1
|
Ahrens MB, Khakh BS, Poskanzer KE. Astrocyte Calcium Signaling. Cold Spring Harb Perspect Biol 2024:a041353. [PMID: 38768971 DOI: 10.1101/cshperspect.a041353] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/22/2024]
Abstract
Astrocytes are predominant glial cells that tile the central nervous system and participate in well-established functional and morphological interactions with neurons, blood vessels, and other glia. These ubiquitous cells display rich intracellular Ca2+ signaling, which has now been studied for over 30 years. In this review, we provide a summary and perspective of recent progress concerning the study of astrocyte intracellular Ca2+ signaling as well as discussion of its potential functions. Progress has occurred in the areas of imaging, silencing, activating, and analyzing astrocyte Ca2+ signals. These insights have collectively permitted exploration of the relationships of astrocyte Ca2+ signals to neural circuit function and behavior in a variety of species. We summarize these aspects along with a framework for mechanistically interpreting behavioral studies to identify directly causal effects. We finish by providing a perspective on new avenues of research concerning astrocyte Ca2+ signaling.
Collapse
Affiliation(s)
- Misha B Ahrens
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, Virginia 20147, USA
| | - Baljit S Khakh
- Department of Physiology and Department of Neurobiology, University of California Los Angeles, Los Angeles, California 90095, USA
| | - Kira E Poskanzer
- Department of Biochemistry & Biophysics, University of California, San Francisco, San Francisco, California 94143, USA
| |
Collapse
|
2
|
Reis FMCV, Maesta-Pereira S, Ollivier M, Schuette PJ, Sethi E, Miranda BA, Iniguez E, Chakerian M, Vaughn E, Sehgal M, Nguyen DCT, Yuan FTH, Torossian A, Ikebara JM, Kihara AH, Silva AJ, Kao JC, Khakh BS, Adhikari A. Control of feeding by a bottom-up midbrain-subthalamic pathway. Nat Commun 2024; 15:2111. [PMID: 38454000 PMCID: PMC10920831 DOI: 10.1038/s41467-024-46430-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2022] [Accepted: 02/26/2024] [Indexed: 03/09/2024] Open
Abstract
Investigative exploration and foraging leading to food consumption have vital importance, but are not well-understood. Since GABAergic inputs to the lateral and ventrolateral periaqueductal gray (l/vlPAG) control such behaviors, we dissected the role of vgat-expressing GABAergic l/vlPAG cells in exploration, foraging and hunting. Here, we show that in mice vgat l/vlPAG cells encode approach to food and consumption of both live prey and non-prey foods. The activity of these cells is necessary and sufficient for inducing food-seeking leading to subsequent consumption. Activation of vgat l/vlPAG cells produces exploratory foraging and compulsive eating without altering defensive behaviors. Moreover, l/vlPAG vgat cells are bidirectionally interconnected to several feeding, exploration and investigation nodes, including the zona incerta. Remarkably, the vgat l/vlPAG projection to the zona incerta bidirectionally controls approach towards food leading to consumption. These data indicate the PAG is not only a final downstream target of top-down exploration and foraging-related inputs, but that it also influences these behaviors through a bottom-up pathway.
Collapse
Affiliation(s)
- Fernando M C V Reis
- Department of Psychology, University of California, Los Angeles, Los Angeles, CA, 90095, USA.
| | - Sandra Maesta-Pereira
- Department of Psychology, University of California, Los Angeles, Los Angeles, CA, 90095, USA
| | - Matthias Ollivier
- Department of Physiology, University of California, Los Angeles, Los Angeles, CA, 90095, USA
| | - Peter J Schuette
- Department of Psychology, University of California, Los Angeles, Los Angeles, CA, 90095, USA
| | - Ekayana Sethi
- Department of Psychology, University of California, Los Angeles, Los Angeles, CA, 90095, USA
| | - Blake A Miranda
- Department of Psychology, University of California, Los Angeles, Los Angeles, CA, 90095, USA
| | - Emily Iniguez
- Department of Psychology, University of California, Los Angeles, Los Angeles, CA, 90095, USA
| | - Meghmik Chakerian
- Department of Psychology, University of California, Los Angeles, Los Angeles, CA, 90095, USA
| | - Eric Vaughn
- Department of Molecular and Cellular Biology, Harvard University, Cambridge, MA, 02138, USA
| | - Megha Sehgal
- Department of Neurobiology, University of California, Los Angeles, Los Angeles, USA
| | - Darren C T Nguyen
- Department of Psychology, University of California, Los Angeles, Los Angeles, CA, 90095, USA
| | - Faith T H Yuan
- Department of Psychology, University of California, Los Angeles, Los Angeles, CA, 90095, USA
| | - Anita Torossian
- Department of Psychology, University of California, Los Angeles, Los Angeles, CA, 90095, USA
| | - Juliane M Ikebara
- Centro de Matemática, Computação e Cognição, Universidade Federal do ABC, São Bernardo do Campo, SP, 09606-070, Brazil
| | - Alexandre H Kihara
- Centro de Matemática, Computação e Cognição, Universidade Federal do ABC, São Bernardo do Campo, SP, 09606-070, Brazil
| | - Alcino J Silva
- Department of Psychology, University of California, Los Angeles, Los Angeles, CA, 90095, USA
- Department of Neurobiology, University of California, Los Angeles, Los Angeles, USA
- Department of Psychiatry & Biobehavioral Sciences, University of California, Los Angeles, Los Angeles, USA
| | - Jonathan C Kao
- Department of Electrical and Computer Engineering, University of California, Los Angeles, Los Angeles, CA, 90095, USA
| | - Baljit S Khakh
- Department of Physiology, University of California, Los Angeles, Los Angeles, CA, 90095, USA
| | - Avishek Adhikari
- Department of Psychology, University of California, Los Angeles, Los Angeles, CA, 90095, USA.
| |
Collapse
|
3
|
Soto JS, Jami-Alahmadi Y, Wohlschlegel JA, Khakh BS. In vivo identification of astrocyte and neuron subproteomes by proximity-dependent biotinylation. Nat Protoc 2024; 19:896-927. [PMID: 38062165 DOI: 10.1038/s41596-023-00923-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2023] [Accepted: 10/03/2023] [Indexed: 02/08/2024]
Abstract
The central nervous system (CNS) comprises diverse and morphologically complex cells. To understand the molecular basis of their physiology, it is crucial to assess proteins expressed within intact cells. Commonly used methods utilize cell dissociation and sorting to isolate specific cell types such as neurons and astrocytes, the major CNS cells. Proteins purified from isolated cells are identified by mass spectrometry-based proteomics. However, dissociation and cell-sorting methods lead to near total loss of cellular morphology, thereby losing proteins from key relevant subcompartments such as processes, end feet, dendrites and axons. Here we provide a systematic protocol for cell- and subcompartment-specific labeling and identification of proteins found within intact astrocytes and neurons in vivo. This protocol utilizes the proximity-dependent biotinylation system BioID2, selectively expressed in either astrocytes or neurons, to label proximal proteins in a cell-specific manner. BioID2 is targeted genetically to assess the subproteomes of subcellular compartments such as the plasma membrane and sites of cell-cell contacts. We describe in detail the expression methods (variable timing), stereotaxic surgeries for expression (1-2 d and then 3 weeks), in vivo protein labeling (7 d), protein isolation (2-3 d), protein identification methods (2-3 d) and data analysis (1 week). The protocol can be applied to any area of the CNS in mouse models of physiological processes and for disease-related research.
Collapse
Affiliation(s)
- Joselyn S Soto
- Department of Physiology, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA, USA.
| | - Yasaman Jami-Alahmadi
- Department of Biological Chemistry, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA, USA
| | - James A Wohlschlegel
- Department of Biological Chemistry, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA, USA
| | - Baljit S Khakh
- Department of Physiology, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA, USA.
- Department of Neurobiology, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA, USA.
| |
Collapse
|
4
|
Ollivier M, Soto JS, Linker KE, Moye SL, Jami-Alahmadi Y, Jones AE, Divakaruni AS, Kawaguchi R, Wohlschlegel JA, Khakh BS. Crym-positive striatal astrocytes gate perseverative behaviour. Nature 2024; 627:358-366. [PMID: 38418885 PMCID: PMC10937394 DOI: 10.1038/s41586-024-07138-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2023] [Accepted: 01/31/2024] [Indexed: 03/02/2024]
Abstract
Astrocytes are heterogeneous glial cells of the central nervous system1-3. However, the physiological relevance of astrocyte diversity for neural circuits and behaviour remains unclear. Here we show that a specific population of astrocytes in the central striatum expresses μ-crystallin (encoded by Crym in mice and CRYM in humans) that is associated with several human diseases, including neuropsychiatric disorders4-7. In adult mice, reducing the levels of μ-crystallin in striatal astrocytes through CRISPR-Cas9-mediated knockout of Crym resulted in perseverative behaviours, increased fast synaptic excitation in medium spiny neurons and dysfunctional excitatory-inhibitory synaptic balance. Increased perseveration stemmed from the loss of astrocyte-gated control of neurotransmitter release from presynaptic terminals of orbitofrontal cortex-striatum projections. We found that perseveration could be remedied using presynaptic inhibitory chemogenetics8, and that this treatment also corrected the synaptic deficits. Together, our findings reveal converging molecular, synaptic, circuit and behavioural mechanisms by which a molecularly defined and allocated population of striatal astrocytes gates perseveration phenotypes that accompany neuropsychiatric disorders9-12. Our data show that Crym-positive striatal astrocytes have key biological functions within the central nervous system, and uncover astrocyte-neuron interaction mechanisms that could be targeted in treatments for perseveration.
Collapse
Affiliation(s)
- Matthias Ollivier
- Department of Physiology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, USA
| | - Joselyn S Soto
- Department of Physiology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, USA
| | - Kay E Linker
- Department of Physiology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, USA
| | - Stefanie L Moye
- Department of Physiology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, USA
| | - Yasaman Jami-Alahmadi
- Department of Biological Chemistry, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, USA
| | - Anthony E Jones
- Department of Molecular and Medical Pharmacology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, USA
| | - Ajit S Divakaruni
- Department of Molecular and Medical Pharmacology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, USA
| | - Riki Kawaguchi
- Center for Neurobehavioral Genetics, Semel Institute for Neuroscience and Human Behavior, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, USA
| | - James A Wohlschlegel
- Department of Biological Chemistry, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, USA
| | - Baljit S Khakh
- Department of Physiology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, USA.
- Department of Neurobiology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, USA.
| |
Collapse
|
5
|
Iyer M, Kantarci H, Cooper MH, Ambiel N, Novak SW, Andrade LR, Lam M, Jones G, Münch AE, Yu X, Khakh BS, Manor U, Zuchero JB. Oligodendrocyte calcium signaling promotes actin-dependent myelin sheath extension. Nat Commun 2024; 15:265. [PMID: 38177161 PMCID: PMC10767123 DOI: 10.1038/s41467-023-44238-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2023] [Accepted: 12/05/2023] [Indexed: 01/06/2024] Open
Abstract
Myelin is essential for rapid nerve signaling and is increasingly found to play important roles in learning and in diverse diseases of the CNS. Morphological parameters of myelin such as sheath length are thought to precisely tune conduction velocity, but the mechanisms controlling sheath morphology are poorly understood. Local calcium signaling has been observed in nascent myelin sheaths and can be modulated by neuronal activity. However, the role of calcium signaling in sheath formation remains incompletely understood. Here, we use genetic tools to attenuate oligodendrocyte calcium signaling during myelination in the developing mouse CNS. Surprisingly, genetic calcium attenuation does not grossly affect the number of myelinated axons or myelin thickness. Instead, calcium attenuation causes myelination defects resulting in shorter, dysmorphic sheaths. Mechanistically, calcium attenuation reduces actin filaments in oligodendrocytes, and an intact actin cytoskeleton is necessary and sufficient to achieve accurate myelin morphology. Together, our work reveals a cellular mechanism required for accurate CNS myelin formation and may provide mechanistic insight into how oligodendrocytes respond to neuronal activity to sculpt and refine myelin sheaths.
Collapse
Affiliation(s)
- Manasi Iyer
- Department of Neurosurgery, Stanford University School of Medicine, Stanford, CA, USA
| | - Husniye Kantarci
- Department of Neurosurgery, Stanford University School of Medicine, Stanford, CA, USA
| | - Madeline H Cooper
- Department of Neurosurgery, Stanford University School of Medicine, Stanford, CA, USA
| | - Nicholas Ambiel
- Department of Neurosurgery, Stanford University School of Medicine, Stanford, CA, USA
| | - Sammy Weiser Novak
- Waitt Advanced Biophotonics Center, Salk Institute for Biological Studies, La Jolla, CA, USA
| | - Leonardo R Andrade
- Waitt Advanced Biophotonics Center, Salk Institute for Biological Studies, La Jolla, CA, USA
| | - Mable Lam
- Department of Neurosurgery, Stanford University School of Medicine, Stanford, CA, USA
| | - Graham Jones
- Department of Neurosurgery, Stanford University School of Medicine, Stanford, CA, USA
| | - Alexandra E Münch
- Department of Neurosurgery, Stanford University School of Medicine, Stanford, CA, USA
| | - Xinzhu Yu
- Department of Molecular and Integrative Physiology, Beckman Institute, University of Illinois at Urbana-, Champaign, IL, USA
- Department of Physiology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, USA
| | - Baljit S Khakh
- Department of Physiology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, USA
| | - Uri Manor
- Waitt Advanced Biophotonics Center, Salk Institute for Biological Studies, La Jolla, CA, USA
- Department of Cell and Developmental Biology, University of California, San Diego, San Diego, CA, USA
| | - J Bradley Zuchero
- Department of Neurosurgery, Stanford University School of Medicine, Stanford, CA, USA.
| |
Collapse
|
6
|
Baldwin KT, Murai KK, Khakh BS. Astrocyte morphology. Trends Cell Biol 2023:S0962-8924(23)00204-0. [PMID: 38180380 DOI: 10.1016/j.tcb.2023.09.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2023] [Revised: 09/18/2023] [Accepted: 09/29/2023] [Indexed: 01/06/2024]
Abstract
Astrocytes are predominant glial cells that tile the central nervous system (CNS). A cardinal feature of astrocytes is their complex and visually enchanting morphology, referred to as bushy, spongy, and star-like. A central precept of this review is that such complex morphological shapes evolved to allow astrocytes to contact and signal with diverse cells at a range of distances in order to sample, regulate, and contribute to the extracellular milieu, and thus participate widely in cell-cell signaling during physiology and disease. The recent use of improved imaging methods and cell-specific molecular evaluations has revealed new information on the structural organization and molecular underpinnings of astrocyte morphology, the mechanisms of astrocyte morphogenesis, and the contributions to disease states of reduced morphology. These insights have reignited interest in astrocyte morphological complexity as a cornerstone of fundamental glial biology and as a critical substrate for multicellular spatial and physiological interactions in the CNS.
Collapse
Affiliation(s)
- Katherine T Baldwin
- Neuroscience Center, University of North Carolina, Chapel Hill, NC 27599, USA; Department of Cell Biology and Physiology, University of North Carolina, Chapel Hill, NC 27599, USA.
| | - Keith K Murai
- Centre for Research in Neuroscience, Department of Neurology and Neurosurgery, Brain Repair and Integrative Neuroscience Program, The Research Institute of the McGill University Health Centre, Montreal General Hospital, 1650 Cedar Avenue, Montreal, QC H3G 1A4, Canada.
| | - Baljit S Khakh
- Department of Physiology, David Geffen School of Medicine, University of California Los Angeles, 10833 Le Conte Avenue, Los Angeles, CA 90034, USA; Department of Neurobiology, David Geffen School of Medicine, University of California Los Angeles, 10833 Le Conte Avenue, Los Angeles, CA 90034, USA.
| |
Collapse
|
7
|
Iyer M, Kantarci H, Ambiel N, Novak SW, Andrade LR, Lam M, Münch AE, Yu X, Khakh BS, Manor U, Zuchero JB. Oligodendrocyte calcium signaling sculpts myelin sheath morphology. bioRxiv 2023:2023.04.11.536299. [PMID: 37090556 PMCID: PMC10120717 DOI: 10.1101/2023.04.11.536299] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/25/2023]
Abstract
Myelin is essential for rapid nerve signaling and is increasingly found to play important roles in learning and in diverse diseases of the CNS. Morphological parameters of myelin such as sheath length and thickness are regulated by neuronal activity and can precisely tune conduction velocity, but the mechanisms controlling sheath morphology are poorly understood. Local calcium signaling has been observed in nascent myelin sheaths and can be modulated by neuronal activity. However, the role of calcium signaling in sheath formation and remodeling is unknown. Here, we used genetic tools to attenuate oligodendrocyte calcium signaling during active myelination in the developing mouse CNS. Surprisingly, we found that genetic calcium attenuation did not grossly affect the number of myelinated axons or myelin thickness. Instead, calcium attenuation caused striking myelination defects resulting in shorter, dysmorphic sheaths. Mechanistically, calcium attenuation reduced actin filaments in oligodendrocytes, and an intact actin cytoskeleton was necessary and sufficient to achieve accurate myelin morphology. Together, our work reveals a novel cellular mechanism required for accurate CNS myelin formation and provides mechanistic insight into how oligodendrocytes may respond to neuronal activity to sculpt myelin sheaths throughout the nervous system.
Collapse
|
8
|
Soto JS, Jami-Alahmadi Y, Chacon J, Moye SL, Diaz-Castro B, Wohlschlegel JA, Khakh BS. Astrocyte-neuron subproteomes and obsessive-compulsive disorder mechanisms. Nature 2023; 616:764-773. [PMID: 37046092 PMCID: PMC10132990 DOI: 10.1038/s41586-023-05927-7] [Citation(s) in RCA: 15] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2021] [Accepted: 03/07/2023] [Indexed: 04/14/2023]
Abstract
Astrocytes and neurons extensively interact in the brain. Identifying astrocyte and neuron proteomes is essential for elucidating the protein networks that dictate their respective contributions to physiology and disease. Here we used cell-specific and subcompartment-specific proximity-dependent biotinylation1 to study the proteomes of striatal astrocytes and neurons in vivo. We evaluated cytosolic and plasma membrane compartments for astrocytes and neurons to discover how these cells differ at the protein level in their signalling machinery. We also assessed subcellular compartments of astrocytes, including end feet and fine processes, to reveal their subproteomes and the molecular basis of essential astrocyte signalling and homeostatic functions. Notably, SAPAP3 (encoded by Dlgap3), which is associated with obsessive-compulsive disorder (OCD) and repetitive behaviours2-8, was detected at high levels in striatal astrocytes and was enriched within specific astrocyte subcompartments where it regulated actin cytoskeleton organization. Furthermore, genetic rescue experiments combined with behavioural analyses and molecular assessments in a mouse model of OCD4 lacking SAPAP3 revealed distinct contributions of astrocytic and neuronal SAPAP3 to repetitive and anxiety-related OCD-like phenotypes. Our data define how astrocytes and neurons differ at the protein level and in their major signalling pathways. Moreover, they reveal how astrocyte subproteomes vary between physiological subcompartments and how both astrocyte and neuronal SAPAP3 mechanisms contribute to OCD phenotypes in mice. Our data indicate that therapeutic strategies that target both astrocytes and neurons may be useful to explore in OCD and potentially other brain disorders.
