego, La Jolla, CA, USA.
- Center for Neural Circuits and Behavior, University of California, San Diego, La Jolla, CA, USA.
- Department of Neurosciences, University of California, San Diego, School of Medicine, La Jolla, CA, USA.
- Halıcıoğlu Data Science Institute, University of California, San Diego, La Jolla, CA, USA.
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102
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Swanson JL, Chin PS, Romero JM, Srivastava S, Ortiz-Guzman J, Hunt PJ, Arenkiel BR. Advancements in the Quest to Map, Monitor, and Manipulate Neural Circuitry. Front Neural Circuits 2022; 16:886302. [PMID: 35719420 PMCID: PMC9204427 DOI: 10.3389/fncir.2022.886302] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2022] [Accepted: 04/27/2022] [Indexed: 01/27/2023] Open
Abstract
Neural circuits and the cells that comprise them represent the functional units of the brain. Circuits relay and process sensory information, maintain homeostasis, drive behaviors, and facilitate cognitive functions such as learning and memory. Creating a functionally-precise map of the mammalian brain requires anatomically tracing neural circuits, monitoring their activity patterns, and manipulating their activity to infer function. Advancements in cell-type-specific genetic tools allow interrogation of neural circuits with increased precision. This review provides a broad overview of recombination-based and activity-driven genetic targeting approaches, contemporary viral tracing strategies, electrophysiological recording methods, newly developed calcium, and voltage indicators, and neurotransmitter/neuropeptide biosensors currently being used to investigate circuit architecture and function. Finally, it discusses methods for acute or chronic manipulation of neural activity, including genetically-targeted cellular ablation, optogenetics, chemogenetics, and over-expression of ion channels. With this ever-evolving genetic toolbox, scientists are continuing to probe neural circuits with increasing resolution, elucidating the structure and function of the incredibly complex mammalian brain.
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Affiliation(s)
- Jessica L. Swanson
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, United States
- Jan and Dan Duncan Neurological Research Institute, Texas Children’s Hospital, Houston, TX, United States
| | - Pey-Shyuan Chin
- Jan and Dan Duncan Neurological Research Institute, Texas Children’s Hospital, Houston, TX, United States
- Department of Neuroscience, Baylor College of Medicine, Houston, TX, United States
| | - Juan M. Romero
- Jan and Dan Duncan Neurological Research Institute, Texas Children’s Hospital, Houston, TX, United States
- Department of Neuroscience, Baylor College of Medicine, Houston, TX, United States
- Medical Scientist Training Program, Baylor College of Medicine, Houston, TX, United States
| | - Snigdha Srivastava
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, United States
- Jan and Dan Duncan Neurological Research Institute, Texas Children’s Hospital, Houston, TX, United States
- Medical Scientist Training Program, Baylor College of Medicine, Houston, TX, United States
| | - Joshua Ortiz-Guzman
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, United States
- Jan and Dan Duncan Neurological Research Institute, Texas Children’s Hospital, Houston, TX, United States
| | - Patrick J. Hunt
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, United States
- Jan and Dan Duncan Neurological Research Institute, Texas Children’s Hospital, Houston, TX, United States
- Medical Scientist Training Program, Baylor College of Medicine, Houston, TX, United States
| | - Benjamin R. Arenkiel
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, United States
- Jan and Dan Duncan Neurological Research Institute, Texas Children’s Hospital, Houston, TX, United States
- Department of Neuroscience, Baylor College of Medicine, Houston, TX, United States
- Medical Scientist Training Program, Baylor College of Medicine, Houston, TX, United States
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103
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Circularized fluorescent nanodiscs for probing protein-lipid interactions. Commun Biol 2022; 5:507. [PMID: 35618817 PMCID: PMC9135701 DOI: 10.1038/s42003-022-03443-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2021] [Accepted: 05/03/2022] [Indexed: 12/29/2022] Open
Abstract
Protein–lipid interactions are vital for numerous transmembrane signaling pathways. However, simple tools to characterize these interactions remain scarce and are much needed to advance our understanding of signal transduction across lipid bilayers. To tackle this challenge, we herein engineer nanodisc as a robust fluorescent sensor for reporting membrane biochemical reactions. We circularize nanodiscs via split GFP and thereby create an intensity-based fluorescent sensor (isenND) for detecting membrane binding and remodeling events. We show that isenND responds robustly and specifically to the action of a diverse array of membrane-interacting proteins and peptides, ranging from synaptotagmin and synuclein involved in neurotransmission to viral fusion peptides of HIV-1 and SARS-CoV-2. Together, isenND can serve as a versatile biochemical reagent useful for basic and translational research of membrane biology. A fluorescent probe for detecting membrane protein binding and remodeling events is presented, which relies on split-GFP technology to generate circularized nanodiscs useful in membrane protein biophysics and structural biology.
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104
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Ortega-de San Luis C, Ryan TJ. Understanding the physical basis of memory: Molecular mechanisms of the engram. J Biol Chem 2022; 298:101866. [PMID: 35346687 PMCID: PMC9065729 DOI: 10.1016/j.jbc.2022.101866] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2021] [Revised: 03/08/2022] [Accepted: 03/11/2022] [Indexed: 12/18/2022] Open
Abstract
Memory, defined as the storage and use of learned information in the brain, is necessary to modulate behavior and critical for animals to adapt to their environments and survive. Despite being a cornerstone of brain function, questions surrounding the molecular and cellular mechanisms of how information is encoded, stored, and recalled remain largely unanswered. One widely held theory is that an engram is formed by a group of neurons that are active during learning, which undergoes biochemical and physical changes to store information in a stable state, and that are later reactivated during recall of the memory. In the past decade, the development of engram labeling methodologies has proven useful to investigate the biology of memory at the molecular and cellular levels. Engram technology allows the study of individual memories associated with particular experiences and their evolution over time, with enough experimental resolution to discriminate between different memory processes: learning (encoding), consolidation (the passage from short-term to long-term memories), and storage (the maintenance of memory in the brain). Here, we review the current understanding of memory formation at a molecular and cellular level by focusing on insights provided using engram technology.
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Affiliation(s)
- Clara Ortega-de San Luis
- School of Biochemistry and Immunology and Trinity College Institute of Neuroscience, Trinity College Dublin, Dublin, Ireland.
| | - Tomás J Ryan
- School of Biochemistry and Immunology and Trinity College Institute of Neuroscience, Trinity College Dublin, Dublin, Ireland; Florey Institute of Neuroscience and Mental Health, Melbourne Brain Centre, University of Melbourne, Parkville, Victoria, Australia; Child & Brain Development Program, Canadian Institute for Advanced Research (CIFAR), Toronto, Ontario, Canada.
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105
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Li S, Zhou Q, Liu E, Du H, Yu N, Yu H, Wang W, Li M, Weng Y, Gao Y, Pi G, Wang X, Ke D, Wang J. Alzheimer-like tau accumulation in dentate gyrus mossy cells induces spatial cognitive deficits by disrupting multiple memory-related signaling and inhibiting local neural circuit. Aging Cell 2022; 21:e13600. [PMID: 35355405 PMCID: PMC9124302 DOI: 10.1111/acel.13600] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2022] [Revised: 02/28/2022] [Accepted: 03/14/2022] [Indexed: 12/22/2022] Open
Abstract
Abnormal tau accumulation and spatial memory loss constitute characteristic pathology and symptoms of Alzheimer disease (AD). Yet, the intrinsic connections and the mechanism between them are not fully understood. In the current study, we observed a prominent accumulation of the AD‐like hyperphosphorylated and truncated tau (hTau N368) proteins in hippocampal dentate gyrus (DG) mossy cells of 3xTg‐AD mice. Further investigation demonstrated that the ventral DG (vDG) mossy cell‐specific overexpressing hTau for 3 months induced spatial cognitive deficits, while expressing hTau N368 for only 1 month caused remarkable spatial cognitive impairment with more prominent tau pathologies. By in vivo electrophysiological and optic fiber recording, we observed that the vDG mossy cell‐specific overexpression of hTau N368 disrupted theta oscillations with local neural network inactivation in the dorsal DG subset, suggesting impairment of the ventral to dorsal neural circuit. The mossy cell‐specific transcriptomic data revealed that multiple AD‐associated signaling pathways were disrupted by hTau N368, including reduction of synapse‐associated proteins, inhibition of AKT and activation of glycogen synthase kinase‐3β. Importantly, chemogenetic activating mossy cells efficiently attenuated the hTau N368‐induced spatial cognitive deficits. Together, our findings indicate that the mossy cell pathological tau accumulation could induce the AD‐like spatial memory deficit by inhibiting the local neural network activity, which not only reveals new pathogenesis underlying the mossy cell‐related spatial memory loss but also provides a mouse model of Mossy cell‐specific hTau accumulation for drug development in AD and the related tauopathies.
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Affiliation(s)
- Shihong Li
- Department of Pathophysiology School of Basic Medicine Key Laboratory of Education Ministry of China/Hubei Province for Neurological Disorders Tongji Medical College Huazhong University of Science and Technology Wuhan China
| | - Qiuzhi Zhou
- Department of Pathophysiology School of Basic Medicine Key Laboratory of Education Ministry of China/Hubei Province for Neurological Disorders Tongji Medical College Huazhong University of Science and Technology Wuhan China
| | - Enjie Liu
- Department of Pathology The First Affiliated Hospital of Zhengzhou University Zhengzhou China
| | - Huiyun Du
- Department of Physiology School of Basic Medicine and Tongji Medical College Huazhong University of Science and Technology Wuhan China
| | - Nana Yu
- Department of Pathophysiology School of Basic Medicine Key Laboratory of Education Ministry of China/Hubei Province for Neurological Disorders Tongji Medical College Huazhong University of Science and Technology Wuhan China
| | - Haitao Yu
- Department of Pathophysiology School of Basic Medicine Key Laboratory of Education Ministry of China/Hubei Province for Neurological Disorders Tongji Medical College Huazhong University of Science and Technology Wuhan China
| | - Weijin Wang
- Department of Pathophysiology School of Basic Medicine Key Laboratory of Education Ministry of China/Hubei Province for Neurological Disorders Tongji Medical College Huazhong University of Science and Technology Wuhan China
| | - Mengzhu Li
- Department of Pathophysiology School of Basic Medicine Key Laboratory of Education Ministry of China/Hubei Province for Neurological Disorders Tongji Medical College Huazhong University of Science and Technology Wuhan China
| | - Ying Weng
- Department of Pathophysiology School of Basic Medicine Key Laboratory of Education Ministry of China/Hubei Province for Neurological Disorders Tongji Medical College Huazhong University of Science and Technology Wuhan China
| | - Yang Gao
- Department of Pathophysiology School of Basic Medicine Key Laboratory of Education Ministry of China/Hubei Province for Neurological Disorders Tongji Medical College Huazhong University of Science and Technology Wuhan China
| | - Guilin Pi
- Department of Pathophysiology School of Basic Medicine Key Laboratory of Education Ministry of China/Hubei Province for Neurological Disorders Tongji Medical College Huazhong University of Science and Technology Wuhan China
| | - Xin Wang
- Department of Pathophysiology School of Basic Medicine Key Laboratory of Education Ministry of China/Hubei Province for Neurological Disorders Tongji Medical College Huazhong University of Science and Technology Wuhan China
| | - Dan Ke
- Department of Pathophysiology School of Basic Medicine Key Laboratory of Education Ministry of China/Hubei Province for Neurological Disorders Tongji Medical College Huazhong University of Science and Technology Wuhan China
| | - Jian‐Zhi Wang
- Department of Pathophysiology School of Basic Medicine Key Laboratory of Education Ministry of China/Hubei Province for Neurological Disorders Tongji Medical College Huazhong University of Science and Technology Wuhan China
- Co‐Innovation Center of Neuroregeneration Nantong University Nantong China
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106
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Wu Z, Lin D, Li Y. Pushing the frontiers: tools for monitoring neurotransmitters and neuromodulators. Nat Rev Neurosci 2022; 23:257-274. [PMID: 35361961 PMCID: PMC11163306 DOI: 10.1038/s41583-022-00577-6] [Citation(s) in RCA: 69] [Impact Index Per Article: 34.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/21/2022] [Indexed: 12/26/2022]
Abstract
Neurotransmitters and neuromodulators have a wide range of key roles throughout the nervous system. However, their dynamics in both health and disease have been challenging to assess, owing to the lack of in vivo tools to track them with high spatiotemporal resolution. Thus, developing a platform that enables minimally invasive, large-scale and long-term monitoring of neurotransmitters and neuromodulators with high sensitivity, high molecular specificity and high spatiotemporal resolution has been essential. Here, we review the methods available for monitoring the dynamics of neurotransmitters and neuromodulators. Following a brief summary of non-genetically encoded methods, we focus on recent developments in genetically encoded fluorescent indicators, highlighting how these novel indicators have facilitated advances in our understanding of the functional roles of neurotransmitters and neuromodulators in the nervous system. These studies present a promising outlook for the future development and use of tools to monitor neurotransmitters and neuromodulators.
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Affiliation(s)
- Zhaofa Wu
- State Key Laboratory of Membrane Biology, Peking University School of Life Sciences, Beijing, China
- PKU-IDG/McGovern Institute for Brain Research, Beijing, China
| | - Dayu Lin
- Neuroscience Institute, New York University Grossman School of Medicine, New York, NY, USA
- Department of Psychiatry, New York University Grossman School of Medicine, New York, NY, USA
| | - Yulong Li
- State Key Laboratory of Membrane Biology, Peking University School of Life Sciences, Beijing, China.
- PKU-IDG/McGovern Institute for Brain Research, Beijing, China.
- Peking-Tsinghua Center for Life Sciences, Academy for Advanced Interdisciplinary Studies, Peking University, Beijing, China.
- Chinese Institute for Brain Research, Beijing, China.
- Institute of Molecular Physiology, Shenzhen Bay Laboratory, Shenzhen, China.
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107
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Müller JA, Betzin J, Santos-Tejedor J, Mayer A, Oprişoreanu AM, Engholm-Keller K, Paulußen I, Gulakova P, McGovern TD, Gschossman LJ, Schönhense E, Wark JR, Lamprecht A, Becker AJ, Waardenberg AJ, Graham ME, Dietrich D, Schoch S. A presynaptic phosphosignaling hub for lasting homeostatic plasticity. Cell Rep 2022; 39:110696. [PMID: 35443170 DOI: 10.1016/j.celrep.2022.110696] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2020] [Revised: 11/26/2021] [Accepted: 03/29/2022] [Indexed: 11/29/2022] Open
Abstract
Stable function of networks requires that synapses adapt their strength to levels of neuronal activity, and failure to do so results in cognitive disorders. How such homeostatic regulation may be implemented in mammalian synapses remains poorly understood. Here we show that the phosphorylation status of several positions of the active-zone (AZ) protein RIM1 are relevant for synaptic glutamate release. Position RIMS1045 is necessary and sufficient for expression of silencing-induced homeostatic plasticity and is kept phosphorylated by serine arginine protein kinase 2 (SRPK2). SRPK2-induced upscaling of synaptic release leads to additional RIM1 nanoclusters and docked vesicles at the AZ and is not observed in the absence of RIM1 and occluded by RIMS1045E. Our data suggest that SRPK2 and RIM1 represent a presynaptic phosphosignaling hub that is involved in the homeostatic balance of synaptic coupling of neuronal networks.
