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Marchesani F, Comani VB, Bruno S, Mozzarelli A, Carcelli M, Pollegioni L, Caldinelli L, Peracchi A, Campanini B. Effect of l-serine and magnesium ions on the functional properties of human phosphoserine phosphatase and its pathogenetic variants. Biochim Biophys Acta Mol Basis Dis 2024; 1870:167034. [PMID: 38278334 DOI: 10.1016/j.bbadis.2024.167034] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2023] [Revised: 01/13/2024] [Accepted: 01/18/2024] [Indexed: 01/28/2024]
Abstract
L-Ser supply in the central nervous system of mammals mostly relies on its endogenous biosynthesis by the phosphorylated pathway (PP). Defects in any of the three enzymes operating in the pathway result in a group of neurometabolic diseases collectively known as serine deficiency disorders (SDDs). Phosphoserine phosphatase (PSP) catalyzes the last, irreversible step of the PP. Here we investigated in detail the role of physiological modulators of human PSP activity and the properties of three natural PSP variants (A35T, D32N and M52T) associated with SDDs. Our results, partially contradicting previous reports, indicate that: i. PSP is almost fully saturated with Mg2+ under physiological conditions and fluctuations in Mg2+ and Ca2+ concentrations are unlikely to play a modulatory role on PSP activity; ii. Inhibition by L-Ser, albeit at play on the isolated PSP, does not exert any effect on the flux through the PP unless the enzyme activity is severely impaired by inactivating substitutions; iii. The so-far poorly investigated A35T substitution was the most detrimental, with a 50-fold reduction in catalytic efficiency, and a reduction in thermal stability (as well as an increase in the IC50 for L-Ser). The M52T substitution had similar, but milder effects, while the D32N variant behaved like the wild-type enzyme. iv. Predictions of the structural effects of the A35T and M52T substitutions with ColabFold suggest that they might affect the structure of the flexible helix-loop region.
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Affiliation(s)
| | | | - Stefano Bruno
- Department of Food and Drug, University of Parma, 43124 Parma, Italy; Biopharmanet-TEC, University of Parma, 43124 Parma, Italy
| | | | - Mauro Carcelli
- Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, 43124 Parma, Italy
| | - Loredano Pollegioni
- The Protein Factory 2.0, Department of Biotechnology and Life Sciences, University of Insubria, 21100 Varese, Italy
| | - Laura Caldinelli
- The Protein Factory 2.0, Department of Biotechnology and Life Sciences, University of Insubria, 21100 Varese, Italy
| | - Alessio Peracchi
- Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, 43124 Parma, Italy.
| | - Barbara Campanini
- Department of Food and Drug, University of Parma, 43124 Parma, Italy; Biopharmanet-TEC, University of Parma, 43124 Parma, Italy.
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2
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Albini M, Krawczun-Rygmaczewska A, Cesca F. Astrocytes and brain-derived neurotrophic factor (BDNF). Neurosci Res 2023; 197:42-51. [PMID: 36780947 DOI: 10.1016/j.neures.2023.02.001] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2022] [Revised: 01/17/2023] [Accepted: 02/02/2023] [Indexed: 02/13/2023]
Abstract
Astrocytes are emerging in the neuroscience field as crucial modulators of brain functions, from the molecular control of synaptic plasticity to orchestrating brain-wide circuit activity for cognitive processes. The cellular pathways through which astrocytes modulate neuronal activity and plasticity are quite diverse. In this review, we focus on neurotrophic pathways, mostly those mediated by brain-derived neurotrophic factor (BDNF). Neurotrophins are a well-known family of trophic factors with pleiotropic functions in neuronal survival, maturation and activity. Within the brain, BDNF is the most abundantly expressed and most studied of all neurotrophins. While we have detailed knowledge of the effect of BDNF on neurons, much less is known about its physiology on astroglia. However, over the last years new findings emerged demonstrating that astrocytes take an active part into BDNF physiology. In this work, we discuss the state-of-the-art knowledge about astrocytes and BDNF. Indeed, astrocytes sense extracellular BDNF through its specific TrkB receptors and activate intracellular responses that greatly vary depending on the brain area, stage of development and receptors expressed. Astrocytes also uptake and recycle BDNF / proBDNF at synapses contributing to synaptic plasticity. Finally, experimental evidence is now available describing deficits in astrocytic BDNF in several neuropathologies, suggesting that astrocytic BDNF may represent a promising target for clinical translation.
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Affiliation(s)
- Martina Albini
- Department of Experimental Medicine, University of Genova, Italy; IIT Center for Synaptic Neuroscience and Technology, Genova, Italy
| | - Alicja Krawczun-Rygmaczewska
- IIT Center for Synaptic Neuroscience and Technology, Genova, Italy; Department of Life Sciences, University of Trieste, Italy
| | - Fabrizia Cesca
- IIT Center for Synaptic Neuroscience and Technology, Genova, Italy; Department of Life Sciences, University of Trieste, Italy.
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3
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Cabirol MJ, Cardoit L, Courtand G, Mayeur ME, Simmers J, Pascual O, Thoby-Brisson M. Microglia shape the embryonic development of mammalian respiratory networks. eLife 2022; 11:80352. [PMID: 36321865 PMCID: PMC9629827 DOI: 10.7554/elife.80352] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2022] [Accepted: 10/20/2022] [Indexed: 11/06/2022] Open
Abstract
Microglia, brain-resident macrophages, play key roles during prenatal development in defining neural circuitry function, including ensuring proper synaptic wiring and maintaining homeostasis. Mammalian breathing rhythmogenesis arises from interacting brainstem neural networks that are assembled during embryonic development, but the specific role of microglia in this process remains unknown. Here, we investigated the anatomical and functional consequences of respiratory circuit formation in the absence of microglia. We first established the normal distribution of microglia within the wild-type (WT, Spi1+/+ (Pu.1 WT)) mouse (Mus musculus) brainstem at embryonic ages when the respiratory networks are known to emerge (embryonic day (E) 14.5 for the parafacial respiratory group (epF) and E16.5 for the preBötzinger complex (preBötC)). In transgenic mice depleted of microglia (Spi1−/− (Pu.1 KO) mutant), we performed anatomical staining, calcium imaging, and electrophysiological recordings of neuronal activities in vitro to assess the status of these circuits at their respective times of functional emergence. Spontaneous respiratory-related activity recorded from reduced in vitro preparations showed an abnormally slow rhythm frequency expressed by the epF at E14.5, the preBötC at E16.5, and in the phrenic motor nerves from E16.5 onwards. These deficits were associated with a reduced number of active epF neurons, defects in commissural projections that couple the bilateral preBötC half-centers, and an accompanying decrease in their functional coordination. These abnormalities probably contribute to eventual neonatal death, since plethysmography revealed that E18.5 Spi1−/− embryos are unable to sustain breathing activity ex utero. Our results thus point to a crucial contribution of microglia in the proper establishment of the central respiratory command during embryonic development.
