1
|
Sepulveda J, Kim JY, Binder J, Vicini S, Rebeck GW. APOE4 genotype and aging impair injury-induced microglial behavior in brain slices, including toward Aβ, through P2RY12. Mol Neurodegener 2024; 19:24. [PMID: 38468308 DOI: 10.1186/s13024-024-00714-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2023] [Accepted: 02/22/2024] [Indexed: 03/13/2024] Open
Abstract
Microglia are highly dynamic cells that play a critical role in tissue homeostasis through the surveillance of brain parenchyma and response to cues associated with damage. Aging and APOE4 genotype are the strongest risk factors for Alzheimer's disease (AD), but how they affect microglial dynamics remains unclear. Using ex vivo confocal microscopy, we analyzed microglial dynamic behaviors in the entorhinal cortex (EC) and hippocampus CA1 of 6-, 12-, and 21-month-old mice APOE3 or APOE4 knock-in mice expressing GFP under the CX3CR1 promoter. To study microglia surveillance, we imaged microglia baseline motility for 20 min and measured the extension and retraction of processes. We found that APOE4 microglia exhibited significantly less brain surveillance (27%) compared to APOE3 microglia in 6-month-old mice; aging exacerbated this deficit. To measure microglia response to damage, we imaged process motility in response to ATP, an injury-associated signal, for 30 min. We found APOE4 microglia extended their processes significantly slower (0.9 µm/min, p < 0.005) than APOE3 microglia (1.1 μm/min) in 6-month-old animals. APOE-associated alterations in microglia motility were observed in 12- and 21-month-old animals, and this effect was exacerbated with aging in APOE4 microglia. We measured protein and mRNA levels of P2RY12, a core microglial receptor required for process movement in response to damage. We found that APOE4 microglia express significantly less P2RY12 receptors compared to APOE3 microglia despite no changes in P2RY12 transcripts. To examine if the effect of APOE4 on the microglial response to ATP also applied to amyloid β (Aβ), we infused locally Hi-Lyte Fluor 555-labeled Aβ in acute brain slices of 6-month-old mice and imaged microglia movement for 2 h. APOE4 microglia showed a significantly slower (p < 0.0001) process movement toward the Aβ, and less Aβ coverage at early time points after Aβ injection. To test whether P2RY12 is involved in process movement in response to Aβ, we treated acute brain slices with a P2RY12 antagonist before Aβ injection; microglial processes no longer migrated towards Aβ. These results provide mechanistic insights into the impact of APOE4 genotype and aging in dynamic microglial behaviors prior to gross Aβ pathology and could help explain how APOE4 brains are more susceptible to AD pathogenesis.
Collapse
Affiliation(s)
- Jordy Sepulveda
- Department of Pharmacology & Physiology, Georgetown University, Washington, DC, 20007, USA
| | - Jennifer Yejean Kim
- Department of Neuroscience, Georgetown University, Washington, DC, 20007, USA
| | - Joseph Binder
- Department of Neuroscience, Georgetown University, Washington, DC, 20007, USA
| | - Stefano Vicini
- Department of Pharmacology & Physiology, Georgetown University, Washington, DC, 20007, USA
| | - G William Rebeck
- Department of Neuroscience, Georgetown University, Washington, DC, 20007, USA.
| |
Collapse
|
2
|
Kang S, Hong SI, Kang S, Song M, Yang MA, Essa H, Baker M, Lee J, Bruce RA, Lee SW, Choi DS. Astrocyte activities in the external globus pallidus regulate action-selection strategies in reward-seeking behaviors. SCIENCE ADVANCES 2023; 9:eadh9239. [PMID: 37327345 PMCID: PMC10275597 DOI: 10.1126/sciadv.adh9239] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/22/2023] [Accepted: 05/12/2023] [Indexed: 06/18/2023]
Abstract
An imbalance in goal-directed and habitual behavioral control is a hallmark of decision-making-related disorders, including addiction. Although external globus pallidus (GPe) is critical for action selection, which harbors enriched astrocytes, the role of GPe astrocytes involved in action-selection strategies remained unknown. Using in vivo calcium signaling with fiber photometry, we found substantially attenuated GPe astrocytic activity during habitual learning compared to goal-directed learning. The support vector machine analysis predicted the behavioral outcomes. Chemogenetic activation of the astrocytes or inhibition of GPe pan-neuronal activities facilitates the transition from habit to goal-directed reward-seeking behavior. Next, we found increased astrocyte-specific GABA (γ-aminobutyric acid) transporter type 3 (GAT3) messenger RNA expression during habit learning. Notably, the pharmacological inhibition of GAT3 occluded astrocyte activation-induced transition from habitual to goal-directed behavior. On the other hand, attentional stimuli shifted the habit to goal-directed behaviors. Our findings suggest that the GPe astrocytes regulate the action selection strategy and behavioral flexibility.
Collapse
Affiliation(s)
- Shinwoo Kang
- Department of Molecular Pharmacology and Experimental Therapeutics, Mayo Clinic College of Medicine and Science, Rochester, MN, USA
| | - Sa-Ik Hong
- Department of Molecular Pharmacology and Experimental Therapeutics, Mayo Clinic College of Medicine and Science, Rochester, MN, USA
| | - Seungwoo Kang
- Department of Molecular Pharmacology and Experimental Therapeutics, Mayo Clinic College of Medicine and Science, Rochester, MN, USA
- Department of Pharmacology and Toxicology, Medical College of Georgia, Augusta University, Augusta, GA, USA
| | - Minryung Song
- Department of Bio and Brain Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, Republic of Korea
| | - Minsu Abel Yang
- Department of Bio and Brain Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, Republic of Korea
- Program of Brain and Cognitive Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, Republic of Korea
| | - Hesham Essa
- Department of Molecular Pharmacology and Experimental Therapeutics, Mayo Clinic College of Medicine and Science, Rochester, MN, USA
| | - Matthew Baker
- Department of Molecular Pharmacology and Experimental Therapeutics, Mayo Clinic College of Medicine and Science, Rochester, MN, USA
| | - Jeyeon Lee
- Department of Radiology, Mayo Clinic College of Medicine and Science, Rochester, MN, USA
| | - Robert A. Bruce
- Department of Molecular Pharmacology and Experimental Therapeutics, Mayo Clinic College of Medicine and Science, Rochester, MN, USA
| | - Sang Wan Lee
- Department of Bio and Brain Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, Republic of Korea
- Department of Brain and Cognitive Sciences, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, Republic of Korea
- Kim Jaechul Graduate School of AI, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, Republic of Korea
| | - Doo-Sup Choi
- Department of Molecular Pharmacology and Experimental Therapeutics, Mayo Clinic College of Medicine and Science, Rochester, MN, USA
- Department of Psychiatry and Psychology, Mayo Clinic College of Medicine and Science, Rochester, MN, USA
- Neuroscience Program, Mayo Clinic College of Medicine and Science, Rochester, MN, USA
| |
Collapse
|
3
|
Goenaga J, Araque A, Kofuji P, Herrera Moro Chao D. Calcium signaling in astrocytes and gliotransmitter release. Front Synaptic Neurosci 2023; 15:1138577. [PMID: 36937570 PMCID: PMC10017551 DOI: 10.3389/fnsyn.2023.1138577] [Citation(s) in RCA: 17] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2023] [Accepted: 02/16/2023] [Indexed: 03/06/2023] Open
Abstract
Glia are as numerous in the brain as neurons and widely known to serve supportive roles such as structural scaffolding, extracellular ionic and neurotransmitter homeostasis, and metabolic support. However, over the past two decades, several lines of evidence indicate that astrocytes, which are a type of glia, play active roles in neural information processing. Astrocytes, although not electrically active, can exhibit a form of excitability by dynamic changes in intracellular calcium levels. They sense synaptic activity and release neuroactive substances, named gliotransmitters, that modulate neuronal activity and synaptic transmission in several brain areas, thus impacting animal behavior. This "dialogue" between astrocytes and neurons is embodied in the concept of the tripartite synapse that includes astrocytes as integral elements of synaptic function. Here, we review the recent work and discuss how astrocytes via calcium-mediated excitability modulate synaptic information processing at various spatial and time scales.
Collapse
|
4
|
Kruyer A. Astrocyte Heterogeneity in Regulation of Synaptic Activity. Cells 2022; 11:cells11193135. [PMID: 36231097 PMCID: PMC9562199 DOI: 10.3390/cells11193135] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2022] [Revised: 10/02/2022] [Accepted: 10/02/2022] [Indexed: 02/07/2023] Open
Abstract
Our awareness of the number of synapse regulatory functions performed by astroglia is rapidly expanding, raising interesting questions regarding astrocyte heterogeneity and specialization across brain regions. Whether all astrocytes are poised to signal in a multitude of ways, or are instead tuned to surrounding synapses and how astroglial signaling is altered in psychiatric and cognitive disorders are fundamental questions for the field. In recent years, molecular and morphological characterization of astroglial types has broadened our ability to design studies to better analyze and manipulate specific functions of astroglia. Recent data emerging from these studies will be discussed in depth in this review. I also highlight remaining questions emerging from new techniques recently applied toward understanding the roles of astrocytes in synapse regulation in the adult brain.