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Affiliation(s)
- Johannes Alexander Müller
- Section for Translational Epilepsy Research, Department of Neuropathology, University Hospital Bonn, Bonn, Germany; Department of Neurosurgery, University Hospital Bonn, Bonn, Germany
| | - Julia Betzin
- Section for Translational Epilepsy Research, Department of Neuropathology, University Hospital Bonn, Bonn, Germany
| | - Jorge Santos-Tejedor
- Section for Translational Epilepsy Research, Department of Neuropathology, University Hospital Bonn, Bonn, Germany
| | - Annika Mayer
- Section for Translational Epilepsy Research, Department of Neuropathology, University Hospital Bonn, Bonn, Germany
| | - Ana-Maria Oprişoreanu
- Section for Translational Epilepsy Research, Department of Neuropathology, University Hospital Bonn, Bonn, Germany
| | - Kasper Engholm-Keller
- Department of Biochemistry and Molecular Biology, University of Southern Denmark, Odense, Denmark; Synapse Proteomics, Children's Medical Research Institute, The University of Sydney, Westmead, NSW, Australia
| | | | - Polina Gulakova
- Section for Translational Epilepsy Research, Department of Neuropathology, University Hospital Bonn, Bonn, Germany; Department of Neurosurgery, University Hospital Bonn, Bonn, Germany
| | | | - Lena Johanna Gschossman
- Section for Translational Epilepsy Research, Department of Neuropathology, University Hospital Bonn, Bonn, Germany; Department of Neurosurgery, University Hospital Bonn, Bonn, Germany
| | - Eva Schönhense
- Section for Translational Epilepsy Research, Department of Neuropathology, University Hospital Bonn, Bonn, Germany
| | - Jesse R Wark
- Synapse Proteomics, Children's Medical Research Institute, The University of Sydney, Westmead, NSW, Australia
| | - Alf Lamprecht
- Department of Pharmaceutics, Bonn University, Bonn, Germany
| | - Albert J Becker
- Section for Translational Epilepsy Research, Department of Neuropathology, University Hospital Bonn, Bonn, Germany
| | - Ashley J Waardenberg
- Australian Institute for Tropical Health and Medicine, James Cook University, Smithfield, QLD 4878, Australia; i-Synapse, Cairns, QLD, Australia
| | - Mark E Graham
- Synapse Proteomics, Children's Medical Research Institute, The University of Sydney, Westmead, NSW, Australia
| | - Dirk Dietrich
- Department of Neurosurgery, University Hospital Bonn, Bonn, Germany.
| | - Susanne Schoch
- Section for Translational Epilepsy Research, Department of Neuropathology, University Hospital Bonn, Bonn, Germany.
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108
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Wang CS, Chanaday NL, Monteggia LM, Kavalali ET. Probing the segregation of evoked and spontaneous neurotransmission via photobleaching and recovery of a fluorescent glutamate sensor. eLife 2022; 11:e76008. [PMID: 35420542 PMCID: PMC9129874 DOI: 10.7554/elife.76008] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2021] [Accepted: 04/08/2022] [Indexed: 11/13/2022] Open
Abstract
Synapses maintain both action potential-evoked and spontaneous neurotransmitter release; however, organization of these two forms of release within an individual synapse remains unclear. Here, we used photobleaching properties of iGluSnFR, a fluorescent probe that detects glutamate, to investigate the subsynaptic organization of evoked and spontaneous release in primary hippocampal cultures. In nonneuronal cells and neuronal dendrites, iGluSnFR fluorescence is intensely photobleached and recovers via diffusion of nonphotobleached probes with a time constant of ~10 s. After photobleaching, while evoked iGluSnFR events could be rapidly suppressed, their recovery required several hours. In contrast, iGluSnFR responses to spontaneous release were comparatively resilient to photobleaching, unless the complete pool of iGluSnFR was activated by glutamate perfusion. This differential effect of photobleaching on different modes of neurotransmission is consistent with a subsynaptic organization where sites of evoked glutamate release are clustered and corresponding iGluSnFR probes are diffusion restricted, while spontaneous release sites are broadly spread across a synapse with readily diffusible iGluSnFR probes.
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Affiliation(s)
- Camille S Wang
- Vanderbilt Brain Institute, Vanderbilt UniversityNashvilleUnited States
| | - Natali L Chanaday
- Department of Pharmacology, Vanderbilt UniversityNashvilleUnited States
| | - Lisa M Monteggia
- Vanderbilt Brain Institute, Vanderbilt UniversityNashvilleUnited States
- Department of Pharmacology, Vanderbilt UniversityNashvilleUnited States
| | - Ege T Kavalali
- Vanderbilt Brain Institute, Vanderbilt UniversityNashvilleUnited States
- Department of Pharmacology, Vanderbilt UniversityNashvilleUnited States
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109
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Hirrlinger J, Nimmerjahn A. A perspective on astrocyte regulation of neural circuit function and animal behavior. Glia 2022; 70:1554-1580. [PMID: 35297525 PMCID: PMC9291267 DOI: 10.1002/glia.24168] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2021] [Revised: 01/19/2022] [Accepted: 02/27/2022] [Indexed: 12/16/2022]
Abstract
Studies over the past two decades have demonstrated that astrocytes are
tightly associated with neurons and play pivotal roles in neural circuit
development, operation, and adaptation in health and disease. Nevertheless,
precisely how astrocytes integrate diverse neuronal signals, modulate neural
circuit structure and function at multiple temporal and spatial scales, and
influence animal behavior or disease through aberrant excitation and molecular
output remains unclear. This Perspective discusses how new and state-of-the-art
approaches, including fluorescence indicators, opto- and chemogenetic actuators,
genetic targeting tools, quantitative behavioral assays, and computational
methods, might help resolve these longstanding questions. It also addresses
complicating factors in interpreting astrocytes’ role in neural circuit
regulation and animal behavior, such as their heterogeneity, metabolism, and
inter-glial communication. Research on these questions should provide a deeper
mechanistic understanding of astrocyte-neuron assemblies’ role in neural
circuit function, complex behaviors, and disease.
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Affiliation(s)
- Johannes Hirrlinger
- Carl-Ludwig-Institute for Physiology, Medical Faculty, University of Leipzig, Leipzig, Germany.,Department of Neurogenetics, Max-Planck-Institute for Multidisciplinary Sciences, Göttingen, Germany
| | - Axel Nimmerjahn
- Waitt Advanced Biophotonics Center, The Salk Institute for Biological Studies, La Jolla, California
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110
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Brandner S, Aicher S, Schroeter S, Swierzy I, Kinfe TM, Buchfelder M, Maslarova A, Stadlbauer A. Real-time imaging of glutamate transients in the extracellular space of acute human brain slices using a single-wavelength glutamate fluorescence nanosensor. Sci Rep 2022; 12:3926. [PMID: 35273260 PMCID: PMC8913701 DOI: 10.1038/s41598-022-07940-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2021] [Accepted: 02/22/2022] [Indexed: 12/12/2022] Open
Abstract
Glutamate is the most important excitatory neurotransmitter in the brain. The ability to assess glutamate release and re-uptake with high spatial and temporal resolution is crucial to understand the involvement of this primary excitatory neurotransmitter in both normal brain function and different neurological disorders. Real-time imaging of glutamate transients by fluorescent nanosensors has been accomplished in rat brain slices. We performed for the first time single-wavelength glutamate nanosensor imaging in human cortical brain slices obtained from patients who underwent epilepsy surgery. The glutamate fluorescence nanosensor signals of the electrically stimulated human cortical brain slices showed steep intensity increase followed by an exponential decrease. The spatial distribution and the time course of the signal were in good agreement with the position of the stimulation electrode and the dynamics of the electrical stimulation, respectively. Pharmacological manipulation of glutamate release and reuptake was associated with corresponding changes in the glutamate fluorescence nanosensor signals. We demonstrated that the recently developed fluorescent nanosensors for glutamate allow to detect neuronal activity in acute human cortical brain slices with high spatiotemporal precision. Future application to tissue samples from different pathologies may provide new insights into pathophysiology without the limitations of an animal model.
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Affiliation(s)
- Sebastian Brandner
- Department of Neurosurgery, University Hospital Erlangen, Schwabachanlage 6, 91054, Erlangen, Germany.
| | - Simon Aicher
- Department of Neurosurgery, University Hospital Erlangen, Schwabachanlage 6, 91054, Erlangen, Germany
| | - Sarah Schroeter
- Department of Neurosurgery, University Hospital Erlangen, Schwabachanlage 6, 91054, Erlangen, Germany.,Center for Musculoskeletal Surgery Osnabrück (OZMC), Klinikum Osnabrück, Osnabrück, Germany
| | - Izabela Swierzy
- Department of Neurosurgery, University Hospital Erlangen, Schwabachanlage 6, 91054, Erlangen, Germany
| | - Thomas M Kinfe
- Department of Neurosurgery, University Hospital Erlangen, Schwabachanlage 6, 91054, Erlangen, Germany.,Division of Functional Neurosurgery and Stereotaxy, University Hospital Erlangen, Erlangen, Germany
| | - Michael Buchfelder
- Department of Neurosurgery, University Hospital Erlangen, Schwabachanlage 6, 91054, Erlangen, Germany
| | - Anna Maslarova
- Department of Neurosurgery, University Hospital Erlangen, Schwabachanlage 6, 91054, Erlangen, Germany
| | - Andreas Stadlbauer
- Department of Neurosurgery, University Hospital Erlangen, Schwabachanlage 6, 91054, Erlangen, Germany.,Institute of Medical Radiology, University Clinic St. Pölten, Karl Landsteiner University of Health Sciences, St. Pölten, Austria
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111
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Upmanyu N, Jin J, Emde HVD, Ganzella M, Bösche L, Malviya VN, Zhuleku E, Politi AZ, Ninov M, Silbern I, Leutenegger M, Urlaub H, Riedel D, Preobraschenski J, Milosevic I, Hell SW, Jahn R, Sambandan S. Colocalization of different neurotransmitter transporters on synaptic vesicles is sparse except for VGLUT1 and ZnT3. Neuron 2022; 110:1483-1497.e7. [PMID: 35263617 DOI: 10.1016/j.neuron.2022.02.008] [Citation(s) in RCA: 21] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2021] [Revised: 01/08/2022] [Accepted: 02/10/2022] [Indexed: 12/26/2022]
Abstract
Vesicular transporters (VTs) define the type of neurotransmitter that synaptic vesicles (SVs) store and release. While certain mammalian neurons release multiple transmitters, it is not clear whether the release occurs from the same or distinct vesicle pools at the synapse. Using quantitative single-vesicle imaging, we show that a vast majority of SVs in the rodent brain contain only one type of VT, indicating specificity for a single neurotransmitter. Interestingly, SVs containing dual transporters are highly diverse (27 types) but small in proportion (2% of all SVs), excluding the largest pool that carries VGLUT1 and ZnT3 (34%). Using VGLUT1-ZnT3 SVs, we demonstrate that the transporter colocalization influences the SV content and synaptic quantal size. Thus, the presence of diverse transporters on the same vesicle is bona fide, and depending on the VT types, this may act to regulate neurotransmitter type, content, and release in space and time.
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Affiliation(s)
- Neha Upmanyu
- Synaptic Metal Ion Dynamics and Signaling, Max Planck Institute for Multidisciplinary Sciences, Göttingen 37077, Germany; Laboratory of Neurobiology, Max Planck Institute for Multidisciplinary Sciences, Göttingen 37077, Germany
| | - Jialin Jin
- European Neurosciences Institute, A Joint Initiative of the University Medical Center Göttingen and the Max Planck Society, Göttingen 37077, Germany
| | - Henrik von der Emde
- Department of NanoBiophotonics, Max Planck Institute for Multidisciplinary Sciences, Göttingen 37077, Germany
| | - Marcelo Ganzella
- Laboratory of Neurobiology, Max Planck Institute for Multidisciplinary Sciences, Göttingen 37077, Germany
| | - Leon Bösche
- Synaptic Metal Ion Dynamics and Signaling, Max Planck Institute for Multidisciplinary Sciences, Göttingen 37077, Germany; Laboratory of Neurobiology, Max Planck Institute for Multidisciplinary Sciences, Göttingen 37077, Germany
| | - Viveka Nand Malviya
- Laboratory of Neurobiology, Max Planck Institute for Multidisciplinary Sciences, Göttingen 37077, Germany
| | - Evi Zhuleku
- Laboratory of Neurobiology, Max Planck Institute for Multidisciplinary Sciences, Göttingen 37077, Germany
| | - Antonio Zaccaria Politi
- Live-Cell Imaging Facility, Max Planck Institute for Multidisciplinary Sciences, Göttingen 37077, Germany
| | - Momchil Ninov
- Bioanalytical Mass Spectrometry, Max Planck Institute for Multidisciplinary Sciences, Göttingen 37077, Germany; Institute of Clinical Chemistry, University Medical Center Göttingen, Göttingen 37075, Germany
| | - Ivan Silbern
- Bioanalytical Mass Spectrometry, Max Planck Institute for Multidisciplinary Sciences, Göttingen 37077, Germany; Institute of Clinical Chemistry, University Medical Center Göttingen, Göttingen 37075, Germany
| | - Marcel Leutenegger
- Department of NanoBiophotonics, Max Planck Institute for Multidisciplinary Sciences, Göttingen 37077, Germany
| | - Henning Urlaub
- Bioanalytical Mass Spectrometry, Max Planck Institute for Multidisciplinary Sciences, Göttingen 37077, Germany; Institute of Clinical Chemistry, University Medical Center Göttingen, Göttingen 37075, Germany
| | - Dietmar Riedel
- Department of Structural Dynamics, Max Planck Institute for Multidisciplinary Sciences, Göttingen 37077, Germany
| | - Julia Preobraschenski
- Laboratory of Neurobiology, Max Planck Institute for Multidisciplinary Sciences, Göttingen 37077, Germany; Institute for Auditory Neuroscience, University Medical Center Göttingen, Göttingen 37075, Germany; Cluster of Excellence "Multiscale Bioimaging: from Molecular Machines to Networks of Excitable Cells" (MBExC), University of Göttingen, Göttingen 37075, Germany
| | - Ira Milosevic
- Wellcome Centre for Human Genetics, Nuffield Department of Medicine, NIHR Oxford Biomedical Research Centre, University of Oxford, Oxford OX3 7BN, UK; Multidisciplinary Institute of Ageing, MIA-Portugal, University of Coimbra, Coimbra 3000-370, Portugal
| | - Stefan W Hell
- Department of NanoBiophotonics, Max Planck Institute for Multidisciplinary Sciences, Göttingen 37077, Germany; Department of Optical Nanoscopy, Max Planck Institute for Medical Research, Heidelberg 69028, Germany
| | - Reinhard Jahn
- Laboratory of Neurobiology, Max Planck Institute for Multidisciplinary Sciences, Göttingen 37077, Germany
| | - Sivakumar Sambandan
- Synaptic Metal Ion Dynamics and Signaling, Max Planck Institute for Multidisciplinary Sciences, Göttingen 37077, Germany; Laboratory of Neurobiology, Max Planck Institute for Multidisciplinary Sciences, Göttingen 37077, Germany; Department of NanoBiophotonics, Max Planck Institute for Multidisciplinary Sciences, Göttingen 37077, Germany.