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Affiliation(s)
- Marie-Jeanne Cabirol
- Institut de Neurosciences Cognitives et Intégratives d'Aquitaine, CNRS, Université de Bordeaux, Bordeaux, France
| | - Laura Cardoit
- Institut de Neurosciences Cognitives et Intégratives d'Aquitaine, CNRS, Université de Bordeaux, Bordeaux, France
| | - Gilles Courtand
- Institut de Neurosciences Cognitives et Intégratives d'Aquitaine, CNRS, Université de Bordeaux, Bordeaux, France
| | - Marie-Eve Mayeur
- MeLis INSERM U1314-CNRS UMR 5284, Faculté Rockefeller, Lyon, France
| | - John Simmers
- Institut de Neurosciences Cognitives et Intégratives d'Aquitaine, CNRS, Université de Bordeaux, Bordeaux, France
| | - Olivier Pascual
- MeLis INSERM U1314-CNRS UMR 5284, Faculté Rockefeller, Lyon, France
| | - Muriel Thoby-Brisson
- Institut de Neurosciences Cognitives et Intégratives d'Aquitaine, CNRS, Université de Bordeaux, Bordeaux, France
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4
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Bioinformatics Analysis of Potential Biomarkers and Pathway Identification for Major Depressive Disorder. COMPUTATIONAL AND MATHEMATICAL METHODS IN MEDICINE 2021; 2021:3036741. [PMID: 34394704 PMCID: PMC8357473 DOI: 10.1155/2021/3036741] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/27/2021] [Accepted: 07/19/2021] [Indexed: 11/18/2022]
Abstract
Aiming at a more comprehensive understanding of the molecular biomarkers and potential mechanisms of major depressive disorder (MDD), from the Gene Expression Omnibus (GEO) database, we first obtained mRNA expression profiles and identified 585 differentially expressed genes (DEGs) through the R software, including 263 upregulated genes and 322 downregulated genes. Then, through the Kyoto Encyclopedia of Genome and Genome (KEGG) pathway and biological process (BP) analysis, we found that the upregulated and downregulated DEGs were abundant in different pathways, respectively. It was noteworthy that upregulated DEGs were the most significantly enriched in the mTOR signaling pathway. Subsequently, through the protein-protein interaction (PPI) network, we identified seven hub genes, namely, EXOSC2, CAMK2A, PRIM1, SMC4, TYMS, CDK6, and RPA2. Finally, through gene set enrichment analysis (GSEA), we obtained that hypoxia, epithelial-mesenchymal transition, hedgehog signaling, and reactive oxygen species pathway were the enriched pathways for MDD patients. The above data results would provide a new direction for the treatment of MDD patients.
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5
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Fernández-Blanco Á, Dierssen M. Rethinking Intellectual Disability from Neuro- to Astro-Pathology. Int J Mol Sci 2020; 21:E9039. [PMID: 33261169 PMCID: PMC7730506 DOI: 10.3390/ijms21239039] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2020] [Revised: 11/24/2020] [Accepted: 11/25/2020] [Indexed: 12/26/2022] Open
Abstract
Neurodevelopmental disorders arise from genetic and/or from environmental factors and are characterized by different degrees of intellectual disability. The mechanisms that govern important processes sustaining learning and memory, which are severely affected in intellectual disability, have classically been thought to be exclusively under neuronal control. However, this vision has recently evolved into a more integrative conception in which astroglia, rather than just acting as metabolic supply and structural anchoring for neurons, interact at distinct levels modulating neuronal communication and possibly also cognitive processes. Recently, genetic tools have made it possible to specifically manipulate astrocyte activity unraveling novel functions that involve astrocytes in memory function in the healthy brain. However, astrocyte manipulation has also underscored potential mechanisms by which dysfunctional astrocytes could contribute to memory deficits in several neurodevelopmental disorders revealing new pathogenic mechanisms in intellectual disability. Here, we review the current knowledge about astrocyte dysfunction that might contribute to learning and memory impairment in neurodevelopmental disorders, with special focus on Fragile X syndrome and Down syndrome.
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Affiliation(s)
- Álvaro Fernández-Blanco
- Centre for Genomic Regulation (CRG), The Barcelona Institute of Science and Technology, Dr. Aiguader 88, 08003 Barcelona, Spain;
| | - Mara Dierssen
- Centre for Genomic Regulation (CRG), The Barcelona Institute of Science and Technology, Dr. Aiguader 88, 08003 Barcelona, Spain;
- Universitat Pompeu Fabra (UPF), Dr. Aiguader 88, 08003 Barcelona, Spain
- Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), 28029 Madrid, Spain
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6
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Perez DM. α 1-Adrenergic Receptors in Neurotransmission, Synaptic Plasticity, and Cognition. Front Pharmacol 2020; 11:581098. [PMID: 33117176 PMCID: PMC7553051 DOI: 10.3389/fphar.2020.581098] [Citation(s) in RCA: 53] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2020] [Accepted: 09/11/2020] [Indexed: 12/14/2022] Open
Abstract
α1-adrenergic receptors are G-Protein Coupled Receptors that are involved in neurotransmission and regulate the sympathetic nervous system through binding and activating the neurotransmitter, norepinephrine, and the neurohormone, epinephrine. There are three α1-adrenergic receptor subtypes (α1A, α1B, α1D) that are known to play various roles in neurotransmission and cognition. They are related to two other adrenergic receptor families that also bind norepinephrine and epinephrine, the β- and α2-, each with three subtypes (β1, β2, β3, α2A, α2B, α2C). Previous studies assessing the roles of α1-adrenergic receptors in neurotransmission and cognition have been inconsistent. This was due to the use of poorly-selective ligands and many of these studies were published before the characterization of the cloned receptor subtypes and the subsequent development of animal models. With the availability of more-selective ligands and the development of animal models, a clearer picture of their role in cognition and neurotransmission can be assessed. In this review, we highlight the significant role that the α1-adrenergic receptor plays in regulating synaptic efficacy, both short and long-term synaptic plasticity, and its regulation of different types of memory. We will also present evidence that the α1-adrenergic receptors, and particularly the α1A-adrenergic receptor subtype, are a potentially good target to treat a wide variety of neurological conditions with diminished cognition.