Collapse
Affiliation(s)
- Anna Kruyer
- Department of Neuroscience, Medical University of South Carolina, Charleston, SC 29425, USA
| |
Collapse
|
5
|
Barber CN, Goldschmidt HL, Lilley B, Bygrave AM, Johnson RC, Huganir RL, Zack DJ, Raben DM. Differential expression patterns of phospholipase D isoforms 1 and 2 in the mammalian brain and retina. J Lipid Res 2022; 63:100247. [PMID: 35764123 PMCID: PMC9305353 DOI: 10.1016/j.jlr.2022.100247] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2021] [Revised: 06/10/2022] [Accepted: 06/20/2022] [Indexed: 01/16/2023] Open
Abstract
Phosphatidic acid is a key signaling molecule heavily implicated in exocytosis due to its protein-binding partners and propensity to induce negative membrane curvature. One phosphatidic acid-producing enzyme, phospholipase D (PLD), has also been implicated in neurotransmission. Unfortunately, due to the unreliability of reagents, there has been confusion in the literature regarding the expression of PLD isoforms in the mammalian brain which has hampered our understanding of their functional roles in neurons. To address this, we generated epitope-tagged PLD1 and PLD2 knockin mice using CRISPR/Cas9. Using these mice, we show that PLD1 and PLD2 are both localized at synapses by adulthood, with PLD2 expression being considerably higher in glial cells and PLD1 expression predominating in neurons. Interestingly, we observed that only PLD1 is expressed in the mouse retina, where it is found in the synaptic plexiform layers. These data provide critical information regarding the localization and potential role of PLDs in the central nervous system.
Collapse
Affiliation(s)
- Casey N Barber
- Department of Biological Chemistry, The Johns Hopkins University School of Medicine, Baltimore, MD, USA; Solomon H. Snyder Department of Neuroscience, The Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Hana L Goldschmidt
- Solomon H. Snyder Department of Neuroscience, The Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Brendan Lilley
- Department of Ophthalmology, Wilmer Eye Institute, The Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Alexei M Bygrave
- Solomon H. Snyder Department of Neuroscience, The Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Richard C Johnson
- Solomon H. Snyder Department of Neuroscience, The Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Richard L Huganir
- Solomon H. Snyder Department of Neuroscience, The Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Donald J Zack
- Department of Ophthalmology, Wilmer Eye Institute, The Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Daniel M Raben
- Department of Biological Chemistry, The Johns Hopkins University School of Medicine, Baltimore, MD, USA.
| |
Collapse
|
6
|
Beiter RM, Rivet-Noor C, Merchak AR, Bai R, Johanson DM, Slogar E, Sol-Church K, Overall CC, Gaultier A. Evidence for oligodendrocyte progenitor cell heterogeneity in the adult mouse brain. Sci Rep 2022; 12:12921. [PMID: 35902669 PMCID: PMC9334628 DOI: 10.1038/s41598-022-17081-7] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2022] [Accepted: 07/20/2022] [Indexed: 12/25/2022] Open
Abstract
Oligodendrocyte progenitor cells (OPCs) account for approximately 5% of the adult brain and have been historically studied for their role in myelination. In the adult brain, OPCs maintain their proliferative capacity and ability to differentiate into oligodendrocytes throughout adulthood, even though relatively few mature oligodendrocytes are produced post-developmental myelination. Recent work has begun to demonstrate that OPCs likely perform multiple functions in both homeostasis and disease and can significantly impact behavioral phenotypes such as food intake and depressive symptoms. However, the exact mechanisms through which OPCs might influence brain function remain unclear. The first step in further exploration of OPC function is to profile the transcriptional repertoire and assess the heterogeneity of adult OPCs. In this work, we demonstrate that adult OPCs are transcriptionally diverse and separate into two distinct populations in the homeostatic brain. These two groups show distinct transcriptional signatures and enrichment of biological processes unique to individual OPC populations. We have validated these OPC populations using multiple methods, including multiplex RNA in situ hybridization and RNA flow cytometry. This study provides an important resource that profiles the transcriptome of adult OPCs and will provide a toolbox for further investigation into novel OPC functions.
Collapse
Affiliation(s)
- Rebecca M Beiter
- Department of Neuroscience, Center for Brain Immunology and Glia, University of Virginia School of Medicine, Charlottesville, VA, 22908, USA.,Graduate Program in Neuroscience, University of Virginia School of Medicine, Charlottesville, VA, 22908, USA
| | - Courtney Rivet-Noor
- Department of Neuroscience, Center for Brain Immunology and Glia, University of Virginia School of Medicine, Charlottesville, VA, 22908, USA.,Graduate Program in Neuroscience, University of Virginia School of Medicine, Charlottesville, VA, 22908, USA
| | - Andrea R Merchak
- Department of Neuroscience, Center for Brain Immunology and Glia, University of Virginia School of Medicine, Charlottesville, VA, 22908, USA.,Graduate Program in Neuroscience, University of Virginia School of Medicine, Charlottesville, VA, 22908, USA
| | - Robin Bai
- Department of Neuroscience, Center for Brain Immunology and Glia, University of Virginia School of Medicine, Charlottesville, VA, 22908, USA
| | - David M Johanson
- Department of Neuroscience, Center for Brain Immunology and Glia, University of Virginia School of Medicine, Charlottesville, VA, 22908, USA
| | - Erica Slogar
- Department of Neuroscience, Center for Brain Immunology and Glia, University of Virginia School of Medicine, Charlottesville, VA, 22908, USA
| | - Katia Sol-Church
- Genome Analysis and Technology Core, University of Virginia School of Medicine, Charlottesville, VA, 22908, USA
| | - Christopher C Overall
- Department of Neuroscience, Center for Brain Immunology and Glia, University of Virginia School of Medicine, Charlottesville, VA, 22908, USA
| | - Alban Gaultier
- Department of Neuroscience, Center for Brain Immunology and Glia, University of Virginia School of Medicine, Charlottesville, VA, 22908, USA. .,Graduate Program in Neuroscience, University of Virginia School of Medicine, Charlottesville, VA, 22908, USA.
| |
Collapse
|
7
|
Region-Specific Characteristics of Astrocytes and Microglia: A Possible Involvement in Aging and Diseases. Cells 2022; 11:cells11121902. [PMID: 35741031 PMCID: PMC9220858 DOI: 10.3390/cells11121902] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2022] [Revised: 06/07/2022] [Accepted: 06/10/2022] [Indexed: 11/17/2022] Open
Abstract
Although different regions of the brain are dedicated to specific functions, the intra- and inter-regional heterogeneity of astrocytes and microglia in these regions has not yet been fully understood. Recently, an advancement in various technologies, such as single-cell RNA sequencing, has allowed for the discovery of astrocytes and microglia with distinct molecular fingerprints and varying functions in the brain. In addition, the regional heterogeneity of astrocytes and microglia exhibits different functions in several situations, such as aging and neurodegenerative diseases. Therefore, investigating the region-specific astrocytes and microglia is important in understanding the overall function of the brain. In this review, we summarize up-to-date research on various intra- and inter-regional heterogeneities of astrocytes and microglia, and provide information on how they can be applied to aging and neurodegenerative diseases.
Collapse
|
8
|
Ortinski PI, Reissner KJ, Turner J, Anderson TA, Scimemi A. Control of complex behavior by astrocytes and microglia. Neurosci Biobehav Rev 2022; 137:104651. [PMID: 35367512 DOI: 10.1016/j.neubiorev.2022.104651] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2021] [Revised: 01/28/2022] [Accepted: 03/21/2022] [Indexed: 02/07/2023]
Abstract
Evidence that glial cells influence behavior has been gaining a steady foothold in scientific literature. Out of the five main subtypes of glial cells in the brain, astrocytes and microglia have received an outsized share of attention with regard to shaping a wide spectrum of behavioral phenomena and there is growing appreciation that the signals intrinsic to these cells as well as their interactions with surrounding neurons reflect behavioral history in a brain region-specific manner. Considerable regional diversity of glial cell phenotypes is beginning to be recognized and may contribute to behavioral outcomes arising from circuit-specific computations within and across discrete brain nuclei. Here, we summarize current knowledge on the impact of astrocyte and microglia activity on behavioral outcomes, with a specific focus on brain areas relevant to higher cognitive control, reward-seeking, and circadian regulation.