Collapse
Affiliation(s)
- Joselyn S Soto
- Department of Physiology, University of California, Los Angeles, CA, USA
| | - Yasaman Jami-Alahmadi
- Department of Biological Chemistry, David Geffen School of Medicine, University of California, Los Angeles, CA, USA
| | - Jakelyn Chacon
- Department of Physiology, University of California, Los Angeles, CA, USA
| | - Stefanie L Moye
- Department of Physiology, University of California, Los Angeles, CA, USA
| | - Blanca Diaz-Castro
- Department of Physiology, University of California, Los Angeles, CA, USA
- UK Dementia Research Institute and Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh, UK
| | - James A Wohlschlegel
- Department of Biological Chemistry, David Geffen School of Medicine, University of California, Los Angeles, CA, USA
| | - Baljit S Khakh
- Department of Physiology, University of California, Los Angeles, CA, USA.
- Department of Neurobiology, University of California, Los Angeles, CA, USA.
| |
Collapse
|
9
|
Khakh BS, Goldman SA. Astrocytic contributions to Huntington's disease pathophysiology. Ann N Y Acad Sci 2023; 1522:42-59. [PMID: 36864567 PMCID: PMC10145027 DOI: 10.1111/nyas.14977] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/04/2023]
Abstract
Huntington's disease (HD) is a fatal, monogenic, autosomal dominant neurodegenerative disease caused by a polyglutamine-encoding CAG expansion in the huntingtin (HTT) gene that results in mutant huntingtin proteins (mHTT) in cells throughout the body. Although large parts of the central nervous system (CNS) are affected, the striatum is especially vulnerable and undergoes marked atrophy. Astrocytes are abundant within the striatum and contain mHTT in HD, as well as in mouse models of the disease. We focus on striatal astrocytes and summarize how they participate in, and contribute to, molecular pathophysiology and disease-related phenotypes in HD model mice. Where possible, reference is made to pertinent astrocyte alterations in human HD. Astrocytic dysfunctions related to cellular morphology, extracellular ion and neurotransmitter homeostasis, and metabolic support all accompany the development and progression of HD, in both transgenic mouse and human cellular and chimeric models of HD. These findings reveal the potential for the therapeutic targeting of astrocytes so as to restore synaptic as well as tissue homeostasis in HD. Elucidation of the mechanisms by which astrocytes contribute to HD pathogenesis may inform a broader understanding of the role of glial pathology in neurodegenerative disorders and, by so doing, enable new strategies of glial-directed therapeutics.
Collapse
Affiliation(s)
- Baljit S. Khakh
- Department of Physiology, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, California, USA
- Department of Neurobiology, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, California, USA
| | - Steven A. Goldman
- Center for Translational Neuromedicine, University of Rochester Medical Center, Rochester, New York, USA
- Center for Translational Neuromedicine, University of Copenhagen Faculty of Health and Medical Sciences, Copenhagen, Denmark
| |
Collapse
|
10
|
Soto JS, Khakh BS. Cell morphology: Astrocyte structure at the nanoscale. Curr Biol 2023; 33:R200-R202. [PMID: 36917946 DOI: 10.1016/j.cub.2023.01.045] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/14/2023]
Abstract
Astrocytes, the most abundant glial cells in the central nervous system, play vital roles in maintaining neuronal function. A new study using focused ion-beam scanning electron microscopy reveals the architecture of astrocytes at the nanoscale and provides new insights on how astrocytes perform their diverse activities.
Collapse
Affiliation(s)
- Joselyn S Soto
- Department of Physiology, David Geffen School of Medicine, University of California Los Angeles, 10833 Le Conte Avenue, Los Angeles, CA 90095-1751, USA.
| | - Baljit S Khakh
- Department of Physiology, David Geffen School of Medicine, University of California Los Angeles, 10833 Le Conte Avenue, Los Angeles, CA 90095-1751, USA.
| |
Collapse
|
11
|
Gangwani MR, Soto JS, Jami-Alahmadi Y, Tiwari S, Kawaguchi R, Wohlschlegel JA, Khakh BS. Neuronal and astrocytic contributions to Huntington's disease dissected with zinc finger protein transcriptional repressors. Cell Rep 2023; 42:111953. [PMID: 36640336 PMCID: PMC9898160 DOI: 10.1016/j.celrep.2022.111953] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2022] [Revised: 12/15/2022] [Accepted: 12/15/2022] [Indexed: 01/09/2023] Open
Abstract
Huntington's disease (HD) is caused by expanded CAG repeats in the huntingtin gene (HTT) resulting in expression of mutant HTT proteins (mHTT) with extended polyglutamine tracts, including in striatal neurons and astrocytes. It is unknown whether pathophysiology in vivo can be attenuated by lowering mHTT in either cell type throughout the brain, and the relative contributions of neurons and astrocytes to HD remain undefined. We use zinc finger protein (ZFP) transcriptional repressors to cell-selectively lower mHTT in vivo. Astrocytes display loss of essential functions such as cholesterol metabolism that are partly driven by greater neuronal dysfunctions, which encompass neuromodulation, synaptic, and intracellular signaling pathways. Using transcriptomics, proteomics, electrophysiology, and behavior, we dissect neuronal and astrocytic contributions to HD pathophysiology. Remarkably, brain-wide delivery of neuronal ZFPs results in strong mHTT lowering, rescue of HD-associated behavioral and molecular phenotypes, and significant extension of lifespan, findings that support translational development.
Collapse
Affiliation(s)
- Mohitkumar R. Gangwani
- Department of Physiology, University of California Los Angeles. Los Angeles, CA 90095-1751, USA
| | - Joselyn S. Soto
- Department of Physiology, University of California Los Angeles. Los Angeles, CA 90095-1751, USA
| | - Yasaman Jami-Alahmadi
- Department of Biological Chemistry, University of California Los Angeles. Los Angeles, CA 90095-1751, USA
| | - Srushti Tiwari
- Department of Physiology, University of California Los Angeles. Los Angeles, CA 90095-1751, USA
| | - Riki Kawaguchi
- Center for Neurobehavioral Genetics, Semel Institute for Neuroscience and Human Behavior, University of California Los Angeles. Los Angeles, CA 90095-1751, USA
| | - James A. Wohlschlegel
- Department of Biological Chemistry, University of California Los Angeles. Los Angeles, CA 90095-1751, USA
| | - Baljit S. Khakh
- Department of Physiology, University of California Los Angeles. Los Angeles, CA 90095-1751, USA,Department of Neurobiology, University of California Los Angeles. Los Angeles, CA 90095-1751, USA
| |
Collapse
|
12
|
Endo F, Kasai A, Soto JS, Yu X, Qu Z, Hashimoto H, Gradinaru V, Kawaguchi R, Khakh BS. Molecular basis of astrocyte diversity and morphology across the CNS in health and disease. Science 2022; 378:eadc9020. [PMID: 36378959 PMCID: PMC9873482 DOI: 10.1126/science.adc9020] [Citation(s) in RCA: 106] [Impact Index Per Article: 53.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Astrocytes, a type of glia, are abundant and morphologically complex cells. Here, we report astrocyte molecular profiles, diversity, and morphology across the mouse central nervous system (CNS). We identified shared and region-specific astrocytic genes and functions and explored the cellular origins of their regional diversity. We identified gene networks correlated with astrocyte morphology, several of which unexpectedly contained Alzheimer's disease (AD) risk genes. CRISPR/Cas9-mediated reduction of candidate genes reduced astrocyte morphological complexity and resulted in cognitive deficits. The same genes were down-regulated in human AD, in an AD mouse model that displayed reduced astrocyte morphology, and in other human brain disorders. We thus provide comprehensive molecular data on astrocyte diversity and mechanisms across the CNS and on the molecular basis of astrocyte morphology in health and disease.
Collapse
Affiliation(s)
- Fumito Endo
- Department of Physiology, University of California Los Angeles; Los Angeles USA
| | - Atsushi Kasai
- Laboratory of Molecular Neuropharmacology, Graduate School of Pharmaceutical Sciences, Osaka University; Suita, Osaka, Japan
| | - Joselyn S. Soto
- Department of Physiology, University of California Los Angeles; Los Angeles USA
| | - Xinzhu Yu
- Department of Physiology, University of California Los Angeles; Los Angeles USA
| | - Zhe Qu
- Division of Biology and Biological Engineering, California Institute of Technology; Pasadena, USA
| | - Hitoshi Hashimoto
- Laboratory of Molecular Neuropharmacology, Graduate School of Pharmaceutical Sciences, Osaka University; Suita, Osaka, Japan,Molecular Research Center for Children’s Mental Development, United Graduate School of Child Development, Osaka University; Suita, Osaka, Japan,Division of Bioscience, Institute for Datability Science, Osaka University; Suita, Osaka, Japan.,Open and Transdisciplinary Research Initiatives, Osaka University; Suita, Osaka, Japan,Department of Molecular Pharmaceutical Science, Graduate School of Medicine, Osaka University; Suita, Osaka, Japan
| | - Viviana Gradinaru
- Division of Biology and Biological Engineering, California Institute of Technology; Pasadena, USA
| | - Riki Kawaguchi
- Center for Neurobehavioral Genetics, Semel Institute for Neuroscience and Human Behavior, University of California Los Angeles; Los Angeles USA
| | - Baljit S. Khakh
- Department of Physiology, University of California Los Angeles; Los Angeles USA,Department of Neurobiology, University of California Los Angeles; Los Angeles USA,Corresponding author.
| |
Collapse
|
13
|
Badia-Soteras A, Heistek TS, Kater MSJ, Mak A, Negrean A, van den Oever MC, Mansvelder HD, Khakh BS, Min R, Smit AB, Verheijen MHG. Retraction of Astrocyte Leaflets From the Synapse Enhances Fear Memory. Biol Psychiatry 2022:S0006-3223(22)01705-X. [PMID: 36702661 DOI: 10.1016/j.biopsych.2022.10.013] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/22/2022] [Revised: 10/07/2022] [Accepted: 10/20/2022] [Indexed: 01/28/2023]
Abstract
BACKGROUND The formation and retrieval of fear memories depends on orchestrated synaptic activity of neuronal ensembles within the hippocampus, and it is becoming increasingly evident that astrocytes residing in the environment of these synapses play a central role in shaping cellular memory representations. Astrocyte distal processes, known as leaflets, fine-tune synaptic activity by clearing neurotransmitters and limiting glutamate diffusion. However, how astroglial synaptic coverage contributes to mnemonic processing of fearful experiences remains largely unknown. METHODS We used electron microscopy to observe changes in astroglial coverage of hippocampal synapses during consolidation of fear memory in mice. To manipulate astroglial synaptic coverage, we depleted ezrin, an integral leaflet-structural protein, from hippocampal astrocytes using CRISPR (clustered regularly interspaced short palindromic repeats)/Cas9 gene editing. Next, a combination of Föster resonance energy transfer analysis, genetically encoded glutamate sensors, and whole-cell patch-clamp recordings was used to determine whether the proximity of astrocyte leaflets to the synapse is critical for synaptic integrity and function. RESULTS We found that consolidation of a recent fear memory is accompanied by a transient retraction of astrocyte leaflets from hippocampal synapses and increased activation of NMDA receptors. Accordingly, astrocyte-specific depletion of ezrin resulted in shorter astrocyte leaflets and reduced astrocyte contact with the synaptic cleft, which consequently boosted extrasynaptic glutamate diffusion and NMDA receptor activation. Importantly, after fear conditioning, these cellular phenotypes translated to increased retrieval-evoked activation of CA1 pyramidal neurons and enhanced fear memory expression. CONCLUSIONS Together, our data show that withdrawal of astrocyte leaflets from the synaptic cleft is an experience-induced, temporally regulated process that gates the strength of fear memories.
Collapse
Affiliation(s)
- Aina Badia-Soteras
- Department of Molecular and Cellular Neuroscience, Center for Neurogenomics and Cognitive Research, Amsterdam Neuroscience, Vrije Universiteit Amsterdam, Amsterdam, the Netherlands
| | - Tim S Heistek
- Department of Integrative Neurophysiology, Center for Neurogenomics and Cognitive Research, Amsterdam Neuroscience, Vrije Universiteit Amsterdam, Amsterdam, the Netherlands
| | - Mandy S J Kater
- Department of Molecular and Cellular Neuroscience, Center for Neurogenomics and Cognitive Research, Amsterdam Neuroscience, Vrije Universiteit Amsterdam, Amsterdam, the Netherlands
| | - Aline Mak
- Department of Molecular and Cellular Neuroscience, Center for Neurogenomics and Cognitive Research, Amsterdam Neuroscience, Vrije Universiteit Amsterdam, Amsterdam, the Netherlands
| | - Adrian Negrean
- Department of Integrative Neurophysiology, Center for Neurogenomics and Cognitive Research, Amsterdam Neuroscience, Vrije Universiteit Amsterdam, Amsterdam, the Netherlands
| | - Michel C van den Oever
- Department of Molecular and Cellular Neuroscience, Center for Neurogenomics and Cognitive Research, Amsterdam Neuroscience, Vrije Universiteit Amsterdam, Amsterdam, the Netherlands
| | - Huibert D Mansvelder
- Department of Integrative Neurophysiology, Center for Neurogenomics and Cognitive Research, Amsterdam Neuroscience, Vrije Universiteit Amsterdam, Amsterdam, the Netherlands
| | - Baljit S Khakh
- Department of Physiology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, California; Department of Neurobiology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, California
| | - Rogier Min
- Department of Integrative Neurophysiology, Center for Neurogenomics and Cognitive Research, Amsterdam Neuroscience, Vrije Universiteit Amsterdam, Amsterdam, the Netherlands; Department of Child Neurology, Emma Children's Hospital, Amsterdam University Medical Centers, Amsterdam Neuroscience, Vrije Universiteit Amsterdam, Amsterdam, the Netherlands
| | - August B Smit
- Department of Molecular and Cellular Neuroscience, Center for Neurogenomics and Cognitive Research, Amsterdam Neuroscience, Vrije Universiteit Amsterdam, Amsterdam, the Netherlands
| | - Mark H G Verheijen
- Department of Molecular and Cellular Neuroscience, Center for Neurogenomics and Cognitive Research, Amsterdam Neuroscience, Vrije Universiteit Amsterdam, Amsterdam, the Netherlands.
| |
Collapse
|
14
|
Cho FS, Vainchtein ID, Voskobiynyk Y, Morningstar AR, Aparicio F, Higashikubo B, Ciesielska A, Broekaart DWM, Anink JJ, van Vliet EA, Yu X, Khakh BS, Aronica E, Molofsky AV, Paz JT. Enhancing GAT-3 in thalamic astrocytes promotes resilience to brain injury in rodents. Sci Transl Med 2022; 14:eabj4310. [PMID: 35857628 DOI: 10.1126/scitranslmed.abj4310] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Inflammatory processes induced by brain injury are important for recovery; however, when uncontrolled, inflammation can be deleterious, likely explaining why most anti-inflammatory treatments have failed to improve neurological outcomes after brain injury in clinical trials. In the thalamus, chronic activation of glial cells, a proxy of inflammation, has been suggested as an indicator of increased seizure risk and cognitive deficits that develop after cortical injury. Furthermore, lesions in the thalamus, more than other brain regions, have been reported in patients with viral infections associated with neurological deficits, such as SARS-CoV-2. However, the extent to which thalamic inflammation is a driver or by-product of neurological deficits remains unknown. Here, we found that thalamic inflammation in mice was sufficient to phenocopy the cellular and circuit hyperexcitability, enhanced seizure risk, and disruptions in cortical rhythms that develop after cortical injury. In our model, down-regulation of the GABA transporter GAT-3 in thalamic astrocytes mediated this neurological dysfunction. In addition, GAT-3 was decreased in regions of thalamic reactive astrocytes in mouse models of cortical injury. Enhancing GAT-3 in thalamic astrocytes prevented seizure risk, restored cortical states, and was protective against severe chemoconvulsant-induced seizures and mortality in a mouse model of traumatic brain injury, emphasizing the potential of therapeutically targeting this pathway. Together, our results identified a potential therapeutic target for reducing negative outcomes after brain injury.