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Affiliation(s)
- Dianne M Perez
- The Lerner Research Institute, The Cleveland Clinic Foundation, Cleveland, OH, United States
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7
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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.
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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
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8
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Jaudon F, Chiacchiaretta M, Albini M, Ferroni S, Benfenati F, Cesca F. Kidins220/ARMS controls astrocyte calcium signaling and neuron-astrocyte communication. Cell Death Differ 2020; 27:1505-1519. [PMID: 31624352 PMCID: PMC7206051 DOI: 10.1038/s41418-019-0431-5] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2018] [Revised: 09/30/2019] [Accepted: 09/30/2019] [Indexed: 12/22/2022] Open
Abstract
Through their ability to modulate synaptic transmission, glial cells are key regulators of neuronal circuit formation and activity. Kidins220/ARMS (kinase-D interacting substrate of 220 kDa/ankyrin repeat-rich membrane spanning) is one of the key effectors of the neurotrophin pathways in neurons where it is required for differentiation, survival, and plasticity. However, its role in glial cells remains largely unknown. Here, we show that ablation of Kidins220 in primary cultured astrocytes induced defects in calcium (Ca2+) signaling that were linked to altered store-operated Ca2+ entry and strong overexpression of the transient receptor potential channel TRPV4. Moreover, Kidins220-/- astrocytes were more sensitive to genotoxic stress. We also show that Kidins220 expression in astrocytes is required for the establishment of proper connectivity of cocultured wild-type neurons. Altogether, our data reveal a previously unidentified role for astrocyte-expressed Kidins220 in the control of glial Ca2+ dynamics, survival/death pathways and astrocyte-neuron communication.
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Affiliation(s)
- Fanny Jaudon
- Center for Synaptic Neuroscience and Technology, Istituto Italiano di Tecnologia, 16132, Genova, Italy
| | - Martina Chiacchiaretta
- Center for Synaptic Neuroscience and Technology, Istituto Italiano di Tecnologia, 16132, Genova, Italy
- Department of Neuroscience, Tufts University School of Medicine, Boston, MA, USA
| | - Martina Albini
- Center for Synaptic Neuroscience and Technology, Istituto Italiano di Tecnologia, 16132, Genova, Italy
- Department of Experimental Medicine, University of Genova, 16132, Genova, Italy
| | - Stefano Ferroni
- Department of Pharmacy and Biotechnology, University of Bologna, 40126, Bologna, Italy
| | - Fabio Benfenati
- Center for Synaptic Neuroscience and Technology, Istituto Italiano di Tecnologia, 16132, Genova, Italy
- IRCCS Ospedale Policlinico San Martino, Genova, Italy
| | - Fabrizia Cesca
- Center for Synaptic Neuroscience and Technology, Istituto Italiano di Tecnologia, 16132, Genova, Italy.
- Department of Life Sciences, University of Trieste, 34127, Trieste, Italy.
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9
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Hampel H, Caraci F, Cuello AC, Caruso G, Nisticò R, Corbo M, Baldacci F, Toschi N, Garaci F, Chiesa PA, Verdooner SR, Akman-Anderson L, Hernández F, Ávila J, Emanuele E, Valenzuela PL, Lucía A, Watling M, Imbimbo BP, Vergallo A, Lista S. A Path Toward Precision Medicine for Neuroinflammatory Mechanisms in Alzheimer's Disease. Front Immunol 2020; 11:456. [PMID: 32296418 PMCID: PMC7137904 DOI: 10.3389/fimmu.2020.00456] [Citation(s) in RCA: 182] [Impact Index Per Article: 45.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2019] [Accepted: 02/27/2020] [Indexed: 12/13/2022] Open
Abstract
Neuroinflammation commences decades before Alzheimer's disease (AD) clinical onset and represents one of the earliest pathomechanistic alterations throughout the AD continuum. Large-scale genome-wide association studies point out several genetic variants—TREM2, CD33, PILRA, CR1, MS4A, CLU, ABCA7, EPHA1, and HLA-DRB5-HLA-DRB1—potentially linked to neuroinflammation. Most of these genes are involved in proinflammatory intracellular signaling, cytokines/interleukins/cell turnover, synaptic activity, lipid metabolism, and vesicle trafficking. Proteomic studies indicate that a plethora of interconnected aberrant molecular pathways, set off and perpetuated by TNF-α, TGF-β, IL-1β, and the receptor protein TREM2, are involved in neuroinflammation. Microglia and astrocytes are key cellular drivers and regulators of neuroinflammation. Under physiological conditions, they are important for neurotransmission and synaptic homeostasis. In AD, there is a turning point throughout its pathophysiological evolution where glial cells sustain an overexpressed inflammatory response that synergizes with amyloid-β and tau accumulation, and drives synaptotoxicity and neurodegeneration in a self-reinforcing manner. Despite a strong therapeutic rationale, previous clinical trials investigating compounds with anti-inflammatory properties, including non-steroidal anti-inflammatory drugs (NSAIDs), did not achieve primary efficacy endpoints. It is conceivable that study design issues, including the lack of diagnostic accuracy and biomarkers for target population identification and proof of mechanism, may partially explain the negative outcomes. However, a recent meta-analysis indicates a potential biological effect of NSAIDs. In this regard, candidate fluid biomarkers of neuroinflammation are under analytical/clinical validation, i.e., TREM2, IL-1β, MCP-1, IL-6, TNF-α receptor complexes, TGF-β, and YKL-40. PET radio-ligands are investigated to accomplish in vivo and longitudinal regional exploration of neuroinflammation. Biomarkers tracking different molecular pathways (body fluid matrixes) along with brain neuroinflammatory endophenotypes (neuroimaging markers), can untangle temporal–spatial dynamics between neuroinflammation and other AD pathophysiological mechanisms. Robust biomarker–drug codevelopment pipelines are expected to enrich large-scale clinical trials testing new-generation compounds active, directly or indirectly, on neuroinflammatory targets and displaying putative disease-modifying effects: novel NSAIDs, AL002 (anti-TREM2 antibody), anti-Aβ protofibrils (BAN2401), and AL003 (anti-CD33 antibody). As a next step, taking advantage of breakthrough and multimodal techniques coupled with a systems biology approach is the path to pursue for developing individualized therapeutic strategies targeting neuroinflammation under the framework of precision medicine.