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112
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Chohan MO, Kopelman JM, Yueh H, Fazlali Z, Greene N, Harris AZ, Balsam PD, Leonardo ED, Kramer ER, Veenstra-VanderWeele J, Ahmari SE. Developmental impact of glutamate transporter overexpression on dopaminergic neuron activity and stereotypic behavior. Mol Psychiatry 2022; 27:1515-1526. [PMID: 35058566 PMCID: PMC9106836 DOI: 10.1038/s41380-021-01424-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/05/2021] [Revised: 10/30/2021] [Accepted: 12/16/2021] [Indexed: 11/09/2022]
Abstract
Obsessive-compulsive disorder (OCD) is a disabling condition that often begins in childhood. Genetic studies in OCD have pointed to SLC1A1, which encodes the neuronal glutamate transporter EAAT3, with evidence suggesting that increased expression contributes to risk. In mice, midbrain Slc1a1 expression supports repetitive behavior in response to dopaminergic agonists, aligning with neuroimaging and pharmacologic challenge studies that have implicated the dopaminergic system in OCD. These findings suggest that Slc1a1 may contribute to compulsive behavior through altered dopaminergic transmission; however, this theory has not been mechanistically tested. To examine the developmental impact of Slc1a1 overexpression on compulsive-like behaviors, we, therefore, generated a novel mouse model to perform targeted, reversible overexpression of Slc1a1 in dopaminergic neurons. Mice with life-long overexpression of Slc1a1 showed a significant increase in amphetamine (AMPH)-induced stereotypy and hyperlocomotion. Single-unit recordings demonstrated that Slc1a1 overexpression was associated with increased firing of dopaminergic neurons. Furthermore, dLight1.1 fiber photometry showed that these behavioral abnormalities were associated with increased dorsal striatum dopamine release. In contrast, no impact of overexpression was observed on anxiety-like behaviors or SKF-38393-induced grooming. Importantly, overexpression solely in adulthood failed to recapitulate these behavioral phenotypes, suggesting that overexpression during development is necessary to generate AMPH-induced phenotypes. However, doxycycline-induced reversal of Slc1a1/EAAT3 overexpression in adulthood normalized both the increased dopaminergic firing and AMPH-induced responses. These data indicate that the pathologic effects of Slc1a1/EAAT3 overexpression on dopaminergic neurotransmission and AMPH-induced stereotyped behavior are developmentally mediated, and support normalization of EAAT3 activity as a potential treatment target for basal ganglia-mediated repetitive behaviors.
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Affiliation(s)
- Muhammad O. Chohan
- Department of Psychiatry, Columbia University, New York, NY, USA,New York State Psychiatric Institute, New York, NY, USA
| | - Jared M. Kopelman
- Department of Psychiatry, Translational Neuroscience Program, University of Pittsburgh, Pittsburgh, PA, USA,Center for the Neural Basis of Cognition, Carnegie Mellon University, Pittsburgh, PA, USA
| | - Hannah Yueh
- Department of Psychiatry, Columbia University, New York, NY, USA,New York State Psychiatric Institute, New York, NY, USA
| | - Zeinab Fazlali
- Department of Psychiatry, Columbia University, New York, NY, USA,New York State Psychiatric Institute, New York, NY, USA
| | - Natasha Greene
- New York State Psychiatric Institute, New York, NY, USA,Department of Psychology, Barnard College of Columbia University, New York, NY, USA
| | - Alexander Z. Harris
- Department of Psychiatry, Columbia University, New York, NY, USA,New York State Psychiatric Institute, New York, NY, USA
| | - Peter D. Balsam
- Department of Psychiatry, Columbia University, New York, NY, USA,New York State Psychiatric Institute, New York, NY, USA,Department of Psychology, Barnard College of Columbia University, New York, NY, USA
| | - E. David Leonardo
- Department of Psychiatry, Columbia University, New York, NY, USA,New York State Psychiatric Institute, New York, NY, USA
| | - Edgar R. Kramer
- Peninsula Medical School, Faculty of Health, University of Plymouth, Plymouth, Devon, UK
| | - Jeremy Veenstra-VanderWeele
- Department of Psychiatry, Columbia University, New York, NY, USA. .,New York State Psychiatric Institute, New York, NY, USA.
| | - Susanne E. Ahmari
- Department of Psychiatry, Translational Neuroscience Program, University of Pittsburgh, Pittsburgh, PA, USA,Center for the Neural Basis of Cognition, Carnegie Mellon University, Pittsburgh, PA, USA
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113
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Jackson RE, Compans B, Burrone J. Correlative Live-Cell and Super-Resolution Imaging to Link Presynaptic Molecular Organisation With Function. Front Synaptic Neurosci 2022; 14:830583. [PMID: 35242024 PMCID: PMC8885727 DOI: 10.3389/fnsyn.2022.830583] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2021] [Accepted: 01/12/2022] [Indexed: 11/13/2022] Open
Abstract
Information transfer at synapses occurs when vesicles fuse with the plasma membrane to release neurotransmitters, which then bind to receptors at the postsynaptic membrane. The process of neurotransmitter release varies dramatically between different synapses, but little is known about how this heterogeneity emerges. The development of super-resolution microscopy has revealed that synaptic proteins are precisely organised within and between the two parts of the synapse and that this precise spatiotemporal organisation fine-tunes neurotransmission. However, it remains unclear if variability in release probability could be attributed to the nanoscale organisation of one or several proteins of the release machinery. To begin to address this question, we have developed a pipeline for correlative functional and super-resolution microscopy, taking advantage of recent technological advancements enabling multicolour imaging. Here we demonstrate the combination of live imaging of SypHy-RGECO, a unique dual reporter that simultaneously measures presynaptic calcium influx and neurotransmitter release, with post hoc immunolabelling and multicolour single molecule localisation microscopy, to investigate the structure-function relationship at individual presynaptic boutons.
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Affiliation(s)
- Rachel E. Jackson
- Centre for Developmental Neurobiology, Institute of Psychiatry, Psychology and Neuroscience, King’s College London, London, United Kingdom
- MRC Centre for Neurodevelopmental Disorders, Institute of Psychiatry, Psychology and Neuroscience, King’s College London, London, United Kingdom
| | - Benjamin Compans
- Centre for Developmental Neurobiology, Institute of Psychiatry, Psychology and Neuroscience, King’s College London, London, United Kingdom
- MRC Centre for Neurodevelopmental Disorders, Institute of Psychiatry, Psychology and Neuroscience, King’s College London, London, United Kingdom
| | - Juan Burrone
- Centre for Developmental Neurobiology, Institute of Psychiatry, Psychology and Neuroscience, King’s College London, London, United Kingdom
- MRC Centre for Neurodevelopmental Disorders, Institute of Psychiatry, Psychology and Neuroscience, King’s College London, London, United Kingdom
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114
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Hao Y, Plested AJ. Seeing glutamate at central synapses. J Neurosci Methods 2022; 375:109531. [DOI: 10.1016/j.jneumeth.2022.109531] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2021] [Revised: 02/11/2022] [Accepted: 02/14/2022] [Indexed: 12/15/2022]
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115
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Pulin M, Stockhausen KE, Masseck OA, Kubitschke M, Busse B, Wiegert JS, Oertner TG. Orthogonally-polarized excitation for improved two-photon and second-harmonic-generation microscopy, applied to neurotransmitter imaging with GPCR-based sensors. BIOMEDICAL OPTICS EXPRESS 2022; 13:777-790. [PMID: 35284188 PMCID: PMC8884218 DOI: 10.1364/boe.448760] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/17/2021] [Revised: 01/06/2022] [Accepted: 01/06/2022] [Indexed: 06/14/2023]
Abstract
Fluorescent proteins are excited by light that is polarized parallel to the dipole axis of the chromophore. In two-photon microscopy, polarized light is used for excitation. Here we reveal surprisingly strong polarization sensitivity in a class of genetically encoded, GPCR-based neurotransmitter sensors. In tubular structures such as dendrites, this effect led to a complete loss of membrane signal in dendrites running parallel to the polarization direction of the excitation beam. To reduce the sensitivity to dendritic orientation, we designed an optical device that generates interleaved pulse trains of orthogonal polarization. The passive device, which we inserted in the beam path of an existing two-photon microscope, removed the strong direction bias from fluorescence and second-harmonic (SHG) images. We conclude that for optical measurements of transmitter concentration with GPCR-based sensors, orthogonally polarized excitation is essential.
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Affiliation(s)
- Mauro Pulin
- Institute for Synaptic Physiology, ZMNH, University Medical Center Hamburg-Eppendorf, 20251 Hamburg, Germany
- Research Group Synaptic Wiring and Information Processing, ZMNH, University Medical Center Hamburg-Eppendorf, 20251 Hamburg, Germany
| | - Kilian E. Stockhausen
- Department of Osteology and Biomechanics, University Medical Center Hamburg-Eppendorf, 22529 Hamburg, Germany
| | - Olivia A. Masseck
- Synthetic Biology, University of Bremen, Leobener Str. 5, 28359 Bremen, Germany
| | - Martin Kubitschke
- Synthetic Biology, University of Bremen, Leobener Str. 5, 28359 Bremen, Germany
| | - Björn Busse
- Department of Osteology and Biomechanics, University Medical Center Hamburg-Eppendorf, 22529 Hamburg, Germany
- Interdisciplinary Competence Center for Interface Research (ICCIR), University Medical Center Hamburg-Eppendorf, 20251 Hamburg, Germany
| | - J. Simon Wiegert
- Research Group Synaptic Wiring and Information Processing, ZMNH, University Medical Center Hamburg-Eppendorf, 20251 Hamburg, Germany
| | - Thomas G. Oertner
- Institute for Synaptic Physiology, ZMNH, University Medical Center Hamburg-Eppendorf, 20251 Hamburg, Germany
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116
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Bradberry MM, Chapman ER. All-optical monitoring of excitation-secretion coupling demonstrates that SV2A functions downstream of evoked Ca 2+ entry. J Physiol 2022; 600:645-654. [PMID: 34957569 PMCID: PMC8810609 DOI: 10.1113/jp282601] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2021] [Accepted: 12/22/2021] [Indexed: 02/03/2023] Open
Abstract
SV2A, an essential transporter-like synaptic vesicle protein, is a major target for antiepileptic drugs and a receptor for clostridial neurotoxins including Botox. While SV2A is required for normal levels of evoked neurotransmitter release, the mechanism underlying this role remains unclear. Here, we introduce a new chemogenetic approach for all-optical monitoring of excitation-secretion coupling, and we demonstrate its use in characterizing the SV2A knockout (KO) phenotype in cultured hippocampal neurons. This method employs the HaloTag system to target a robust small-molecule Ca2+ indicator, JF646 -BAPTA, to the presynaptic compartment. The far-red fluorescence of this indicator enables multiplexing with the fluorescent glutamate sensor iGluSnFR for detection of presynaptic Ca2+ influx and glutamate release at the same axonal boutons. Evoked glutamate release probability was reduced in SV2A KO neurons without a change in presynaptic Ca2+ entry, suggesting that SV2A supports vesicle fusion by increasing the functional availability, or efficiency, of the Ca2+ -regulated membrane fusion machinery. KEY POINTS: One of the most prescribed antiepileptic medications, levetiracetam, acts by binding a protein of uncertain molecular function. This transporter-like protein, SV2A, is trafficked to synaptic vesicles and acts to support neurotransmitter release, but the mechanism underlying this function has not been determined In this study, we sought to establish whether SV2A changes Ca2+ signalling at nerve terminals, which is a key regulatory system for synaptic vesicle exocytosis. To do so, we adapted new chemogenetic tools to perform all-optical measurements of presynaptic Ca2+ and glutamate release in neurons lacking SV2A. Our measurements showed that loss of SV2A reduces glutamate release without reducing Ca2+ influx at hippocampal nerve terminals, demonstrating that SV2A increases the likelihood that Ca2+ will trigger synaptic vesicle fusion.
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Affiliation(s)
- Mazdak M. Bradberry
- Howard Hughes Medical Institute and Department of Neuroscience, University of Wisconsin School of Medicine and Public Health, 1111 Highland Ave, Madison, WI 53705,Medical Scientist Training Program, University of Wisconsin School of Medicine and Public Health, 1111 Highland Ave, Madison, WI 53705
| | - Edwin R. Chapman
- Howard Hughes Medical Institute and Department of Neuroscience, University of Wisconsin School of Medicine and Public Health, 1111 Highland Ave, Madison, WI 53705
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117
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Matthews EA, Sun W, McMahon SM, Doengi M, Halka L, Anders S, Müller JA, Steinlein P, Vana NS, van Dyk G, Pitsch J, Becker AJ, Pfeifer A, Kavalali ET, Lamprecht A, Henneberger C, Stein V, Schoch S, Dietrich D. Optical analysis of glutamate spread in the neuropil. Cereb Cortex 2022; 32:3669-3689. [PMID: 35059716 PMCID: PMC9433421 DOI: 10.1093/cercor/bhab440] [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: 08/08/2021] [Revised: 11/03/2021] [Accepted: 11/09/2021] [Indexed: 11/16/2022] Open
Abstract
Fast synaptic communication uses diffusible transmitters whose spread is limited by uptake mechanisms. However, on the submicron-scale, the distance between two synapses, the extent of glutamate spread has so far remained difficult to measure. Here, we show that quantal glutamate release from individual hippocampal synapses activates extracellular iGluSnFr molecules at a distance of >1.5 μm. 2P-glutamate uncaging near spines further showed that alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA)-Rs and N-methyl-D-aspartate (NMDA)-Rs respond to distant uncaging spots at approximately 800 and 2000 nm, respectively, when releasing the amount of glutamate contained in approximately five synaptic vesicles. The uncaging-induced remote activation of AMPA-Rs was facilitated by blocking glutamate transporters but only modestly decreased by elevating the recording temperature. When mimicking release from neighboring synapses by three simultaneous uncaging spots in the microenvironment of a spine, AMPA-R-mediated responses increased supra-additively. Interfering with extracellular glutamate diffusion through a glutamate scavenger system weakly reduced field synaptic responses but not the quantal amplitude. Together, our data suggest that the neuropil is more permissive to short-range spread of transmitter than suggested by theory, that multivesicular release could regularly coactivate nearest neighbor synapses and that on this scale glutamate buffering by transporters primarily limits the spread of transmitter and allows for cooperative glutamate signaling in extracellular microdomains.
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Affiliation(s)
| | | | | | - M Doengi
- Institute of Physiology, Medical Faculty, University of Bonn, 53115 Bonn, Germany
| | - L Halka
- Institute of Physiology, Medical Faculty, University of Bonn, 53115 Bonn, Germany
| | - S Anders
- Institute of Cellular Neurosciences, Medical Faculty, University of Bonn, 53127 Bonn, Germany
| | - J A Müller
- Section for Translational Epilepsy Research, Department of Neuropathology, University Hospital Bonn, 53127 Bonn, Germany
| | - P Steinlein
- Department of Neurosurgery, University Hospital Bonn, 53127 Bonn, Germany,Department of Pharmaceutics, Institute of Pharmacy, University of Bonn, Bonn, Germany
| | - N S Vana
- Department of Neurosurgery, University Hospital Bonn, 53127 Bonn, Germany
| | - G van Dyk
- Department of Neurosurgery, University Hospital Bonn, 53127 Bonn, Germany
| | - J Pitsch
- Section for Translational Epilepsy Research, Department of Neuropathology, University Hospital Bonn, 53127 Bonn, Germany,Department of Epileptology, University Hospital Bonn, 53127 Bonn, Germany
| | - A J Becker
- Section for Translational Epilepsy Research, Department of Neuropathology, University Hospital Bonn, 53127 Bonn, Germany,Department of Epileptology, University Hospital Bonn, 53127 Bonn, Germany
| | - A Pfeifer
- Institute of Pharmacology and Toxicology, University Hospital, University of Bonn, 53127 Bonn, Germany
| | - E T Kavalali
- Department of Pharmacology, The Vanderbilt Brain Institute, Vanderbilt University, Nashville, TN 37240-7933, USA
| | - A Lamprecht
- Department of Pharmaceutics, Institute of Pharmacy, University of Bonn, Bonn, Germany
| | - C Henneberger
- Institute of Cellular Neurosciences, Medical Faculty, University of Bonn, 53127 Bonn, Germany,German Center for Neurodegenerative Diseases (DZNE), 53127 Bonn, Germany,Institute of Neurology, University College London, London, WC1N 3BG, UK
| | - V Stein
- Institute of Physiology, Medical Faculty, University of Bonn, 53115 Bonn, Germany
| | - S Schoch
- Address correspondence to Prof. Dr Dirk Dietrich, Department of Neurosurgery, University Hospital Bonn, Venusberg Campus 1, Bonn 53127, Germany. ; and Prof. Dr Susanne Schoch, Institute of Neuropathology, University Hospital Bonn, Venusberg Campus 1, Bonn 53127, Germany.
| | - D Dietrich
- Address correspondence to Prof. Dr Dirk Dietrich, Department of Neurosurgery, University Hospital Bonn, Venusberg Campus 1, Bonn 53127, Germany. ; and Prof. Dr Susanne Schoch, Institute of Neuropathology, University Hospital Bonn, Venusberg Campus 1, Bonn 53127, Germany.