Collapse
Affiliation(s)
- Frances S Cho
- Gladstone Institute of Neurological Disease, San Francisco, CA 94158, USA.,Neuroscience Graduate Program, University of California, San Francisco, San Francisco, CA 94158, USA.,Department of Neurology, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Ilia D Vainchtein
- Department of Psychiatry/Weill Institute for Neurosciences, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Yuliya Voskobiynyk
- Gladstone Institute of Neurological Disease, San Francisco, CA 94158, USA
| | | | - Francisco Aparicio
- Neuroscience Graduate Program, University of California, San Francisco, San Francisco, CA 94158, USA.,Department of Neurology, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Bryan Higashikubo
- Gladstone Institute of Neurological Disease, San Francisco, CA 94158, USA
| | | | - Diede W M Broekaart
- Amsterdam UMC location University of Amsterdam, Department of (Neuro)Pathology, Amsterdam Neuroscience, Meibergdreef 9, Amsterdam 1105 AZ, Netherlands
| | - Jasper J Anink
- Amsterdam UMC location University of Amsterdam, Department of (Neuro)Pathology, Amsterdam Neuroscience, Meibergdreef 9, Amsterdam 1105 AZ, Netherlands
| | - Erwin A van Vliet
- Amsterdam UMC location University of Amsterdam, Department of (Neuro)Pathology, Amsterdam Neuroscience, Meibergdreef 9, Amsterdam 1105 AZ, Netherlands.,Swammerdam Institute for Life Sciences, Center for Neuroscience, University of Amsterdam, Amsterdam 1098 XH, Netherlands
| | - Xinzhu Yu
- Department of Physiology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095, USA.,Department of Neurobiology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Baljit S Khakh
- Department of Physiology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095, USA.,Department of Neurobiology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Eleonora Aronica
- Amsterdam UMC location University of Amsterdam, Department of (Neuro)Pathology, Amsterdam Neuroscience, Meibergdreef 9, Amsterdam 1105 AZ, Netherlands.,Stichting Epilepsie Instellingen Nederland (SEIN), Heemstede 2103 SW, Netherlands
| | - Anna V Molofsky
- Neuroscience Graduate Program, University of California, San Francisco, San Francisco, CA 94158, USA.,Department of Psychiatry/Weill Institute for Neurosciences, University of California, San Francisco, San Francisco, CA 94158, USA.,Kavli Institute for Fundamental Neuroscience, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Jeanne T Paz
- Gladstone Institute of Neurological Disease, San Francisco, CA 94158, USA.,Neuroscience Graduate Program, University of California, San Francisco, San Francisco, CA 94158, USA.,Department of Neurology, University of California, San Francisco, San Francisco, CA 94158, USA.,Kavli Institute for Fundamental Neuroscience, University of California, San Francisco, San Francisco, CA 94158, USA
| |
Collapse
|
15
|
Bravo-Ferrer I, Khakh BS, Díaz-Castro B. Cell-specific RNA purification to study translatomes of mouse central nervous system. STAR Protoc 2022; 3:101397. [PMID: 35620074 PMCID: PMC9127423 DOI: 10.1016/j.xpro.2022.101397] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Cell-specific RNA sequencing has revolutionized the study of cell biology. Here, we present a protocol to assess cell-specific translatomes of genetically targeted cell types. We focus on astrocytes and describe RNA purification using RiboTag tools. Unlike single-cell RNA sequencing, this approach allows high sequencing depth to detect low expression genes, and the exploration of RNAs translated in subcellular compartments. Furthermore, it avoids underestimation of transcripts from cells susceptible to cell isolation procedures. The protocol can be applied to a variety of cell types. For complete details on the use and execution of this protocol, please refer to Chai et al. (2017), Díaz-Castro et al. (2021), Díaz-Castro et al. (2019), Srinivasan et al. (2016), and Yu et al. (2018). A protocol for investigating cell-specific translatomes in mouse brain cells Purification of RNA from genetically targeted cells using RiboTag tools Recommended antibodies and oligonucleotides to assess brain-cell specificity Sample quality assessment tips for generating the most reliable data
Collapse
Affiliation(s)
- Isabel Bravo-Ferrer
- UK Dementia Research Institute, University of Edinburgh, Chancellor’s Building, Edinburgh EH16 4SB, Scotland, UK
- Centre for Discovery Brain Sciences, University of Edinburgh, Chancellor’s Building, Edinburgh EH16 4SB, Scotland, UK
| | - Baljit S. Khakh
- Department of Physiology, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA 90095-1751, USA
- Department of Neurobiology, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA 90095-1751, USA
| | - Blanca Díaz-Castro
- UK Dementia Research Institute, University of Edinburgh, Chancellor’s Building, Edinburgh EH16 4SB, Scotland, UK
- Centre for Discovery Brain Sciences, University of Edinburgh, Chancellor’s Building, Edinburgh EH16 4SB, Scotland, UK
- Corresponding author
| |
Collapse
|
16
|
Yu X, Khakh BS. SnapShot: Astrocyte interactions. Cell 2022; 185:220-220.e1. [DOI: 10.1016/j.cell.2021.09.029] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
|
17
|
Diaz-Castro B, Bernstein AM, Coppola G, Sofroniew MV, Khakh BS. Molecular and functional properties of cortical astrocytes during peripherally induced neuroinflammation. Cell Rep 2021; 36:109508. [PMID: 34380036 PMCID: PMC8418871 DOI: 10.1016/j.celrep.2021.109508] [Citation(s) in RCA: 39] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2021] [Revised: 05/14/2021] [Accepted: 07/20/2021] [Indexed: 01/30/2023] Open
Abstract
Astrocytic contributions to neuroinflammation are widely implicated in disease, but they remain incompletely explored. We assess medial prefrontal cortex (PFC) and visual cortex (VCX) astrocyte and whole-tissue gene expression changes in mice following peripherally induced neuroinflammation triggered by a systemic bacterial endotoxin, lipopolysaccharide, which produces sickness-related behaviors, including anhedonia. Neuroinflammation-mediated behavioral changes and astrocyte-specific gene expression alterations peak when anhedonia is greatest and then reverse to normal. Notably, region-specific molecular identities of PFC and VCX astrocytes are largely maintained during reactivity changes. Gene pathway analyses reveal alterations of diverse cell signaling pathways, including changes in cell-cell interactions of multiple cell types that may underlie the central effects of neuroinflammation. Certain astrocyte molecular signatures accompanying neuroinflammation are shared with changes reported in Alzheimer's disease and mouse models. However, we find no evidence of altered neuronal survival or function in the PFC even when neuroinflammation-induced astrocyte reactivity and behavioral changes are significant.
Collapse
Affiliation(s)
- Blanca Diaz-Castro
- Department of Physiology, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA 90095-1751, USA; UK Dementia Research Institute and Centre for Discovery Brain Sciences, University of Edinburgh, Chancellor's Building, Edinburgh, Scotland EH16 4SB, UK.
| | - Alexander M Bernstein
- Department of Neurobiology, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA 90095-1751, USA
| | - Giovanni Coppola
- Department of Psychiatry and Biobehavioral Sciences, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA 90095-1751, USA; Center for Neurobehavioral Genetics, Semel Institute for Neuroscience and Human Behavior, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA 90095-1751, USA
| | - Michael V Sofroniew
- Department of Neurobiology, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA 90095-1751, USA
| | - Baljit S Khakh
- Department of Physiology, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA 90095-1751, USA; Department of Neurobiology, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA 90095-1751, USA.
| |
Collapse
|
18
|
Nagai J, Bellafard A, Qu Z, Yu X, Ollivier M, Gangwani MR, Diaz-Castro B, Coppola G, Schumacher SM, Golshani P, Gradinaru V, Khakh BS. Specific and behaviorally consequential astrocyte G q GPCR signaling attenuation in vivo with iβARK. Neuron 2021; 109:2256-2274.e9. [PMID: 34139149 PMCID: PMC8418870 DOI: 10.1016/j.neuron.2021.05.023] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2020] [Revised: 04/14/2021] [Accepted: 05/18/2021] [Indexed: 12/25/2022]
Abstract
Astrocytes respond to neurotransmitters and neuromodulators using G-protein-coupled receptors (GPCRs) to mediate physiological responses. Despite their importance, there has been no method to genetically, specifically, and effectively attenuate astrocyte Gq GPCR pathways to explore consequences of this prevalent signaling mechanism in vivo. We report a 122-residue inhibitory peptide from β-adrenergic receptor kinase 1 (iβARK; and inactive D110A control) to attenuate astrocyte Gq GPCR signaling. iβARK significantly attenuated Gq GPCR Ca2+ signaling in brain slices and, in vivo, altered behavioral responses, spared other GPCR responses, and did not alter astrocyte spontaneous Ca2+ signals, morphology, electrophysiological properties, or gene expression in the striatum. Furthermore, brain-wide attenuation of astrocyte Gq GPCR signaling with iβARK using PHP.eB adeno-associated viruses (AAVs), when combined with c-Fos mapping, suggested nuclei-specific contributions to behavioral adaptation and spatial memory. iβARK extends the toolkit needed to explore functions of astrocyte Gq GPCR signaling within neural circuits in vivo.
Collapse
Affiliation(s)
- Jun Nagai
- Department of Physiology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095-1751, USA; RIKEN Center for Brain Science, 2-1 Hirosawa Wako City, Saitama 351-0198, Japan
| | - Arash Bellafard
- Department of Neurology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095-1751, USA
| | - Zhe Qu
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA 91125, USA
| | - Xinzhu Yu
- Department of Physiology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095-1751, USA; Department of Molecular and Integrative Physiology, University of Illinois at Urbana-Champaign, 514 Burrill Hall, 407 S. Goodwin Ave, Urbana, IL 61801, USA
| | - Matthias Ollivier
- Department of Physiology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095-1751, USA
| | - Mohitkumar R Gangwani
- Department of Physiology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095-1751, USA
| | - Blanca Diaz-Castro
- Department of Physiology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095-1751, USA
| | - Giovanni Coppola
- Department of Neurology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095-1751, USA; Department of Psychiatry and Biobehavioral Sciences, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095-1751, USA; Center for Neurobehavioral Genetics, Semel Institute for Neuroscience and Human Behavior, University of California, Los Angeles, Los Angeles, CA 90095-1751, USA
| | - Sarah M Schumacher
- Department of Cardiovascular & Metabolic Sciences, Lerner Research Institute, Cleveland Clinic, 9500 Euclid Avenue, Cleveland, OH 44195, USA
| | - Peyman Golshani
- Department of Neurology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095-1751, USA; Department of Psychiatry and Biobehavioral Sciences, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095-1751, USA; Center for Neurobehavioral Genetics, Semel Institute for Neuroscience and Human Behavior, University of California, Los Angeles, Los Angeles, CA 90095-1751, USA; Integrative Center for Learning and Memory, University of California, Los Angeles, Los Angeles, CA 90095-1751, USA; West LA Veterans Affairs Medical Center, Los Angeles, CA 90073, USA; Intellectual and Developmental Disabilities Research Center, Los Angeles, CA, USA
| | - Viviana Gradinaru
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA 91125, USA
| | - Baljit S Khakh
- Department of Physiology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095-1751, USA; Department of Neurobiology, University of California, David Geffen School of Medicine, Los Angeles, Los Angeles, CA 90095-1751, USA.
| |
Collapse
|
19
|
Yu X, Moye SL, Khakh BS. Local and CNS-Wide Astrocyte Intracellular Calcium Signaling Attenuation In Vivo with CalEx flox Mice. J Neurosci 2021; 41:4556-4574. [PMID: 33903221 PMCID: PMC8260243 DOI: 10.1523/jneurosci.0085-21.2021] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2021] [Revised: 03/21/2021] [Accepted: 03/30/2021] [Indexed: 01/12/2023] Open
Abstract
Astrocytes exist throughout the CNS and affect neural circuits and behavior through intracellular Ca2+ signaling. Studying the function(s) of astrocyte Ca2+ signaling has proven difficult because of the paucity of tools to achieve selective attenuation. Based on recent studies, we generated and used male and female knock-in mice for Cre-dependent expression of mCherry-tagged hPMCA2w/b to attenuate astrocyte Ca2+ signaling in genetically defined cells in vivo (CalExflox mice for Calcium Extrusion). We characterized CalExflox mice following local AAV-Cre microinjections into the striatum and found reduced astrocyte Ca2+ signaling (∼90%) accompanied with repetitive self-grooming behavior. We also crossed CalExflox mice to astrocyte-specific Aldh1l1-Cre/ERT2 mice to achieve inducible global CNS-wide Ca2+ signaling attenuation. Within 6 d of induction in the bigenic mice, we observed significantly altered ambulation in the open field, disrupted motor coordination and gait, and premature lethality. Furthermore, with histologic, imaging, and transcriptomic analyses, we identified cellular and molecular alterations in the cerebellum following mCherry-tagged hPMCA2w/b expression. Our data show that expression of mCherry-tagged hPMCA2w/b with CalExflox mice throughout the CNS resulted in substantial attenuation of astrocyte Ca2+ signaling and significant behavioral alterations in adult mice. We interpreted these findings candidly in relation to the ability of CalEx to attenuate astrocyte Ca2+ signaling, with regards to additional mechanistic interpretations of the data, and their relation to past studies that reduced astrocyte Ca2+ signaling throughout the CNS. The data and resources provide complementary ways to interrogate the function(s) of astrocytes in multiple experimental scenarios.SIGNIFICANCE STATEMENT Astrocytes represent a significant fraction of all brain cells and tile the entire central nervous system. Unlike neurons, astrocytes lack propagated electrical signals. Instead, astrocytes are proposed to use diverse and dynamic intracellular Ca2+ signals to communicate with other cells. An open question concerns if and how astrocyte Ca2+ signaling regulates behavior in adult mice. We approached this problem by generating a new transgenic mouse line to achieve inducible astrocyte Ca2+ signaling attenuation in vivo We report our data with this mouse line and we interpret the findings candidly in relation to past studies and within the framework of different mechanistic interpretations.
Collapse
Affiliation(s)
- Xinzhu Yu
- Department of Physiology
- Department of Molecular and Integrative Physiology, Beckman Institute, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801-3704
| | | | - Baljit S Khakh
- Department of Physiology
- Department of Neurobiology, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, California 90095-1751
| |
Collapse
|
20
|
Rajbhandari AK, Octeau CJ, Gonzalez S, Pennington ZT, Mohamed F, Trott J, Chavez J, Ngyuen E, Keces N, Hong WZ, Neve RL, Waschek J, Khakh BS, Fanselow MS. A Basomedial Amygdala to Intercalated Cells Microcircuit Expressing PACAP and Its Receptor PAC1 Regulates Contextual Fear. J Neurosci 2021; 41:3446-3461. [PMID: 33637560 PMCID: PMC8051692 DOI: 10.1523/jneurosci.2564-20.2021] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2020] [Revised: 02/12/2021] [Accepted: 02/17/2021] [Indexed: 11/21/2022] Open
Abstract
Trauma can cause dysfunctional fear regulation leading some people to develop disorders, such as post-traumatic stress disorder (PTSD). The amygdala regulates fear, whereas PACAP (pituitary adenylate activating peptide) and PAC1 receptors are linked to PTSD symptom severity at genetic/epigenetic levels, with a strong link in females with PTSD. We discovered a PACAPergic projection from the basomedial amygdala (BMA) to the medial intercalated cells (mICCs) in adult mice. In vivo optogenetic stimulation of this pathway increased CFOS expression in mICCs, decreased fear recall, and increased fear extinction. Selective deletion of PAC1 receptors from the mICCs in females reduced fear acquisition, but enhanced fear generalization and reduced fear extinction in males. Optogenetic stimulation of the BMA-mICC PACAPergic pathway produced EPSCs in mICC neurons, which were enhanced by the PAC1 receptor antagonist, PACAP 6-38. Our findings show that mICCs modulate contextual fear in a dynamic and sex-dependent manner via a microcircuit containing the BMA and mICCs, and in a manner that was dependent on behavioral state.SIGNIFICANCE STATEMENT Traumatic stress can affect different aspects of fear behaviors, including fear learning, generalization of learned fear to novel contexts, how the fear of the original context is recalled, and how fear is reduced over time. While the amygdala has been studied for its role in regulation of different aspects of fear, the molecular circuitry of this structure is quite complex. In addition, aspects of fear can be modulated differently in males and females. Our findings show that a specific circuitry containing the neuropeptide PACAP and its receptor, PAC1, regulates various aspects of fear, including acquisition, generalization, recall, and extinction in a sexually dimorphic manner, characterizing a novel pathway that modulates traumatic fear.
Collapse
Affiliation(s)
- Abha K Rajbhandari
- Department of Psychology, University of California, Los Angeles, California 90095
- Staglin Center for Brain and Behavior, University of California, Los Angeles, California 90095
| | - Christopher J Octeau
- Department of Physiology, University of California, Los Angeles, California 90095
| | - Sarah Gonzalez
- Department of Psychology, University of California, Los Angeles, California 90095
- Staglin Center for Brain and Behavior, University of California, Los Angeles, California 90095
| | - Zachary T Pennington
- Department of Psychology, University of California, Los Angeles, California 90095
| | - Farzanna Mohamed
- Department of Psychiatry, Icahn School of Medicine at Mount Sinai, New York, New York 10029
| | - Jeremy Trott
- Department of Psychology, University of California, Los Angeles, California 90095
- Staglin Center for Brain and Behavior, University of California, Los Angeles, California 90095
| | - Jasmine Chavez
- Department of Psychology, University of California, Los Angeles, California 90095
| | - Erin Ngyuen
- Department of Psychology, University of California, Los Angeles, California 90095
| | - Natasha Keces
- Department of Psychology, University of California, Los Angeles, California 90095
| | - Weizhe Z Hong
- Department of Neurobiology, University of California, Los Angeles, California 90095
| | - Rachael L Neve
- Gene Delivery Technology Core, Massachusetts General Hospital, Boston, Massachusetts, California 02114
| | - James Waschek
- Department of Psychiatry, University of California, Los Angeles, California 90095
| | - Baljit S Khakh
- Department of Physiology, University of California, Los Angeles, California 90095
- Department of Neurobiology, University of California, Los Angeles, California 90095
| | - Michael S Fanselow
- Department of Psychology, University of California, Los Angeles, California 90095
- Staglin Center for Brain and Behavior, University of California, Los Angeles, California 90095
| |
Collapse
|
21
|
Kronschläger MT, Siegert ASM, Resch FJ, Rajendran PS, Khakh BS, Sandkühler J. Lamina-specific properties of spinal astrocytes. Glia 2021; 69:1749-1766. [PMID: 33694249 PMCID: PMC8252791 DOI: 10.1002/glia.23990] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2021] [Revised: 02/24/2021] [Accepted: 02/26/2021] [Indexed: 12/19/2022]
Abstract
Astrocytes are indispensable for proper neuronal functioning. Given the diverse needs of neuronal circuits and the variety of tasks astrocytes perform, the perceived homogeneous nature of astrocytes has been questioned. In the spinal dorsal horn, complex neuronal circuitries regulate the integration of sensory information of different modalities. The dorsal horn is organized in a distinct laminar manner based on termination patterns of high‐ and low‐threshold afferent fibers and neuronal properties. Neurons in laminae I (L1) and II (L2) integrate potentially painful, nociceptive information, whereas neurons in lamina III (L3) and deeper laminae integrate innocuous, tactile information from the periphery. Sensory information is also integrated by an uncharacterized network of astrocytes. How these lamina‐specific characteristics of neuronal circuits of the dorsal horn are of functional importance for properties of astrocytes is currently unknown. We addressed if astrocytes in L1, L2, and L3 of the upper dorsal horn of mice are differentially equipped for the needs of neuronal circuits that process sensory information of different modalities. We found that astrocytes in L1 and L2 were characterized by a higher density, higher expression of GFAP, Cx43, and GLAST and a faster coupling speed than astrocytes located in L3. L1 astrocytes were more responsive to Kir4.1 blockade and had higher levels of AQP4 compared to L3 astrocytes. In contrast, basic membrane properties, network formation, and somatic intracellular calcium signaling were similar in L1–L3 astrocytes. Our data indicate that the properties of spinal astrocytes are fine‐tuned for the integration of nociceptive versus tactile information.