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Affiliation(s)
- Harald Hampel
- Sorbonne University, GRC no. 21, Alzheimer Precision Medicine (APM), AP-HP, Pitié-Salpêtrière Hospital, Boulevard de l'hôpital, Paris, France
| | - Filippo Caraci
- Department of Drug Sciences, University of Catania, Catania, Italy.,Oasi Research Institute-IRCCS, Troina, Italy
| | - A Claudio Cuello
- Department of Neurology and Neurosurgery, McGill University, Montreal, QC, Canada.,Department of Anatomy and Cell Biology, McGill University, Montreal, QC, Canada.,Department of Pharmacology and Therapeutics, McGill University, Montreal, QC, Canada.,Department of Pharmacology, University of Oxford, Oxford, United Kingdom
| | | | - Robert Nisticò
- Laboratory of Neuropharmacology, EBRI Rita Levi-Montalcini Foundation, Rome, Italy.,School of Pharmacy, Department of Biology, University of Rome Tor Vergata, Rome, Italy
| | - Massimo Corbo
- Department of Neurorehabilitation Sciences, Casa Cura Policlinico, Milan, Italy
| | - Filippo Baldacci
- Sorbonne University, GRC no. 21, Alzheimer Precision Medicine (APM), AP-HP, Pitié-Salpêtrière Hospital, Boulevard de l'hôpital, Paris, France.,Brain & Spine Institute (ICM), INSERM U 1127, CNRS UMR 7225, Boulevard de l'hôpital, Paris, France.,Institute of Memory and Alzheimer's Disease (IM2A), Department of Neurology, Pitié-Salpêtrière Hospital, AP-HP, Paris, France.,Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy
| | - Nicola Toschi
- Department of Biomedicine and Prevention, University of Rome "Tor Vergata", Rome, Italy.,Department of Radiology, "Athinoula A. Martinos" Center for Biomedical Imaging, Boston, MA, United States.,Harvard Medical School, Boston, MA, United States
| | - Francesco Garaci
- Department of Biomedicine and Prevention, University of Rome "Tor Vergata", Rome, Italy.,Casa di Cura "San Raffaele Cassino", Cassino, Italy
| | - Patrizia A Chiesa
- Sorbonne University, GRC no. 21, Alzheimer Precision Medicine (APM), AP-HP, Pitié-Salpêtrière Hospital, Boulevard de l'hôpital, Paris, France.,Brain & Spine Institute (ICM), INSERM U 1127, CNRS UMR 7225, Boulevard de l'hôpital, Paris, France.,Institute of Memory and Alzheimer's Disease (IM2A), Department of Neurology, Pitié-Salpêtrière Hospital, AP-HP, Paris, France
| | | | | | - Félix Hernández
- Centro de Biología Molecular Severo Ochoa (CSIC-UAM), Madrid, Spain.,Network Center for Biomedical Research in Neurodegenerative Diseases (CIBERNED), Madrid, Spain
| | - Jesús Ávila
- Centro de Biología Molecular Severo Ochoa (CSIC-UAM), Madrid, Spain.,Network Center for Biomedical Research in Neurodegenerative Diseases (CIBERNED), Madrid, Spain
| | | | | | - Alejandro Lucía
- Faculty of Sport Sciences, Universidad Europea de Madrid, Madrid, Spain.,Research Institute of the Hospital 12 de Octubre ("imas"), Madrid, Spain.,Centro de Investigación Biomédica en Red Fragilidad y Envejecimiento Saludable (CIBERFES), Madrid, Spain
| | | | - Bruno P Imbimbo
- Research & Development Department, Chiesi Farmaceutici, Parma, Italy
| | - Andrea Vergallo
- Sorbonne University, GRC no. 21, Alzheimer Precision Medicine (APM), AP-HP, Pitié-Salpêtrière Hospital, Boulevard de l'hôpital, Paris, France
| | - Simone Lista
- Sorbonne University, GRC no. 21, Alzheimer Precision Medicine (APM), AP-HP, Pitié-Salpêtrière Hospital, Boulevard de l'hôpital, Paris, France.,Brain & Spine Institute (ICM), INSERM U 1127, CNRS UMR 7225, Boulevard de l'hôpital, Paris, France.,Institute of Memory and Alzheimer's Disease (IM2A), Department of Neurology, Pitié-Salpêtrière Hospital, AP-HP, Paris, France
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10
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Calcium Signaling in Neurons and Glial Cells: Role of Cav1 channels. Neuroscience 2019; 421:95-111. [DOI: 10.1016/j.neuroscience.2019.09.041] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2019] [Revised: 09/27/2019] [Accepted: 09/30/2019] [Indexed: 11/18/2022]
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11
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The reduction of astrocytes and brain volume loss in anorexia nervosa-the impact of starvation and refeeding in a rodent model. Transl Psychiatry 2019; 9:159. [PMID: 31164627 PMCID: PMC6548775 DOI: 10.1038/s41398-019-0493-7] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/10/2018] [Revised: 02/28/2019] [Accepted: 04/10/2019] [Indexed: 11/16/2022] Open
Abstract
Anorexia nervosa (AN) is an often chronic, difficult to treat illness that leads to brain volume reductions in gray and white matter. The underlying pathophysiology is poorly understood, despite its potential importance in explaining the neuropsychological deficits and clinical symptoms associated with the illness. We used the activity-based anorexia model (ABA), which includes food reduction and running wheel access in female rats to study brain changes after starvation and refeeding. Longitudinal animal MRI and post-mortem brain sections confirmed a reduction in the mean brain volumes of ABA animals compared to controls. In addition, the mean number of astrocytes was reduced by over 50% in the cerebral cortex and corpus callosum, while the mean number of neurons was unchanged. Furthermore, mean astrocytic GFAP mRNA expression was similarly reduced in the ABA animals, as was the mean cell proliferation rate, whereas the mean apoptosis rate did not increase. After refeeding, the starvation-induced effects were almost completely reversed. The observation of the astrocyte reduction in our AN animal model is an important new finding that could help explain starvation-induced neuropsychological changes in patients with AN. Astrocyte-targeted research and interventions could become a new focus for both AN research and therapy.