Collapse
Affiliation(s)
- P I Ortinski
- Department of Neuroscience, University of Kentucky, USA
| | - K J Reissner
- Department of Psychology and Neuroscience, University of North Carolina Chapel Hill, USA
| | - J Turner
- Department of Pharmaceutical Sciences, University of Kentucky, USA
| | - T A Anderson
- Department of Neuroscience, University of Kentucky, USA
| | - A Scimemi
- Department of Biology, State University of New York at Albany, USA
| |
Collapse
|
9
|
Sobolczyk M, Boczek T. Astrocytic Calcium and cAMP in Neurodegenerative Diseases. Front Cell Neurosci 2022; 16:889939. [PMID: 35663426 PMCID: PMC9161693 DOI: 10.3389/fncel.2022.889939] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2022] [Accepted: 05/05/2022] [Indexed: 12/18/2022] Open
Abstract
It is commonly accepted that the role of astrocytes exceeds far beyond neuronal scaffold and energy supply. Their unique morphological and functional features have recently brough much attention as it became evident that they play a fundamental role in neurotransmission and interact with synapses. Synaptic transmission is a highly orchestrated process, which triggers local and transient elevations in intracellular Ca2+, a phenomenon with specific temporal and spatial properties. Presynaptic activation of Ca2+-dependent adenylyl cyclases represents an important mechanism of synaptic transmission modulation. This involves activation of the cAMP-PKA pathway to regulate neurotransmitter synthesis, release and storage, and to increase neuroprotection. This aspect is of paramount importance for the preservation of neuronal survival and functionality in several pathological states occurring with progressive neuronal loss. Hence, the aim of this review is to discuss mutual relationships between cAMP and Ca2+ signaling and emphasize those alterations at the Ca2+/cAMP crosstalk that have been identified in neurodegenerative disorders, such as Alzheimer's and Parkinson's disease.
Collapse
|
10
|
Ramon-Duaso C, Conde-Moro AR, Busquets-Garcia A. Astroglial cannabinoid signaling and behavior. Glia 2022; 71:60-70. [PMID: 35293647 DOI: 10.1002/glia.24171] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2022] [Revised: 03/07/2022] [Accepted: 03/10/2022] [Indexed: 11/11/2022]
Abstract
In neuroscience, the explosion of innovative and advanced technical accomplishments is fundamental to understanding brain functioning. For example, the possibility to distinguish glial and neuronal activities at the synaptic level and/or the appearance of new genetic tools to specifically monitor and manipulate astroglial functions revealed that astrocytes are involved in several facets of behavioral control. In this sense, the discovery of functional presence of type-1 cannabinoid receptors in astrocytes has led to identify important behavioral responses mediated by this specific pool of cannabinoid receptors. Thus, astroglial type-1 cannabinoid receptors are in the perfect place to play a role in a complex scenario in which astrocytes sense neuronal activity, release gliotransmitters and modulate the activity of other neurons, ultimately controlling behavioral responses. In this review, we will describe the known behavioral implications of astroglial cannabinoid signaling and highlight exciting unexplored research avenues on how astroglial cannabinoid signaling could affect behavior.
Collapse
Affiliation(s)
- Carla Ramon-Duaso
- Cell-Type Mechanisms in Normal and Pathological Behavior Research Group, Neuroscience Programme, IMIM Hospital del Mar Medical Research Institute, Barcelona, Spain
| | - Ana Rocio Conde-Moro
- Cell-Type Mechanisms in Normal and Pathological Behavior Research Group, Neuroscience Programme, IMIM Hospital del Mar Medical Research Institute, Barcelona, Spain
| | - Arnau Busquets-Garcia
- Cell-Type Mechanisms in Normal and Pathological Behavior Research Group, Neuroscience Programme, IMIM Hospital del Mar Medical Research Institute, Barcelona, Spain
| |
Collapse
|
11
|
Tatsumi K, Kinugawa K, Isonishi A, Kitabatake M, Okuda H, Takemura S, Tanaka T, Mori E, Wanaka A. Olig2-astrocytes express neutral amino acid transporter SLC7A10 (Asc-1) in the adult brain. Mol Brain 2021; 14:163. [PMID: 34749773 PMCID: PMC8573876 DOI: 10.1186/s13041-021-00874-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2021] [Accepted: 10/28/2021] [Indexed: 11/23/2022] Open
Abstract
We have reported that the transcription factor Olig2 labels a subpopulation of astrocytes (Olig2-astrocytes), which show distribution patterns different from those of GFAP-expressing astrocytes (GFAP-astrocytes) in the adult brain. Here, to uncover the specific functions of Olig2-astrocytes, we first analyzed public single-cell RNA-seq databases of adult mouse brains. Unbiased classification of gene expression profiles and subsequent gene ontology analyses revealed that the majority of Olig2-astrocytes belonged to an astrocytic cluster that is enriched for transporter-related genes. SLC7A10 (also known as ASC-1) was one of the representative neutral amino acid transporter genes in the cluster. To complement the in silico data analyses, we differentially isolated Olig2- and GFAP-astrocytes from the same frozen section of the lateral globus pallidus using laser microdissection and compared their gene expression by quantitative reverse transcription PCR. We confirmed that Olig2 and GFAP mRNAs were preferentially expressed in the Olig2- and GFAP-astrocytes, respectively, indicating that the laser microdissection method yielded minimal cross-contamination between two types of cells. The Olig2-astrocytes expressed significantly higher levels of SLC7A10 mRNA than the GFAP-astrocytes, corroborating the in silico data. We next localized SLC7A10 protein by immunohistochemistry in the lateral globus pallidus, which was also genetically labeled for Olig2. SLC7A10 co-localized with Olig2-genetic labeling, especially on the fine processes of Olig2-astrocytes. These results are consistent with the recent discovery that SLC7A10 is expressed not only in neurons but also in a subset of astrocytes. Taken together, our findings suggest that SLC7A10 exerts specific functions in Olig2-astrocytes of the adult brain.
Collapse
Affiliation(s)
- Kouko Tatsumi
- Department of Anatomy and Neuroscience, Faculty of Medicine, Nara Medical University, Kashihara, Nara, 634-8521, Japan.
| | - Kaoru Kinugawa
- Department of Neurology, Faculty of Medicine, Nara Medical University, Kashihara, Nara, 634-8521, Japan
| | - Ayami Isonishi
- Department of Anatomy and Neuroscience, Faculty of Medicine, Nara Medical University, Kashihara, Nara, 634-8521, Japan
| | - Masahiro Kitabatake
- Department of Immunology, Faculty of Medicine, Nara Medical University, Kashihara, Nara, 634-8521, Japan
| | - Hiroaki Okuda
- Department of Anatomy, Graduate School of Medical Science, Kanazawa University, Kanazawa, Ishikawa, 920-1192, Japan
| | - Shoko Takemura
- Department of Anatomy and Neuroscience, Faculty of Medicine, Nara Medical University, Kashihara, Nara, 634-8521, Japan
| | - Tatsuhide Tanaka
- Department of Anatomy and Neuroscience, Faculty of Medicine, Nara Medical University, Kashihara, Nara, 634-8521, Japan
| | - Eiichiro Mori
- Department of Future Basic Medicine, Faculty of Medicine, Nara Medical University, Kashihara, Nara, 634-8521, Japan
| | - Akio Wanaka
- Department of Anatomy and Neuroscience, Faculty of Medicine, Nara Medical University, Kashihara, Nara, 634-8521, Japan
| |
Collapse
|
12
|
Necula D, Cho FS, He A, Paz JT. Secondary thalamic neuroinflammation after focal cortical stroke and traumatic injury mirrors corticothalamic functional connectivity. J Comp Neurol 2021; 530:998-1019. [PMID: 34633669 PMCID: PMC8957545 DOI: 10.1002/cne.25259] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2021] [Revised: 10/03/2021] [Accepted: 10/04/2021] [Indexed: 12/29/2022]
Abstract
While cortical injuries, such as traumatic brain injury (TBI) and neocortical stroke, acutely disrupt the neocortex, most of their consequent disabilities reflect secondary injuries that develop over time. Thalamic neuroinflammation has been proposed to be a biomarker of cortical injury and of the long-term cognitive and neurological deficits that follow. However, the extent to which thalamic neuroinflammation depends on the type of cortical injury or its location remains unknown. Using two mouse models of focal neocortical injury that do not directly damage subcortical structures-controlled cortical impact and photothrombotic ischemic stroke-we found that chronic neuroinflammation in the thalamic region mirrors the functional connections with the injured cortex, and that sensory corticothalamic regions may be more likely to sustain long-term damage than nonsensory circuits. Currently, heterogeneous clinical outcomes complicate treatment. Understanding how thalamic inflammation depends on the injury site can aid in predicting features of subsequent deficits and lead to more effective, customized therapies.