Collapse
Affiliation(s)
- Mira T Kronschläger
- Department of Neurophysiology, Center for Brain Research, Medical University of Vienna, Vienna, Austria.,Department of Physiology, David Geffen Schoof of Medicine, University of California Los Angeles, Los Angeles, California, USA
| | - Anna S M Siegert
- Department of Neurophysiology, Center for Brain Research, Medical University of Vienna, Vienna, Austria
| | - Felix J Resch
- Department of Neurophysiology, Center for Brain Research, Medical University of Vienna, Vienna, Austria
| | - Pradeep S Rajendran
- UCLA Cardiac Arrhythmia Center, Neurocardiology Research Program of Excellence, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, California, USA
| | - Baljit S Khakh
- Department of Physiology, David Geffen Schoof of Medicine, University of California Los Angeles, Los Angeles, California, USA
| | - Jürgen Sandkühler
- Department of Neurophysiology, Center for Brain Research, Medical University of Vienna, Vienna, Austria
| |
Collapse
|
22
|
Escartin C, Galea E, Lakatos A, O'Callaghan JP, Petzold GC, Serrano-Pozo A, Steinhäuser C, Volterra A, Carmignoto G, Agarwal A, Allen NJ, Araque A, Barbeito L, Barzilai A, Bergles DE, Bonvento G, Butt AM, Chen WT, Cohen-Salmon M, Cunningham C, Deneen B, De Strooper B, Díaz-Castro B, Farina C, Freeman M, Gallo V, Goldman JE, Goldman SA, Götz M, Gutiérrez A, Haydon PG, Heiland DH, Hol EM, Holt MG, Iino M, Kastanenka KV, Kettenmann H, Khakh BS, Koizumi S, Lee CJ, Liddelow SA, MacVicar BA, Magistretti P, Messing A, Mishra A, Molofsky AV, Murai KK, Norris CM, Okada S, Oliet SHR, Oliveira JF, Panatier A, Parpura V, Pekna M, Pekny M, Pellerin L, Perea G, Pérez-Nievas BG, Pfrieger FW, Poskanzer KE, Quintana FJ, Ransohoff RM, Riquelme-Perez M, Robel S, Rose CR, Rothstein JD, Rouach N, Rowitch DH, Semyanov A, Sirko S, Sontheimer H, Swanson RA, Vitorica J, Wanner IB, Wood LB, Wu J, Zheng B, Zimmer ER, Zorec R, Sofroniew MV, Verkhratsky A. Reactive astrocyte nomenclature, definitions, and future directions. Nat Neurosci 2021; 24:312-325. [PMID: 33589835 PMCID: PMC8007081 DOI: 10.1038/s41593-020-00783-4] [Citation(s) in RCA: 961] [Impact Index Per Article: 320.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2020] [Accepted: 12/16/2020] [Indexed: 12/18/2022]
Abstract
Reactive astrocytes are astrocytes undergoing morphological, molecular, and functional remodeling in response to injury, disease, or infection of the CNS. Although this remodeling was first described over a century ago, uncertainties and controversies remain regarding the contribution of reactive astrocytes to CNS diseases, repair, and aging. It is also unclear whether fixed categories of reactive astrocytes exist and, if so, how to identify them. We point out the shortcomings of binary divisions of reactive astrocytes into good-vs-bad, neurotoxic-vs-neuroprotective or A1-vs-A2. We advocate, instead, that research on reactive astrocytes include assessment of multiple molecular and functional parameters-preferably in vivo-plus multivariate statistics and determination of impact on pathological hallmarks in relevant models. These guidelines may spur the discovery of astrocyte-based biomarkers as well as astrocyte-targeting therapies that abrogate detrimental actions of reactive astrocytes, potentiate their neuro- and glioprotective actions, and restore or augment their homeostatic, modulatory, and defensive functions.
Collapse
Affiliation(s)
- Carole Escartin
- Université Paris-Saclay, CEA, CNRS, MIRCen, Laboratoire des Maladies Neurodégénératives, Fontenay-aux-Roses, France.
| | - Elena Galea
- Institut de Neurociències and Departament de Bioquímica i Biologia Molecular, Unitat de Bioquímica de Medicina, Universitat Autònoma de Barcelona, Barcelona, Spain.
- ICREA, Barcelona, Spain.
| | - András Lakatos
- John van Geest Centre for Brain Repair and Division of Stem Cell Neurobiology, Department of Clinical Neurosciences, University of Cambridge, Cambridge, UK
- Wellcome Trust-MRC Cambridge Stem Cell Institute, Cambridge Biomedical Campus, Cambridge, UK
| | - James P O'Callaghan
- Health Effects Laboratory Division, Centers for Disease Control and Prevention, National Institute for Occupational Safety and Health, Morgantown, West Virginia, USA
| | - Gabor C Petzold
- German Center for Neurodegenerative Diseases (DZNE), Bonn, Germany
- Division of Vascular Neurology, Department of Neurology, University Hospital Bonn, Bonn, Germany
| | - Alberto Serrano-Pozo
- Alzheimer Research Unit, Department of Neurology, Massachusetts General Hospital, Charlestown, Massachusetts, USA
- Harvard Medical School, Boston, Massachusetts, USA
| | - Christian Steinhäuser
- Institute of Cellular Neurosciences, Medical Faculty, University of Bonn, Bonn, Germany
| | - Andrea Volterra
- Department of Fundamental Neuroscience, University of Lausanne, Lausanne, Switzerland
| | - Giorgio Carmignoto
- Neuroscience Institute, Italian National Research Council (CNR), Padua, Italy
- Department of Biomedical Sciences, University of Padua, Padua, Italy
| | - Amit Agarwal
- The Chica and Heinz Schaller Research Group, Institute for Anatomy and Cell Biology, Heidelberg University, Heidelberg, Germany
| | - Nicola J Allen
- Salk Institute for Biological Studies, Molecular Neurobiology Laboratory, La Jolla, California, USA
| | - Alfonso Araque
- Department of Neuroscience, University of Minnesota, Minneapolis, Minnesota, USA
| | | | - Ari Barzilai
- Department of Neurobiology, George S. Wise, Faculty of Life Sciences and Sagol School of Neuroscience, Tel Aviv University, Ramat Aviv Tel Aviv, Israel
| | - Dwight E Bergles
- The Solomon H. Snyder Department of Neuroscience, Kavli Neuroscience Discovery Institute, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Gilles Bonvento
- Université Paris-Saclay, CEA, CNRS, MIRCen, Laboratoire des Maladies Neurodégénératives, Fontenay-aux-Roses, France
| | - Arthur M Butt
- School of Pharmacy and Biomedical Science, University of Portsmouth, Portsmouth, UK
| | - Wei-Ting Chen
- Center for Brain and Disease Research, VIB and University of Leuven, Leuven, Belgium
| | - Martine Cohen-Salmon
- 'Physiology and Physiopathology of the Gliovascular Unit' Research Group, Center for Interdisciplinary Research in Biology (CIRB), College de France, Unité Mixte de Recherche 7241 CNRS, Unité1050 INSERM, PSL Research University, Paris, France
| | - Colm Cunningham
- Trinity Biomedical Sciences Institute & Trinity College Institute of Neuroscience, School of Biochemistry & Immunology, Trinity College Dublin, Dublin, Republic of Ireland
| | - Benjamin Deneen
- Center for Cell and Gene Therapy, Department of Neurosurgery, Baylor College of Medicine, Houston, Texas, USA
| | - Bart De Strooper
- Center for Brain and Disease Research, VIB and University of Leuven, Leuven, Belgium
- UK Dementia Research Institute at the University College London, London, UK
| | - Blanca Díaz-Castro
- UK Dementia Research Institute at the University of Edinburgh, Centre for Discovery Brain Sciences, Edinburgh, UK
| | - Cinthia Farina
- Institute of Experimental Neurology (INSpe) and Division of Neuroscience, San Raffaele Scientific Institute, Milan, Italy
| | | | - Vittorio Gallo
- Center for Neuroscience Research, Children's National Research Institute, Children's National Hospital, Washington DC, USA
| | - James E Goldman
- Department of Pathology & Cell Biology, Columbia University, New York, New York, USA
| | - Steven A Goldman
- University of Rochester Medical Center, Rochester, New York, USA
- Center for Translational Neuromedicine, University of Copenhagen Faculty of Health and Medical Science and Rigshospitalet, Kobenhavn N, Denmark
| | - Magdalena Götz
- Physiological Genomics, Biomedical Center, Ludwig-Maximilians-Universitaet & Institute of Stem Cell Research, Helmholtz Center Munich, Munich, Germany
- Synergy, Excellence Cluster of Systems Neurology, Biomedical Center, Munich, Germany
| | - Antonia Gutiérrez
- Dpto. Biología Celular, Genética y Fisiología, Instituto de Investigación Biomédica de Málaga-IBIMA, Facultad de Ciencias, Universidad de Málaga, Málaga, Spain
- Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Madrid, Spain
| | - Philip G Haydon
- Department of Neuroscience, Tufts University School of Medicine, Boston, Massachusetts, USA
| | - Dieter H Heiland
- Microenvironment and Immunology Research Laboratory, Medical Center, Faculty of Medicine, University of Freiburg, Freiburg, Germany
- Department of Neurosurgery, Medical Center, University of Freiburg, Faculty of Medicine, Freiburg, Germany
| | - Elly M Hol
- Department of Translational Neuroscience, University Medical Center Utrecht Brain Center, Utrecht University, Utrecht, The Netherlands
| | - Matthew G Holt
- Laboratory of Glia Biology, VIB-KU Leuven Center for Brain and Disease Research, Leuven, Belgium
| | - Masamitsu Iino
- Division of Cellular and Molecular Pharmacology, Nihon University School of Medicine, Tokyo, Japan
| | - Ksenia V Kastanenka
- Massachusetts General Hospital, Harvard Medical School, Charlestown, Massachusetts, USA
| | - Helmut Kettenmann
- Cellular Neurosciences, Max Delbrück Center for Molecular Medicine in the Helmholtz Association, Berlin, Germany
| | - Baljit S Khakh
- Department of Physiology, David Geffen School of Medicine at UCLA, Los Angeles, California, USA
| | - Schuichi Koizumi
- Department of Neuropharmacology, Interdisciplinary Graduate School of Medicine, University of Yamanashi, Yamanashi, Japan
| | - C Justin Lee
- Center for Cognition and Sociality, Institute for Basic Science 55, Expo-ro, Yuseong-gu, Daejeon, Korea
| | - Shane A Liddelow
- Neuroscience Institute, Department of Neuroscience and Physiology, Department of Ophthalmology, NYU School of Medicine, New York, USA
| | - Brian A MacVicar
- Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, British Columbia, Canada
| | - Pierre Magistretti
- Division of Biological and Environmental Sciences and Engineering, King Abdullah University of Science and Technology (KAUST), Thuwal, Saudi Arabia
- Centre de Neurosciences Psychiatriques, University of Lausanne and CHUV, Site de Cery, Prilly-Lausanne, Lausanne, Switzerland
| | - Albee Messing
- Waisman Center and School of Veterinary Medicine, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Anusha Mishra
- Department of Neurology Jungers Center for Neurosciences Research and Knight Cardiovascular Institute, Oregon Health & Science University, Portland, Oregon, USA
| | - Anna V Molofsky
- Departments of Psychiatry/Weill Institute for Neuroscience University of California, San Francisco, California, USA
| | - Keith K Murai
- Centre for Research in Neuroscience, Department of Neurology & Neurosurgery, Brain Repair and Integrative Neuroscience Program, Research Institute of the McGill University Health Centre, Montreal, Quebec, Canada
| | - Christopher M Norris
- Sanders-Brown Center on Aging, University of Kentucky College of Medicine, Lexington, Kentucky, USA
| | - Seiji Okada
- Department of Immunobiology and Neuroscience, Medical Institute of Bioregulation, Kyushu University, Fukuoka, Japan
| | - Stéphane H R Oliet
- Université de Bordeaux, Inserm, Neurocentre Magendie, U1215, Bordeaux, France
| | - João F Oliveira
- Life and Health Sciences Research Institute (ICVS), School of Medicine, University of Minho, Braga, Portugal
- ICVS/3B's -PT Government Associate Laboratory, Braga/Guimarães, Portugal
- IPCA-EST-2Ai, Polytechnic Institute of Cávado and Ave, Applied Artificial Intelligence Laboratory, Campus of IPCA, Barcelos, Portugal
| | - Aude Panatier
- Université de Bordeaux, Inserm, Neurocentre Magendie, U1215, Bordeaux, France
| | - Vladimir Parpura
- Department of Neurobiology, The University of Alabama at Birmingham, Birmingham, Alabama, USA
| | - Marcela Pekna
- Laboratory of Regenerative Neuroimmunology, Center for Brain Repair, Department of Clinical Neuroscience, Institute of Neuroscience and Physiology, Sahlgrenska Academy at the University of Gothenburg, Gothenburg, Sweden
| | - Milos Pekny
- Laboratory of Astrocyte Biology and CNS Regeneration, Center for Brain Repair, Department of Clinical Neuroscience, Institute of Neuroscience and Physiology, Sahlgrenska Academy at the University of Gothenburg, Gothenburg, Sweden
| | - Luc Pellerin
- INSERM U1082, Université de Poitiers, Poitiers, France
| | - Gertrudis Perea
- Department of Functional and Systems Neurobiology, Cajal Institute, CSIC, Madrid, Spain
| | - Beatriz G Pérez-Nievas
- Department of Basic and Clinical Neuroscience, Maurice Wohl Clinical Neuroscience Institute, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK
| | - Frank W Pfrieger
- Centre National de la Recherche Scientifique, Université de Strasbourg, Institut des Neurosciences Cellulaires et Intégratives, Strasbourg, France
| | - Kira E Poskanzer
- Department of Biochemistry & Biophysics, Kavli Institute for Fundamental Neuroscience, University of California, San Francisco, California, USA
| | - Francisco J Quintana
- Ann Romney Center for Neurologic Diseases, Brigham and Women's Hospital, Harvard Medical School. Associate Member, The Broad Institute, Boston, Massachusetts, USA
| | | | - Miriam Riquelme-Perez
- Université Paris-Saclay, CEA, CNRS, MIRCen, Laboratoire des Maladies Neurodégénératives, Fontenay-aux-Roses, France
| | - Stefanie Robel
- Fralin Biomedical Research Institute at Virginia Tech Carilion, School of Neuroscience Virginia Tech, Riverside Circle, Roanoke, Virginia, USA
| | - Christine R Rose
- Institute of Neurobiology, Heinrich Heine University, Düsseldorf, Germany
| | - Jeffrey D Rothstein
- Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Nathalie Rouach
- Neuroglial Interactions in Cerebral Physiology and Pathologies, Center for Interdisciplinary Research in Biology, Collège de France, CNRS UMR 7241, INSERM U1050, Labex Memolife, PSL Research University Paris, Paris, France
| | - David H Rowitch
- Wellcome Trust-MRC Cambridge Stem Cell Institute, Cambridge Biomedical Campus, Cambridge, UK
| | - Alexey Semyanov
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Moscow, Russia
- Sechenov First Moscow State Medical University, Moscow, Russia
| | - Swetlana Sirko
- Physiological Genomics, Biomedical Center, LMU Munich, Munich, Germany
- Institute for Stem Cell Research, Helmholtz Zentrum Munich, Neuherberg, Germany
| | - Harald Sontheimer
- Virginia Tech School of Neuroscience and Center for Glial Biology in Health, Disease and Cancer, Virginia Tech at the Fralin Biomedical Research Institute, Roanoke, Virginia, USA
| | - Raymond A Swanson
- Dept. of Neurology, University of California San Francisco and San Francisco Veterans Affairs Health Care System, San Francisco, California, USA
| | - Javier Vitorica
- Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Madrid, Spain
- Dept. Bioquímica y Biología Molecular, Instituto de Biomedicina de Sevilla, Universidad de Sevilla, Hospital Virgen del Rocío/CSIC, Sevilla, Spain
| | - Ina-Beate Wanner
- Semel Institute for Neuroscience & Human Behavior, IDDRC, David Geffen School of Medicine, UCLA, Los Angeles, California, USA
| | - Levi B Wood
- George W. Woodruff School of Mechanical Engineering, Wallace H. Coulter Department of Biomedical Engineering at Georgia Tech and Emory, and Parker H. Petit Institute for Bioengineering & Bioscience, Georgia Institute of Technology, Atlanta, Georgia, USA
| | - Jiaqian Wu
- The Vivian L. Smith Department of Neurosurgery, Center for Stem Cell and Regenerative Medicine, MD Anderson Cancer Center UTHealth Graduate School of Biomedical Sciences, McGovern Medical School, UTHealth, University of Texas Health Science Center at Houston, Houston, TX, USA
| | - Binhai Zheng
- Department of Neurosciences, UC San Diego School of Medicine, La Jolla; VA San Diego Research Service, San Diego, CA, USA
| | - Eduardo R Zimmer
- Department of Pharmacology, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil
| | - Robert Zorec
- Laboratory of Neuroendocrinology, Molecular Cell Physiology, Institute of Pathophysiology, University of Ljubljana, Faculty of Medicine, Ljubljana, Slovenia
- Celica Biomedical, 1000, Ljubljana, Slovenia
| | - Michael V Sofroniew
- Department of Neurobiology, David Geffen School of Medicine, University of California, Los Angeles, California, USA.
| | - Alexei Verkhratsky
- Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, UK.
- Achúcarro Basque Center for Neuroscience, IKERBASQUE, Basque Foundation for Science, Bilbao, Spain.
| |
Collapse
|
23
|
Nagai J, Yu X, Papouin T, Cheong E, Freeman MR, Monk KR, Hastings MH, Haydon PG, Rowitch D, Shaham S, Khakh BS. Behaviorally consequential astrocytic regulation of neural circuits. Neuron 2020; 109:576-596. [PMID: 33385325 DOI: 10.1016/j.neuron.2020.12.008] [Citation(s) in RCA: 115] [Impact Index Per Article: 28.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2020] [Revised: 11/23/2020] [Accepted: 12/07/2020] [Indexed: 12/16/2022]
Abstract
Astrocytes are a large and diverse population of morphologically complex cells that exist throughout nervous systems of multiple species. Progress over the last two decades has shown that astrocytes mediate developmental, physiological, and pathological processes. However, a long-standing open question is how astrocytes regulate neural circuits in ways that are behaviorally consequential. In this regard, we summarize recent studies using Caenorhabditis elegans, Drosophila melanogaster, Danio rerio, and Mus musculus. The data reveal diverse astrocyte mechanisms operating in seconds or much longer timescales within neural circuits and shaping multiple behavioral outputs. We also refer to human diseases that have a known primary astrocytic basis. We suggest that including astrocytes in mechanistic, theoretical, and computational studies of neural circuits provides new perspectives to understand behavior, its regulation, and its disease-related manifestations.