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12
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Borrachero‐Conejo AI, Saracino E, Natali M, Prescimone F, Karges S, Bonetti S, Nicchia GP, Formaggio F, Caprini M, Zamboni R, Mercuri F, Toffanin S, Muccini M, Benfenati V. Electrical Stimulation by an Organic Transistor Architecture Induces Calcium Signaling in Nonexcitable Brain Cells. Adv Healthc Mater 2019; 8:e1801139. [PMID: 30565894 DOI: 10.1002/adhm.201801139] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2018] [Revised: 10/15/2018] [Indexed: 12/31/2022]
Abstract
Organic bioelectronics have a huge potential to generate interfaces and devices for the study of brain functions and for the therapy of brain pathologies. In this context, increasing efforts are needed to develop technologies for monitoring and stimulation of nonexcitable brain cells, called astrocytes. Astroglial calcium signaling plays, indeed, a pivotal role in the physiology and pathophysiology of the brain. Here, the use of transparent organic cell stimulating and sensing transistor (O-CST) architecture, fabricated with N,N'-ditridecylperylene-3,4,9,10-tetracarboxylic diimide (P13), to elicit and monitor intracellular calcium concentration ([Ca2+ ]i ) in primary rat neocortical astrocytes is demonstrated. The transparency of O-CST allows performing calcium imaging experiments, showing that extracellular electrical stimulation of astrocytes induces a drastic increase in [Ca2+ ]i . Pharmacological studies indicate that transient receptor potential (TRP) superfamily are critical mediators of the [Ca2+ ]i increase. Experimental and computational analyses show that [Ca2+ ]i response is enabled by the O-CST device architecture. Noteworthy, the extracellular field application induces a slight but significant increase in the cell volume. Collectively, it is shown that the O-CST is capable of selectively evoking astrocytes [Ca2+ ]i , paving the way to the development of organic bioelectronic devices as glial interfaces to excite and control physiology of non-neuronal brain cells.
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Affiliation(s)
- Ana Isabel Borrachero‐Conejo
- Consiglio Nazionale delle Ricerche (CNR) Istituto per lo Studio dei Materiali Nanostrutturati (ISMN) Via Gobetti 101 40129 Bologna Italy
| | - Emanuela Saracino
- Consiglio Nazionale delle Ricerche (CNR) Istituto per la Sintesi Organica e la Fotoreattività (ISOF) Via Gobetti 101 40129 Bologna Italy
| | - Marco Natali
- Consiglio Nazionale delle Ricerche (CNR) Istituto per lo Studio dei Materiali Nanostrutturati (ISMN) Via Gobetti 101 40129 Bologna Italy
| | - Federico Prescimone
- Consiglio Nazionale delle Ricerche (CNR) Istituto per lo Studio dei Materiali Nanostrutturati (ISMN) Via Gobetti 101 40129 Bologna Italy
| | - Saskia Karges
- Consiglio Nazionale delle Ricerche (CNR) Istituto per lo Studio dei Materiali Nanostrutturati (ISMN) Via Gobetti 101 40129 Bologna Italy
| | - Simone Bonetti
- Consiglio Nazionale delle Ricerche (CNR) Istituto per lo Studio dei Materiali Nanostrutturati (ISMN) Via Gobetti 101 40129 Bologna Italy
| | - Grazia Paola Nicchia
- Prof. G. P. Nicchia Biotecnologie e Biofarmaceutica University of Bari Aldo Moro Via Orabona 4 70125 Bari Italy
| | - Francesco Formaggio
- Dipartimento di Farmacia e Biotecnologie (FaBit) University of Bologna Via San Donato 15 Bologna 40129 Italy
| | - Marco Caprini
- Dipartimento di Farmacia e Biotecnologie (FaBit) University of Bologna Via San Donato 15 Bologna 40129 Italy
| | - Roberto Zamboni
- Consiglio Nazionale delle Ricerche (CNR) Istituto per la Sintesi Organica e la Fotoreattività (ISOF) Via Gobetti 101 40129 Bologna Italy
| | - Francesco Mercuri
- Consiglio Nazionale delle Ricerche (CNR) Istituto per lo Studio dei Materiali Nanostrutturati (ISMN) Via Gobetti 101 40129 Bologna Italy
| | - Stefano Toffanin
- Consiglio Nazionale delle Ricerche (CNR) Istituto per lo Studio dei Materiali Nanostrutturati (ISMN) Via Gobetti 101 40129 Bologna Italy
| | - Michele Muccini
- Consiglio Nazionale delle Ricerche (CNR) Istituto per lo Studio dei Materiali Nanostrutturati (ISMN) Via Gobetti 101 40129 Bologna Italy
| | - Valentina Benfenati
- Consiglio Nazionale delle Ricerche (CNR) Istituto per la Sintesi Organica e la Fotoreattività (ISOF) Via Gobetti 101 40129 Bologna Italy
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13
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Glial cells modulate hippocampal synaptic plasticity in morphine dependent rats. Brain Res Bull 2018; 140:97-106. [DOI: 10.1016/j.brainresbull.2018.04.006] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2018] [Revised: 03/28/2018] [Accepted: 04/11/2018] [Indexed: 12/24/2022]
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Beheshti S, Zeinali R, Esmaeili A. Rapid upregulation of the hippocampal connexins 36 and 45 mRNA levels during memory consolidation. Behav Brain Res 2017; 320:85-90. [PMID: 27913256 DOI: 10.1016/j.bbr.2016.11.048] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2016] [Revised: 11/25/2016] [Accepted: 11/28/2016] [Indexed: 10/20/2022]
Abstract
Gap junction channels are implicated in learning and memory process. However, their role on each of the particular stages of memory formation has been studied less. In this study, the time profile of the expression levels of hippocampal connexins 36 and 45 (Cx36 and Cx45) mRNAs was measured during memory consolidation, in a passive avoidance paradigm. Totally 30 adult male rats were distributed into 5 groups of each 6. At different times profiles (30min, 3, 6 and 24h) following training, rats were decapitated and their hippocampi were immediately removed and frozen in liquid nitrogen. Total RNA was extracted and cDNA was synthesized, using oligo-dt primers. A quantitative real-time PCR was used to measure the levels of each of Cx36 and Cx45 mRNAs. Both connexins showed a rapid upregulation (30min) at the transcriptional level, which declined in later times and reached to the control level at 24h. The rapid up-regulation of Cx36 and Cx45 mRNAs might be accompanied with increasing intercellular coupling via gap junction channels and neuronal oscillatory activities required for memory consolidation. The results highlight the role of gap junctional coupling between hippocampal neurons during memory consolidation in the physiological conditions.