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118
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Chemogenetic approaches to dissect the role of H2O2 in redox-dependent pathways using genetically encoded biosensors. Biochem Soc Trans 2022; 50:335-345. [PMID: 35015078 DOI: 10.1042/bst20210506] [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: 11/25/2021] [Revised: 12/20/2021] [Accepted: 12/21/2021] [Indexed: 11/17/2022]
Abstract
Chemogenetic tools are recombinant enzymes that can be targeted to specific organelles and tissues. The provision or removal of the enzyme substrate permits control of its biochemical activities. Yeast-derived enzyme D-amino acid oxidase (DAAO) represents the first of its kind for a substrate-based chemogenetic approach to modulate H2O2 concentrations within cells. Combining these powerful enzymes with multiparametric imaging methods exploiting genetically encoded biosensors has opened new lines of investigations in life sciences. In recent years, the chemogenetic DAAO approach has proven beneficial to establish a new role for (patho)physiological oxidative stress on redox-dependent signaling and metabolic pathways in cultured cells and animal model systems. This mini-review covers established or emerging methods and assesses newer approaches exploiting chemogenetic tools combined with genetically encoded biosensors.
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119
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Nichols AL, Blumenfeld Z, Fan C, Luebbert L, Blom AEM, Cohen BN, Marvin JS, Borden PM, Kim CH, Muthusamy AK, Shivange AV, Knox HJ, Campello HR, Wang JH, Dougherty DA, Looger LL, Gallagher T, Rees DC, Lester HA. Fluorescence activation mechanism and imaging of drug permeation with new sensors for smoking-cessation ligands. eLife 2022; 11:e74648. [PMID: 34982029 PMCID: PMC8820738 DOI: 10.7554/elife.74648] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2021] [Accepted: 01/03/2022] [Indexed: 12/16/2022] Open
Abstract
Nicotinic partial agonists provide an accepted aid for smoking cessation and thus contribute to decreasing tobacco-related disease. Improved drugs constitute a continued area of study. However, there remains no reductionist method to examine the cellular and subcellular pharmacokinetic properties of these compounds in living cells. Here, we developed new intensity-based drug-sensing fluorescent reporters (iDrugSnFRs) for the nicotinic partial agonists dianicline, cytisine, and two cytisine derivatives - 10-fluorocytisine and 9-bromo-10-ethylcytisine. We report the first atomic-scale structures of liganded periplasmic binding protein-based biosensors, accelerating development of iDrugSnFRs and also explaining the activation mechanism. The nicotinic iDrugSnFRs detect their drug partners in solution, as well as at the plasma membrane (PM) and in the endoplasmic reticulum (ER) of cell lines and mouse hippocampal neurons. At the PM, the speed of solution changes limits the growth and decay rates of the fluorescence response in almost all cases. In contrast, we found that rates of membrane crossing differ among these nicotinic drugs by >30-fold. The new nicotinic iDrugSnFRs provide insight into the real-time pharmacokinetic properties of nicotinic agonists and provide a methodology whereby iDrugSnFRs can inform both pharmaceutical neuroscience and addiction neuroscience.
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Affiliation(s)
- Aaron L Nichols
- Division of Biology and Biological Engineering, California Institute of TechnologyPasadenaUnited States
| | - Zack Blumenfeld
- Division of Biology and Biological Engineering, California Institute of TechnologyPasadenaUnited States
- Keck School of Medicine, University of Southern CaliforniaLos AngelesUnited States
| | - Chengcheng Fan
- Division of Chemistry and Chemical Engineering, California Institute of TechnologyPasadenaUnited States
| | - Laura Luebbert
- Division of Biology and Biological Engineering, California Institute of TechnologyPasadenaUnited States
- Institute of Biology, Leiden UniversityLeidenNetherlands
| | - Annet EM Blom
- Division of Chemistry and Chemical Engineering, California Institute of TechnologyPasadenaUnited States
| | - Bruce N Cohen
- Division of Biology and Biological Engineering, California Institute of TechnologyPasadenaUnited States
| | - Jonathan S Marvin
- Janelia Research Campus, Howard Hughes Medical InstituteAshburnUnited States
| | - Philip M Borden
- Janelia Research Campus, Howard Hughes Medical InstituteAshburnUnited States
| | - Charlene H Kim
- Division of Biology and Biological Engineering, California Institute of TechnologyPasadenaUnited States
| | - Anand K Muthusamy
- Division of Chemistry and Chemical Engineering, California Institute of TechnologyPasadenaUnited States
| | - Amol V Shivange
- Division of Biology and Biological Engineering, California Institute of TechnologyPasadenaUnited States
| | - Hailey J Knox
- Division of Chemistry and Chemical Engineering, California Institute of TechnologyPasadenaUnited States
| | | | - Jonathan H Wang
- Division of Biology and Biological Engineering, California Institute of TechnologyPasadenaUnited States
| | - Dennis A Dougherty
- Division of Chemistry and Chemical Engineering, California Institute of TechnologyPasadenaUnited States
| | - Loren L Looger
- Janelia Research Campus, Howard Hughes Medical InstituteAshburnUnited States
| | | | - Douglas C Rees
- Division of Chemistry and Chemical Engineering, California Institute of TechnologyPasadenaUnited States
- Howard Hughes Medical Institute, California Institute of TechnologyPasadenaUnited States
| | - Henry A Lester
- Division of Biology and Biological Engineering, California Institute of TechnologyPasadenaUnited States
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120
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Filevich O, Etchenique R. Photochemical biosignaling with ruthenium complexes. BIOMEDICAL APPLICATIONS OF INORGANIC PHOTOCHEMISTRY 2022. [DOI: 10.1016/bs.adioch.2022.04.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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121
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Chou N, Shin H, Kim K, Chae U, Jang M, Jeong U, Hwang K, Yi B, Lee SE, Woo J, Cho Y, Lee C, Baker BJ, Oh S, Nam M, Choi N, Cho I. A Multimodal Multi-Shank Fluorescence Neural Probe for Cell-Type-Specific Electrophysiology in Multiple Regions across a Neural Circuit. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2022; 9:e2103564. [PMID: 34796701 PMCID: PMC8805556 DOI: 10.1002/advs.202103564] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/16/2021] [Revised: 10/25/2021] [Indexed: 05/27/2023]
Abstract
Cell-type-specific, activity-dependent electrophysiology can allow in-depth analysis of functional connectivity inside complex neural circuits composed of various cell types. To date, optics-based fluorescence recording devices enable monitoring cell-type-specific activities. However, the monitoring is typically limited to a single brain region, and the temporal resolution is significantly low. Herein, a multimodal multi-shank fluorescence neural probe that allows cell-type-specific electrophysiology from multiple deep-brain regions at a high spatiotemporal resolution is presented. A photodiode and an electrode-array pair are monolithically integrated on each tip of a minimal-form-factor silicon device. Both fluorescence and electrical signals are successfully measured simultaneously in GCaMP6f expressing mice, and the cell type from sorted neural spikes is identified. The probe's capability of combined electro-optical recordings for cell-type-specific electrophysiology at multiple brain regions within a neural circuit is demonstrated. The new experimental paradigm to enable the precise investigation of functional connectivity inside and across complex neural circuits composed of various cell types is expected.
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Affiliation(s)
- Namsun Chou
- Center for BioMicrosystems, Brain Science InstituteKorea Institute of Science and Technology5, Hwarang‐ro 14‐gil, Seongbuk‐guSeoul02792Republic of Korea
| | - Hyogeun Shin
- Center for BioMicrosystems, Brain Science InstituteKorea Institute of Science and Technology5, Hwarang‐ro 14‐gil, Seongbuk‐guSeoul02792Republic of Korea
| | - Kanghwan Kim
- Center for BioMicrosystems, Brain Science InstituteKorea Institute of Science and Technology5, Hwarang‐ro 14‐gil, Seongbuk‐guSeoul02792Republic of Korea
| | - Uikyu Chae
- Center for BioMicrosystems, Brain Science InstituteKorea Institute of Science and Technology5, Hwarang‐ro 14‐gil, Seongbuk‐guSeoul02792Republic of Korea
- School of Electrical EngineeringKorea University145 Anam‐ro, Seongbuk‐guSeoul02841Republic of Korea
| | - Minsu Jang
- Center for BioMicrosystems, Brain Science InstituteKorea Institute of Science and Technology5, Hwarang‐ro 14‐gil, Seongbuk‐guSeoul02792Republic of Korea
| | - Ui‐Jin Jeong
- Center for BioMicrosystems, Brain Science InstituteKorea Institute of Science and Technology5, Hwarang‐ro 14‐gil, Seongbuk‐guSeoul02792Republic of Korea
- School of Electrical EngineeringKorea University145 Anam‐ro, Seongbuk‐guSeoul02841Republic of Korea
| | - Kyeong‐Seob Hwang
- Center for BioMicrosystems, Brain Science InstituteKorea Institute of Science and Technology5, Hwarang‐ro 14‐gil, Seongbuk‐guSeoul02792Republic of Korea
- School of Mechanical EngineeringYonsei University50 Yonsei‐ro, Seodaemun‐guSeoul03722Republic of Korea
| | - Bumjun Yi
- Center for Functional ConnectomicsBrain Science InstituteKorea Institute of Science and Technology5, Hwarang‐ro 14‐gil, Seongbuk‐guSeoul02792Republic of Korea
| | - Seung Eun Lee
- Virus Facility, Research Animal Resource CenterBrain Science InstituteKorea Institute of Science and Technology5, Hwarang‐ro 14‐gil, Seongbuk‐guSeoul02792Republic of Korea
| | - Jiwan Woo
- Center for Neuroscience, Brain Science InstituteKorea Institute of Science and Technology5, Hwarang‐ro 14‐gil, Seongbuk‐guSeoul02792Republic of Korea
| | - Yakdol Cho
- Center for Neuroscience, Brain Science InstituteKorea Institute of Science and Technology5, Hwarang‐ro 14‐gil, Seongbuk‐guSeoul02792Republic of Korea
| | - Changhyuk Lee
- Center for BioMicrosystems, Brain Science InstituteKorea Institute of Science and Technology5, Hwarang‐ro 14‐gil, Seongbuk‐guSeoul02792Republic of Korea
| | - Bradley J. Baker
- Center for Functional ConnectomicsBrain Science InstituteKorea Institute of Science and Technology5, Hwarang‐ro 14‐gil, Seongbuk‐guSeoul02792Republic of Korea
| | - Soo‐Jin Oh
- Center for Neuroscience, Brain Science InstituteKorea Institute of Science and Technology5, Hwarang‐ro 14‐gil, Seongbuk‐guSeoul02792Republic of Korea
| | - Min‐Ho Nam
- Center for Neuroscience, Brain Science InstituteKorea Institute of Science and Technology5, Hwarang‐ro 14‐gil, Seongbuk‐guSeoul02792Republic of Korea
| | - Nakwon Choi
- Center for BioMicrosystems, Brain Science InstituteKorea Institute of Science and Technology5, Hwarang‐ro 14‐gil, Seongbuk‐guSeoul02792Republic of Korea
- KU‐KIST Graduate School of Converging Science and TechnologyKorea University145 Anam‐ro, Seongbuk‐guSeoul02841Republic of Korea
- Division of Bio‐Medical Science and Technology, KIST SchoolKorea University of Science and Technology5, Hwarang‐ro 14‐gil, Seongbuk‐guSeoul02792Republic of Korea
| | - Il‐Joo Cho
- Center for BioMicrosystems, Brain Science InstituteKorea Institute of Science and Technology5, Hwarang‐ro 14‐gil, Seongbuk‐guSeoul02792Republic of Korea
- School of Electrical and Electronics EngineeringYonsei University50 Yonsei‐ro, Seodaemun‐guSeoul03722Republic of Korea
- Yonsei‐KIST Convergence Research InstituteYonsei University50 Yonsei‐ro, Seodaemun‐guSeoul03722Republic of Korea
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122
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Emerging strategies for the genetic dissection of gene functions, cell types, and neural circuits in the mammalian brain. Mol Psychiatry 2022; 27:422-435. [PMID: 34561609 DOI: 10.1038/s41380-021-01292-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/12/2020] [Revised: 08/17/2021] [Accepted: 09/08/2021] [Indexed: 02/08/2023]
Abstract
The mammalian brain is composed of a large number of highly diverse cell types with different molecular, anatomical, and functional features. Distinct cellular identities are generated during development under the regulation of intricate genetic programs and manifested through unique combinations of gene expression. Recent advancements in our understanding of the molecular and cellular mechanisms underlying the assembly, function, and pathology of the brain circuitry depend on the invention and application of genetic strategies that engage intrinsic gene regulatory mechanisms. Here we review the strategies for gene regulation on DNA, RNA, and protein levels and their applications in cell type targeting and neural circuit dissection. We highlight newly emerged strategies and emphasize the importance of combinatorial approaches. We also discuss the potential caveats and pitfalls in current methods and suggest future prospects to improve their comprehensiveness and versatility.
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123
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Chemically stable fluorescent proteins for advanced microscopy. Nat Methods 2022; 19:1612-1621. [PMID: 36344833 PMCID: PMC9718679 DOI: 10.1038/s41592-022-01660-7] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2022] [Accepted: 09/26/2022] [Indexed: 11/09/2022]
Abstract
We report the rational engineering of a remarkably stable yellow fluorescent protein (YFP), 'hyperfolder YFP' (hfYFP), that withstands chaotropic conditions that denature most biological structures within seconds, including superfolder green fluorescent protein (GFP). hfYFP contains no cysteines, is chloride insensitive and tolerates aldehyde and osmium tetroxide fixation better than common fluorescent proteins, enabling its use in expansion and electron microscopies. We solved crystal structures of hfYFP (to 1.7-Å resolution), a monomeric variant, monomeric hyperfolder YFP (1.6 Å) and an mGreenLantern mutant (1.2 Å), and then rationally engineered highly stable 405-nm-excitable GFPs, large Stokes shift (LSS) monomeric GFP (LSSmGFP) and LSSA12 from these structures. Lastly, we directly exploited the chemical stability of hfYFP and LSSmGFP by devising a fluorescence-assisted protein purification strategy enabling all steps of denaturing affinity chromatography to be visualized using ultraviolet or blue light. hfYFP and LSSmGFP represent a new generation of robustly stable fluorescent proteins developed for advanced biotechnological applications.