Collapse
Affiliation(s)
- Deanna Necula
- Gladstone Institute of Neurological Disease, San Francisco, California, USA.,Neuroscience Graduate Program, University of California, San Francisco, California, USA.,Department of Neurology and the Kavli Institute for Fundamental Neuroscience, University of California San Francisco, San Francisco, California, USA
| | - Frances S Cho
- Gladstone Institute of Neurological Disease, San Francisco, California, USA.,Neuroscience Graduate Program, University of California, San Francisco, California, USA.,Department of Neurology and the Kavli Institute for Fundamental Neuroscience, University of California San Francisco, San Francisco, California, USA
| | - Andrea He
- Gladstone Institute of Neurological Disease, San Francisco, California, USA
| | - Jeanne T Paz
- Gladstone Institute of Neurological Disease, San Francisco, California, USA.,Neuroscience Graduate Program, University of California, San Francisco, California, USA.,Department of Neurology and the Kavli Institute for Fundamental Neuroscience, University of California San Francisco, San Francisco, California, USA
| |
Collapse
|
13
|
McCann MS, Fernandez HR, Flowers SA, Maguire-Zeiss KA. Polychlorinated biphenyls induce oxidative stress and metabolic responses in astrocytes. Neurotoxicology 2021; 86:59-68. [PMID: 34265337 PMCID: PMC8440398 DOI: 10.1016/j.neuro.2021.07.001] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2021] [Revised: 06/16/2021] [Accepted: 07/08/2021] [Indexed: 11/16/2022]
Abstract
Exposure to environmental toxicants is prevalent, hazardous and linked to varied detrimental health outcomes and disease. Polychlorinated biphenyls (PCBs), a class of hazardous organic chlorines once widely used for industrial purposes, are associated with neurodegenerative disease and oxidative stress in both in vitro and in vivo models. Here, we investigated the impact of Aroclor 1254, a commercially available PCB mixture, on primary murine astrocytes to determine the response to this once ubiquitously used toxicant on the most numerous cells of the central nervous system (CNS). Astrocytes are a critical component of homeostasis throughout the CNS, including at the blood-brain barrier, where they serve as the primary defense against xenobiotics entering the CNS, and at the synapse, where they are closely coupled to neurons through several metabolic pathways. We hypothesized that PCBs cause astrocytic oxidative stress and related dysfunction including altered metabolism. We exposed primary murine cortical astrocytes to PCBs and report an increased expression of antioxidant genes (Prdx1, Gsta2, Gfap, Amigo2) in response to oxidative stress. Our data show increased ATP production and spare respiratory capacity in astrocytes exposed to 10 μM (∼ 3 ppm) PCBs. This dose also causes an increase in glucose uptake that is not seen at a higher dose (50 μM) suggesting that, at a lower dose, astrocytes are able to engage compensatory mechanisms to promote survival. Together, these data suggest that exposure to PCBs impact astrocytic metabolism, which is important to consider both in the context of human health and disease and in in vitro and in vivo disease models.
Collapse
Affiliation(s)
- Mondona S McCann
- Department of Neuroscience, Georgetown University Medical Center, Washington D.C., United States; Interdisciplinary Program in Neuroscience, Georgetown University Medical Center, Washington D.C., United States
| | - Harvey R Fernandez
- Department of Neuroscience, Georgetown University Medical Center, Washington D.C., United States
| | - Sarah A Flowers
- Department of Neuroscience, Georgetown University Medical Center, Washington D.C., United States
| | - Kathleen A Maguire-Zeiss
- Department of Neuroscience, Georgetown University Medical Center, Washington D.C., United States; Interdisciplinary Program in Neuroscience, Georgetown University Medical Center, Washington D.C., United States.
| |
Collapse
|
14
|
Zanfardino P, Doccini S, Santorelli FM, Petruzzella V. Tackling Dysfunction of Mitochondrial Bioenergetics in the Brain. Int J Mol Sci 2021; 22:8325. [PMID: 34361091 PMCID: PMC8348117 DOI: 10.3390/ijms22158325] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2021] [Revised: 07/29/2021] [Accepted: 07/30/2021] [Indexed: 12/15/2022] Open
Abstract
Oxidative phosphorylation (OxPhos) is the basic function of mitochondria, although the landscape of mitochondrial functions is continuously growing to include more aspects of cellular homeostasis. Thanks to the application of -omics technologies to the study of the OxPhos system, novel features emerge from the cataloging of novel proteins as mitochondrial thus adding details to the mitochondrial proteome and defining novel metabolic cellular interrelations, especially in the human brain. We focussed on the diversity of bioenergetics demand and different aspects of mitochondrial structure, functions, and dysfunction in the brain. Definition such as 'mitoexome', 'mitoproteome' and 'mitointeractome' have entered the field of 'mitochondrial medicine'. In this context, we reviewed several genetic defects that hamper the last step of aerobic metabolism, mostly involving the nervous tissue as one of the most prominent energy-dependent tissues and, as consequence, as a primary target of mitochondrial dysfunction. The dual genetic origin of the OxPhos complexes is one of the reasons for the complexity of the genotype-phenotype correlation when facing human diseases associated with mitochondrial defects. Such complexity clinically manifests with extremely heterogeneous symptoms, ranging from organ-specific to multisystemic dysfunction with different clinical courses. Finally, we briefly discuss the future directions of the multi-omics study of human brain disorders.
Collapse
Affiliation(s)
- Paola Zanfardino
- Department of Medical Basic Sciences, Neurosciences and Sense Organs, University of Bari Aldo Moro, 70124 Bari, Italy;
| | - Stefano Doccini
- IRCCS Fondazione Stella Maris, Calambrone, 56128 Pisa, Italy;
| | | | - Vittoria Petruzzella
- Department of Medical Basic Sciences, Neurosciences and Sense Organs, University of Bari Aldo Moro, 70124 Bari, Italy;
| |
Collapse
|
15
|
Nanclares C, Baraibar AM, Araque A, Kofuji P. Dysregulation of Astrocyte-Neuronal Communication in Alzheimer's Disease. Int J Mol Sci 2021; 22:7887. [PMID: 34360652 PMCID: PMC8346080 DOI: 10.3390/ijms22157887] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2021] [Revised: 07/19/2021] [Accepted: 07/20/2021] [Indexed: 12/16/2022] Open
Abstract
Recent studies implicate astrocytes in Alzheimer's disease (AD); however, their role in pathogenesis is poorly understood. Astrocytes have well-established functions in supportive functions such as extracellular ionic homeostasis, structural support, and neurovascular coupling. However, emerging research on astrocytic function in the healthy brain also indicates their role in regulating synaptic plasticity and neuronal excitability via the release of neuroactive substances named gliotransmitters. Here, we review how this "active" role of astrocytes at synapses could contribute to synaptic and neuronal network dysfunction and cognitive impairment in AD.
Collapse
Affiliation(s)
| | | | | | - Paulo Kofuji
- Department of Neuroscience, University of Minnesota, Minneapolis, MN 55455, USA; (C.N.); (A.M.B.); (A.A.)
| |
Collapse
|
16
|
Patterson KC, Kahanovitch U, Gonçalves CM, Hablitz JJ, Staruschenko A, Mulkey DK, Olsen ML. K ir 5.1-dependent CO 2 /H + -sensitive currents contribute to astrocyte heterogeneity across brain regions. Glia 2021; 69:310-325. [PMID: 32865323 PMCID: PMC8665280 DOI: 10.1002/glia.23898] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2019] [Revised: 07/24/2020] [Accepted: 07/26/2020] [Indexed: 09/19/2023]
Abstract
Astrocyte heterogeneity is an emerging concept in which astrocytes within or between brain regions show variable morphological and/or gene expression profiles that presumably reflect different functional roles. Recent evidence indicates that retrotrapezoid nucleus (RTN) astrocytes sense changes in tissue CO2/ H+ to regulate respiratory activity; however, mechanism(s) by which they do so remain unclear. Alterations in inward K+ currents represent a potential mechanism by which CO2 /H+ signals may be conveyed to neurons. Here, we use slice electrophysiology in rats of either sex to show that RTN astrocytes intrinsically respond to CO2 /H+ by inhibition of an inward rectifying potassium (Kir ) conductance and depolarization of the membrane, while cortical astrocytes do not exhibit such CO2 /H+ -sensitive properties. Application of Ba2+ mimics the effect of CO2 /H+ on RTN astrocytes as measured by reductions in astrocyte Kir -like currents and increased RTN neuronal firing. These CO2 /H+ -sensitive currents increase developmentally, in parallel to an increased expression in Kir 4.1 and Kir 5.1 in the brainstem. Finally, the involvement of Kir 5.1 in the CO2 /H+ -sensitive current was verified using a Kir5.1 KO rat. These data suggest that Kir inhibition by CO2 /H+ may govern the degree to which astrocytes mediate downstream chemoreceptive signaling events through cell-autonomous mechanisms. These results identify Kir channels as potentially important regional CO2 /H+ sensors early in development, thus expanding our understanding of how astrocyte heterogeneity may uniquely support specific neural circuits and behaviors.