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Affiliation(s)
- Siamak Beheshti
- Division of Animal Sciences, Department of Biology, Faculty of Sciences, University of Isfahan, Isfahan, Iran.
| | - Reyhaneh Zeinali
- Division of Animal Sciences, Department of Biology, Faculty of Sciences, University of Isfahan, Isfahan, Iran
| | - Abolghasem Esmaeili
- Division of Cellular and Molecular Biology, Department of Biology, Faculty of Sciences, University of Isfahan, Isfahan, Iran
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15
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Protocol for culturing low density pure rat hippocampal neurons supported by mature mixed neuron cultures. J Neurosci Methods 2016; 277:38-45. [PMID: 27956052 DOI: 10.1016/j.jneumeth.2016.12.002] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2016] [Revised: 11/24/2016] [Accepted: 12/03/2016] [Indexed: 02/03/2023]
Abstract
BACKGROUND primary hippocampal neuron cultures allow for subcellular morphological dissection, easy access to drug treatment and electrophysiology analysis of individual neurons, and is therefore an ideal model for the study of neuron physiology. While neuron and glia mixed cultures are relatively easy to prepare, pure neurons are particular hard to culture at low densities which are suitable for morphology studies. This may be due to a lack of neurotrophic factors such as brain derived neurotrophic factor (BDNF), neurotrophin-3 (NT3) and Glial cell line-derived neurotrophic factor (GDNF). NEW METHOD In this study we used a two step protocol in which neuron-glia mixed cultures were initially prepared for maturation to support the growth of young neurons plated at very low densities. COMPARISON WITH EXISTING METHODS Our protocol showed that neurotrophic support resulted in physiologically functional hippocampal neurons with larger cell body, increased neurite length and decreased branching and complexity compared to cultures prepared using a conventional method. CONCLUSION Our protocol provides a novel way to culture highly uniformed hippocampal neurons for acquiring high quality, neuron based data.
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16
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Astrocytes: Orchestrating synaptic plasticity? Neuroscience 2015; 323:43-61. [PMID: 25862587 DOI: 10.1016/j.neuroscience.2015.04.001] [Citation(s) in RCA: 161] [Impact Index Per Article: 17.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2015] [Revised: 03/25/2015] [Accepted: 04/01/2015] [Indexed: 01/09/2023]
Abstract
Synaptic plasticity is the capacity of a preexisting connection between two neurons to change in strength as a function of neural activity. Because synaptic plasticity is the major candidate mechanism for learning and memory, the elucidation of its constituting mechanisms is of crucial importance in many aspects of normal and pathological brain function. In particular, a prominent aspect that remains debated is how the plasticity mechanisms, that encompass a broad spectrum of temporal and spatial scales, come to play together in a concerted fashion. Here we review and discuss evidence that pinpoints to a possible non-neuronal, glial candidate for such orchestration: the regulation of synaptic plasticity by astrocytes.
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17
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Lee J, Chun YE, Han KS, Lee J, Woo DH, Lee CJ. Ca(2+) Entry is Required for Mechanical Stimulation-induced ATP Release from Astrocyte. Exp Neurobiol 2015; 24:17-23. [PMID: 25792866 PMCID: PMC4363330 DOI: 10.5607/en.2015.24.1.17] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2015] [Revised: 02/28/2015] [Accepted: 03/02/2015] [Indexed: 11/19/2022] Open
Abstract
Astrocytes and neurons are inseparable partners in the brain. Neurotransmitters released from neurons activate corresponding G protein-coupled receptors (GPCR) expressed in astrocytes, resulting in release of gliotransmitters such as glutamate, D-serine, and ATP. These gliotransmitters in turn influence neuronal excitability and synaptic activities. Among these gliotransmitters, ATP regulates the level of network excitability and is critically involved in sleep homeostasis and astrocytic Ca2+ oscillations. ATP is known to be released from astrocytes by Ca2+-dependent manner. However, the precise source of Ca2+, whether it is Ca2+ entry from outside of cell or from the intracellular store, is still not clear yet. Here, we performed sniffer patch to detect ATP release from astrocyte by using various stimulation. We found that ATP was not released from astrocyte when Ca2+ was released from intracellular stores by activation of Gαq-coupled GPCR including PAR1, P2YR, and B2R. More importantly, mechanical stimulation (MS)-induced ATP release from astrocyte was eliminated when external Ca2+ was omitted. Our results suggest that Ca2+ entry, but not release from intracellular Ca2+ store, is critical for MS-induced ATP release from astrocyte.
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Affiliation(s)
- Jaekwang Lee
- Center for Functional Connectomics, and Center for Neural Science, Korea Institute of Science and Technology (KIST), Seoul 136-791, Korea
| | - Ye-Eun Chun
- Center for Functional Connectomics, and Center for Neural Science, Korea Institute of Science and Technology (KIST), Seoul 136-791, Korea. ; Neuroscience Program, University of Science and Technology (UST), Daejeon 305-350, Korea
| | - Kyung-Seok Han
- Center for Functional Connectomics, and Center for Neural Science, Korea Institute of Science and Technology (KIST), Seoul 136-791, Korea
| | - Jungmoo Lee
- Center for Functional Connectomics, and Center for Neural Science, Korea Institute of Science and Technology (KIST), Seoul 136-791, Korea. ; KU-KIST Graduate School of Converging Science and Technology, Seoul 136-701, Korea
| | - Dong Ho Woo
- Center for Functional Connectomics, and Center for Neural Science, Korea Institute of Science and Technology (KIST), Seoul 136-791, Korea
| | - C Justin Lee
- Center for Functional Connectomics, and Center for Neural Science, Korea Institute of Science and Technology (KIST), Seoul 136-791, Korea. ; Neuroscience Program, University of Science and Technology (UST), Daejeon 305-350, Korea. ; KU-KIST Graduate School of Converging Science and Technology, Seoul 136-701, Korea
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18
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Decrock E, De Bock M, Wang N, Bol M, Gadicherla AK, Leybaert L. Electroporation loading and flash photolysis to investigate intra- and intercellular Ca2+ signaling. Cold Spring Harb Protoc 2015; 2015:239-49. [PMID: 25734071 DOI: 10.1101/pdb.top066068] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Many cellular functions are driven by variations in the intracellular Ca(2+) concentration ([Ca(2+)]i), which may appear as a single-event transient [Ca(2+)]i elevation, repetitive [Ca(2+)]i increases known as Ca(2+) oscillations, or [Ca(2+)]i increases propagating in the cytoplasm as Ca(2+) waves. Additionally, [Ca(2+)]i changes can be communicated between cells as intercellular Ca(2+) waves (ICWs). ICWs are mediated by two possible mechanisms acting in parallel: one involving gap junctions that form channels directly linking the cytoplasm of adjacent cells and one involving a paracrine messenger, in most cases ATP, that is released into the extracellular space, leading to [Ca(2+)]i changes in neighboring cells. The intracellular messenger inositol 1,4,5-trisphosphate (IP3) that triggers Ca(2+) release from Ca(2+) stores is crucial in these two ICW propagation scenarios, and is also a potent trigger to initiate ICWs. Loading inactive, "caged" IP3 into cells followed by photolytic "uncaging" with UV light, thereby liberating IP3, is a well-established method to trigger [Ca(2+)]i changes in single cells that is also effective in initiating ICWs. We here describe a method to load cells with caged IP3 by local electroporation of monolayer cell cultures and to apply flash photolysis to increase intracellular IP3 and induce [Ca(2+)]i changes, or initiate ICWs. Moreover, the electroporation method allows loading of membrane-impermeable agents that interfere with IP3 and Ca(2+) signaling.