Collapse
Affiliation(s)
- Jun Nagai
- Department of Physiology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095-1751, USA; RIKEN Center for Brain Science, 2-1 Hirosawa Wako City, Saitama 351-0198, Japan
| | - Xinzhu Yu
- Department of Physiology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095-1751, USA; Department of Molecular and Integrative Physiology, University of Illinois at Urbana-Champaign, 514 Burrill Hall, 407 S. Goodwin Ave, Urbana, IL 61801, USA
| | - Thomas Papouin
- Department of Neuroscience, Washington University in St. Louis, School of Medicine, Campus Box 8108, 660 South Euclid Ave., St. Louis, MO 63110, USA
| | - Eunji Cheong
- Department of Biotechnology, College of Life Science and Biotechnology, Yonsei University, Seoul 03722, South Korea
| | - Marc R Freeman
- The Vollum Institute, Oregon Health & Science University, 3181 SW Sam Jackson Park Road, Portland, OR 97239, USA
| | - Kelly R Monk
- The Vollum Institute, Oregon Health & Science University, 3181 SW Sam Jackson Park Road, Portland, OR 97239, USA
| | - Michael H Hastings
- MRC Laboratory of Molecular Biology, Cambridge Biomedical Campus, Francis Crick Avenue, Cambridge CB2 0QH, UK
| | - Philip G Haydon
- Department of Neuroscience, Tufts University School of Medicine, 136 Harrison Avenue, Boston, MA 02111, USA
| | - David Rowitch
- Department of Paediatrics, Wellcome-MRC Cambridge Stem Cell Institute, University of Cambridge, Cambridge, UK; Departments of Pediatrics and Neurosurgery, Eli and Edythe Broad Center of Regeneration Medicine and Stem Cell Research, University of California, San Francisco, San Francisco, CA, USA
| | - Shai Shaham
- Laboratory of Developmental Genetics, The Rockefeller University, 1230 York Avenue, New York, NY 10065, USA
| | - Baljit S Khakh
- Department of Physiology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095-1751, USA; Department of Neurobiology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095-1751, USA.
| |
Collapse
|
24
|
Yu X, Nagai J, Marti-Solano M, Soto JS, Coppola G, Babu MM, Khakh BS. Context-Specific Striatal Astrocyte Molecular Responses Are Phenotypically Exploitable. Neuron 2020; 108:1146-1162.e10. [PMID: 33086039 DOI: 10.1016/j.neuron.2020.09.021] [Citation(s) in RCA: 61] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2020] [Revised: 08/13/2020] [Accepted: 09/16/2020] [Indexed: 12/14/2022]
Abstract
Astrocytes tile the central nervous system and are widely implicated in brain diseases, but the molecular mechanisms by which astrocytes contribute to brain disorders remain incompletely explored. By performing astrocyte gene expression analyses following 14 experimental perturbations of relevance to the striatum, we discovered that striatal astrocytes mount context-specific molecular responses at the level of genes, pathways, and upstream regulators. Through data mining, we also identified astrocyte pathways in Huntington's disease (HD) that were reciprocally altered with respect to the activation of striatal astrocyte G protein-coupled receptor (GPCR) signaling. Furthermore, selective striatal astrocyte stimulation of the Gi-GPCR pathway in vivo corrected several HD-associated astrocytic, synaptic, and behavioral phenotypes, with accompanying improvement of HD-associated astrocyte signaling pathways, including those related to synaptogenesis and neuroimmune functions. Overall, our data show that astrocytes are malleable, using context-specific responses that can be dissected molecularly and used for phenotypic benefit in brain disorders.
Collapse
Affiliation(s)
- Xinzhu Yu
- Department of Physiology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095-1751, USA
| | - Jun Nagai
- Department of Physiology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095-1751, USA
| | - Maria Marti-Solano
- MRC Laboratory of Molecular Biology, Cambridge Biomedical Campus, Francis Crick Avenue, Cambridge CB2 0QH, UK
| | - Joselyn S Soto
- Department of Physiology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095-1751, USA
| | - Giovanni Coppola
- Department of Neurology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095-1751, USA; Department of Psychiatry and Biobehavioral Sciences, Semel Institute for Neuroscience and Human Behavior, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095-1751, USA; Center for Neurobehavioral Genetics, Semel Institute for Neuroscience and Human Behavior, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095-1751, USA
| | - M Madan Babu
- MRC Laboratory of Molecular Biology, Cambridge Biomedical Campus, Francis Crick Avenue, Cambridge CB2 0QH, UK; Department of Structural Biology and Center for Data Driven Discovery, St. Jude Children's Research Hospital, Memphis, TN 38105-3678, USA
| | - Baljit S Khakh
- Department of Physiology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095-1751, USA; Department of Neurobiology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095-1751, USA.
| |
Collapse
|
25
|
Diaz-Castro B, Gangwani MR, Yu X, Coppola G, Khakh BS. Astrocyte molecular signatures in Huntington's disease. Sci Transl Med 2020; 11:11/514/eaaw8546. [PMID: 31619545 DOI: 10.1126/scitranslmed.aaw8546] [Citation(s) in RCA: 120] [Impact Index Per Article: 30.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2019] [Accepted: 08/02/2019] [Indexed: 12/14/2022]
Abstract
Astrocytes are implicated in neurodegenerative disorders and may contribute to striatal neuron loss or dysfunction in Huntington's disease (HD). Here, we assessed striatal astrocyte gene and protein signatures in two HD mouse models at three stages and compared our results to human HD data at four clinical grades and to mice exhibiting polyglutamine length-dependent pathology. We found disease-model and stage-specific alterations and discovered a core disease-associated astrocyte molecular signature comprising 62 genes that were conserved between mice and humans. Our results show little evidence of neurotoxic A1 astrocytes that have been proposed to be causal for neuronal death in neurodegenerative disorders such as HD. Furthermore, 61 of the 62-core gene expression changes within astrocytes were reversed in a HD mouse model by lowering astrocyte mutant huntingtin protein (mHTT) expression using zinc finger protein (ZFP) transcriptional repressors. Our findings indicate that HD astrocytes progressively lose essential normal functions, some of which can be remedied by lowering mHTT. The data have implications for neurodegenerative disease rescue and repair strategies as well as specific therapeutic relevance for mHTT reduction and contribute to a better understanding of fundamental astrocyte biology and its contributions to disease.
Collapse
Affiliation(s)
- Blanca Diaz-Castro
- Department of Physiology, University of California, Los Angeles, Los Angeles, CA 90095-1751, USA
| | - Mohitkumar R Gangwani
- Department of Physiology, University of California, Los Angeles, Los Angeles, CA 90095-1751, USA
| | - Xinzhu Yu
- Department of Physiology, University of California, Los Angeles, Los Angeles, CA 90095-1751, USA
| | - Giovanni Coppola
- Department of Neurology, University of California, Los Angeles, Los Angeles, CA 90095-1751, USA.,Department of Psychiatry and Biobehavioral Sciences, University of California, Los Angeles, Los Angeles, CA 90095-1751, USA.,Center for Neurobehavioral Genetics, Semel Institute for Neuroscience and Human Behavior, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095-1751, USA
| | - Baljit S Khakh
- Department of Physiology, University of California, Los Angeles, Los Angeles, CA 90095-1751, USA. .,Department of Neurobiology, University of California, Los Angeles, Los Angeles, CA 90095-1751, USA
| |
Collapse
|
26
|
Octeau JC, Gangwani MR, Allam SL, Tran D, Huang S, Hoang-Trong TM, Golshani P, Rumbell TH, Kozloski JR, Khakh BS. Transient, Consequential Increases in Extracellular Potassium Ions Accompany Channelrhodopsin2 Excitation. Cell Rep 2020; 27:2249-2261.e7. [PMID: 31116972 PMCID: PMC6582980 DOI: 10.1016/j.celrep.2019.04.078] [Citation(s) in RCA: 57] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2018] [Revised: 03/04/2019] [Accepted: 04/17/2019] [Indexed: 12/13/2022] Open
Abstract
Channelrhodopsin2 (ChR2) optogenetic excitation is widely used to study neurons, astrocytes, and circuits. Using complementary approaches in situ and in vivo, we found that ChR2 stimulation leads to significant transient elevation of extracellular potassium ions by ~5 mM. Such elevations were detected in ChR2-expressing mice, following local in vivo expression of ChR2(H134R) with adeno-associated viruses (AAVs), in different brain areas and when ChR2 was expressed in neurons or astrocytes. In particular, ChR2-mediated excitation of striatal astrocytes was sufficient to increase medium spiny neuron (MSN) excitability and immediate early gene expression. The effects on MSN excitability were recapitulated in silico with a computational MSN model and detected in vivo as increased action potential firing in awake, behaving mice. We show that transient, physiologically consequential increases in extracellular potassium ions accompany ChR2 optogenetic excitation. This coincidental effect may be important to consider during astrocyte studies employing ChR2 to interrogate neural circuits and animal behavior. Using multiple approaches, Octeau et al. discover that optogenetic excitation of ChR2-expressing cells leads to significant transient extracellular potassium ion elevations that increase neuronal excitability and immediate early gene expression in neurons following in vivo stimulation.
Collapse
Affiliation(s)
- J Christopher Octeau
- Department of Physiology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095-1751, USA
| | - Mohitkumar R Gangwani
- Department of Physiology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095-1751, USA
| | - Sushmita L Allam
- IBM T.J. Watson Research Center, P.O. Box 218, 1101 Kitchawan Road, Yorktown Heights, NY 10598, USA
| | - Duy Tran
- Department of Neurology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095-1751, USA
| | - Shuhan Huang
- Department of Physiology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095-1751, USA
| | - Tuan M Hoang-Trong
- IBM T.J. Watson Research Center, P.O. Box 218, 1101 Kitchawan Road, Yorktown Heights, NY 10598, USA
| | - Peyman Golshani
- Department of Neurology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095-1751, USA; Department of Psychiatry and Biobehavioral Sciences, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095-1751, USA; Intellectual and Developmental Disabilities Research Center, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095-1751, USA; Center for Neurobehavioral Genetics, Semel Institute for Neuroscience and Human Behavior, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095-1751, USA
| | - Timothy H Rumbell
- IBM T.J. Watson Research Center, P.O. Box 218, 1101 Kitchawan Road, Yorktown Heights, NY 10598, USA
| | - James R Kozloski
- IBM T.J. Watson Research Center, P.O. Box 218, 1101 Kitchawan Road, Yorktown Heights, NY 10598, USA
| | - Baljit S Khakh
- Department of Physiology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095-1751, USA; Department of Neurobiology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095-1751, USA.
| |
Collapse
|
27
|
Abstract
Astrocytes are morphologically complex, ubiquitous cells that are viewed as a homogeneous population tiling the entire central nervous system (CNS). However, this view has been challenged in the last few years with the availability of RNA sequencing, immunohistochemistry, electron microscopy, morphological reconstruction, and imaging data. These studies suggest that astrocytes represent a diverse population of cells and that they display brain area- and disease-specific properties and functions. In this review, we summarize these observations, emphasize areas where clear conclusions can be made, and discuss potential unifying themes. We also identify knowledge gaps that need to be addressed in order to exploit astrocyte diversity as a biological phenomenon of physiological relevance in the CNS. We thus provide a summary and a perspective on astrocyte diversity in the vertebrate CNS.
Collapse
Affiliation(s)
- Baljit S Khakh
- Departments of Physiology and Neurobiology, David Geffen School of Medicine, University of California, Los Angeles, California 90095, USA;
| | - Benjamin Deneen
- Department of Neuroscience and Center for Cell and Gene Therapy, Baylor College of Medicine, Houston, Texas 77030, USA;
| |
Collapse
|
28
|
Badia-Soteras A, Octeau JC, Verheijen MHG, Khakh BS. Assessing Neuron-Astrocyte Spatial Interactions Using the Neuron-Astrocyte Proximity Assay. Curr Protoc Neurosci 2020; 91:e91. [PMID: 32068967 PMCID: PMC7123847 DOI: 10.1002/cpns.91] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Astrocytes are morphologically complex cells with numerous close contacts with neurons at the level of their somata, branches, and branchlets. The smallest astrocyte processes make discrete contacts with synapses at scales that cannot be observed by standard light microscopy. At such contact points, astrocytes are thought to perform both homeostatic and neuromodulatory roles-functions that are proposed to be determined by their close spatial apposition. To study such spatial interactions, we previously developed a Förster resonance energy transfer (FRET)-based approach, which enables observation and tracking of the static and dynamic proximity of astrocyte processes with synapses. The approach is compatible with standard imaging techniques such as confocal microscopy and permits assessment of the most proximate contacts between astrocytes and neurons in live tissues. In this protocol article we describe the approach to analyze the contacts between striatal astrocyte processes and corticostriatal neuronal projection terminals onto medium spiny neurons. We report the required protocols in detail, including adeno-associated virus microinjections, acute brain slice preparation, imaging, and post hoc FRET quantification. The article provides a detailed description that can be used to characterize and study astrocyte process proximity to synapses in living tissue. © 2020 by John Wiley & Sons, Inc. Basic Protocol 1: Förster resonance energy transfer imaging in cultured cells Basic Protocol 2: Förster resonance energy transfer imaging with the neuron-astrocyte proximity assay in acute brain slices.
Collapse
Affiliation(s)
- Aina Badia-Soteras
- Department of Molecular & Cellular Neurobiology, Center for Neurogenomics and Cognitive Research, Amsterdam Neuroscience, VU University Amsterdam, Amsterdam, 1081 HV, The Netherlands
| | - J. Christopher Octeau
- Department of Physiology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095-1751, USA
| | - Mark H. G. Verheijen
- Department of Molecular & Cellular Neurobiology, Center for Neurogenomics and Cognitive Research, Amsterdam Neuroscience, VU University Amsterdam, Amsterdam, 1081 HV, The Netherlands
| | - Baljit S. Khakh
- Department of Physiology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095-1751, USA
- Department of Neurobiology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095-1751, USA
| |
Collapse
|
29
|
|
30
|
Shuman T, Aharoni D, Cai DJ, Lee CR, Chavlis S, Page-Harley L, Vetere LM, Feng Y, Yang CY, Mollinedo-Gajate I, Chen L, Pennington ZT, Taxidis J, Flores SE, Cheng K, Javaherian M, Kaba CC, Rao N, La-Vu M, Pandi I, Shtrahman M, Bakhurin KI, Masmanidis SC, Khakh BS, Poirazi P, Silva AJ, Golshani P. Breakdown of spatial coding and interneuron synchronization in epileptic mice. Nat Neurosci 2020. [PMID: 31907437 DOI: 10.1038/s41593-019-0559-0.e] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/16/2023]
Abstract
Temporal lobe epilepsy causes severe cognitive deficits, but the circuit mechanisms remain unknown. Interneuron death and reorganization during epileptogenesis may disrupt the synchrony of hippocampal inhibition. To test this, we simultaneously recorded from the CA1 and dentate gyrus in pilocarpine-treated epileptic mice with silicon probes during head-fixed virtual navigation. We found desynchronized interneuron firing between the CA1 and dentate gyrus in epileptic mice. Since hippocampal interneurons control information processing, we tested whether CA1 spatial coding was altered in this desynchronized circuit, using a novel wire-free miniscope. We found that CA1 place cells in epileptic mice were unstable and completely remapped across a week. This spatial instability emerged around 6 weeks after status epilepticus, well after the onset of chronic seizures and interneuron death. Finally, CA1 network modeling showed that desynchronized inputs can impair the precision and stability of CA1 place cells. Together, these results demonstrate that temporally precise intrahippocampal communication is critical for spatial processing.
Collapse
Affiliation(s)
- Tristan Shuman
- Nash Family Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY, USA.
- Department of Neurology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, USA.
| | - Daniel Aharoni
- Department of Neurology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, USA
- Integrative Center for Learning and Memory, University of California, Los Angeles, Los Angeles, CA, USA
| | - Denise J Cai
- Nash Family Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY, USA
- Department of Neurobiology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, USA
| | - Christopher R Lee
- Nash Family Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY, USA
- Department of Neurology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, USA
| | - Spyridon Chavlis
- Institute of Molecular Biology and Biotechnology (IMBB), Foundation for Research and Technology Hellas (FORTH), Heraklion, Greece
| | - Lucia Page-Harley
- Nash Family Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Lauren M Vetere
- Nash Family Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Yu Feng
- Nash Family Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Chen Yi Yang
- Department of Neurology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, USA
| | - Irene Mollinedo-Gajate
- Department of Neurology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, USA
| | - Lingxuan Chen
- Nash Family Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Zachary T Pennington
- Nash Family Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Jiannis Taxidis
- Department of Neurology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, USA
| | - Sergio E Flores
- Department of Neurology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, USA
| | - Kevin Cheng
- Department of Neurology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, USA
| | - Milad Javaherian
- Department of Neurology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, USA
| | - Christina C Kaba
- Department of Neurology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, USA
| | - Naina Rao
- Department of Neurology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, USA
| | - Mimi La-Vu
- Department of Neurobiology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, USA
| | - Ioanna Pandi
- Institute of Molecular Biology and Biotechnology (IMBB), Foundation for Research and Technology Hellas (FORTH), Heraklion, Greece
- School of Medicine, University of Crete, Heraklion, Greece
| | - Matthew Shtrahman
- Department of Neurosciences, University of California, San Diego, La Jolla, CA, USA
| | - Konstantin I Bakhurin
- Department of Neurobiology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, USA
| | - Sotiris C Masmanidis
- Department of Neurobiology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, USA
| | - Baljit S Khakh
- Department of Physiology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, USA
| | - Panayiota Poirazi
- Institute of Molecular Biology and Biotechnology (IMBB), Foundation for Research and Technology Hellas (FORTH), Heraklion, Greece.
| | - Alcino J Silva
- Integrative Center for Learning and Memory, University of California, Los Angeles, Los Angeles, CA, USA
- Department of Neurobiology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, USA
- Semel Institute for Neuroscience and Human Behavior, University of California, Los Angeles, Los Angeles, CA, USA
- Department of Psychology, University of California, Los Angeles, Los Angeles, CA, USA
| | - Peyman Golshani
- Department of Neurology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, USA.
- Integrative Center for Learning and Memory, University of California, Los Angeles, Los Angeles, CA, USA.
- Department of Physiology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, USA.
- Semel Institute for Neuroscience and Human Behavior, University of California, Los Angeles, Los Angeles, CA, USA.
- West LA Veterans Affairs Medical Center, Los Angeles, CA, USA.