Collapse
Affiliation(s)
- Kelsey C Patterson
- Department of Cell, Developmental, and Integrative Biology, University of Alabama at Birmingham, Birmingham, Alabama 35294, USA
| | - Uri Kahanovitch
- School of Neuroscience, Virginia Polytechnic Institute and State University, Blacksburg, VA, USA
| | | | - John J Hablitz
- Department of Neurobiology, University of Alabama at Birmingham, Birmingham, Alabama 35294, USA
| | - Alexander Staruschenko
- Department of Physiology, Medical College of Wisconsin, Milwaukee, WI 53226, USA
- Cardiovascular Center, Medical College of Wisconsin, Milwaukee, WI 53226, USA
| | - Daniel K Mulkey
- Department of Physiology and Neurobiology, University of Connecticut, Storrs, CT 06269, USA
| | - Michelle L Olsen
- School of Neuroscience, Virginia Polytechnic Institute and State University, Blacksburg, VA, USA
| |
Collapse
|
17
|
Aboufares El Alaoui A, Jackson M, Fabri M, de Vivo L, Bellesi M. Characterization of Subcellular Organelles in Cortical Perisynaptic Astrocytes. Front Cell Neurosci 2021; 14:573944. [PMID: 33633542 PMCID: PMC7901967 DOI: 10.3389/fncel.2020.573944] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2020] [Accepted: 12/30/2020] [Indexed: 01/18/2023] Open
Abstract
Perisynaptic astrocytic processes (PAPs) carry out several different functions, from metabolite clearing to control of neuronal excitability and synaptic plasticity. All these functions are likely orchestrated by complex cellular machinery that resides within the PAPs and relies on a fine interplay between multiple subcellular components. However, traditional transmission electron microscopy (EM) studies have found that PAPs are remarkably poor of intracellular organelles, failing to explain how such a variety of PAP functions are achieved in the absence of a proportional complex network of intracellular structures. Here, we use serial block-face scanning EM to reconstruct and describe in three dimensions PAPs and their intracellular organelles in two different mouse cortical regions. We described five distinct organelles, which included empty and full endosomes, phagosomes, mitochondria, and endoplasmic reticulum (ER) cisternae, distributed within three PAPs categories (branches, branchlets, and leaflets). The majority of PAPs belonged to the leaflets category (~60%), with branchlets representing a minority (~37%). Branches were rarely in contact with synapses (<3%). Branches had a higher density of mitochondria and ER cisternae than branchlets and leaflets. Also, branches and branchlets displayed organelles more frequently than leaflets. Endosomes and phagosomes, which accounted for more than 60% of all the organelles detected, were often associated with the same PAP. Likewise, mitochondria and ER cisternae, representing ~40% of all organelles were usually associated. No differences were noted between the organelle distribution of the somatosensory and the anterior cingulate cortex. Finally, the organelle distribution in PAPs did not largely depend on the presence of a spine apparatus or a pre-synaptic mitochondrion in the synapse that PAPs were enwrapping, with some exceptions regarding the presence of phagosomes and ER cisternae, which were slightly more represented around synapses lacking a spine apparatus and a presynaptic mitochondrion, respectively. Thus, PAPs contain several subcellular organelles that could underlie the diverse astrocytic functions carried out at central synapses.
Collapse
Affiliation(s)
- Amina Aboufares El Alaoui
- Department of Experimental and Clinical Medicine, Marche Polytechnic University, Ancona, Italy.,School of Physiology, Pharmacology, and Neuroscience, University of Bristol, Bristol, United Kingdom
| | - Molly Jackson
- School of Physiology, Pharmacology, and Neuroscience, University of Bristol, Bristol, United Kingdom
| | - Mara Fabri
- Department of Experimental and Clinical Medicine, Marche Polytechnic University, Ancona, Italy
| | - Luisa de Vivo
- School of Physiology, Pharmacology, and Neuroscience, University of Bristol, Bristol, United Kingdom
| | - Michele Bellesi
- School of Physiology, Pharmacology, and Neuroscience, University of Bristol, Bristol, United Kingdom
| |
Collapse
|
18
|
Astrocytes and oligodendrocytes in the thalamus jointly maintain synaptic activity by supplying metabolites. Cell Rep 2021; 34:108642. [PMID: 33472059 DOI: 10.1016/j.celrep.2020.108642] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2019] [Revised: 10/23/2020] [Accepted: 12/21/2020] [Indexed: 12/19/2022] Open
Abstract
Thalamic astrocytes and oligodendrocytes are coupled via gap junctions and form panglial networks. Here, we show that these networks have a key role in energy supply of neurons. Filling an astrocyte or an oligodendrocyte in acute slices with glucose or lactate is sufficient to rescue the decline of stimulation-induced field post-synaptic potential (fPSP) amplitudes during extracellular glucose deprivation (EGD). In mice lacking oligodendroglial coupling, loading an astrocyte with glucose does not rescue the EGD-mediated loss of fPSPs. Monocarboxylate and glucose transporters are required for rescuing synaptic activity during EGD. In mice deficient in astrocyte coupling, filling of an oligodendrocyte with glucose does not rescue fPSPs during EGD. Our results demonstrate that, in the thalamus, astrocytes and oligodendrocytes are jointly engaged in delivering energy substrates for sustaining neuronal activity and suggest that oligodendrocytes exert their effect mainly by assisting astrocytes in metabolite transfer to the postsynapse.
Collapse
|
19
|
Roth RH, Ding JB. From Neurons to Cognition: Technologies for Precise Recording of Neural Activity Underlying Behavior. BME FRONTIERS 2020; 2020:7190517. [PMID: 37849967 PMCID: PMC10521756 DOI: 10.34133/2020/7190517] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2020] [Accepted: 10/27/2020] [Indexed: 10/19/2023] Open
Abstract
Understanding how brain activity encodes information and controls behavior is a long-standing question in neuroscience. This complex problem requires converging efforts from neuroscience and engineering, including technological solutions to perform high-precision and large-scale recordings of neuronal activity in vivo as well as unbiased methods to reliably measure and quantify behavior. Thanks to advances in genetics, molecular biology, engineering, and neuroscience, in recent decades, a variety of optical imaging and electrophysiological approaches for recording neuronal activity in awake animals have been developed and widely applied in the field. Moreover, sophisticated computer vision and machine learning algorithms have been developed to analyze animal behavior. In this review, we provide an overview of the current state of technology for neuronal recordings with a focus on optical and electrophysiological methods in rodents. In addition, we discuss areas that future technological development will need to cover in order to further our understanding of the neural activity underlying behavior.
Collapse
Affiliation(s)
- Richard H Roth
- Department of Neurosurgery, Stanford University, Stanford, CA 94305, USA
| | - Jun B Ding
- Department of Neurosurgery, Stanford University, Stanford, CA 94305, USA
- Department of Neurology and Neurological Sciences, Stanford University, Stanford, CA 94305, USA
| |
Collapse
|
20
|
Borggrewe M, Grit C, Vainchtein ID, Brouwer N, Wesseling EM, Laman JD, Eggen BJL, Kooistra SM, Boddeke EWGM. Regionally diverse astrocyte subtypes and their heterogeneous response to EAE. Glia 2020; 69:1140-1154. [PMID: 33332631 PMCID: PMC7985878 DOI: 10.1002/glia.23954] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2020] [Revised: 11/30/2020] [Accepted: 12/02/2020] [Indexed: 12/20/2022]
Abstract
Astrocytes fulfil many functions in the central nervous system (CNS), including contribution to the blood brain barrier, synapse formation, and trophic support. In addition, they can mount an inflammatory response and are heterogeneous in morphology and function. To extensively characterize astrocyte subtypes, we FACS‐isolated and gene expression profiled distinct astrocyte subtypes from three central nervous system regions; forebrain, hindbrain and spinal cord. Astrocyte subpopulations were separated based on GLAST/SLC1A3 and ACSA‐2/ATP1B2 cell surface expression. The local brain environment proved key in establishing different transcriptional programs in astrocyte subtypes. Transcriptional differences between subtypes were also apparent in experimental autoimmune encephalomyelitis (EAE) mice, where these astrocyte subtypes showed distinct responses. While gene expression signatures associated with blood–brain barrier maintenance were lost, signatures involved in neuroinflammation and neurotoxicity were increased in spinal cord astrocytes, especially during acute disease stages. In chronic stages of EAE, this reactive astrocyte signature was slightly decreased, while obtaining a more proliferative profile, which might be relevant for glia scar formation and tissue regeneration. Morphological heterogeneity of astrocytes previously indicated the presence of astrocyte subtypes, and here we show diversity based on transcriptome variation associated with brain regions and differential responsiveness to a neuroinflammatory insult (EAE).