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Affiliation(s)
- Elke Decrock
- Department of Basic Medical Sciences, Physiology Group, Ghent University, 9000 Ghent, Belgium
| | - Marijke De Bock
- Department of Basic Medical Sciences, Physiology Group, Ghent University, 9000 Ghent, Belgium
| | - Nan Wang
- Department of Basic Medical Sciences, Physiology Group, Ghent University, 9000 Ghent, Belgium
| | - Mélissa Bol
- Department of Basic Medical Sciences, Physiology Group, Ghent University, 9000 Ghent, Belgium
| | - Ashish K Gadicherla
- Department of Basic Medical Sciences, Physiology Group, Ghent University, 9000 Ghent, Belgium
| | - Luc Leybaert
- Department of Basic Medical Sciences, Physiology Group, Ghent University, 9000 Ghent, Belgium
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19
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Broussard GJ, Liang R, Tian L. Monitoring activity in neural circuits with genetically encoded indicators. Front Mol Neurosci 2014; 7:97. [PMID: 25538558 PMCID: PMC4256991 DOI: 10.3389/fnmol.2014.00097] [Citation(s) in RCA: 101] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2014] [Accepted: 11/15/2014] [Indexed: 12/18/2022] Open
Abstract
Recent developments in genetically encoded indicators of neural activity (GINAs) have greatly advanced the field of systems neuroscience. As they are encoded by DNA, GINAs can be targeted to genetically defined cellular populations. Combined with fluorescence microscopy, most notably multi-photon imaging, GINAs allow chronic simultaneous optical recordings from large populations of neurons or glial cells in awake, behaving mammals, particularly rodents. This large-scale recording of neural activity at multiple temporal and spatial scales has greatly advanced our understanding of the dynamics of neural circuitry underlying behavior—a critical first step toward understanding the complexities of brain function, such as sensorimotor integration and learning. Here, we summarize the recent development and applications of the major classes of GINAs. In particular, we take an in-depth look at the design of available GINA families with a particular focus on genetically encoded calcium indicators (GCaMPs), sensors probing synaptic activity, and genetically encoded voltage indicators. Using the family of the GCaMP as an example, we review established sensor optimization pipelines. We also discuss practical considerations for end users of GINAs about experimental methods including approaches for gene delivery, imaging system requirements, and data analysis techniques. With the growing toolbox of GINAs and with new microscopy techniques pushing beyond their current limits, the age of light can finally achieve the goal of broad and dense sampling of neuronal activity across time and brain structures to obtain a dynamic picture of brain function.
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Affiliation(s)
- Gerard J Broussard
- Department of Biochemistry and Molecular Medicine, University of California Davis Davis, CA, USA ; Neuroscience Graduate Group, University of California Davis Davis, CA, USA
| | - Ruqiang Liang
- Department of Biochemistry and Molecular Medicine, University of California Davis Davis, CA, USA
| | - Lin Tian
- Department of Biochemistry and Molecular Medicine, University of California Davis Davis, CA, USA ; Neuroscience Graduate Group, University of California Davis Davis, CA, USA
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20
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Moon JY, Roh DH, Yoon SY, Choi SR, Kwon SG, Choi HS, Kang SY, Han HJ, Beitz AJ, Oh SB, Lee JH. σ1 receptors activate astrocytes via p38 MAPK phosphorylation leading to the development of mechanical allodynia in a mouse model of neuropathic pain. Br J Pharmacol 2014; 171:5881-97. [PMID: 25158784 PMCID: PMC4290724 DOI: 10.1111/bph.12893] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2014] [Revised: 08/12/2014] [Accepted: 08/21/2014] [Indexed: 12/24/2022] Open
Abstract
BACKGROUND AND PURPOSE Spinal astrocytes have emerged as important mechanistic contributors to the genesis of mechanical allodynia (MA) in neuropathic pain. We recently demonstrated that the spinal sigma non-opioid intracellular receptor 1 (σ1 receptor) modulates p38 MAPK phosphorylation (p-p38), which plays a critical role in the induction of MA in neuropathic rats. However, the histological and physiological relationships among σ1, p-p38 and astrocyte activation is unclear. EXPERIMENTAL APPROACH We investigated: (i) the precise location of σ1 receptors and p-p38 in spinal dorsal horn; (ii) whether the inhibition of σ1 receptors or p38 modulates chronic constriction injury (CCI)-induced astrocyte activation; and (iii) whether this modulation of astrocyte activity is associated with MA development in CCI mice. KEY RESULTS The expression of σ1 receptors was significantly increased in astrocytes on day 3 following CCI surgery. Sustained intrathecal treatment with the σ1 antagonist, BD-1047, attenuated CCI-induced increase in GFAP-immunoreactive astrocytes, and the treatment combined with fluorocitrate, an astrocyte metabolic inhibitor, synergistically reduced the development of MA, but not thermal hyperalgesia. The number of p-p38-ir astrocytes and neurons, but not microglia was significantly increased. Interestingly, intrathecal BD-1047 attenuated the expression of p-p38 selectively in astrocytes but not in neurons. Moreover, intrathecal treatment with a p38 inhibitor attenuated the GFAP expression, and this treatment combined with fluorocitrate synergistically blocked the induction of MA. CONCLUSIONS AND IMPLICATIONS Spinal σ1 receptors are localized in astrocytes and blockade of σ1 receptors inhibits the pathological activation of astrocytes via modulation of p-p38, which ultimately prevents the development of MA in neuropathic mice.