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124
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Dürst CD, Oertner TG. Imaging Synaptic Glutamate Release with Two-Photon Microscopy in Organotypic Slice Cultures. Methods Mol Biol 2022; 2417:205-219. [PMID: 35099802 DOI: 10.1007/978-1-0716-1916-2_16] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
The strength of an excitatory synapse relies on the amount of glutamate it releases and on the amount of postsynaptic receptors responding to the released glutamate. Here we describe a strategy to investigate presynaptic release independently of postsynaptic receptors, using a genetically encoded glutamate indicator (GEGI) such as iGluSnFR to measure synaptic transmission in rodent organotypic slice cultures. We express the iGluSnFR in CA3 pyramidal cells and perform two-photon glutamate imaging on individual Schaffer collateral boutons in CA1. Sparse labeling is achieved via transfection of pyramidal cells in organotypic hippocampal cultures, and imaging of evoked glutamate transients with two-photon laser scanning microscopy. A spiral scan path over an individual presynaptic bouton allows to sample at high temporal resolution the local release site in order to capture the peak of iGluSnFR transients.
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Affiliation(s)
- Céline D Dürst
- Institute for Synaptic Physiology, Center for Molecular Neurobiology Hamburg, Hamburg, Germany.
- Department of Basic Neurosciences, University Medical Center, Geneva, Switzerland.
| | - Thomas G Oertner
- Institute for Synaptic Physiology, Center for Molecular Neurobiology Hamburg, Hamburg, Germany
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125
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Abstract
Glutamatergic neurotransmission is a widespread form of synaptic excitation in the mammalian brain. The development of genetically encoded fluorescent glutamate sensors allows monitoring synaptic signaling in living brain tissue in real time. Here, we describe single- and two-photon imaging of synaptically evoked glutamatergic population signals in acute hippocampal slices expressing the fluorescent glutamate sensor SF-iGluSnFR.A184S in CA1 or CA3 pyramidal neurons. The protocol can be readily used to study defective synaptic glutamate signaling in mouse models of neuropsychiatric disorders, such as Alzheimer disease. For complete details on the use and execution of this protocol, please refer to Zott et al. (2019).
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126
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Wu Z, He K, Chen Y, Li H, Pan S, Li B, Liu T, Xi F, Deng F, Wang H, Du J, Jing M, Li Y. A sensitive GRAB sensor for detecting extracellular ATP in vitro and in vivo. Neuron 2021; 110:770-782.e5. [PMID: 34942116 DOI: 10.1016/j.neuron.2021.11.027] [Citation(s) in RCA: 65] [Impact Index Per Article: 21.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2021] [Revised: 08/31/2021] [Accepted: 11/22/2021] [Indexed: 12/13/2022]
Abstract
The purinergic transmitter ATP (adenosine 5'-triphosphate) plays an essential role in both the central and peripheral nervous systems, and the ability to directly measure extracellular ATP in real time will increase our understanding of its physiological functions. Here, we developed a sensitive GPCR activation-based ATP sensor called GRABATP1.0, with a robust fluorescence response to extracellular ATP when expressed in several cell types. This sensor has sub-second kinetics, has ATP affinity in the range of tens of nanomolar, and can be used to localize ATP release with subcellular resolution. Using this sensor, we monitored ATP release under a variety of in vitro and in vivo conditions, including stimuli-induced and spontaneous ATP release in primary hippocampal cultures, injury-induced ATP release in a zebrafish model, and lipopolysaccharides-induced ATP-release events in individual astrocytes in the mouse cortex. Thus, the GRABATP1.0 sensor is a sensitive, versatile tool for monitoring ATP release and dynamics under both physiological and pathophysiological conditions.
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Affiliation(s)
- Zhaofa Wu
- State Key Laboratory of Membrane Biology, Peking University School of Life Sciences, Beijing 100871, China; PKU-IDG/McGovern Institute for Brain Research, Beijing 100871, China.
| | - Kaikai He
- State Key Laboratory of Membrane Biology, Peking University School of Life Sciences, Beijing 100871, China; PKU-IDG/McGovern Institute for Brain Research, Beijing 100871, China
| | - Yue Chen
- Chinese Institute for Brain Research, Beijing 102206, China
| | - Hongyu Li
- Institute of Neuroscience, State Key Laboratory of Neuroscience, Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences, 320 Yue-Yang Road, Shanghai 200031, China
| | - Sunlei Pan
- State Key Laboratory of Membrane Biology, Peking University School of Life Sciences, Beijing 100871, China; PKU-IDG/McGovern Institute for Brain Research, Beijing 100871, China; Peking-Tsinghua Center for Life Sciences, Academy for Advanced Interdisciplinary Studies, Peking University, Beijing 100871, China
| | - Bohan Li
- State Key Laboratory of Membrane Biology, Peking University School of Life Sciences, Beijing 100871, China; PKU-IDG/McGovern Institute for Brain Research, Beijing 100871, China
| | - Tingting Liu
- Institute of Neuroscience, State Key Laboratory of Neuroscience, Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences, 320 Yue-Yang Road, Shanghai 200031, China
| | - Fengxue Xi
- Chinese Institute for Brain Research, Beijing 102206, China; School of Basic Medical Sciences, Capital Medical University, Beijing 100069, China
| | - Fei Deng
- State Key Laboratory of Membrane Biology, Peking University School of Life Sciences, Beijing 100871, China; PKU-IDG/McGovern Institute for Brain Research, Beijing 100871, China
| | - Huan Wang
- State Key Laboratory of Membrane Biology, Peking University School of Life Sciences, Beijing 100871, China; PKU-IDG/McGovern Institute for Brain Research, Beijing 100871, China
| | - Jiulin Du
- Institute of Neuroscience, State Key Laboratory of Neuroscience, Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences, 320 Yue-Yang Road, Shanghai 200031, China
| | - Miao Jing
- Chinese Institute for Brain Research, Beijing 102206, China
| | - Yulong Li
- State Key Laboratory of Membrane Biology, Peking University School of Life Sciences, Beijing 100871, China; PKU-IDG/McGovern Institute for Brain Research, Beijing 100871, China; Peking-Tsinghua Center for Life Sciences, Academy for Advanced Interdisciplinary Studies, Peking University, Beijing 100871, China; Chinese Institute for Brain Research, Beijing 102206, China.
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127
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Shindo Y, Fujita K, Tanaka M, Fujio H, Hotta K, Oka K. Mechanical stimulus-evoked signal transduction between keratinocytes and sensory neurons via extracellular ATP. Biochem Biophys Res Commun 2021; 582:131-136. [PMID: 34710828 DOI: 10.1016/j.bbrc.2021.10.046] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2021] [Accepted: 10/20/2021] [Indexed: 12/25/2022]
Abstract
The skin is exposed to various external stimuli. Keratinocytes, which are the main cell type in the epidermis, interact with peripheral sensory neurons and modulate neuronal activity. Recent studies have revealed that keratinocytes play crucial roles in nociception, and that ATP is one of the main mediators of signal transduction from keratinocytes to sensory neurons. However, no quantitative cellular level analyses of ATP-mediated information flow from keratinocytes to sensory dorsal root ganglion (DRG) neurons have been conducted. In this study, we performed simultaneous imaging of cell surface ATP and intracellular Ca2+ signals using both iATPSnFR, a genetically encoded ATP probe localized to the outside of the cell membrane, and the Ca2+ probe, Fura-red. Upon mechanical stimulation of the keratinocyte with a glass needle, an increase in Ca2+ and ATP release were observed around the stimulated area, and these phenomena were positively correlated. In cultured DRG neurons and keratinocytes neighboring the stimulated keratinocyte, increased intracellular Ca2+ concentration and levels of cell surface ATP on the side closer to the stimulated cell were detected. The ratio of Ca2+ response to input ATP signal was significantly larger in DRG neurons than in keratinocytes. We found that DRG neurons were more sensitive to ATP than keratinocytes, and therefore, only DRG neurons responded to ATP at 1 μM or lower concentrations when in co-culture with keratinocytes. Moreover, signals caused by moderate mechanical stimulation of keratinocytes were transmitted predominantly to DRG neurons. These findings would be important in the further determination of the detailed mechanism of nociception in the epidermis.
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Affiliation(s)
- Yutaka Shindo
- Department of Bioscience and Informatics, Faculty of Science and Technology, Keio University, 3-14-1 Hiyoshi, Kohoku-ku, Yokohama, Kanagawa, 223-8522, Japan
| | - Keigo Fujita
- Department of Bioscience and Informatics, Faculty of Science and Technology, Keio University, 3-14-1 Hiyoshi, Kohoku-ku, Yokohama, Kanagawa, 223-8522, Japan
| | - Mari Tanaka
- Department of Bioscience and Informatics, Faculty of Science and Technology, Keio University, 3-14-1 Hiyoshi, Kohoku-ku, Yokohama, Kanagawa, 223-8522, Japan
| | - Hiroki Fujio
- Department of Bioscience and Informatics, Faculty of Science and Technology, Keio University, 3-14-1 Hiyoshi, Kohoku-ku, Yokohama, Kanagawa, 223-8522, Japan
| | - Kohji Hotta
- Department of Bioscience and Informatics, Faculty of Science and Technology, Keio University, 3-14-1 Hiyoshi, Kohoku-ku, Yokohama, Kanagawa, 223-8522, Japan
| | - Kotaro Oka
- Department of Bioscience and Informatics, Faculty of Science and Technology, Keio University, 3-14-1 Hiyoshi, Kohoku-ku, Yokohama, Kanagawa, 223-8522, Japan; Waseda Research Institute for Science and Engineering, Waseda University, 2-2 Wakamatsucho, Shinjuku-ku, Tokyo, 162-8480, Japan; Graduate Institute of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung City, 80708, Taiwan.
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128
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PSD-93 up-regulates the synaptic activity of corticotropin-releasing hormone neurons in the paraventricular nucleus in depression. Acta Neuropathol 2021; 142:1045-1064. [PMID: 34536123 DOI: 10.1007/s00401-021-02371-7] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2021] [Revised: 09/07/2021] [Accepted: 09/10/2021] [Indexed: 12/28/2022]
Abstract
Since the discovery of ketamine anti-depressant effects in last decade, it has effectively revitalized interest in investigating excitatory synapses hypothesis in the pathogenesis of depression. In the present study, we aimed to reveal the excitatory synaptic regulation of corticotropin-releasing hormone (CRH) neuron in the hypothalamus, which is the driving force in hypothalamic-pituitary-adrenal (HPA) axis regulation. This study constitutes the first observation of an increased density of PSD-93-CRH co-localized neurons in the hypothalamic paraventricular nucleus (PVN) of patients with major depression. PSD-93 overexpression in CRH neurons in the PVN induced depression-like behaviors in mice, accompanied by increased serum corticosterone level. PSD-93 knockdown relieved the depression-like phenotypes in a lipopolysaccharide (LPS)-induced depression model. Electrophysiological data showed that PSD-93 overexpression increased CRH neurons synaptic activity, while PSD-93 knockdown decreased CRH neurons synaptic activity. Furthermore, we found that LPS induced increased the release of glutamate from microglia to CRH neurons resulted in depression-like behaviors using fiber photometry recordings. Together, these results show that PSD-93 is involved in the pathogenesis of depression via increasing the synaptic activity of CRH neurons in the PVN, leading to the hyperactivity of the HPA axis that underlies depression-like behaviors.
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129
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Synaptotagmin 1 oligomerization via the juxtamembrane linker regulates spontaneous and evoked neurotransmitter release. Proc Natl Acad Sci U S A 2021; 118:2113859118. [PMID: 34810248 PMCID: PMC8694047 DOI: 10.1073/pnas.2113859118] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/23/2021] [Indexed: 11/18/2022] Open
Abstract
Synaptotagmin 1 (syt1) is a synaptic vesicle (SV) protein that is rapidly activated by Ca2+ influx into presynaptic nerve terminals, triggering SV exocytosis. Syt1 also inhibits exocytosis, prior to Ca2+ influx, and thus helps synchronize evoked exocytosis upon Ca2+ binding. Herein, we identified a cluster of lysine residues, in the oft-ignored juxtamembrane linker region of syt1, that governs homo-multimerization in an anionic lipid-dependent manner. Neutralization of this positively charged region abolished syt1 self-association on phospholipid bilayers in vitro. Subsequently, in neurons, we found mutations that disrupted syt1 self-association were correlated with defects in clamping spontaneous SV release and in triggering and synchronizing evoked exocytosis. Thus, syt1 regulates SV exocytosis as an oligomer via charged residues in the juxtamembrane linker. Synaptotagmin 1 (syt1) is a Ca2+ sensor that regulates synaptic vesicle exocytosis. Cell-based experiments suggest that syt1 functions as a multimer; however, biochemical and electron microscopy studies have yielded contradictory findings regarding putative self-association. Here, we performed dynamic light scattering on syt1 in solution, followed by electron microscopy, and we used atomic force microscopy to study syt1 self-association on supported lipid bilayers under aqueous conditions. Ring-like multimers were clearly observed. Multimerization was enhanced by Ca2+ and required anionic phospholipids. Large ring-like structures (∼180 nm) were reduced to smaller rings (∼30 nm) upon neutralization of a cluster of juxtamembrane lysine residues; further substitution of residues in the second C2-domain completely abolished self-association. When expressed in neurons, syt1 mutants with graded reductions in self-association activity exhibited concomitant reductions in 1) clamping spontaneous release and 2) triggering and synchronizing evoked release. Thus, the juxtamembrane linker of syt1 plays a crucial role in exocytosis by mediating multimerization.
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130
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Yu CH, Stirman JN, Yu Y, Hira R, Smith SL. Diesel2p mesoscope with dual independent scan engines for flexible capture of dynamics in distributed neural circuitry. Nat Commun 2021; 12:6639. [PMID: 34789723 PMCID: PMC8599518 DOI: 10.1038/s41467-021-26736-4] [Citation(s) in RCA: 45] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2021] [Accepted: 10/05/2021] [Indexed: 11/09/2022] Open
Abstract
Imaging the activity of neurons that are widely distributed across brain regions deep in scattering tissue at high speed remains challenging. Here, we introduce an open-source system with Dual Independent Enhanced Scan Engines for Large field-of-view Two-Photon imaging (Diesel2p). Combining optical design, adaptive optics, and temporal multiplexing, the system offers subcellular resolution over a large field-of-view of ~25 mm2, encompassing distances up to 7 mm, with independent scan engines. We demonstrate the flexibility and various use cases of this system for calcium imaging of neurons in the living brain.
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Affiliation(s)
- Che-Hang Yu
- Department of Electrical and Computer Engineering, University of California, Santa Barbara, CA, USA
| | | | - Yiyi Yu
- Department of Electrical and Computer Engineering, University of California, Santa Barbara, CA, USA
| | - Riichiro Hira
- Department of Electrical and Computer Engineering, University of California, Santa Barbara, CA, USA
| | - Spencer L Smith
- Department of Electrical and Computer Engineering, University of California, Santa Barbara, CA, USA.
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131
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Clough M, Chen IA, Park SW, Ahrens AM, Stirman JN, Smith SL, Chen JL. Flexible simultaneous mesoscale two-photon imaging of neural activity at high speeds. Nat Commun 2021; 12:6638. [PMID: 34789730 PMCID: PMC8599611 DOI: 10.1038/s41467-021-26737-3] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2021] [Accepted: 10/05/2021] [Indexed: 12/02/2022] Open
Abstract
Understanding brain function requires monitoring local and global brain dynamics. Two-photon imaging of the brain across mesoscopic scales has presented trade-offs between imaging area and acquisition speed. We describe a flexible cellular resolution two-photon microscope capable of simultaneous video rate acquisition of four independently targetable brain regions spanning an approximate five-millimeter field of view. With this system, we demonstrate the ability to measure calcium activity across mouse sensorimotor cortex at behaviorally relevant timescales.