Collapse
Affiliation(s)
- Malte Borggrewe
- Department of Biomedical Sciences of Cells & Systems, Section Molecular Neurobiology, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | - Corien Grit
- Department of Biomedical Sciences of Cells & Systems, Section Molecular Neurobiology, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | - Ilia D Vainchtein
- Department of Biomedical Sciences of Cells & Systems, Section Molecular Neurobiology, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands.,Department of Psychiatry and Weill Institute for Neurosciences, University of California, San Francisco, California, USA
| | - Nieske Brouwer
- Department of Biomedical Sciences of Cells & Systems, Section Molecular Neurobiology, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | - Evelyn M Wesseling
- Department of Biomedical Sciences of Cells & Systems, Section Molecular Neurobiology, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | - Jon D Laman
- Department of Biomedical Sciences of Cells & Systems, Section Molecular Neurobiology, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | - Bart J L Eggen
- Department of Biomedical Sciences of Cells & Systems, Section Molecular Neurobiology, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | - Susanne M Kooistra
- Department of Biomedical Sciences of Cells & Systems, Section Molecular Neurobiology, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | - Erik W G M Boddeke
- Department of Biomedical Sciences of Cells & Systems, Section Molecular Neurobiology, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands.,Center for Healthy Ageing, Department of Cellular and Molecular Medicine, University of Copenhagen, Copenhagen, Denmark
| |
Collapse
|
21
|
Jadhav VS, Lin PBC, Pennington T, Di Prisco GV, Jannu AJ, Xu G, Moutinho M, Zhang J, Atwood BK, Puntambekar SS, Bissel SJ, Oblak AL, Landreth GE, Lamb BT. Trem2 Y38C mutation and loss of Trem2 impairs neuronal synapses in adult mice. Mol Neurodegener 2020; 15:62. [PMID: 33115519 PMCID: PMC7594478 DOI: 10.1186/s13024-020-00409-0] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2020] [Accepted: 10/01/2020] [Indexed: 12/16/2022] Open
Abstract
BACKGROUND Triggering receptor expressed on myeloid cells 2 (TREM2) is expressed in the brain exclusively on microglia and genetic variants are linked to neurodegenerative diseases including Alzheimer's disease (AD), frontotemporal dementia (FTD) and Nasu Hakola Disease (NHD). The Trem2 variant R47H, confers substantially elevated risk of developing late onset Alzheimer's disease, while NHD-linked Trem2 variants like Y38C, are associated with development of early onset dementia with white matter pathology. However, it is not known how these Trem2 species, predisposes individuals to presenile dementia. METHODS To investigate if Trem2 Y38C or loss of Trem2 alters neuronal function we generated a novel mouse model to introduce the NHD Trem2 Y38C variant in murine Trem2 using CRISPR/Cas9 technology. Trem2Y38C/Y38C and Trem2-/- mice were assessed for Trem2 expression, differentially expressed genes, synaptic protein levels and synaptic plasticity using biochemical, electrophysiological and transcriptomic approaches. RESULTS While mice harboring the Trem2 Y38C exhibited normal expression levels of TREM2, the pathological outcomes phenocopied Trem2-/- mice at 6 months. Transcriptomic analysis revealed altered expression of neuronal and oligodendrocytes/myelin genes. We observed regional decreases in synaptic protein levels, with the most affected synapses in the hippocampus. These alterations were associated with reduced synaptic plasticity. CONCLUSION Our findings provide in vivo evidence that Trem2 Y38C disrupts normal TREM2 functions. Trem2Y38C/Y38C and Trem2-/- mice demonstrated altered gene expression, changes in microglia morphology, loss of synaptic proteins and reduced hippocampal synaptic plasticity at 6 months in absence of any pathological triggers like amyloid. This suggests TREM2 impacts neuronal functions providing molecular insights on the predisposition of individuals with TREM2 variants resulting in presenile dementia.
Collapse
Affiliation(s)
- Vaishnavi S Jadhav
- Paul and Carole Stark Neurosciences Research Institute, Indiana University, School of Medicine, Indianapolis, IN, 46202, USA
| | - Peter B C Lin
- Paul and Carole Stark Neurosciences Research Institute, Indiana University, School of Medicine, Indianapolis, IN, 46202, USA
| | - Taylor Pennington
- Paul and Carole Stark Neurosciences Research Institute, Indiana University, School of Medicine, Indianapolis, IN, 46202, USA
- Department of Pharmacology and Toxicology, Indiana University, School of Medicine, Indianapolis, IN, 46202, USA
| | - Gonzalo Viana Di Prisco
- Paul and Carole Stark Neurosciences Research Institute, Indiana University, School of Medicine, Indianapolis, IN, 46202, USA
- Department of Pharmacology and Toxicology, Indiana University, School of Medicine, Indianapolis, IN, 46202, USA
| | - Asha Jacob Jannu
- Department of Medicine, Indiana University School of Medicine, Indianapolis, IN, 462020, USA
| | - Guixiang Xu
- Paul and Carole Stark Neurosciences Research Institute, Indiana University, School of Medicine, Indianapolis, IN, 46202, USA
- Department of Medical and Molecular Genetics, Indiana University, School of Medicine, Indianapolis, IN, 46202, USA
| | - Miguel Moutinho
- Paul and Carole Stark Neurosciences Research Institute, Indiana University, School of Medicine, Indianapolis, IN, 46202, USA
- Department of Anatomy and Cell Biology, Indiana University, School of Medicine, Indianapolis, IN, 46202, USA
| | - Jie Zhang
- Department of Medical and Molecular Genetics, Indiana University, School of Medicine, Indianapolis, IN, 46202, USA
| | - Brady K Atwood
- Paul and Carole Stark Neurosciences Research Institute, Indiana University, School of Medicine, Indianapolis, IN, 46202, USA
- Department of Pharmacology and Toxicology, Indiana University, School of Medicine, Indianapolis, IN, 46202, USA
| | - Shweta S Puntambekar
- Paul and Carole Stark Neurosciences Research Institute, Indiana University, School of Medicine, Indianapolis, IN, 46202, USA
- Department of Medical and Molecular Genetics, Indiana University, School of Medicine, Indianapolis, IN, 46202, USA
| | - Stephanie J Bissel
- Paul and Carole Stark Neurosciences Research Institute, Indiana University, School of Medicine, Indianapolis, IN, 46202, USA
- Department of Medical and Molecular Genetics, Indiana University, School of Medicine, Indianapolis, IN, 46202, USA
| | - Adrian L Oblak
- Paul and Carole Stark Neurosciences Research Institute, Indiana University, School of Medicine, Indianapolis, IN, 46202, USA
- Department of Radiology & Imaging Sciences, Indiana University School of Medicine, Indianapolis, IN, 46202, USA
| | - Gary E Landreth
- Paul and Carole Stark Neurosciences Research Institute, Indiana University, School of Medicine, Indianapolis, IN, 46202, USA
- Department of Anatomy and Cell Biology, Indiana University, School of Medicine, Indianapolis, IN, 46202, USA
| | - Bruce T Lamb
- Paul and Carole Stark Neurosciences Research Institute, Indiana University, School of Medicine, Indianapolis, IN, 46202, USA.
- Department of Medical and Molecular Genetics, Indiana University, School of Medicine, Indianapolis, IN, 46202, USA.
| |
Collapse
|
22
|
Dere D, Zlomuzica A, Dere E. Channels to consciousness: a possible role of gap junctions in consciousness. Rev Neurosci 2020; 32:/j/revneuro.ahead-of-print/revneuro-2020-0012/revneuro-2020-0012.xml. [PMID: 32853172 DOI: 10.1515/revneuro-2020-0012] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2020] [Accepted: 06/26/2020] [Indexed: 12/20/2022]
Abstract
The neurophysiological basis of consciousness is still unknown and one of the most challenging questions in the field of neuroscience and related disciplines. We propose that consciousness is characterized by the maintenance of mental representations of internal and external stimuli for the execution of cognitive operations. Consciousness cannot exist without working memory, and it is likely that consciousness and working memory share the same neural substrates. Here, we present a novel psychological and neurophysiological framework that explains the role of consciousness for cognition, adaptive behavior, and everyday life. A hypothetical architecture of consciousness is presented that is organized as a system of operation and storage units named platforms that are controlled by a consciousness center (central executive/online platform). Platforms maintain mental representations or contents, are entrusted with different executive functions, and operate at different levels of consciousness. The model includes conscious-mode central executive/online and mental time travel platforms and semiconscious steady-state and preconscious standby platforms. Mental representations or contents are represented by neural circuits and their support cells (astrocytes, oligodendrocytes, etc.) and become conscious when neural circuits reverberate, that is, fire sequentially and continuously with relative synchronicity. Reverberatory activity in neural circuits may be initiated and maintained by pacemaker cells/neural circuit pulsars, enhanced electronic coupling via gap junctions, and unapposed hemichannel opening. The central executive/online platform controls which mental representations or contents should become conscious by recruiting pacemaker cells/neural network pulsars, the opening of hemichannels, and promoting enhanced neural circuit coupling via gap junctions.