- Intellectual and Developmental Disabilities Research Center, University of California, Los Angeles, Los Angeles, CA, USA.
| |
Collapse
|
31
|
Shuman T, Aharoni D, Cai DJ, Lee CR, Chavlis S, Page-Harley L, Vetere LM, Feng Y, Yang CY, Mollinedo-Gajate I, Chen L, Pennington ZT, Taxidis J, Flores SE, Cheng K, Javaherian M, Kaba CC, Rao N, La-Vu M, Pandi I, Shtrahman M, Bakhurin KI, Masmanidis SC, Khakh BS, Poirazi P, Silva AJ, Golshani P. Breakdown of spatial coding and interneuron synchronization in epileptic mice. Nat Neurosci 2020; 23:229-238. [PMID: 31907437 DOI: 10.1038/s41593-019-0559-0] [Citation(s) in RCA: 77] [Impact Index Per Article: 19.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2018] [Accepted: 11/19/2019] [Indexed: 12/19/2022]
Abstract
Temporal lobe epilepsy causes severe cognitive deficits, but the circuit mechanisms remain unknown. Interneuron death and reorganization during epileptogenesis may disrupt the synchrony of hippocampal inhibition. To test this, we simultaneously recorded from the CA1 and dentate gyrus in pilocarpine-treated epileptic mice with silicon probes during head-fixed virtual navigation. We found desynchronized interneuron firing between the CA1 and dentate gyrus in epileptic mice. Since hippocampal interneurons control information processing, we tested whether CA1 spatial coding was altered in this desynchronized circuit, using a novel wire-free miniscope. We found that CA1 place cells in epileptic mice were unstable and completely remapped across a week. This spatial instability emerged around 6 weeks after status epilepticus, well after the onset of chronic seizures and interneuron death. Finally, CA1 network modeling showed that desynchronized inputs can impair the precision and stability of CA1 place cells. Together, these results demonstrate that temporally precise intrahippocampal communication is critical for spatial processing.
Collapse
Affiliation(s)
- Tristan Shuman
- Nash Family Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY, USA. .,Department of Neurology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, USA.
| | - Daniel Aharoni
- Department of Neurology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, USA.,Integrative Center for Learning and Memory, University of California, Los Angeles, Los Angeles, CA, USA
| | - Denise J Cai
- Nash Family Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY, USA.,Department of Neurobiology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, USA
| | - Christopher R Lee
- Nash Family Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY, USA.,Department of Neurology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, USA
| | - Spyridon Chavlis
- Institute of Molecular Biology and Biotechnology (IMBB), Foundation for Research and Technology Hellas (FORTH), Heraklion, Greece
| | - Lucia Page-Harley
- Nash Family Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Lauren M Vetere
- Nash Family Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Yu Feng
- Nash Family Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Chen Yi Yang
- Department of Neurology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, USA
| | - Irene Mollinedo-Gajate
- Department of Neurology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, USA
| | - Lingxuan Chen
- Nash Family Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Zachary T Pennington
- Nash Family Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Jiannis Taxidis
- Department of Neurology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, USA
| | - Sergio E Flores
- Department of Neurology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, USA
| | - Kevin Cheng
- Department of Neurology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, USA
| | - Milad Javaherian
- Department of Neurology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, USA
| | - Christina C Kaba
- Department of Neurology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, USA
| | - Naina Rao
- Department of Neurology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, USA
| | - Mimi La-Vu
- Department of Neurobiology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, USA
| | - Ioanna Pandi
- Institute of Molecular Biology and Biotechnology (IMBB), Foundation for Research and Technology Hellas (FORTH), Heraklion, Greece.,School of Medicine, University of Crete, Heraklion, Greece
| | - Matthew Shtrahman
- Department of Neurosciences, University of California, San Diego, La Jolla, CA, USA
| | - Konstantin I Bakhurin
- Department of Neurobiology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, USA
| | - Sotiris C Masmanidis
- Department of Neurobiology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, USA
| | - Baljit S Khakh
- Department of Physiology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, USA
| | - Panayiota Poirazi
- Institute of Molecular Biology and Biotechnology (IMBB), Foundation for Research and Technology Hellas (FORTH), Heraklion, Greece.
| | - Alcino J Silva
- Integrative Center for Learning and Memory, University of California, Los Angeles, Los Angeles, CA, USA.,Department of Neurobiology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, USA.,Semel Institute for Neuroscience and Human Behavior, University of California, Los Angeles, Los Angeles, CA, USA.,Department of Psychology, University of California, Los Angeles, Los Angeles, CA, USA
| | - Peyman Golshani
- Department of Neurology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, USA. .,Integrative Center for Learning and Memory, University of California, Los Angeles, Los Angeles, CA, USA. .,Department of Physiology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, USA. .,Semel Institute for Neuroscience and Human Behavior, University of California, Los Angeles, Los Angeles, CA, USA. .,West LA Veterans Affairs Medical Center, Los Angeles, CA, USA. .,Intellectual and Developmental Disabilities Research Center, University of California, Los Angeles, Los Angeles, CA, USA.
| |
Collapse
|
32
|
Di Virgilio F, Evans RJ, Falzoni S, Jarvis MF, Kennedy C, Khakh BS, King B, Pellegatti P, Peters JA. P2X receptors (version 2019.4) in the IUPHAR/BPS Guide to Pharmacology Database. ACTA ACUST UNITED AC 2019. [DOI: 10.2218/gtopdb/f77/2019.4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
P2X receptors (nomenclature as agreed by the NC-IUPHAR Subcommittee on P2X Receptors [46, 134]) have a trimeric topology [118, 132, 177] with two putative TM domains, gating primarily Na+, K+ and Ca2+, exceptionally Cl-. The Nomenclature Subcommittee has recommended that for P2X receptors, structural criteria should be the initial criteria for nomenclature where possible. X-ray crystallography indicates that functional P2X receptors are trimeric and three agonist molecules are required to bind to a single receptor in order to activate it [132, 88, 96, 161]. Native receptors may occur as either homotrimers (e.g. P2X1 in smooth muscle) or heterotrimers (e.g. P2X2:P2X3 in the nodose ganglion [251], P2X1:P2X5 in mouse cortical astrocytes [146], and P2X2:P2X5 in mouse dorsal root ganglion, spinal cord and mid pons [50, 207]. P2X2, P2X4 and P2X7 receptors have been shown to form functional homopolymers which, in turn, activate pores permeable to low molecular weight solutes [229]. The hemi-channel pannexin-1 has been implicated in the pore formation induced by P2X7 [188], but not P2X2 [38], receptor activation.
Collapse
|
33
|
|
34
|
Khakh BS. Astrocyte-Neuron Interactions in the Striatum: Insights on Identity, Form, and Function. Trends Neurosci 2019; 42:617-630. [PMID: 31351745 PMCID: PMC6741427 DOI: 10.1016/j.tins.2019.06.003] [Citation(s) in RCA: 59] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2019] [Revised: 06/22/2019] [Accepted: 06/28/2019] [Indexed: 01/09/2023]
Abstract
The physiological functions of astrocytes within neural circuits remain incompletely understood. There has been progress in this regard from recent work on striatal astrocytes, where detailed studies are emerging. In this review, findings on striatal astrocyte identity, form, and function, are summarized with a focus on how astrocytes regulate striatal neurons, circuits, and behavior. Specific features of striatal astrocytes are highlighted to illustrate how they may be specialized to regulate medium spiny neurons (MSNs) by responding to, and altering, excitation and inhibition. Further experiments should reveal additional mechanisms for astrocyte-neuron interactions in the striatum and potentially reveal insights into the functions of astrocytes in neural circuits more generally.
Collapse
Affiliation(s)
- Baljit S Khakh
- Department of Physiology, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA 90095-1751, USA; Department of Neurobiology, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA 90095-1751, USA.
| |
Collapse
|
35
|
Nagai J, Rajbhandari AK, Gangwani MR, Hachisuka A, Coppola G, Masmanidis SC, Fanselow MS, Khakh BS. Hyperactivity with Disrupted Attention by Activation of an Astrocyte Synaptogenic Cue. Cell 2019; 177:1280-1292.e20. [PMID: 31031006 PMCID: PMC6526045 DOI: 10.1016/j.cell.2019.03.019] [Citation(s) in RCA: 175] [Impact Index Per Article: 35.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2018] [Revised: 02/08/2019] [Accepted: 03/07/2019] [Indexed: 11/19/2022]
Abstract
Hyperactivity and disturbances of attention are common behavioral disorders whose underlying cellular and neural circuit causes are not understood. We report the discovery that striatal astrocytes drive such phenotypes through a hitherto unknown synaptic mechanism. We found that striatal medium spiny neurons (MSNs) triggered astrocyte signaling via γ-aminobutyric acid B (GABAB) receptors. Selective chemogenetic activation of this pathway in striatal astrocytes in vivo resulted in acute behavioral hyperactivity and disrupted attention. Such responses also resulted in upregulation of the synaptogenic cue thrombospondin-1 (TSP1) in astrocytes, increased excitatory synapses, enhanced corticostriatal synaptic transmission, and increased MSN action potential firing in vivo. All of these changes were reversed by blocking TSP1 effects. Our data identify a form of bidirectional neuron-astrocyte communication and demonstrate that acute reactivation of a single latent astrocyte synaptogenic cue alters striatal circuits controlling behavior, revealing astrocytes and the TSP1 pathway as therapeutic targets in hyperactivity, attention deficit, and related psychiatric disorders.
Collapse
Affiliation(s)
- Jun Nagai
- Department of Physiology, University of California, Los Angeles, Los Angeles, CA 90095-1751, USA
| | - Abha K Rajbhandari
- Department of Psychology, University of California, Los Angeles, Los Angeles, CA 90095-1751, USA
| | - Mohitkumar R Gangwani
- Department of Physiology, University of California, Los Angeles, Los Angeles, CA 90095-1751, USA
| | - Ayaka Hachisuka
- Department of Neurobiology, University of California, Los Angeles, Los Angeles, CA 90095-1751, USA
| | - Giovanni Coppola
- Department of Neurology, University of California, Los Angeles, Los Angeles, CA 90095-1751, USA; Department of Psychiatry and Biobehavioral Sciences, University of California, Los Angeles, Los Angeles, CA 90095-1751, USA; Center for Neurobehavioral Genetics, Semel Institute for Neuroscience and Human Behavior, University of California, Los Angeles, Los Angeles, CA 90095-1751, USA
| | - Sotiris C Masmanidis
- Department of Neurobiology, University of California, Los Angeles, Los Angeles, CA 90095-1751, USA
| | - Michael S Fanselow
- Department of Psychiatry and Biobehavioral Sciences, University of California, Los Angeles, Los Angeles, CA 90095-1751, USA; Department of Psychology, University of California, Los Angeles, Los Angeles, CA 90095-1751, USA
| | - Baljit S Khakh
- Department of Physiology, University of California, Los Angeles, Los Angeles, CA 90095-1751, USA; Department of Neurobiology, University of California, Los Angeles, Los Angeles, CA 90095-1751, USA.
| |
Collapse
|
36
|
Lobas MA, Tao R, Nagai J, Kronschläger MT, Borden PM, Marvin JS, Looger LL, Khakh BS. A genetically encoded single-wavelength sensor for imaging cytosolic and cell surface ATP. Nat Commun 2019; 10:711. [PMID: 30755613 PMCID: PMC6372613 DOI: 10.1038/s41467-019-08441-5] [Citation(s) in RCA: 153] [Impact Index Per Article: 30.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2018] [Accepted: 01/09/2019] [Indexed: 01/08/2023] Open
Abstract
Adenosine 5' triphosphate (ATP) is a universal intracellular energy source and an evolutionarily ancient, ubiquitous extracellular signal in diverse species. Here, we report the generation and characterization of single-wavelength genetically encoded fluorescent sensors (iATPSnFRs) for imaging extracellular and cytosolic ATP from insertion of circularly permuted superfolder GFP into the epsilon subunit of F0F1-ATPase from Bacillus PS3. On the cell surface and within the cytosol, iATPSnFR1.0 responds to relevant ATP concentrations (30 μM to 3 mM) with fast increases in fluorescence. iATPSnFRs can be genetically targeted to specific cell types and sub-cellular compartments, imaged with standard light microscopes, do not respond to other nucleotides and nucleosides, and when fused with a red fluorescent protein function as ratiometric indicators. After careful consideration of their modest pH sensitivity, iATPSnFRs represent promising reagents for imaging ATP in the extracellular space and within cells during a variety of settings, and for further application-specific refinements.
Collapse
Affiliation(s)
- Mark A Lobas
- Department of Physiology, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA, 90095-1751, USA
- Koniku Inc., 740 Heinz Avenue, Berkeley, CA, 94710, USA
| | - Rongkun Tao
- Department of Physiology, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA, 90095-1751, USA
| | - Jun Nagai
- Department of Physiology, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA, 90095-1751, USA
| | - Mira T Kronschläger
- Department of Physiology, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA, 90095-1751, USA
- Department of Neurophysiology, Center for Brain Research, Medical University of Vienna, Spitalgasse 4, 1090, Vienna, Austria
| | - Philip M Borden
- Janelia Research Campus, 19700 Helix Drive, Ashburn, VA, 20147, USA
| | | | - Loren L Looger
- Janelia Research Campus, 19700 Helix Drive, Ashburn, VA, 20147, USA.
| | - Baljit S Khakh
- Department of Physiology, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA, 90095-1751, USA.
- Department of Neurobiology, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA, 90095-1751, USA.
| |
Collapse
|
37
|
Giovannucci A, Friedrich J, Gunn P, Kalfon J, Brown BL, Koay SA, Taxidis J, Najafi F, Gauthier JL, Zhou P, Khakh BS, Tank DW, Chklovskii DB, Pnevmatikakis EA. CaImAn an open source tool for scalable calcium imaging data analysis. eLife 2019; 8:38173. [PMID: 30652683 PMCID: PMC6342523 DOI: 10.7554/elife.38173] [Citation(s) in RCA: 345] [Impact Index Per Article: 69.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2018] [Accepted: 11/23/2018] [Indexed: 12/11/2022] Open
Abstract
Advances in fluorescence microscopy enable monitoring larger brain areas in-vivo with finer time resolution. The resulting data rates require reproducible analysis pipelines that are reliable, fully automated, and scalable to datasets generated over the course of months. We present CaImAn, an open-source library for calcium imaging data analysis. CaImAn provides automatic and scalable methods to address problems common to pre-processing, including motion correction, neural activity identification, and registration across different sessions of data collection. It does this while requiring minimal user intervention, with good scalability on computers ranging from laptops to high-performance computing clusters. CaImAn is suitable for two-photon and one-photon imaging, and also enables real-time analysis on streaming data. To benchmark the performance of CaImAn we collected and combined a corpus of manual annotations from multiple labelers on nine mouse two-photon datasets. We demonstrate that CaImAn achieves near-human performance in detecting locations of active neurons. The human brain contains billions of cells called neurons that rapidly carry information from one part of the brain to another. Progress in medical research and healthcare is hindered by the difficulty in understanding precisely which neurons are active at any given time. New brain imaging techniques and genetic tools allow researchers to track the activity of thousands of neurons in living animals over many months. However, these experiments produce large volumes of data that researchers currently have to analyze manually, which can take a long time and generate irreproducible results. There is a need to develop new computational tools to analyze such data. The new tools should be able to operate on standard computers rather than just specialist equipment as this would limit the use of the solutions to particularly well-funded research teams. Ideally, the tools should also be able to operate in real-time as several experimental and therapeutic scenarios, like the control of robotic limbs, require this. To address this need, Giovannucci et al. developed a new software package called CaImAn to analyze brain images on a large scale. Firstly, the team developed algorithms that are suitable to analyze large sets of data on laptops and other standard computing equipment. These algorithms were then adapted to operate online in real-time. To test how well the new software performs against manual analysis by human researchers, Giovannucci et al. asked several trained human annotators to identify active neurons that were round or donut-shaped in several sets of imaging data from mouse brains. Each set of data was independently analyzed by three or four researchers who then discussed any neurons they disagreed on to generate a ‘consensus annotation’. Giovannucci et al. then used CaImAn to analyze the same sets of data and compared the results to the consensus annotations. This demonstrated that CaImAn is nearly as good as human researchers at identifying active neurons in brain images. CaImAn provides a quicker method to analyze large sets of brain imaging data and is currently used by over a hundred laboratories across the world. The software is open source, meaning that it is freely-available and that users are encouraged to customize it and collaborate with other users to develop it further.
Collapse
Affiliation(s)
- Andrea Giovannucci
- Center for Computational Biology, Flatiron Institute, Simons Foundation, New York, United States
| | - Johannes Friedrich
- Center for Computational Biology, Flatiron Institute, Simons Foundation, New York, United States.,Department of Statistics, Columbia University, New York, United States.,Center for Theoretical Neuroscience, Columbia University, New York, United States
| | - Pat Gunn
- Center for Computational Biology, Flatiron Institute, Simons Foundation, New York, United States
| | | | - Brandon L Brown
- Department of Physiology, University of California, Los Angeles, Los Angeles, United States
| | - Sue Ann Koay
- Princeton Neuroscience Institute, Princeton University, Princeton, United States
| | - Jiannis Taxidis
- Department of Neurology, University of California, Los Angeles, Los Angeles, United States
| | | | - Jeffrey L Gauthier
- Princeton Neuroscience Institute, Princeton University, Princeton, United States
| | - Pengcheng Zhou
- Department of Statistics, Columbia University, New York, United States.,Center for Theoretical Neuroscience, Columbia University, New York, United States
| | - Baljit S Khakh
- Department of Physiology, University of California, Los Angeles, Los Angeles, United States.,Department of Neurobiology, University of California, Los Angeles, Los Angeles, United States
| | - David W Tank
- Princeton Neuroscience Institute, Princeton University, Princeton, United States
| | - Dmitri B Chklovskii
- Center for Computational Biology, Flatiron Institute, Simons Foundation, New York, United States
| | | |
Collapse
|
38
|
Abstract
One major challenge in neuroscience is to uncover how defined neural circuits in the brain encode, store, modify, and retrieve information. Meeting this challenge comprehensively requires tools capable of recording and manipulating the activity of intact neural networks in naturally behaving animals. Head-mounted miniature microscopes are emerging as a key tool to address this challenge. Here we discuss recent work leading to the miniaturization of neural imaging tools, the current state of the art in this field, and the importance and necessity of open-source options. We finish with a discussion on what the future may hold for miniature microscopy.