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Affiliation(s)
- Mitchell Clough
- Department of Biomedical Engineering, Boston University, Boston, MA, 02215, USA
| | - Ichun Anderson Chen
- Department of Biomedical Engineering, Boston University, Boston, MA, 02215, USA
- Center for Neurophotonics, Boston University, Boston, MA, 02215, USA
| | - Seong-Wook Park
- Department of Biomedical Engineering, Boston University, Boston, MA, 02215, USA
- Center for Neurophotonics, Boston University, Boston, MA, 02215, USA
| | - Allison M Ahrens
- Department of Biology, Boston University, Boston, MA, 02215, USA
| | - Jeffrey N Stirman
- Neuroscience Center, University of North Carolina School of Medicine, Chapel Hill, NC, 27599, USA
| | - Spencer L Smith
- Department of Electrical and Computer Engineering, University of California Santa Barbara, Santa Barbara, CA, 93106, USA
| | - Jerry L Chen
- Department of Biomedical Engineering, Boston University, Boston, MA, 02215, USA.
- Center for Neurophotonics, Boston University, Boston, MA, 02215, USA.
- Department of Biology, Boston University, Boston, MA, 02215, USA.
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132
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Vollmer KM, Doncheck EM, Grant RI, Winston KT, Romanova EV, Bowen CW, Siegler PN, Green LM, Bobadilla AC, Trujillo-Pisanty I, Kalivas PW, Otis JM. A Novel Assay Allowing Drug Self-Administration, Extinction, and Reinstatement Testing in Head-Restrained Mice. Front Behav Neurosci 2021; 15:744715. [PMID: 34776891 PMCID: PMC8585999 DOI: 10.3389/fnbeh.2021.744715] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2021] [Accepted: 09/30/2021] [Indexed: 01/15/2023] Open
Abstract
Multiphoton microscopy is one of several new technologies providing unprecedented insight into the activity dynamics and function of neural circuits. Unfortunately, some of these technologies require experimentation in head-restrained animals, limiting the behavioral repertoire that can be integrated and studied. This issue is especially evident in drug addiction research, as no laboratories have coupled multiphoton microscopy with simultaneous intravenous drug self-administration, a behavioral paradigm that has predictive validity for treatment outcomes and abuse liability. Here, we describe a new experimental assay wherein head-restrained mice will press an active lever, but not inactive lever, for intravenous delivery of heroin or cocaine. Similar to freely moving animals, we find that lever pressing is suppressed through daily extinction training and subsequently reinstated through the presentation of relapse-provoking triggers (drug-associative cues, the drug itself, and stressors). Finally, we show that head-restrained mice will show similar patterns of behavior for oral delivery of a sucrose reward, a common control used for drug self-administration experiments. Overall, these data demonstrate the feasibility of combining drug self-administration experiments with technologies that require head-restraint, such as multiphoton imaging. The assay described could be replicated by interested labs with readily available materials to aid in identifying the neural underpinnings of substance use disorder.
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Affiliation(s)
- Kelsey M Vollmer
- Department of Neuroscience, Medical University of South Carolina, Charleston, SC, United States
| | - Elizabeth M Doncheck
- Department of Neuroscience, Medical University of South Carolina, Charleston, SC, United States
| | - Roger I Grant
- Department of Neuroscience, Medical University of South Carolina, Charleston, SC, United States
| | - Kion T Winston
- Department of Neuroscience, Medical University of South Carolina, Charleston, SC, United States
| | - Elizaveta V Romanova
- Department of Neuroscience, Medical University of South Carolina, Charleston, SC, United States
| | - Christopher W Bowen
- Department of Neuroscience, Medical University of South Carolina, Charleston, SC, United States
| | - Preston N Siegler
- Department of Neuroscience, Medical University of South Carolina, Charleston, SC, United States
| | - Lisa M Green
- Department of Neuroscience, Medical University of South Carolina, Charleston, SC, United States
| | | | | | - Peter W Kalivas
- Department of Neuroscience, Medical University of South Carolina, Charleston, SC, United States
| | - James M Otis
- Department of Neuroscience, Medical University of South Carolina, Charleston, SC, United States.,Hollings Cancer Center, Medical University of South Carolina, Charleston, SC, United States
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133
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Chen W, Natan RG, Yang Y, Chou SW, Zhang Q, Isacoff EY, Ji N. In vivo volumetric imaging of calcium and glutamate activity at synapses with high spatiotemporal resolution. Nat Commun 2021; 12:6630. [PMID: 34785691 PMCID: PMC8595604 DOI: 10.1038/s41467-021-26965-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2021] [Accepted: 10/27/2021] [Indexed: 12/02/2022] Open
Abstract
Studying neuronal activity at synapses requires high spatiotemporal resolution. For high spatial resolution in vivo imaging at depth, adaptive optics (AO) is required to correct sample-induced aberrations. To improve temporal resolution, Bessel focus has been combined with two-photon fluorescence microscopy (2PFM) for fast volumetric imaging at subcellular lateral resolution. To achieve both high-spatial and high-temporal resolution at depth, we develop an efficient AO method that corrects the distorted wavefront of Bessel focus at the objective focal plane and recovers diffraction-limited imaging performance. Applying AO Bessel focus scanning 2PFM to volumetric imaging of zebrafish larval and mouse brains down to 500 µm depth, we demonstrate substantial improvements in the sensitivity and resolution of structural and functional measurements of synapses in vivo. This enables volumetric measurements of synaptic calcium and glutamate activity at high accuracy, including the simultaneous recording of glutamate activity of apical and basal dendritic spines in the mouse cortex.
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Affiliation(s)
- Wei Chen
- grid.47840.3f0000 0001 2181 7878Department of Physics, University of California, Berkeley, CA 97420 USA
| | - Ryan G. Natan
- grid.47840.3f0000 0001 2181 7878Department of Physics, University of California, Berkeley, CA 97420 USA
| | - Yuhan Yang
- grid.47840.3f0000 0001 2181 7878Department of Physics, University of California, Berkeley, CA 97420 USA
| | - Shih-Wei Chou
- grid.47840.3f0000 0001 2181 7878Department of Molecular and Cell Biology, University of California, Berkeley, CA 94720 USA
| | - Qinrong Zhang
- grid.47840.3f0000 0001 2181 7878Department of Physics, University of California, Berkeley, CA 97420 USA
| | - Ehud Y. Isacoff
- grid.47840.3f0000 0001 2181 7878Department of Molecular and Cell Biology, University of California, Berkeley, CA 94720 USA ,grid.47840.3f0000 0001 2181 7878Helen Wills Neuroscience Institute, University of California, Berkeley, CA 94720 USA ,grid.184769.50000 0001 2231 4551Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720 USA
| | - Na Ji
- Department of Physics, University of California, Berkeley, CA, 97420, USA. .,Department of Molecular and Cell Biology, University of California, Berkeley, CA, 94720, USA. .,Helen Wills Neuroscience Institute, University of California, Berkeley, CA, 94720, USA. .,Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA.
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134
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Moran AK, Eiting TP, Wachowiak M. Circuit Contributions to Sensory-Driven Glutamatergic Drive of Olfactory Bulb Mitral and Tufted Cells During Odorant Inhalation. Front Neural Circuits 2021; 15:779056. [PMID: 34776878 PMCID: PMC8578712 DOI: 10.3389/fncir.2021.779056] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2021] [Accepted: 10/06/2021] [Indexed: 11/20/2022] Open
Abstract
In the mammalian olfactory bulb (OB), mitral/tufted (MT) cells respond to odorant inhalation with diverse temporal patterns that are thought to encode odor information. Much of this diversity is already apparent at the level of glutamatergic input to MT cells, which receive direct, monosynaptic excitatory input from olfactory sensory neurons (OSNs) as well as a multisynaptic excitatory drive via glutamatergic interneurons. Both pathways are also subject to modulation by inhibitory circuits in the glomerular layer of the OB. To understand the role of direct OSN input vs. postsynaptic OB circuit mechanisms in shaping diverse dynamics of glutamatergic drive to MT cells, we imaged glutamate signaling onto MT cell dendrites in anesthetized mice while blocking multisynaptic excitatory drive with ionotropic glutamate receptor antagonists and blocking presynaptic modulation of glutamate release from OSNs with GABAB receptor antagonists. GABAB receptor blockade increased the magnitude of inhalation-linked glutamate transients onto MT cell apical dendrites without altering their inhalation-linked dynamics, confirming that presynaptic inhibition impacts the gain of OSN inputs to the OB. Surprisingly, blockade of multisynaptic excitation only modestly impacted glutamatergic input to MT cells, causing a slight reduction in the amplitude of inhalation-linked glutamate transients in response to low odorant concentrations and no change in the dynamics of each transient. The postsynaptic blockade also modestly impacted glutamate dynamics over a slower timescale, mainly by reducing adaptation of the glutamate response across multiple inhalations of odorant. These results suggest that direct glutamatergic input from OSNs provides the bulk of excitatory drive to MT cells, and that diversity in the dynamics of this input may be a primary determinant of the temporal diversity in MT cell responses that underlies odor representations at this stage.
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Affiliation(s)
- Andrew K. Moran
- Interdepartmental Program in Neuroscience, University of Utah, Salt Lake City, UT, United States
- Department of Neurobiology, University of Utah School of Medicine, Salt Lake City, UT, United States
| | - Thomas P. Eiting
- Department of Neurobiology, University of Utah School of Medicine, Salt Lake City, UT, United States
| | - Matt Wachowiak
- Interdepartmental Program in Neuroscience, University of Utah, Salt Lake City, UT, United States
- Department of Neurobiology, University of Utah School of Medicine, Salt Lake City, UT, United States
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135
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Xiao D, Forys BJ, Vanni MP, Murphy TH. MesoNet allows automated scaling and segmentation of mouse mesoscale cortical maps using machine learning. Nat Commun 2021; 12:5992. [PMID: 34645817 PMCID: PMC8514445 DOI: 10.1038/s41467-021-26255-2] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2020] [Accepted: 09/23/2021] [Indexed: 01/17/2023] Open
Abstract
Understanding the basis of brain function requires knowledge of cortical operations over wide spatial scales and the quantitative analysis of brain activity in well-defined brain regions. Matching an anatomical atlas to brain functional data requires substantial labor and expertise. Here, we developed an automated machine learning-based registration and segmentation approach for quantitative analysis of mouse mesoscale cortical images. A deep learning model identifies nine cortical landmarks using only a single raw fluorescent image. Another fully convolutional network was adapted to delimit brain boundaries. This anatomical alignment approach was extended by adding three functional alignment approaches that use sensory maps or spatial-temporal activity motifs. We present this methodology as MesoNet, a robust and user-friendly analysis pipeline using pre-trained models to segment brain regions as defined in the Allen Mouse Brain Atlas. This Python-based toolbox can also be combined with existing methods to facilitate high-throughput data analysis.
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Affiliation(s)
- Dongsheng Xiao
- University of British Columbia, Department of Psychiatry, Kinsmen Laboratory of Neurological Research, Detwiller Pavilion, 2255 Wesbrook Mall, Vancouver, V6T 1Z3, British Columbia, Canada
| | - Brandon J Forys
- University of British Columbia, Department of Psychiatry, Kinsmen Laboratory of Neurological Research, Detwiller Pavilion, 2255 Wesbrook Mall, Vancouver, V6T 1Z3, British Columbia, Canada
- Department of Psychology, Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, British Columbia, Canada
| | - Matthieu P Vanni
- University of British Columbia, Department of Psychiatry, Kinsmen Laboratory of Neurological Research, Detwiller Pavilion, 2255 Wesbrook Mall, Vancouver, V6T 1Z3, British Columbia, Canada
- Université de Montréal, École d'Optométrie, 3744 Jean Brillant H3T 1P1, Montréal, Québec, Canada
| | - Timothy H Murphy
- University of British Columbia, Department of Psychiatry, Kinsmen Laboratory of Neurological Research, Detwiller Pavilion, 2255 Wesbrook Mall, Vancouver, V6T 1Z3, British Columbia, Canada.
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136
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Jiang ZJ, Li W, Yao LH, Saed B, Rao Y, Grewe BS, McGinley A, Varga K, Alford S, Hu YS, Gong LW. TRPM7 is critical for short-term synaptic depression by regulating synaptic vesicle endocytosis. eLife 2021; 10:e66709. [PMID: 34569930 PMCID: PMC8516418 DOI: 10.7554/elife.66709] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2021] [Accepted: 09/10/2021] [Indexed: 12/15/2022] Open
Abstract
Transient receptor potential melastatin 7 (TRPM7) contributes to a variety of physiological and pathological processes in many tissues and cells. With a widespread distribution in the nervous system, TRPM7 is involved in animal behaviors and neuronal death induced by ischemia. However, the physiological role of TRPM7 in central nervous system (CNS) neuron remains unclear. Here, we identify endocytic defects in neuroendocrine cells and neurons from TRPM7 knockout (KO) mice, indicating a role of TRPM7 in synaptic vesicle endocytosis. Our experiments further pinpoint the importance of TRPM7 as an ion channel in synaptic vesicle endocytosis. Ca2+ imaging detects a defect in presynaptic Ca2+ dynamics in TRPM7 KO neuron, suggesting an importance of Ca2+ influx via TRPM7 in synaptic vesicle endocytosis. Moreover, the short-term depression is enhanced in both excitatory and inhibitory synaptic transmissions from TRPM7 KO mice. Taken together, our data suggests that Ca2+ influx via TRPM7 may be critical for short-term plasticity of synaptic strength by regulating synaptic vesicle endocytosis in neurons.
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Affiliation(s)
- Zhong-Jiao Jiang
- Department of Biological Sciences, University of Illinois at ChicagoChicagoUnited States
| | - Wenping Li
- Department of Biological Sciences, University of Illinois at ChicagoChicagoUnited States
| | - Li-Hua Yao
- Department of Biological Sciences, University of Illinois at ChicagoChicagoUnited States
- School of Life Science, Jiangxi Science & Technology Normal UniversityNanchangChina
| | - Badeia Saed
- Department of Chemistry, University of Illinois at ChicagoChicagoUnited States
| | - Yan Rao
- Department of Biological Sciences, University of Illinois at ChicagoChicagoUnited States
| | - Brian S Grewe
- Department of Biological Sciences, University of Illinois at ChicagoChicagoUnited States
| | - Andrea McGinley
- Department of Biological Sciences, University of Illinois at ChicagoChicagoUnited States
| | - Kelly Varga
- Department of Biological Sciences, University of Illinois at ChicagoChicagoUnited States
- Department of Biological Sciences, University of North Texas at DallasDallasUnited States
| | - Simon Alford
- Department of Anatomy and Cell Biology, University of Illinois at ChicagoChicagoUnited States
| | - Ying S Hu
- Department of Chemistry, University of Illinois at ChicagoChicagoUnited States
| | - Liang-Wei Gong
- Department of Biological Sciences, University of Illinois at ChicagoChicagoUnited States
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137
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Vevea JD, Kusick GF, Courtney KC, Chen E, Watanabe S, Chapman ER. Synaptotagmin 7 is targeted to the axonal plasma membrane through γ-secretase processing to promote synaptic vesicle docking in mouse hippocampal neurons. eLife 2021; 10:e67261. [PMID: 34543184 PMCID: PMC8452306 DOI: 10.7554/elife.67261] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2021] [Accepted: 08/27/2021] [Indexed: 12/28/2022] Open
Abstract
Synaptotagmin 7 (SYT7) has emerged as a key regulator of presynaptic function, but its localization and precise role in the synaptic vesicle cycle remain the subject of debate. Here, we used iGluSnFR to optically interrogate glutamate release, at the single-bouton level, in SYT7KO-dissociated mouse hippocampal neurons. We analyzed asynchronous release, paired-pulse facilitation, and synaptic vesicle replenishment and found that SYT7 contributes to each of these processes to different degrees. 'Zap-and-freeze' electron microscopy revealed that a loss of SYT7 diminishes docking of synaptic vesicles after a stimulus and inhibits the recovery of depleted synaptic vesicles after a stimulus train. SYT7 supports these functions from the axonal plasma membrane, where its localization and stability require both γ-secretase-mediated cleavage and palmitoylation. In summary, SYT7 is a peripheral membrane protein that controls multiple modes of synaptic vesicle (SV) exocytosis and plasticity, in part, through enhancing activity-dependent docking of SVs.