Collapse
Affiliation(s)
- Dorothea Dere
- Département UMR 8256 Adaptation Biologique et Vieillissement, Sorbonne Université, Institut de Biologie Paris-Seine, (IBPS), UFR des Sciences de la Vie, Campus Pierre et Marie Curie, Bâtiment B, 9 quai Saint Bernard, F-75005 Paris Cedex, France
| | - Armin Zlomuzica
- Faculty of Psychology, Behavioral and Clinical Neuroscience, University of Bochum, Massenbergstraße 9-13, D-44787 Bochum, Germany
| | - Ekrem Dere
- Département UMR 8256 Adaptation Biologique et Vieillissement, Sorbonne Université, Institut de Biologie Paris-Seine, (IBPS), UFR des Sciences de la Vie, Campus Pierre et Marie Curie, Bâtiment B, 9 quai Saint Bernard, F-75005 Paris Cedex, France
| |
Collapse
|
23
|
Hennes M, Lombaert N, Wahis J, Van den Haute C, Holt MG, Arckens L. Astrocytes shape the plastic response of adult cortical neurons to vision loss. Glia 2020; 68:2102-2118. [DOI: 10.1002/glia.23830] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2019] [Revised: 03/10/2020] [Accepted: 03/13/2020] [Indexed: 12/26/2022]
Affiliation(s)
- Maroussia Hennes
- Department of BiologyKU Leuven Leuven Belgium
- VIB KU Leuven Center for Brain & Disease Research Leuven Belgium
- Leuven Brain Institute Leuven Belgium
| | | | - Jérôme Wahis
- VIB KU Leuven Center for Brain & Disease Research Leuven Belgium
- Leuven Brain Institute Leuven Belgium
- Department of NeurosciencesKU Leuven Leuven Belgium
| | - Chris Van den Haute
- Department of Biomedical SciencesKU Leuven Leuven Belgium
- KU Leuven Viral Vector Core Leuven Belgium
| | - Matthew G. Holt
- VIB KU Leuven Center for Brain & Disease Research Leuven Belgium
- Leuven Brain Institute Leuven Belgium
- Department of NeurosciencesKU Leuven Leuven Belgium
| | - Lutgarde Arckens
- Department of BiologyKU Leuven Leuven Belgium
- Leuven Brain Institute Leuven Belgium
| |
Collapse
|
24
|
Georgiou V, Gkretsi V. The role of fibroblast growth factors and their receptors in gliomas: the mutations involved. Rev Neurosci 2020; 30:543-554. [PMID: 30379640 DOI: 10.1515/revneuro-2018-0051] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2018] [Accepted: 08/10/2018] [Indexed: 11/15/2022]
Abstract
The central nervous system (CNS) comprises of neurons, which are responsible for impulse transmission, and glial cells, which surround neurons providing protection and nutrition. Glial cells are categorized into astrocytes, oligodendrocytes, microglial cells, and ependymal cells. Tumors forming from glial cells are called gliomas, and they are classified accordingly into astrocytomas, oligodendrogliomas, and ependymomas. Gliomas are characterized by high mortality rates and degree of malignancy, heterogeneity, and resistance to treatment. Among the molecular players implicated in glioma pathogenesis are members of the fibroblast growth factor (FGF) superfamily as well as their receptors (FGFRs). In the present study, we provide a review of the literature on the role of FGFs and FGFRs in glioma pathogenesis. We also demonstrate that FGFs, and particularly FGF1 and FGF2, bear a variety of mutations in gliomas, while FGFRs are also crucially involved. In fact, several studies show that in gliomas, FGFRs bear mutations, mainly in the tyrosine kinase domains. Specifically, it appears that FGFR1-TACC1 and FGFR3-TACC3 fusions are common in these receptors. A better understanding of the mutations and the molecular players involved in glioma formation will benefit the scientific community, leading to the development of more effective and innovative therapeutic approaches.
Collapse
Affiliation(s)
- Vasiliki Georgiou
- Biomedical Sciences Program, Department of Life Sciences, School of Sciences, European University of Cyprus, 6, Diogenis Str, Engomi 2404, Nicosia, Cyprus
| | - Vasiliki Gkretsi
- Biomedical Sciences Program, Department of Life Sciences, School of Sciences, European University of Cyprus, 6, Diogenis Str, Engomi 2404, Nicosia, Cyprus
| |
Collapse
|
25
|
Tan YL, Yuan Y, Tian L. Microglial regional heterogeneity and its role in the brain. Mol Psychiatry 2020; 25:351-367. [PMID: 31772305 PMCID: PMC6974435 DOI: 10.1038/s41380-019-0609-8] [Citation(s) in RCA: 271] [Impact Index Per Article: 67.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/07/2019] [Revised: 11/07/2019] [Accepted: 11/13/2019] [Indexed: 02/06/2023]
Abstract
Microglia have been recently shown to manifest a very interesting phenotypical heterogeneity across different regions in the mammalian central nervous system (CNS). However, the underlying mechanism and functional meaning of this phenomenon are currently unclear. Baseline diversities of adult microglia in their cell number, cellular and subcellular structures, molecular signature as well as relevant functions have been discovered. But recent transcriptomic studies using bulk RNAseq and single-cell RNAseq have produced conflicting results on region-specific signatures of microglia. It is highly speculative whether such spatial heterogeneity contributes to varying sensitivities of individual microglia to the same physiological and pathological signals in different CNS regions, and hence underlie their functional relevance for CNS disease development. This review aims to thoroughly summarize up-to-date knowledge on this specific topic and provide some insights on the potential underlying mechanisms, starting from microgliogenesis. Understanding regional heterogeneity of microglia in the context of their diverse neighboring neurons and other glia may provide an important clue for future development of innovative therapies for neuropsychiatric disorders.
Collapse
Affiliation(s)
- Yun-Long Tan
- Psychiatry Research Centre, Beijing Huilongguan Hospital, Peking University Health Science Center, Beijing, China
| | - Yi Yuan
- Children's Hospital of Capital Institute of Pediatrics, Beijing, China
| | - Li Tian
- Psychiatry Research Centre, Beijing Huilongguan Hospital, Peking University Health Science Center, Beijing, China.
- Institute of Biomedicine and Translational Medicine, Department of Physiology, Faculty of Medicine, University of Tartu, Tartu, Estonia.
| |
Collapse
|
26
|
Lin X, Chen Y, Zhang P, Chen G, Zhou Y, Yu X. The potential mechanism of postoperative cognitive dysfunction in older people. Exp Gerontol 2019; 130:110791. [PMID: 31765741 DOI: 10.1016/j.exger.2019.110791] [Citation(s) in RCA: 139] [Impact Index Per Article: 27.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2019] [Revised: 10/18/2019] [Accepted: 11/21/2019] [Indexed: 02/08/2023]
Abstract
Postoperative cognitive dysfunction (POCD) is a common disorder following surgery, which seriously threatens the quality of patients' life, especially the older people. Accumulating attention has been paid to POCD worldwide in pace with the popularization of anesthesia/surgery. The development of medical humanities and rehabilitation medicine sets higher demands on accurate diagnosis and safe treatment system of POCD. Although the research on POCD is in full swing, underlying pathogenesis is still inconclusive due to these conflicting results and controversial evidence. Generally, POCD is closely related to neuropsychiatric diseases such as dementia, depression and Alzheimer's disease in molecular pathways. Researchers have come up with various hypotheses to reveal the mechanisms of POCD, including neuroinflammation, oxidative stress, autophagy disorder, impaired synaptic function, lacking neurotrophic support, etc. Recent work focused on molecular mechanism of POCD in older people has been thoroughly reviewed and summed up here, concerning the changes of peripheral circulation, pathological pathways of central nervous system (CNS), the microbiota-gut-brain axis and the related brain regions. Accordingly, this article provides a better perspective to understand the development situation of POCD in older people, which is conductive to uncover the pathological mechanism and exploit reasonable treatment strategy of POCD.