Collapse
Affiliation(s)
- Daniel Aharoni
- Department of Neurology, Integrative Center for Learning and Memory, Brain Research Institute, University of California, Los Angeles, CA, USA.
| | - Baljit S Khakh
- Departments of Physiology & Neurobiology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, USA
| | - Alcino J Silva
- Departments of Neurobiology and Psychology, Integrative Center for Learning and Memory, Brain Research Institute, University of California, Los Angeles, CA, USA
- Department of Psychiatry & Biobehavioral Sciences, Integrative Center for Learning and Memory, Brain Research Institute, University of California, Los Angeles, CA, USA
| | - Peyman Golshani
- Department of Neurology, Integrative Center for Learning and Memory, Brain Research Institute, University of California, Los Angeles, CA, USA
- Department of Psychiatry & Biobehavioral Sciences, Integrative Center for Learning and Memory, Brain Research Institute, University of California, Los Angeles, CA, USA
| |
Collapse
|
39
|
Yu X, Taylor AMW, Nagai J, Golshani P, Evans CJ, Coppola G, Khakh BS. Reducing Astrocyte Calcium Signaling In Vivo Alters Striatal Microcircuits and Causes Repetitive Behavior. Neuron 2018; 99:1170-1187.e9. [PMID: 30174118 PMCID: PMC6450394 DOI: 10.1016/j.neuron.2018.08.015] [Citation(s) in RCA: 199] [Impact Index Per Article: 33.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2017] [Revised: 05/23/2018] [Accepted: 08/10/2018] [Indexed: 01/01/2023]
Abstract
Astrocytes tile the central nervous system, but their functions in neural microcircuits in vivo and their roles in mammalian behavior remain incompletely defined. We used two-photon laser scanning microscopy, electrophysiology, MINIscopes, RNA-seq, and a genetic approach to explore the effects of reduced striatal astrocyte Ca2+ signaling in vivo. In wild-type mice, reducing striatal astrocyte Ca2+-dependent signaling increased repetitive self-grooming behaviors by altering medium spiny neuron (MSN) activity. The mechanism involved astrocyte-mediated neuromodulation facilitated by ambient GABA and was corrected by blocking astrocyte GABA transporter 3 (GAT-3). Furthermore, in a mouse model of Huntington's disease, dysregulation of GABA and astrocyte Ca2+ signaling accompanied excessive self-grooming, which was relieved by blocking GAT-3. Assessments with RNA-seq revealed astrocyte genes and pathways regulated by Ca2+ signaling in a cell-autonomous and non-cell-autonomous manner, including Rab11a, a regulator of GAT-3 functional expression. Thus, striatal astrocytes contribute to neuromodulation controlling mouse obsessive-compulsive-like behavior.
Collapse
Affiliation(s)
- Xinzhu Yu
- Department of Physiology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095-1751, USA
| | - Anna M W Taylor
- Hatos Center for Neuropharmacology, Semel Institute for Neuroscience and Human Behavior, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095-1751, USA
| | - Jun Nagai
- Department of Physiology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095-1751, USA
| | - Peyman Golshani
- Department of Neurology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095-1751, USA; Department of Psychiatry and Biobehavioral Sciences, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095-1751, USA; Intellectual and Developmental Disabilities Research Center, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095-1751, USA; West Los Angeles VA Medical Center, Los Angeles, CA 90073, USA
| | - Christopher J Evans
- Hatos Center for Neuropharmacology, Semel Institute for Neuroscience and Human Behavior, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095-1751, USA
| | - Giovanni Coppola
- Department of Neurology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095-1751, USA; Department of Psychiatry and Biobehavioral Sciences, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095-1751, USA; Intellectual and Developmental Disabilities Research Center, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095-1751, USA; Center for Neurobehavioral Genetics, Semel Institute for Neuroscience and Human Behavior, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095-1751, USA
| | - Baljit S Khakh
- Department of Physiology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095-1751, USA; Department of Neurobiology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095-1751, USA.
| |
Collapse
|
40
|
Khennouf L, Gesslein B, Brazhe A, Octeau JC, Kutuzov N, Khakh BS, Lauritzen M. Active role of capillary pericytes during stimulation-induced activity and spreading depolarization. Brain 2018; 141:2032-2046. [PMID: 30053174 PMCID: PMC6022680 DOI: 10.1093/brain/awy143] [Citation(s) in RCA: 57] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2017] [Revised: 04/05/2018] [Accepted: 04/07/2018] [Indexed: 12/27/2022] Open
Abstract
Spreading depolarization is assumed to be the mechanism of migraine with aura, which is accompanied by an initial predominant hyperaemic response followed by persistent vasoconstriction. Cerebral blood flow responses are impaired in patients and in experimental animals after spreading depolarization. Understanding the regulation of cortical blood vessels during and after spreading depolarization could help patients with migraine attacks, but our knowledge of these vascular mechanisms is still incomplete. Recent findings show that control of cerebral blood flow does not only occur at the arteriole level but also at capillaries. Pericytes are vascular mural cells that can constrict or relax around capillaries, mediating local cerebral blood flow control. They participate in the constriction observed during brain ischaemia and might be involved the disruption of the microcirculation during spreading depolarization. To further understand the regulation of cerebral blood flow in spreading depolarization, we examined penetrating arterioles and capillaries with respect to vascular branching order, pericyte location and pericyte calcium responses during somatosensory stimulation and spreading depolarization. Mice expressing a red fluorescent indicator and intravenous injections of FITC-dextran were used to visualize pericytes and vessels, respectively, under two-photon microscopy. By engineering a genetically encoded calcium indicator we could record calcium changes in both pericytes around capillaries and vascular smooth muscle cells around arterioles. We show that somatosensory stimulation evoked a decrease in cytosolic calcium in pericytes located on dilating capillaries, up to the second order capillaries. Furthermore, we show that prolonged vasoconstriction following spreading depolarization is strongest in first order capillaries, with a persistent increase in pericyte calcium. We suggest that the persistence of the 'spreading cortical oligaemia' in migraine could be caused by this constriction of cortical capillaries. After spreading depolarization, somatosensory stimulation no longer evoked changes in capillary diameter and pericyte calcium. Thus, calcium changes in pericytes located on first order capillaries may be a key determinant in local blood flow control and a novel vascular mechanism in migraine. We suggest that prevention or treatment of capillary constriction in migraine with aura, which is an independent risk factor for stroke, may be clinically useful.
Collapse
Affiliation(s)
- Lila Khennouf
- Department of Neuroscience and Center for Healthy Aging, University of Copenhagen, Copenhagen N, Denmark
| | - Bodil Gesslein
- Department of Neuroscience and Center for Healthy Aging, University of Copenhagen, Copenhagen N, Denmark
| | - Alexey Brazhe
- Department of Neuroscience and Center for Healthy Aging, University of Copenhagen, Copenhagen N, Denmark
- Department of Biophysics, Faculty of Biology, Moscow State University, Moscow, Russia
| | - J Christopher Octeau
- Department of Physiology, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA, USA
| | - Nikolay Kutuzov
- Department of Neuroscience and Center for Healthy Aging, University of Copenhagen, Copenhagen N, Denmark
| | - Baljit S Khakh
- Department of Physiology, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA, USA
| | - Martin Lauritzen
- Department of Neuroscience and Center for Healthy Aging, University of Copenhagen, Copenhagen N, Denmark
- Department of Clinical Neurophysiology, Rigshospitalet, Glostrup, Denmark
| |
Collapse
|
41
|
Watanabe M, Buth JE, Vishlaghi N, de la Torre-Ubieta L, Taxidis J, Khakh BS, Coppola G, Pearson CA, Yamauchi K, Gong D, Dai X, Damoiseaux R, Aliyari R, Liebscher S, Schenke-Layland K, Caneda C, Huang EJ, Zhang Y, Cheng G, Geschwind DH, Golshani P, Sun R, Novitch BG. Self-Organized Cerebral Organoids with Human-Specific Features Predict Effective Drugs to Combat Zika Virus Infection. Cell Rep 2018; 21:517-532. [PMID: 29020636 DOI: 10.1016/j.celrep.2017.09.047] [Citation(s) in RCA: 251] [Impact Index Per Article: 41.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2017] [Revised: 08/01/2017] [Accepted: 09/14/2017] [Indexed: 12/21/2022] Open
Abstract
The human cerebral cortex possesses distinct structural and functional features that are not found in the lower species traditionally used to model brain development and disease. Accordingly, considerable attention has been placed on the development of methods to direct pluripotent stem cells to form human brain-like structures termed organoids. However, many organoid differentiation protocols are inefficient and display marked variability in their ability to recapitulate the three-dimensional architecture and course of neurogenesis in the developing human brain. Here, we describe optimized organoid culture methods that efficiently and reliably produce cortical and basal ganglia structures similar to those in the human fetal brain in vivo. Neurons within the organoids are functional and exhibit network-like activities. We further demonstrate the utility of this organoid system for modeling the teratogenic effects of Zika virus on the developing brain and identifying more susceptibility receptors and therapeutic compounds that can mitigate its destructive actions.
Collapse
Affiliation(s)
- Momoko Watanabe
- Department of Neurobiology, David Geffen School of Medicine at UCLA, University of California, Los Angeles, Los Angeles, CA 90095, USA; Eli and Edythe Broad Center of Regenerative Medicine and Stem Cell Research, University of California, Los Angeles, Los Angeles, CA 90095, USA; Intellectual and Developmental Disabilities Research Center, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Jessie E Buth
- Department of Neurobiology, David Geffen School of Medicine at UCLA, University of California, Los Angeles, Los Angeles, CA 90095, USA; Eli and Edythe Broad Center of Regenerative Medicine and Stem Cell Research, University of California, Los Angeles, Los Angeles, CA 90095, USA; Intellectual and Developmental Disabilities Research Center, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Neda Vishlaghi
- Department of Neurobiology, David Geffen School of Medicine at UCLA, University of California, Los Angeles, Los Angeles, CA 90095, USA; Eli and Edythe Broad Center of Regenerative Medicine and Stem Cell Research, University of California, Los Angeles, Los Angeles, CA 90095, USA; Intellectual and Developmental Disabilities Research Center, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Luis de la Torre-Ubieta
- Intellectual and Developmental Disabilities Research Center, University of California, Los Angeles, Los Angeles, CA 90095, USA; Center for Autism Research and Treatment and Program in Neurobehavioral Genetics, Semel Institute for Neuroscience and Human Behavior, David Geffen School of Medicine at UCLA, University of California, Los Angeles, Los Angeles, CA 90095, USA; Department of Neurology, David Geffen School of Medicine at UCLA, University of California, Los Angeles, Los Angeles, CA 90095, USA; Department of Psychiatry and Biobehavioral Sciences, Semel Institute for Neuroscience and Human Behavior, David Geffen School of Medicine at UCLA, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Jiannis Taxidis
- Department of Neurology, David Geffen School of Medicine at UCLA, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Baljit S Khakh
- Department of Neurobiology, David Geffen School of Medicine at UCLA, University of California, Los Angeles, Los Angeles, CA 90095, USA; Department of Physiology, David Geffen School of Medicine at UCLA, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Giovanni Coppola
- Intellectual and Developmental Disabilities Research Center, University of California, Los Angeles, Los Angeles, CA 90095, USA; Center for Autism Research and Treatment and Program in Neurobehavioral Genetics, Semel Institute for Neuroscience and Human Behavior, David Geffen School of Medicine at UCLA, University of California, Los Angeles, Los Angeles, CA 90095, USA; Department of Neurology, David Geffen School of Medicine at UCLA, University of California, Los Angeles, Los Angeles, CA 90095, USA; Department of Psychiatry and Biobehavioral Sciences, Semel Institute for Neuroscience and Human Behavior, David Geffen School of Medicine at UCLA, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Caroline A Pearson
- Department of Neurobiology, David Geffen School of Medicine at UCLA, University of California, Los Angeles, Los Angeles, CA 90095, USA; Eli and Edythe Broad Center of Regenerative Medicine and Stem Cell Research, University of California, Los Angeles, Los Angeles, CA 90095, USA; Intellectual and Developmental Disabilities Research Center, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Ken Yamauchi
- Department of Neurobiology, David Geffen School of Medicine at UCLA, University of California, Los Angeles, Los Angeles, CA 90095, USA; Eli and Edythe Broad Center of Regenerative Medicine and Stem Cell Research, University of California, Los Angeles, Los Angeles, CA 90095, USA; Intellectual and Developmental Disabilities Research Center, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Danyang Gong
- Department of Molecular and Medical Pharmacology, University of California, Los Angeles, Los Angeles, CA 90095, USA; California NanoSystems Institute, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Xinghong Dai
- Department of Molecular and Medical Pharmacology, University of California, Los Angeles, Los Angeles, CA 90095, USA; California NanoSystems Institute, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Robert Damoiseaux
- Department of Molecular and Medical Pharmacology, University of California, Los Angeles, Los Angeles, CA 90095, USA; California NanoSystems Institute, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Roghiyh Aliyari
- Department of Microbiology, Immunology and Molecular Genetics, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Simone Liebscher
- Department of Women's Health, Research Institute for Women's Health, Eberhard Karls University Tübingen, 72076 Tübingen, Germany
| | - Katja Schenke-Layland
- Department of Cardiology, David Geffen School of Medicine at UCLA, University of California, Los Angeles, Los Angeles, CA 90095, USA; Department of Women's Health, Research Institute for Women's Health, Eberhard Karls University Tübingen, 72076 Tübingen, Germany; Department of Cell and Tissue Engineering, Fraunhofer Institute for Interfacial Engineering and Biotechnology, 70569 Stuttgart, Germany
| | - Christine Caneda
- Intellectual and Developmental Disabilities Research Center, University of California, Los Angeles, Los Angeles, CA 90095, USA; Department of Psychiatry and Biobehavioral Sciences, Semel Institute for Neuroscience and Human Behavior, David Geffen School of Medicine at UCLA, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Eric J Huang
- Department of Pathology, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Ye Zhang
- Intellectual and Developmental Disabilities Research Center, University of California, Los Angeles, Los Angeles, CA 90095, USA; Department of Psychiatry and Biobehavioral Sciences, Semel Institute for Neuroscience and Human Behavior, David Geffen School of Medicine at UCLA, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Genhong Cheng
- Department of Microbiology, Immunology and Molecular Genetics, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Daniel H Geschwind
- Eli and Edythe Broad Center of Regenerative Medicine and Stem Cell Research, University of California, Los Angeles, Los Angeles, CA 90095, USA; Intellectual and Developmental Disabilities Research Center, University of California, Los Angeles, Los Angeles, CA 90095, USA; Center for Autism Research and Treatment and Program in Neurobehavioral Genetics, Semel Institute for Neuroscience and Human Behavior, David Geffen School of Medicine at UCLA, University of California, Los Angeles, Los Angeles, CA 90095, USA; Department of Neurology, David Geffen School of Medicine at UCLA, University of California, Los Angeles, Los Angeles, CA 90095, USA; Department of Human Genetics, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Peyman Golshani
- Intellectual and Developmental Disabilities Research Center, University of California, Los Angeles, Los Angeles, CA 90095, USA; Center for Autism Research and Treatment and Program in Neurobehavioral Genetics, Semel Institute for Neuroscience and Human Behavior, David Geffen School of Medicine at UCLA, University of California, Los Angeles, Los Angeles, CA 90095, USA; Department of Neurology, David Geffen School of Medicine at UCLA, University of California, Los Angeles, Los Angeles, CA 90095, USA; Department of Psychiatry and Biobehavioral Sciences, Semel Institute for Neuroscience and Human Behavior, David Geffen School of Medicine at UCLA, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Ren Sun
- Department of Molecular and Medical Pharmacology, University of California, Los Angeles, Los Angeles, CA 90095, USA; California NanoSystems Institute, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Bennett G Novitch
- Department of Neurobiology, David Geffen School of Medicine at UCLA, University of California, Los Angeles, Los Angeles, CA 90095, USA; Eli and Edythe Broad Center of Regenerative Medicine and Stem Cell Research, University of California, Los Angeles, Los Angeles, CA 90095, USA; Intellectual and Developmental Disabilities Research Center, University of California, Los Angeles, Los Angeles, CA 90095, USA.
| |
Collapse
|
42
|
Octeau JC, Faas G, Mody I, Khakh BS. Making, Testing, and Using Potassium Ion Selective Microelectrodes in Tissue Slices of Adult Brain. J Vis Exp 2018. [PMID: 29781998 DOI: 10.3791/57511] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
Potassium ions significantly contribute to the resting membrane potential of cells and, therefore, extracellular K+ concentration is a crucial regulator of cell excitability. Altered concentrations of extracellular K+ affect the resting membrane potential and cellular excitability by shifting the equilibria between closed, open and inactivated states for voltage-dependent ion channels that underlie action potential initiation and conduction. Hence, it is valuable to directly measure extracellular K+ dynamics in health and diseased states. Here, we describe how to make, calibrate and use monopolar K+-selective microelectrodes. We deployed them in adult hippocampal brain slices to measure electrically evoked K+ concentration dynamics. The judicious use of such electrodes is an important part of the tool-kit needed to evaluate cellular and biophysical mechanisms that control extracellular K+ concentrations in the nervous system.
Collapse
Affiliation(s)
- J Christopher Octeau
- Department of Physiology, David Geffen School of Medicine, University of California Los Angeles;
| | - Guido Faas
- Department of Neurology, David Geffen School of Medicine, University of California Los Angeles
| | - Istvan Mody
- Department of Physiology, David Geffen School of Medicine, University of California Los Angeles; Department of Neurology, David Geffen School of Medicine, University of California Los Angeles
| | - Baljit S Khakh
- Department of Physiology, David Geffen School of Medicine, University of California Los Angeles; Department of Neurobiology, David Geffen School of Medicine, University of California Los Angeles;
| |
Collapse
|
43
|
Chai H, Diaz-Castro B, Shigetomi E, Monte E, Octeau JC, Yu X, Cohn W, Rajendran PS, Vondriska TM, Whitelegge JP, Coppola G, Khakh BS. Neural Circuit-Specialized Astrocytes: Transcriptomic, Proteomic, Morphological, and Functional Evidence. Neuron 2017; 95:531-549.e9. [PMID: 28712653 PMCID: PMC5811312 DOI: 10.1016/j.neuron.2017.06.029] [Citation(s) in RCA: 459] [Impact Index Per Article: 65.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2017] [Revised: 05/14/2017] [Accepted: 06/16/2017] [Indexed: 12/15/2022]
Abstract
Astrocytes are ubiquitous in the brain and are widely held to be largely identical. However, this view has not been fully tested, and the possibility that astrocytes are neural circuit specialized remains largely unexplored. Here, we used multiple integrated approaches, including RNA sequencing (RNA-seq), mass spectrometry, electrophysiology, immunohistochemistry, serial block-face-scanning electron microscopy, morphological reconstructions, pharmacogenetics, and diffusible dye, calcium, and glutamate imaging, to directly compare adult striatal and hippocampal astrocytes under identical conditions. We found significant differences in electrophysiological properties, Ca2+ signaling, morphology, and astrocyte-synapse proximity between striatal and hippocampal astrocytes. Unbiased evaluation of actively translated RNA and proteomic data confirmed significant astrocyte diversity between hippocampal and striatal circuits. We thus report core astrocyte properties, reveal evidence for specialized astrocytes within neural circuits, and provide new, integrated database resources and approaches to explore astrocyte diversity and function throughout the adult brain. VIDEO ABSTRACT.