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Affiliation(s)
- Jason D Vevea
- Department of Neuroscience, University of Wisconsin-MadisonMadisonUnited States
- Howard Hughes Medical InstituteMadisonUnited States
| | - Grant F Kusick
- Department of Cell Biology, Johns Hopkins University, School of MedicineBaltimoreUnited States
- Biochemistry, Cellular and Molecular Biology Graduate Program, Johns Hopkins University, School of MedicineBaltimoreUnited States
| | - Kevin C Courtney
- Department of Neuroscience, University of Wisconsin-MadisonMadisonUnited States
- Howard Hughes Medical InstituteMadisonUnited States
| | - Erin Chen
- Department of Cell Biology, Johns Hopkins University, School of MedicineBaltimoreUnited States
| | - Shigeki Watanabe
- Department of Cell Biology, Johns Hopkins University, School of MedicineBaltimoreUnited States
- Solomon H. Snyder Department of Neuroscience, Johns Hopkins University, School of MedicineBaltimoreUnited States
| | - Edwin R Chapman
- Department of Neuroscience, University of Wisconsin-MadisonMadisonUnited States
- Howard Hughes Medical InstituteMadisonUnited States
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138
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Zhang S, Ren Q, Novick SJ, Strutzenberg TS, Griffin PR, Bao H. One-step construction of circularized nanodiscs using SpyCatcher-SpyTag. Nat Commun 2021; 12:5451. [PMID: 34521837 PMCID: PMC8440770 DOI: 10.1038/s41467-021-25737-7] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2021] [Accepted: 08/26/2021] [Indexed: 02/07/2023] Open
Abstract
Circularized nandiscs (cNDs) exhibit superb monodispersity and have the potential to transform functional and structural studies of membrane proteins. In particular, cNDs can stabilize large patches of lipid bilayers for the reconstitution of complex membrane biochemical reactions, enabling the capture of crucial intermediates involved in synaptic transmission and viral entry. However, previous methods for building cNDs require multiple steps and suffer from low yields. We herein introduce a simple, one-step approach to ease the construction of cNDs using the SpyCatcher-SpyTag technology. This approach increases the yield of cNDs by over 10-fold and is able to rapidly generates cNDs with diameters ranging from 11 to over 100 nm. We demonstrate the utility of these cNDs for mechanistic interrogations of vesicle fusion and protein-lipid interactions that are unattainable using small nanodiscs. Together, the remarkable performance of SpyCatcher-SpyTag in nanodisc circularization paves the way for the use of cNDs in membrane biochemistry and structural biology.
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Affiliation(s)
- Shanwen Zhang
- Department of Molecular Medicine, The Scripps Research Institute, Jupiter, Florida, USA
| | - Qian Ren
- Department of Molecular Medicine, The Scripps Research Institute, Jupiter, Florida, USA
| | - Scott J Novick
- Department of Molecular Medicine, The Scripps Research Institute, Jupiter, Florida, USA
| | | | - Patrick R Griffin
- Department of Molecular Medicine, The Scripps Research Institute, Jupiter, Florida, USA.
| | - Huan Bao
- Department of Molecular Medicine, The Scripps Research Institute, Jupiter, Florida, USA.
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139
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Climer JR, Dombeck DA. Information Theoretic Approaches to Deciphering the Neural Code with Functional Fluorescence Imaging. eNeuro 2021; 8:ENEURO.0266-21.2021. [PMID: 34433574 PMCID: PMC8474651 DOI: 10.1523/eneuro.0266-21.2021] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2021] [Revised: 07/22/2021] [Accepted: 08/04/2021] [Indexed: 11/21/2022] Open
Abstract
Information theoretic metrics have proven useful in quantifying the relationship between behaviorally relevant parameters and neuronal activity with relatively few assumptions. However, these metrics are typically applied to action potential (AP) recordings and were not designed for the slow timescales and variable amplitudes typical of functional fluorescence recordings (e.g., calcium imaging). The lack of research guidelines on how to apply and interpret these metrics with fluorescence traces means the neuroscience community has yet to realize the power of information theoretic metrics. Here, we used computational methods to create mock AP traces with known amounts of information. From these, we generated fluorescence traces and examined the ability of different information metrics to recover the known information values. We provide guidelines for how to use information metrics when applying them to functional fluorescence and demonstrate their appropriate application to GCaMP6f population recordings from mouse hippocampal neurons imaged during virtual navigation.
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Affiliation(s)
- Jason R Climer
- Department of Neurobiology, Northwestern University, Evanston, 60208 IL
| | - Daniel A Dombeck
- Department of Neurobiology, Northwestern University, Evanston, 60208 IL
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140
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Matsumoto A, Agbariah W, Nolte SS, Andrawos R, Levi H, Sabbah S, Yonehara K. Direction selectivity in retinal bipolar cell axon terminals. Neuron 2021; 109:2928-2942.e8. [PMID: 34390651 PMCID: PMC8478419 DOI: 10.1016/j.neuron.2021.07.008] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2020] [Revised: 06/18/2021] [Accepted: 07/09/2021] [Indexed: 12/20/2022]
Abstract
The ability to encode the direction of image motion is fundamental to our sense of vision. Direction selectivity along the four cardinal directions is thought to originate in direction-selective ganglion cells (DSGCs) because of directionally tuned GABAergic suppression by starburst cells. Here, by utilizing two-photon glutamate imaging to measure synaptic release, we reveal that direction selectivity along all four directions arises earlier than expected at bipolar cell outputs. Individual bipolar cells contained four distinct populations of axon terminal boutons with different preferred directions. We further show that this bouton-specific tuning relies on cholinergic excitation from starburst cells and GABAergic inhibition from wide-field amacrine cells. DSGCs received both tuned directionally aligned inputs and untuned inputs from among heterogeneously tuned glutamatergic bouton populations. Thus, directional tuning in the excitatory visual pathway is incrementally refined at the bipolar cell axon terminals and their recipient DSGC dendrites by two different neurotransmitters co-released from starburst cells. Cardinal direction selectivity emerges at types 7 and 2 bipolar cell axon terminals Starburst amacrine cells are necessary for direction selectivity in bipolar cells Cholinergic excitation and GABAergic inhibition are integrated at axon terminals Direction-selective ganglion cells receive directionally aligned glutamate inputs
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Affiliation(s)
- Akihiro Matsumoto
- Danish Research Institute of Translational Neuroscience - DANDRITE, Nordic-EMBL Partnership for Molecular Medicine, Department of Biomedicine, Aarhus University, Ole Worms Allé 8, 8000 Aarhus C, Denmark
| | - Weaam Agbariah
- Department of Medical Neurobiology, Faculty of Medicine, Hebrew University of Jerusalem, Jerusalem 9112102, Israel
| | - Stella Solveig Nolte
- Danish Research Institute of Translational Neuroscience - DANDRITE, Nordic-EMBL Partnership for Molecular Medicine, Department of Biomedicine, Aarhus University, Ole Worms Allé 8, 8000 Aarhus C, Denmark
| | - Rawan Andrawos
- Department of Medical Neurobiology, Faculty of Medicine, Hebrew University of Jerusalem, Jerusalem 9112102, Israel
| | - Hadara Levi
- Department of Medical Neurobiology, Faculty of Medicine, Hebrew University of Jerusalem, Jerusalem 9112102, Israel
| | - Shai Sabbah
- Department of Medical Neurobiology, Faculty of Medicine, Hebrew University of Jerusalem, Jerusalem 9112102, Israel.
| | - Keisuke Yonehara
- Danish Research Institute of Translational Neuroscience - DANDRITE, Nordic-EMBL Partnership for Molecular Medicine, Department of Biomedicine, Aarhus University, Ole Worms Allé 8, 8000 Aarhus C, Denmark.
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141
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The Cutting Edge of Disease Modeling: Synergy of Induced Pluripotent Stem Cell Technology and Genetically Encoded Biosensors. Biomedicines 2021; 9:biomedicines9080960. [PMID: 34440164 PMCID: PMC8392144 DOI: 10.3390/biomedicines9080960] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2021] [Accepted: 08/02/2021] [Indexed: 11/17/2022] Open
Abstract
The development of cell models of human diseases based on induced pluripotent stem cells (iPSCs) and a cell therapy approach based on differentiated iPSC derivatives has provided a powerful stimulus in modern biomedical research development. Moreover, it led to the creation of personalized regenerative medicine. Due to this, in the last decade, the pathological mechanisms of many monogenic diseases at the cell level have been revealed, and clinical trials of various cell products derived from iPSCs have begun. However, it is necessary to reach a qualitatively new level of research with cell models of diseases based on iPSCs for more efficient searching and testing of drugs. Biosensor technology has a great application prospect together with iPSCs. Biosensors enable researchers to monitor ions, molecules, enzyme activities, and channel conformation in live cells and use them in live imaging and drug screening. These probes facilitate the measurement of steady-state concentrations or activity levels and the observation and quantification of in vivo flux and kinetics. Real-time monitoring of drug action in a specific cellular compartment, organ, or tissue type; the ability to screen at the single-cell resolution; and the elimination of the false-positive results caused by low drug bioavailability that is not detected by in vitro testing methods are a few of the benefits of using biosensors in drug screening. Here, we discuss the possibilities of using biosensor technology in combination with cell models based on human iPSCs and gene editing systems. Furthermore, we focus on the current achievements and problems of using these methods.
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142
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Bonvento G, Bolaños JP. Astrocyte-neuron metabolic cooperation shapes brain activity. Cell Metab 2021; 33:1546-1564. [PMID: 34348099 DOI: 10.1016/j.cmet.2021.07.006] [Citation(s) in RCA: 139] [Impact Index Per Article: 46.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/07/2021] [Revised: 05/11/2021] [Accepted: 07/03/2021] [Indexed: 12/12/2022]
Abstract
The brain has almost no energy reserve, but its activity coordinates organismal function, a burden that requires precise coupling between neurotransmission and energy metabolism. Deciphering how the brain accomplishes this complex task is crucial to understand central facets of human physiology and disease mechanisms. Each type of neural cell displays a peculiar metabolic signature, forcing the intercellular exchange of metabolites that serve as both energy precursors and paracrine signals. The paradigm of this biological feature is the astrocyte-neuron couple, in which the glycolytic metabolism of astrocytes contrasts with the mitochondrial oxidative activity of neurons. Astrocytes generate abundant mitochondrial reactive oxygen species and shuttle to neurons glycolytically derived metabolites, such as L-lactate and L-serine, which sustain energy needs, conserve redox status, and modulate neurotransmitter-receptor activity. Conversely, early disruption of this metabolic cooperation may contribute to the initiation or progression of several neurological diseases, thus requiring innovative therapies to preserve brain energetics.
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Affiliation(s)
- Gilles Bonvento
- Université Paris-Saclay, CEA, CNRS, MIRCen, Laboratoire des Maladies Neurodégénératives, Fontenay-aux-Roses, France.
| | - Juan P Bolaños
- Institute of Functional Biology and Genomics (IBFG), Universidad de Salamanca, CSIC, Salamanca, Spain; Centro de Investigación Biomédica en Red sobre Fragilidad y Envejecimiento Saludable (CIBERFES), Institute of Biomedical Research of Salamanca, Salamanca, Spain
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143
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Broussard GJ, Petreanu L. Eavesdropping wires: Recording activity in axons using genetically encoded calcium indicators. J Neurosci Methods 2021; 360:109251. [PMID: 34119572 PMCID: PMC8363211 DOI: 10.1016/j.jneumeth.2021.109251] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2021] [Revised: 05/31/2021] [Accepted: 06/05/2021] [Indexed: 12/23/2022]
Abstract
Neurons broadcast electrical signals to distal brain regions through extensive axonal arbors. Genetically encoded calcium sensors permit the direct observation of action potential activity at axonal terminals, providing unique insights on the organization and function of neural projections. Here, we consider what information can be gleaned from axonal recordings made at scales ranging from the summed activity extracted from multi-cell axon projections to single boutons. In particular, we discuss the application of different recently developed multi photon and fiber photometry methods for recording neural activity in axons of rodents. We define experimental difficulties associated with imaging approaches in the axonal compartment and highlight the latest methodological advances for addressing these issues. Finally, we reflect on ways in which new technologies can be used in conjunction with axon calcium imaging to address current questions in neurobiology.
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Affiliation(s)
| | - Leopoldo Petreanu
- Champalimaud Research, Champalimaud Center for the Unknown, Lisbon, Portugal.
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144
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Stuyt G, Godenzini L, Palmer LM. Local and Global Dynamics of Dendritic Activity in the Pyramidal Neuron. Neuroscience 2021; 489:176-184. [PMID: 34280492 DOI: 10.1016/j.neuroscience.2021.07.008] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2021] [Revised: 07/06/2021] [Accepted: 07/08/2021] [Indexed: 12/22/2022]
Abstract
There has been increasing interest in the measurement and comparison of activity across compartments of the pyramidal neuron. Dendritic activity can occur both locally, on a single dendritic segment, or globally, involving multiple compartments of the single neuron. Little is known about how these dendritic dynamics shape and contribute to information processing and behavior. Although it has been difficult to characterize local and global activity in vivo due to the technical challenge of simultaneously recording from the entire dendritic arbor and soma, the rise of calcium imaging has driven the increased feasibility and interest of these experiments. However, the distinction between local and global activity made by calcium imaging requires careful consideration. In this review we describe local and global activity, discuss the difficulties and caveats of this distinction, and present the evidence of local and global activity in information processing and behavior.
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Affiliation(s)
- George Stuyt
- Florey Institute of Neuroscience and Mental Health, University of Melbourne, Parkville, Victoria 3052, Australia
| | - Luca Godenzini
- Florey Institute of Neuroscience and Mental Health, University of Melbourne, Parkville, Victoria 3052, Australia
| | - Lucy M Palmer
- Florey Institute of Neuroscience and Mental Health, University of Melbourne, Parkville, Victoria 3052, Australia.
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145
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Neurochemical Signaling of Reward and Aversion to Ventral Tegmental Area Glutamate Neurons. J Neurosci 2021; 41:5471-5486. [PMID: 34001626 DOI: 10.1523/jneurosci.1419-20.2021] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2020] [Revised: 04/29/2021] [Accepted: 05/05/2021] [Indexed: 12/21/2022] Open
Abstract
Ventral tegmental area (VTA) glutamate neurons signal and participate in reward and aversion-based behaviors. However, the neurochemical mechanisms that underlie how these neurons contribute to motivated behaviors is unknown. We used a combination of optical sensors to identify how distinct neurochemical inputs to VTA glutamate neurons participate in motivated behavior within female and male transgenic mice. Activity of glutamate inputs to VTA glutamate neurons increased for both reward-predicting and aversion-predicting cues and aversive outcomes, but subpopulations of glutamate inputs were increased or decreased by reward. For both reward and aversion-based cues and outcomes, activity of GABA inputs to VTA glutamate neurons mostly decreased. GCaMP recordings showed overall population increases in VTA glutamate neuron intracellular calcium during reward and aversion-based cues and outcomes. Electrophysiological recordings of VTA VGluT2 neurons showed that glutamate receptor activation increases firing while loss of excitation via glutamate receptor blockade decreases firing. GABA-A receptor activation decreased VTA glutamate neuron firing but GABA-A receptor blockade did not significantly change VTA glutamate neuron firing. Electrophysiological recordings in coordination with our sensor data suggest that glutamate inputs strongly regulate VTA glutamate neuron participation in diverse motivated behaviors.SIGNIFICANCE STATEMENT Glutamate and GABA are the primary excitatory and inhibitory neurotransmitters of the nervous system. However, identifying how these neurotransmitters regulate motivated behavior has remained challenging because of a lack of tools (1) capable of measuring neurotransmission at the temporal scale of motivated behaviors and (2) capable of capturing chemical signaling onto genetically-distinct neuronal populations. We have overcome these obstacles by implementing genetically-encoded fluorescent indicators to monitor both glutamate and GABA input dynamics exclusively to ventral tegmental area (VTA) glutamate neurons during reward and aversion-based behaviors. We identify that glutamate and GABA inputs to VTA glutamate neurons differentially and dynamically signal reward and aversion-based cues and outcomes. This research provides foundational evidence that links distinct neurotransmitters to motivated behaviors regulated by VTA glutamate neurons.