Collapse
Affiliation(s)
- Xianyi Lin
- Department of Anesthesiology, Sir Run Run Shaw Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang 310016, China
| | - Yeru Chen
- Department of Anesthesiology, Sir Run Run Shaw Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang 310016, China
| | - Piao Zhang
- Department of Anesthesiology, Sir Run Run Shaw Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang 310016, China
| | - Gang Chen
- Department of Anesthesiology, Sir Run Run Shaw Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang 310016, China.
| | - Youfa Zhou
- Department of Anesthesiology, Sir Run Run Shaw Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang 310016, China
| | - Xin Yu
- Department of Anesthesiology, Sir Run Run Shaw Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang 310016, China
| |
Collapse
|
27
|
Rizor A, Pajarillo E, Johnson J, Aschner M, Lee E. Astrocytic Oxidative/Nitrosative Stress Contributes to Parkinson's Disease Pathogenesis: The Dual Role of Reactive Astrocytes. Antioxidants (Basel) 2019; 8:antiox8080265. [PMID: 31374936 PMCID: PMC6719180 DOI: 10.3390/antiox8080265] [Citation(s) in RCA: 64] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2019] [Revised: 07/23/2019] [Accepted: 07/30/2019] [Indexed: 12/20/2022] Open
Abstract
Parkinson’s disease (PD) is the second most common neurodegenerative disease worldwide; it is characterized by dopaminergic neurodegeneration in the substantia nigra pars compacta, but its etiology is not fully understood. Astrocytes, a class of glial cells in the central nervous system (CNS), provide critical structural and metabolic support to neurons, but growing evidence reveals that astrocytic oxidative and nitrosative stress contributes to PD pathogenesis. As astrocytes play a critical role in the production of antioxidants and the detoxification of reactive oxygen and nitrogen species (ROS/RNS), astrocytic oxidative/nitrosative stress has emerged as a critical mediator of the etiology of PD. Cellular stress and inflammation induce reactive astrogliosis, which initiates the production of astrocytic ROS/RNS and may lead to oxidative/nitrosative stress and PD pathogenesis. Although the cause of aberrant reactive astrogliosis is unknown, gene mutations and environmental toxicants may also contribute to astrocytic oxidative/nitrosative stress. In this review, we briefly discuss the physiological functions of astrocytes and the role of astrocytic oxidative/nitrosative stress in PD pathogenesis. Additionally, we examine the impact of PD-related genes such as α-synuclein, protein deglycase DJ-1( DJ-1), Parkin, and PTEN-induced kinase 1 (PINK1) on astrocytic function, and highlight the impact of environmental toxicants, such as 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP), rotenone, manganese, and paraquat, on astrocytic oxidative/nitrosative stress in experimental models.
Collapse
Affiliation(s)
- Asha Rizor
- Department of Pharmaceutical Sciences, College of Pharmacy Florida A&M University, Tallahassee, FL 32301, USA
| | - Edward Pajarillo
- Department of Pharmaceutical Sciences, College of Pharmacy Florida A&M University, Tallahassee, FL 32301, USA
| | - James Johnson
- Department of Pharmaceutical Sciences, College of Pharmacy Florida A&M University, Tallahassee, FL 32301, USA
| | - Michael Aschner
- Department of Molecular Pharmacology, Albert Einstein College of Medicine Bronx, New York, NY 10461, USA
| | - Eunsook Lee
- Department of Pharmaceutical Sciences, College of Pharmacy Florida A&M University, Tallahassee, FL 32301, USA.
| |
Collapse
|
28
|
MacDonald AJ, Robb JL, Morrissey NA, Beall C, Ellacott KLJ. Astrocytes in neuroendocrine systems: An overview. J Neuroendocrinol 2019; 31:e12726. [PMID: 31050045 DOI: 10.1111/jne.12726] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/04/2019] [Revised: 04/26/2019] [Accepted: 04/28/2019] [Indexed: 12/11/2022]
Abstract
A class of glial cell, astrocytes, is highly abundant in the central nervous system (CNS). In addition to maintaining tissue homeostasis, astrocytes regulate neuronal communication and synaptic plasticity. There is an ever-increasing appreciation that astrocytes are involved in the regulation of physiology and behaviour in normal and pathological states, including within neuroendocrine systems. Indeed, astrocytes are direct targets of hormone action in the CNS, via receptors expressed on their surface, and are also a source of regulatory neuropeptides, neurotransmitters and gliotransmitters. Furthermore, as part of the neurovascular unit, astrocytes can regulate hormone entry into the CNS. This review is intended to provide an overview of how astrocytes are impacted by and contribute to the regulation of a diverse range of neuroendocrine systems: energy homeostasis and metabolism, reproduction, fluid homeostasis, the stress response and circadian rhythms.
Collapse
Affiliation(s)
- Alastair J MacDonald
- Neuroendocrine Research Group, Institute of Biomedical & Clinical Sciences, University of Exeter Medical School, Exeter, UK
| | - Josephine L Robb
- Neuroendocrine Research Group, Institute of Biomedical & Clinical Sciences, University of Exeter Medical School, Exeter, UK
| | - Nicole A Morrissey
- Neuroendocrine Research Group, Institute of Biomedical & Clinical Sciences, University of Exeter Medical School, Exeter, UK
| | - Craig Beall
- Neuroendocrine Research Group, Institute of Biomedical & Clinical Sciences, University of Exeter Medical School, Exeter, UK
| | - Kate L J Ellacott
- Neuroendocrine Research Group, Institute of Biomedical & Clinical Sciences, University of Exeter Medical School, Exeter, UK
| |
Collapse
|
29
|
Ventral tegmental area astrocytes orchestrate avoidance and approach behavior. Nat Commun 2019; 10:1455. [PMID: 30926783 PMCID: PMC6440962 DOI: 10.1038/s41467-019-09131-y] [Citation(s) in RCA: 49] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2018] [Accepted: 02/22/2019] [Indexed: 12/28/2022] Open
Abstract
The ventral tegmental area (VTA) is a heterogeneous midbrain structure, containing neurons and astrocytes, that coordinates behaviors by integrating activity from numerous afferents. Within neuron-astrocyte networks, astrocytes control signals from distinct afferents in a circuit-specific manner, but whether this capacity scales up to drive motivated behavior has been undetermined. Using genetic and optical dissection strategies we report that VTA astrocytes tune glutamatergic signaling selectively on local inhibitory neurons to drive a functional circuit for learned avoidance. In this circuit, astrocytes facilitate excitation of VTA GABA neurons to increase inhibition of dopamine neurons, eliciting real-time and learned avoidance behavior that is sufficient to impede expression of preference for reward. Loss of one glutamate transporter (GLT-1) from VTA astrocytes selectively blocks these avoidance behaviors and spares preference for reward. Thus, VTA astrocytes selectively regulate excitation of local GABA neurons to drive a distinct avoidance circuit that opposes approach behavior. Astrocytes can dynamically control glutamate availability at specific active synapses through the glutamate transporter, GLT-1. Here, the authors show that astrocytes in the VTA selectively facilitate excitation of VTA GABAergic neurons to inhibit dopamine neurons and drive avoidance behavior via GLT-1.
Collapse
|
30
|
Peteri UK, Niukkanen M, Castrén ML. Astrocytes in Neuropathologies Affecting the Frontal Cortex. Front Cell Neurosci 2019; 13:44. [PMID: 30809131 PMCID: PMC6379461 DOI: 10.3389/fncel.2019.00044] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2018] [Accepted: 01/28/2019] [Indexed: 01/15/2023] Open
Abstract
To an increasing extent, astrocytes are connected with various neuropathologies. Astrocytes comprise of a heterogeneous population of cells with region- and species-specific properties. The frontal cortex exhibits high levels of plasticity that is required for high cognitive functions and memory making this region especially susceptible to damage. Aberrations in the frontal cortex are involved with several cognitive disorders, including Alzheimer’s disease, Huntington’s disease and frontotemporal dementia. Human induced pluripotent stem cells (iPSCs) provide an alternative for disease modeling and offer possibilities for studies to investigate pathological mechanisms in a cell type-specific manner. Patient-specific iPSC-derived astrocytes have been shown to recapitulate several disease phenotypes. Addressing astrocyte heterogeneity may provide an improved understanding of the mechanisms underlying neurodegenerative diseases.
Collapse
Affiliation(s)
- Ulla-Kaisa Peteri
- Department of Physiology, Faculty of Medicine, University of Helsinki, Helsinki, Finland
| | - Mikael Niukkanen
- Department of Physiology, Faculty of Medicine, University of Helsinki, Helsinki, Finland
| | - Maija L Castrén
- Department of Physiology, Faculty of Medicine, University of Helsinki, Helsinki, Finland
| |
Collapse
|
31
|
Durkee CA, Araque A. Diversity and Specificity of Astrocyte-neuron Communication. Neuroscience 2018; 396:73-78. [PMID: 30458223 DOI: 10.1016/j.neuroscience.2018.11.010] [Citation(s) in RCA: 194] [Impact Index Per Article: 32.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2018] [Revised: 11/08/2018] [Accepted: 11/09/2018] [Indexed: 01/30/2023]
Abstract
Astrocytes are emerging as important players in synaptic function, and, consequently, on brain function and animal behavior. According to the Tripartite Synapse concept, astrocytes are integral elements involved in synaptic function. They establish bidirectional communication with neurons, whereby they respond to synaptically released neurotransmitters and, in turn, release gliotransmitters that influence neuronal and synaptic activity. Accumulating evidence is revealing that the mechanisms and functional consequences of astrocyte-neuron signaling are more complex than originally thought. Furthermore, astrocyte-neuron signaling is not based on broad, unspecific interaction; rather, it is a synapse-, cell- and circuit-specific phenomenon that presents a high degree of complexity. This diversity and complexity of astrocyte-synapse interactions greatly enhance the degrees of freedom of the neural circuits and the consequent computational power of the neural systems.
Collapse
Affiliation(s)
- Caitlin A Durkee
- Department of Neuroscience, University of Minnesota, Minneapolis, MN 55455, USA
| | - Alfonso Araque
- Department of Neuroscience, University of Minnesota, Minneapolis, MN 55455, USA.
| |
Collapse
|