Collapse
Affiliation(s)
- Hua Chai
- Department of Physiology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095-1751, USA
| | - Blanca Diaz-Castro
- Department of Physiology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095-1751, USA
| | - Eiji Shigetomi
- Department of Physiology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095-1751, USA; Department of Neuropharmacology, Interdisciplinary Graduate School of Medicine, University of Yamanashi, Yamanashi 409-3898, Japan, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095-1751, USA
| | - Emma Monte
- Department of Anesthesiology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095-1751, USA
| | - J Christopher Octeau
- Department of Physiology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095-1751, USA
| | - Xinzhu Yu
- Department of Physiology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095-1751, USA
| | - Whitaker Cohn
- Pasarow Mass Spectrometry Laboratory, Semel Institute for Neuroscience and Human Behavior, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095-1751, USA; Brain Research Institute, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095-1751, USA
| | - Pradeep S Rajendran
- UCLA Cardiac Arrhythmia Center, Neurocardiology Research Center for Excellence, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095-1751, USA
| | - Thomas M Vondriska
- Department of Physiology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095-1751, USA; Department of Anesthesiology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095-1751, USA; Department of Medicine, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095-1751, USA
| | - Julian P Whitelegge
- Pasarow Mass Spectrometry Laboratory, Semel Institute for Neuroscience and Human Behavior, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095-1751, USA; Brain Research Institute, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095-1751, USA
| | - Giovanni Coppola
- Department of Neurology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095-1751, USA; Department of Psychiatry and Biobehavioral Sciences, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095-1751, USA; Center for Neurobehavioral Genetics, Semel Institute for Neuroscience and Human Behavior, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095-1751, USA
| | - Baljit S Khakh
- Department of Physiology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095-1751, USA; Department of Neurobiology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095-1751, USA.
| |
Collapse
|
44
|
Khakh BS, Beaumont V, Cachope R, Munoz-Sanjuan I, Goldman SA, Grantyn R. Unravelling and Exploiting Astrocyte Dysfunction in Huntington's Disease. Trends Neurosci 2017; 40:422-437. [PMID: 28578789 PMCID: PMC5706770 DOI: 10.1016/j.tins.2017.05.002] [Citation(s) in RCA: 125] [Impact Index Per Article: 17.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2017] [Revised: 04/24/2017] [Accepted: 05/01/2017] [Indexed: 01/02/2023]
Abstract
Astrocytes are abundant within mature neural circuits and are involved in brain disorders. Here, we summarize our current understanding of astrocytes and Huntington's disease (HD), with a focus on correlative and causative dysfunctions of ion homeostasis, calcium signaling, and neurotransmitter clearance, as well as on the use of transplanted astrocytes to produce therapeutic benefit in mouse models of HD. Overall, the data suggest that astrocyte dysfunction is an important contributor to the onset and progression of some HD symptoms in mice. Additional exploration of astrocytes in HD mouse models and humans is needed and may provide new therapeutic opportunities to explore in conjunction with neuronal rescue and repair strategies.
Collapse
Affiliation(s)
- Baljit S Khakh
- Department of Physiology, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA 90095-1751, USA; Neurobiology, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA 90095-1751, USA.
| | - Vahri Beaumont
- CHDI Management/CHDI Foundation, 6080 Center Drive, Los Angeles, CA 90045, USA
| | - Roger Cachope
- CHDI Management/CHDI Foundation, 6080 Center Drive, Los Angeles, CA 90045, USA
| | | | - Steven A Goldman
- Center for Translational Neuromedicine, University of Rochester, Rochester, NY 14642, USA; Center for Neuroscience, University of Copenhagen, 2200 Copenhagen N, Denmark
| | - Rosemarie Grantyn
- Exzellenzcluster NeuroCure & Abt. Experimentelle Neurologie, Charité - Universitätsmedizin Berlin, Robert-Koch-Platz 4, D-10115 Berlin, Germany
| |
Collapse
|
45
|
Srinivasan R, Lu TY, Chai H, Xu J, Huang BS, Golshani P, Coppola G, Khakh BS. New Transgenic Mouse Lines for Selectively Targeting Astrocytes and Studying Calcium Signals in Astrocyte Processes In Situ and In Vivo. Neuron 2016; 92:1181-1195. [PMID: 27939582 PMCID: PMC5403514 DOI: 10.1016/j.neuron.2016.11.030] [Citation(s) in RCA: 237] [Impact Index Per Article: 29.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2016] [Revised: 10/14/2016] [Accepted: 11/15/2016] [Indexed: 11/23/2022]
Abstract
Astrocytes exist throughout the nervous system and are proposed to affect neural circuits and behavior. However, studying astrocytes has proven difficult because of the lack of tools permitting astrocyte-selective genetic manipulations. Here, we report the generation of Aldh1l1-Cre/ERT2 transgenic mice to selectively target astrocytes in vivo. We characterized Aldh1l1-Cre/ERT2 mice using imaging, immunohistochemistry, AAV-FLEX-GFP microinjections, and crosses to RiboTag, Ai95, and new Cre-dependent membrane-tethered Lck-GCaMP6f knockin mice that we also generated. Two to three weeks after tamoxifen induction, Aldh1l1-Cre/ERT2 selectively targeted essentially all adult (P80) brain astrocytes with no detectable neuronal contamination, resulting in expression of cytosolic and Lck-GCaMP6f, and permitting subcellular astrocyte calcium imaging during startle responses in vivo. Crosses with RiboTag mice allowed sequencing of actively translated mRNAs and determination of the adult cortical astrocyte transcriptome. Thus, we provide well-characterized, easy-to-use resources with which to selectively study astrocytes in situ and in vivo in multiple experimental scenarios.
Collapse
Affiliation(s)
- Rahul Srinivasan
- Department of Physiology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095-1751, USA
| | - Tsai-Yi Lu
- Department of Physiology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095-1751, USA
| | - Hua Chai
- Department of Physiology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095-1751, USA
| | - Ji Xu
- Department of Physiology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095-1751, USA
| | - Ben S Huang
- Department of Neurology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095-1751, USA
| | - Peyman Golshani
- Department of Neurology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095-1751, USA; Department of Psychiatry and Biobehavioral Sciences, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095-1751, USA; Integrative Center for Learning and Memory, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095-1751, USA; West Los Angeles VA Medical Center, Los Angeles, CA 90073, USA
| | - Giovanni Coppola
- Department of Neurology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095-1751, USA; Department of Psychiatry and Biobehavioral Sciences, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095-1751, USA; Center for Neurobehavioral Genetics, Semel Institute for Neuroscience and Human Behavior, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095-1751, USA
| | - Baljit S Khakh
- Department of Physiology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095-1751, USA; Department of Neurobiology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095-1751, USA.
| |
Collapse
|
46
|
Xu J, Bernstein AM, Wong A, Lu XH, Khoja S, Yang XW, Davies DL, Micevych P, Sofroniew MV, Khakh BS. P2X4 Receptor Reporter Mice: Sparse Brain Expression and Feeding-Related Presynaptic Facilitation in the Arcuate Nucleus. J Neurosci 2016; 36:8902-20. [PMID: 27559172 PMCID: PMC4995303 DOI: 10.1523/jneurosci.1496-16.2016] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2016] [Revised: 06/17/2016] [Accepted: 06/20/2016] [Indexed: 11/21/2022] Open
Abstract
UNLABELLED P2X4 receptors are ATP-gated cation channels that are widely expressed in the nervous system. To identify P2X4 receptor-expressing cells, we generated BAC transgenic mice expressing tdTomato under the control of the P2X4 receptor gene (P2rx4). We found sparse populations of tdTomato-positive neurons in most brain areas with patterns that matched P2X4 mRNA distribution. tdTomato expression within microglia was low but was increased by an experimental manipulation that triggered microglial activation. We found surprisingly high tdTomato expression in the hypothalamic arcuate nucleus (Arc) (i.e., within parts of the neural circuitry controlling feeding). Immunohistochemistry and genetic crosses of P2rx4 tdTomato mice with cell-specific GFP reporter lines showed that the tdTomato-expressing cells were mainly AgRP-NPY neurons and tanycytes. There was no electrophysiological evidence for functional expression of P2X4 receptors on AgRP-NPY neuron somata, but instead, we found clear evidence for functional presynaptic P2X4 receptor-mediated responses in terminals of AgRP-NPY neurons onto two of their postsynaptic targets (Arc POMC and paraventricular nucleus neurons), where ATP dramatically facilitated GABA release. The presynaptic responses onto POMC neurons, and the expression of tdTomato in AgRP-NPY neurons and tanycytes, were significantly decreased by food deprivation in male mice in a manner that was partially reversed by the satiety-related peptide leptin. Overall, we provide well-characterized tdTomato reporter mice to study P2X4-expressing cells in the brain, new insights on feeding-related regulation of presynaptic P2X4 receptor responses, and the rationale to explore extracellular ATP signaling in the control of feeding behaviors. SIGNIFICANCE STATEMENT Cells expressing ATP-gated P2X4 receptors have proven problematic to identify and study in brain slice preparations because P2X4 expression is sparse. To address this limitation, we generated and characterized BAC transgenic P2rx4 tdTomato reporter mice. We report the distribution of tdTomato-expressing cells throughout the brain and particularly strong expression in the hypothalamic arcuate nucleus. Together, our studies provide a new, well-characterized tool with which to study P2X4 receptor-expressing cells. The electrophysiological studies enabled by this mouse suggest previously unanticipated roles for ATP and P2X4 receptors in the neural circuitry controlling feeding.
Collapse
Affiliation(s)
- Ji Xu
- Departments of Physiology and
| | - Alexander M Bernstein
- Neurobiology, David Geffen School of Medicine, University of California-Los Angeles, Los Angeles, California 90095
| | - Angela Wong
- Neurobiology, David Geffen School of Medicine, University of California-Los Angeles, Los Angeles, California 90095
| | - Xiao-Hong Lu
- Center for Neurobehavioral Genetics, Semel Institute for Neuroscience and Human Behavior, University of California-Los Angeles, Los Angeles, California 90095
| | - Sheraz Khoja
- Department of Pharmacology and Pharmaceutical Sciences, University of Southern California, Los Angeles, California 90089
| | - X William Yang
- Center for Neurobehavioral Genetics, Semel Institute for Neuroscience and Human Behavior, University of California-Los Angeles, Los Angeles, California 90095, Department of Psychiatry and Biobehavioral Sciences, David Geffen School of Medicine, University of California-Los Angeles, Los Angeles, California 90095, and
| | - Daryl L Davies
- Titus Family Department of Clinical Pharmacy, School of Pharmacy, University of Southern California, Los Angeles, California 90089
| | - Paul Micevych
- Neurobiology, David Geffen School of Medicine, University of California-Los Angeles, Los Angeles, California 90095
| | - Michael V Sofroniew
- Neurobiology, David Geffen School of Medicine, University of California-Los Angeles, Los Angeles, California 90095
| | - Baljit S Khakh
- Departments of Physiology and Neurobiology, David Geffen School of Medicine, University of California-Los Angeles, Los Angeles, California 90095,
| |
Collapse
|
47
|
Abstract
Astrocytes are abundant glial cells that tile the entire central nervous system and mediate well-established functions for neurons, blood vessels, and other glia. These ubiquitous cells display intracellular Ca(2+) signals, which have been intensely studied for 25 years. Recently, the use of improved methods has unearthed the panoply of astrocyte Ca(2+) signals and a variable landscape of basal Ca(2+) levels. In vivo studies have started to reveal the settings under which astrocytes display behaviorally relevant Ca(2+) signaling. Studies in mice have emphasized how astrocyte Ca(2+) signaling is altered in distinct neurodegenerative diseases. Progress in the past few years, fueled by methodological advances, has thus reignited interest in astrocyte Ca(2+) signaling for brain function and dysfunction.
Collapse
Affiliation(s)
- Eiji Shigetomi
- Department of Neuropharmacology, Interdisciplinary Graduate School of Medicine, University of Yamanashi, 1110 Shimokato, Chuo, Yamanashi 409-3898, Japan
| | - Sandip Patel
- Department of Cell and Developmental Biology, University College London, Gower Street, London WC1E 6BT, UK
| | - Baljit S Khakh
- Department of Physiology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095-1751, USA; Department of Neurobiology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095-1751, USA.
| |
Collapse
|
48
|
Akassoglou K, Agalliu D, Chang CJ, Davalos D, Grutzendler J, Hillman EMC, Khakh BS, Kleinfeld D, McGavern DB, Nelson SJ, Zlokovic BV. Neurovascular and Immuno-Imaging: From Mechanisms to Therapies. Proceedings of the Inaugural Symposium. Front Neurosci 2016; 10:46. [PMID: 26941593 PMCID: PMC4761864 DOI: 10.3389/fnins.2016.00046] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2015] [Accepted: 02/01/2016] [Indexed: 12/20/2022] Open
Abstract
Breakthrough advances in intravital imaging have launched a new era for the study of dynamic interactions at the neurovascular interface in health and disease. The first Neurovascular and Immuno-Imaging Symposium was held at the Gladstone Institutes, University of California, San Francisco in March, 2015. This highly interactive symposium brought together a group of leading researchers who discussed how recent studies have unraveled fundamental biological mechanisms in diverse scientific fields such as neuroscience, immunology, and vascular biology, both under physiological and pathological conditions. These Proceedings highlight how advances in imaging technologies and their applications revolutionized our understanding of the communication between brain, immune, and vascular systems and identified novel targets for therapeutic intervention in neurological diseases.
Collapse
Affiliation(s)
- Katerina Akassoglou
- Gladstone Institute of Neurological Disease, University of California, San FranciscoSan Francisco, CA, USA; Department of Neurology, University of California, San FranciscoSan Francisco, CA, USA
| | - Dritan Agalliu
- Departments of Neurology, Pathology and Cell Biology and Pharmacology, Columbia University Medical Center New York, NY, USA
| | - Christopher J Chang
- Departments of Chemistry and Molecular and Cell Biology, Howard Hughes Medical Institute, Helen Wills Neuroscience Institute, University of California, Berkeley Berkeley, CA, USA
| | - Dimitrios Davalos
- Department of Neurosciences, Lerner Research Institute, Cleveland Clinic Foundation Cleveland, OH, USA
| | | | - Elizabeth M C Hillman
- Laboratory for Functional Optical Imaging, Departments of Biomedical Engineering and Radiology, Kavli Institute for Brain Science, Columbia University New York, NY, USA
| | - Baljit S Khakh
- Departments of Neurobiology and Physiology, David Geffen School of Medicine, University of California, Los Angeles Los Angeles, CA, USA
| | - David Kleinfeld
- Department of Physics and Section of Neurobiology, University of California, San Diego La Jolla, CA, USA
| | - Dorian B McGavern
- Viral Immunology and Intravital Imaging Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health Bethesda, MD, USA
| | - Sarah J Nelson
- Department of Radiology and Biomedical Imaging, University of California, San Francisco San Francisco, CA, USA
| | - Berislav V Zlokovic
- Department of Physiology and Biophysics, Keck School of Medicine, Zilkha Neurogenetic Institute, University of Southern California Los Angeles, CA, USA
| |
Collapse
|
49
|
Srinivasan R, Huang BS, Venugopal S, Johnston AD, Chai H, Zeng H, Golshani P, Khakh BS. Ca(2+) signaling in astrocytes from Ip3r2(-/-) mice in brain slices and during startle responses in vivo. Nat Neurosci 2015; 18:708-17. [PMID: 25894291 PMCID: PMC4429056 DOI: 10.1038/nn.4001] [Citation(s) in RCA: 321] [Impact Index Per Article: 35.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2015] [Accepted: 03/15/2015] [Indexed: 12/11/2022]
Abstract
Intracellular Ca2+ signaling is considered important for multiple astrocyte functions in neural circuits. However, mice devoid of inositol triphosphate type 2 receptors (IP3R2) reportedly lack all astrocyte Ca2+ signaling, but display no neuronal or neurovascular deficits, implying that astrocyte Ca2+ fluctuations play no role(s) in these functions. An assumption has been that loss of somatic Ca2+ fluctuations also reflects similar loss within astrocyte processes. Here, we tested this assumption and found diverse types of Ca2+ fluctuations within astrocytes, with most occurring within processes rather than in somata. These fluctuations were preserved in IP3R2−/− mice in brain slices and in vivo, occurred in endfeet, were increased by G-protein coupled receptor activation and by startle-induced neuromodulatory responses. Our data reveal novel Ca2+ fluctuations within astrocytes and highlight limitations of studies that used IP3R2−/− mice to evaluate astrocyte contributions to neural circuit function and mouse behavior.
Collapse
Affiliation(s)
- Rahul Srinivasan
- Department of Physiology, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, California, USA
| | - Ben S Huang
- Department of Neurology, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, California, USA
| | - Sharmila Venugopal
- Department of Physiology, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, California, USA
| | - April D Johnston
- Department of Physiology, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, California, USA
| | - Hua Chai
- Department of Physiology, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, California, USA
| | - Hongkui Zeng
- Allen Institute for Brain Science, Seattle, Washington, USA
| | - Peyman Golshani
- 1] Department of Neurology, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, California, USA. [2] Integrative Center for Learning and Memory, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, California, USA. [3] West Los Angeles VA Medical Center, Los Angeles, California, USA
| | - Baljit S Khakh
- 1] Department of Physiology, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, California, USA. [2] Department of Neurobiology, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, California, USA
| |
Collapse
|
50
|
Abstract
We provide an overview of recent progress on the study of astrocyte intracellular Ca(2+) signaling. We consider the methods that have been used to monitor astrocyte Ca(2+) signals, the various types of Ca(2+) signals that have been discovered (waves, microdomains, and intrinsic fluctuations), the approaches used to broadly trigger and block Ca(2+) signals, and, where possible, the proposed and demonstrated physiological roles for astrocyte Ca(2+) signals within neuronal microcircuits. Although important progress has been made, we suggest that further detailed work is needed to explore the biophysics and molecular mechanisms of Ca(2+) signaling within entire astrocytes, including their fine distal extensions, such as processes that interact spatially with neurons and blood vessels. Improved methods are also needed to mimic and block molecularly defined types of Ca(2+) signals within genetically specified populations of astrocytes. Moreover, it will be essential to study astrocyte Ca(2+) activity in vivo to distinguish between pharmacological and physiological activity, and to study Ca(2+) activity in situ to rigorously explore mechanisms. Once methods to reliably measure, mimic, and block specific astrocyte Ca(2+) signals with high temporal and spatial precision are available, researchers will be able to carefully explore the correlative and causative roles that Ca(2+) signals may play in the functions of astrocytes, blood vessels, neurons, and microcircuits in the healthy and diseased brain.
Collapse
Affiliation(s)
- Baljit S Khakh
- Departments of Physiology and Neurobiology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, California 90095
| | - Ken D McCarthy
- Department of Pharmacology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599-7365
| |
Collapse
|