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146
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Piller M, Werkman IL, Brown RI, Latimer AJ, Kucenas S. Glutamate Signaling via the AMPAR Subunit GluR4 Regulates Oligodendrocyte Progenitor Cell Migration in the Developing Spinal Cord. J Neurosci 2021; 41:5353-5371. [PMID: 33975920 PMCID: PMC8221590 DOI: 10.1523/jneurosci.2562-20.2021] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2020] [Revised: 04/28/2021] [Accepted: 05/03/2021] [Indexed: 11/21/2022] Open
Abstract
Oligodendrocyte progenitor cells (OPCs) are specified from discrete precursor populations during gliogenesis and migrate extensively from their origins, ultimately distributing throughout the brain and spinal cord during early development. Subsequently, a subset of OPCs differentiates into mature oligodendrocytes, which myelinate axons. This process is necessary for efficient neuronal signaling and organism survival. Previous studies have identified several factors that influence OPC development, including excitatory glutamatergic synapses that form between neurons and OPCs during myelination. However, little is known about how glutamate signaling affects OPC migration before myelination. In this study, we use in vivo, time-lapse imaging in zebrafish in conjunction with genetic and pharmacological perturbation to investigate OPC migration and myelination when the GluR4A ionotropic glutamate receptor subunit is disrupted. In our studies, we observed that gria4a mutant embryos and larvae displayed abnormal OPC migration and altered dorsoventral distribution in the spinal cord. Genetic mosaic analysis confirmed that these effects were cell-autonomous, and we identified that voltage-gated calcium channels were downstream of glutamate receptor signaling in OPCs and could rescue the migration and myelination defects we observed when glutamate signaling was perturbed. These results offer new insights into the complex system of neuron-OPC interactions and reveal a cell-autonomous role for glutamatergic signaling in OPCs during neural development.SIGNIFICANCE STATEMENT The migration of oligodendrocyte progenitor cells (OPCs) is an essential process during development that leads to uniform oligodendrocyte distribution and sufficient myelination for central nervous system function. Here, we demonstrate that the AMPA receptor (AMPAR) subunit GluR4A is an important driver of OPC migration and myelination in vivo and that activated voltage-gated calcium channels are downstream of glutamate receptor signaling in mediating this migration.
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Affiliation(s)
- Melanie Piller
- Department of Biology, University of Virginia, Charlottesville, Virginia 22904
| | - Inge L Werkman
- Department of Biology, University of Virginia, Charlottesville, Virginia 22904
| | - Robin Isadora Brown
- Department of Biology, University of Virginia, Charlottesville, Virginia 22904
| | - Andrew J Latimer
- Department of Biology, University of Virginia, Charlottesville, Virginia 22904
| | - Sarah Kucenas
- Department of Biology, University of Virginia, Charlottesville, Virginia 22904
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147
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Keller JP, Marvin JS, Lacin H, Lemon WC, Shea J, Kim S, Lee RT, Koyama M, Keller PJ, Looger LL. In vivo glucose imaging in multiple model organisms with an engineered single-wavelength sensor. Cell Rep 2021; 35:109284. [PMID: 34161775 DOI: 10.1016/j.celrep.2021.109284] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2019] [Revised: 03/06/2020] [Accepted: 06/01/2021] [Indexed: 12/23/2022] Open
Abstract
Glucose is arguably the most important molecule in metabolism, and its dysregulation underlies diabetes. We describe a family of single-wavelength genetically encoded glucose sensors with a high signal-to-noise ratio, fast kinetics, and affinities varying over four orders of magnitude (1 μM to 10 mM). The sensors allow mechanistic characterization of glucose transporters expressed in cultured cells with high spatial and temporal resolution. Imaging of neuron/glia co-cultures revealed ∼3-fold faster glucose changes in astrocytes. In larval Drosophila central nervous system explants, intracellular neuronal glucose fluxes suggested a rostro-caudal transport pathway in the ventral nerve cord neuropil. In zebrafish, expected glucose-related physiological sequelae of insulin and epinephrine treatments were directly visualized. Additionally, spontaneous muscle twitches induced glucose uptake in muscle, and sensory and pharmacological perturbations produced large changes in the brain. These sensors will enable rapid, high-resolution imaging of glucose influx, efflux, and metabolism in behaving animals.
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Affiliation(s)
- Jacob P Keller
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA, USA.
| | - Jonathan S Marvin
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA, USA
| | - Haluk Lacin
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA, USA
| | - William C Lemon
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA, USA
| | - Jamien Shea
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA, USA
| | - Soomin Kim
- Harvard Department of Stem Cell and Regenerative Biology, Harvard Stem Cell Institute, Harvard Medical School, Brigham and Women's Hospital, Cambridge, MA, USA
| | - Richard T Lee
- Harvard Department of Stem Cell and Regenerative Biology, Harvard Stem Cell Institute, Harvard Medical School, Brigham and Women's Hospital, Cambridge, MA, USA; The Cardiovascular Division, Department of Medicine, Harvard Medical School, Brigham and Women's Hospital, Cambridge, MA, USA
| | - Minoru Koyama
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA, USA
| | - Philipp J Keller
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA, USA
| | - Loren L Looger
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA, USA.
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148
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Post MR, Sulzer D. The chemical tools for imaging dopamine release. Cell Chem Biol 2021; 28:748-764. [PMID: 33894160 PMCID: PMC8532025 DOI: 10.1016/j.chembiol.2021.04.005] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2020] [Revised: 02/23/2021] [Accepted: 04/06/2021] [Indexed: 02/07/2023]
Abstract
Dopamine is a modulatory neurotransmitter involved in learning, motor functions, and reward. Many neuropsychiatric disorders, including Parkinson's disease, autism, and schizophrenia, are associated with imbalances or dysfunction in the dopaminergic system. Yet, our understanding of these pervasive public health issues is limited by our ability to effectively image dopamine in humans, which has long been a goal for chemists and neuroscientists. The last two decades have witnessed the development of many molecules used to trace dopamine. We review the small molecules, nanoparticles, and protein sensors used with fluorescent microscopy/photometry, MRI, and PET that shape dopamine research today. None of these tools observe dopamine itself, but instead harness the biology of the dopamine system-its synthetic and metabolic pathways, synaptic vesicle cycle, and receptors-in elegant ways. Their advantages and weaknesses are covered here, along with recent examples and the chemistry and biology that allow them to function.
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Affiliation(s)
- Michael R Post
- Department of Psychiatry, Columbia University Medical Center, New York, NY, USA; Division of Molecular Therapeutics, New York State Psychiatric Institute, New York, NY, USA.
| | - David Sulzer
- Departments of Psychiatry, Neurology, and Pharmacology, Columbia University Medical Center, New York, NY, USA; Division of Molecular Therapeutics, New York State Psychiatric Institute, New York, NY, USA.
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149
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Klatt O, Repetto D, Brockhaus J, Reissner C, El Khallouqi A, Rohlmann A, Heine M, Missler M. Endogenous β-neurexins on axons and within synapses show regulated dynamic behavior. Cell Rep 2021; 35:109266. [PMID: 34133920 DOI: 10.1016/j.celrep.2021.109266] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2020] [Revised: 12/21/2020] [Accepted: 05/26/2021] [Indexed: 11/25/2022] Open
Abstract
Neurexins are key organizer molecules that regulate synaptic function and are implicated in autism and schizophrenia. β-neurexins interact with numerous cell adhesion and receptor molecules, but their neuronal localization remains elusive. Using single-molecule tracking and high-resolution microscopy to detect neurexin1β and neurexin3β in primary hippocampal neurons from knockin mice, we demonstrate that endogenous β-neurexins are present in fewer than half of excitatory and inhibitory synapses. Moreover, we observe a large extrasynaptic pool of β-neurexins on axons and show that axonal β-neurexins diffuse with higher surface mobility than those transiently confined within synapses. Stimulation of neuronal activity further increases the mobility of synaptic and axonal β-neurexins, whereas inhibition causes the opposite. Blocking ectodomain cleavage by metalloproteases also reduces β-neurexin mobility and enhances glutamate release. These findings suggest that the surface mobility of endogenous β-neurexins inside and outside of synapses is dynamically regulated and linked to neuronal activity.
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Affiliation(s)
- Oliver Klatt
- Institute of Anatomy and Molecular Neurobiology, Westfälische Wilhelms-University, 48149 Münster, Germany; Functional Neurobiology Group, Institute for Developmental Biology and Neurobiology, Johannes Gutenberg University, 55128 Mainz, Germany
| | - Daniele Repetto
- Institute of Anatomy and Molecular Neurobiology, Westfälische Wilhelms-University, 48149 Münster, Germany
| | - Johannes Brockhaus
- Institute of Anatomy and Molecular Neurobiology, Westfälische Wilhelms-University, 48149 Münster, Germany
| | - Carsten Reissner
- Institute of Anatomy and Molecular Neurobiology, Westfälische Wilhelms-University, 48149 Münster, Germany
| | - Abderazzaq El Khallouqi
- Functional Neurobiology Group, Institute for Developmental Biology and Neurobiology, Johannes Gutenberg University, 55128 Mainz, Germany
| | - Astrid Rohlmann
- Institute of Anatomy and Molecular Neurobiology, Westfälische Wilhelms-University, 48149 Münster, Germany
| | - Martin Heine
- Functional Neurobiology Group, Institute for Developmental Biology and Neurobiology, Johannes Gutenberg University, 55128 Mainz, Germany.
| | - Markus Missler
- Institute of Anatomy and Molecular Neurobiology, Westfälische Wilhelms-University, 48149 Münster, Germany.
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150
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Luchsinger JR, Fetterly TL, Williford KM, Salimando GJ, Doyle MA, Maldonado J, Simerly RB, Winder DG, Centanni SW. Delineation of an insula-BNST circuit engaged by struggling behavior that regulates avoidance in mice. Nat Commun 2021; 12:3561. [PMID: 34117229 PMCID: PMC8196075 DOI: 10.1038/s41467-021-23674-z] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2020] [Accepted: 05/07/2021] [Indexed: 12/31/2022] Open
Abstract
Active responses to stressors involve motor planning, execution, and feedback. Here we identify an insular cortex to BNST (insula→BNST) circuit recruited during restraint stress-induced active struggling that modulates affective behavior. We demonstrate that activity in this circuit tightly follows struggling behavioral events and that the size of the fluorescent sensor transient reports the duration of the struggle event, an effect that fades with repeated exposure to the homotypic stressor. Struggle events are associated with enhanced glutamatergic- and decreased GABAergic signaling in the insular cortex, indicating the involvement of a larger circuit. We delineate the afferent network for this pathway, identifying substantial input from motor- and premotor cortex, somatosensory cortex, and the amygdala. To begin to dissect these incoming signals, we examine the motor cortex input, and show that the cells projecting from motor regions to insular cortex are engaged shortly before struggle event onset. This study thus demonstrates a role for the insula→BNST pathway in monitoring struggling activity and regulating affective behavior.
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Affiliation(s)
- Joseph R Luchsinger
- Vanderbilt Center for Addiction Research, Vanderbilt University School of Medicine, Nashville, TN, USA
- Vanderbilt Brain Institute, Vanderbilt University School of Medicine, Nashville, TN, USA
- Vanderbilt J.F. Kennedy Center for Research on Human Development, Vanderbilt University School of Medicine, Nashville, TN, USA
| | - Tracy L Fetterly
- Vanderbilt Center for Addiction Research, Vanderbilt University School of Medicine, Nashville, TN, USA
- Vanderbilt Brain Institute, Vanderbilt University School of Medicine, Nashville, TN, USA
- Vanderbilt J.F. Kennedy Center for Research on Human Development, Vanderbilt University School of Medicine, Nashville, TN, USA
| | - Kellie M Williford
- Vanderbilt Center for Addiction Research, Vanderbilt University School of Medicine, Nashville, TN, USA
- Vanderbilt Brain Institute, Vanderbilt University School of Medicine, Nashville, TN, USA
- Vanderbilt J.F. Kennedy Center for Research on Human Development, Vanderbilt University School of Medicine, Nashville, TN, USA
| | - Gregory J Salimando
- Vanderbilt Center for Addiction Research, Vanderbilt University School of Medicine, Nashville, TN, USA
- Vanderbilt Brain Institute, Vanderbilt University School of Medicine, Nashville, TN, USA
- Vanderbilt J.F. Kennedy Center for Research on Human Development, Vanderbilt University School of Medicine, Nashville, TN, USA
| | - Marie A Doyle
- Vanderbilt Center for Addiction Research, Vanderbilt University School of Medicine, Nashville, TN, USA
- Vanderbilt Brain Institute, Vanderbilt University School of Medicine, Nashville, TN, USA
- Vanderbilt J.F. Kennedy Center for Research on Human Development, Vanderbilt University School of Medicine, Nashville, TN, USA
- Department of Molecular Physiology & Biophysics, Vanderbilt University School of Medicine, Nashville, TN, USA
| | - Jose Maldonado
- Vanderbilt Center for Addiction Research, Vanderbilt University School of Medicine, Nashville, TN, USA
- Vanderbilt Brain Institute, Vanderbilt University School of Medicine, Nashville, TN, USA
- Vanderbilt J.F. Kennedy Center for Research on Human Development, Vanderbilt University School of Medicine, Nashville, TN, USA
- Department of Molecular Physiology & Biophysics, Vanderbilt University School of Medicine, Nashville, TN, USA
| | - Richard B Simerly
- Vanderbilt Center for Addiction Research, Vanderbilt University School of Medicine, Nashville, TN, USA.
- Vanderbilt Brain Institute, Vanderbilt University School of Medicine, Nashville, TN, USA.
- Vanderbilt J.F. Kennedy Center for Research on Human Development, Vanderbilt University School of Medicine, Nashville, TN, USA.
- Department of Molecular Physiology & Biophysics, Vanderbilt University School of Medicine, Nashville, TN, USA.
| | - Danny G Winder
- Vanderbilt Center for Addiction Research, Vanderbilt University School of Medicine, Nashville, TN, USA.
- Vanderbilt Brain Institute, Vanderbilt University School of Medicine, Nashville, TN, USA.
- Vanderbilt J.F. Kennedy Center for Research on Human Development, Vanderbilt University School of Medicine, Nashville, TN, USA.
- Department of Molecular Physiology & Biophysics, Vanderbilt University School of Medicine, Nashville, TN, USA.
- Department of Psychiatry and Behavioral Sciences, Vanderbilt University School of Medicine, Nashville, TN, USA.
| | - Samuel W Centanni
- Vanderbilt Center for Addiction Research, Vanderbilt University School of Medicine, Nashville, TN, USA.
- Department of Molecular Physiology & Biophysics, Vanderbilt University School of Medicine, Nashville, TN, USA.
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