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Affiliation(s)
- J Y Moon
- Department of Veterinary Physiology, College of Veterinary Medicine and Research Institute for Veterinary Science, Seoul National UniversitySeoul, Korea
| | - D H Roh
- Department of Maxillofacial Tissue Regeneration, Kyung Hee University School of DentistrySeoul, Korea
| | - S Y Yoon
- Laboratory of Molecular Signal Transduction, Center for Neural Science, Korea Institute of Science and Technology (KIST)Seoul, Korea
| | - S R Choi
- Department of Veterinary Physiology, College of Veterinary Medicine and Research Institute for Veterinary Science, Seoul National UniversitySeoul, Korea
| | - S G Kwon
- Department of Veterinary Physiology, College of Veterinary Medicine and Research Institute for Veterinary Science, Seoul National UniversitySeoul, Korea
| | - H S Choi
- Department of Veterinary Physiology, College of Veterinary Medicine and Research Institute for Veterinary Science, Seoul National UniversitySeoul, Korea
| | - S Y Kang
- Acupuncture, Moxibustion and Meridian Research Group, Medical Research Division, Korea Institute of Oriental MedicineDaejeon, Korea
| | - H J Han
- Department of Veterinary Physiology, College of Veterinary Medicine and Research Institute for Veterinary Science, Seoul National UniversitySeoul, Korea
| | - A J Beitz
- Department of Veterinary and Biomedical Sciences, College of Veterinary Medicine, University of MinnesotaSt Paul, MN, USA
| | - S B Oh
- Pain Cognitive Function Research Center, Department of Brain and Cognitive Sciences College of Natural Sciences, Dental Research Institute and Department of Neurobiology and Physiology, School of Dentistry, Seoul National UniversitySeoul, Korea
| | - J H Lee
- Department of Veterinary Physiology, College of Veterinary Medicine and Research Institute for Veterinary Science, Seoul National UniversitySeoul, Korea
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21
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Gruol DL. IL-6 regulation of synaptic function in the CNS. Neuropharmacology 2014; 96:42-54. [PMID: 25445486 DOI: 10.1016/j.neuropharm.2014.10.023] [Citation(s) in RCA: 163] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2014] [Revised: 10/23/2014] [Accepted: 10/24/2014] [Indexed: 12/20/2022]
Abstract
A growing body of evidence supports a role for glial-produced neuroimmune factors, including the cytokine IL-6, in CNS physiology and pathology. CNS expression of IL-6 has been documented in the normal CNS at low levels and at elevated levels in several neurodegenerative or psychiatric disease states as well as in CNS infection and injury. The altered CNS function associated with these conditions raises the possibility that IL-6 has neuronal or synaptic actions. Studies in in vitro and in vivo models confirmed this possibility and showed that IL-6 can regulate a number of important neuronal and synaptic functions including synaptic transmission and synaptic plasticity, an important cellular mechanism of memory and learning. Behavioral studies in animal models provided further evidence of an important role for IL-6 as a regulator of CNS pathways that are critical to cognitive function. This review summarizes studies that have lead to our current state of knowledge. In spite of the progress that has been made, there is a need for a greater understanding of the physiological and pathophysiological actions of IL-6 in the CNS, the mechanisms underlying these actions, conditions that induce production of IL-6 in the CNS and therapeutic strategies that could ameliorate or promote IL-6 actions. This article is part of a Special Issue entitled 'Neuroimmunology and Synaptic Function'.
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Affiliation(s)
- Donna L Gruol
- Molecular and Cellular Neuroscience Department, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA 92037, USA.
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22
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The role of astrocytes in the regulation of synaptic plasticity and memory formation. Neural Plast 2013; 2013:185463. [PMID: 24369508 PMCID: PMC3867861 DOI: 10.1155/2013/185463] [Citation(s) in RCA: 111] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2013] [Revised: 10/07/2013] [Accepted: 11/05/2013] [Indexed: 12/22/2022] Open
Abstract
Astrocytes regulate synaptic transmission and play a role in the formation of new memories, long-term potentiation (LTP), and functional synaptic plasticity. Specifically, astroglial release of glutamate, ATP, and cytokines likely alters the survivability and functioning of newly formed connections. Among these pathways, regulation of glutamate appears to be most directly related to the promotion of LTP, which is highly dependent on the synchronization of synaptic receptors through the regulation of excitatory postsynaptic potentials. Moreover, regulation of postsynaptic glutamate receptors, particularly AMPA receptors, is dependent on signaling by ATP synthesized in astrocytes. Finally, cytokine signaling is also implicated in regulating LTP, but is likely most important in plasticity following tissue damage. Despite the role of these signaling factors in regulating LTP and functional plasticity, an integrative model of these factors has not yet been elucidated. In this review, we seek to summarize the current body of evidence on astrocytic mechanisms for regulation of LTP and functional plasticity, and provide an integrative model of the processes.
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23
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Hulme SR, Jones OD, Raymond CR, Sah P, Abraham WC. Mechanisms of heterosynaptic metaplasticity. Philos Trans R Soc Lond B Biol Sci 2013; 369:20130148. [PMID: 24298150 DOI: 10.1098/rstb.2013.0148] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
Synaptic plasticity is fundamental to the neural processes underlying learning and memory. Interestingly, synaptic plasticity itself can be dynamically regulated by prior activity, in a process termed 'metaplasticity', which can be expressed both homosynaptically and heterosynaptically. Here, we focus on heterosynaptic metaplasticity, particularly long-range interactions between synapses spread across dendritic compartments, and review evidence for intracellular versus intercellular signalling pathways leading to this effect. Of particular interest is our previously reported finding that priming stimulation in stratum oriens of area CA1 in the hippocampal slice heterosynaptically inhibits subsequent long-term potentiation and facilitates long-term depression in stratum radiatum. As we have excluded the most likely intracellular signalling pathways that might mediate this long-range heterosynaptic effect, we consider the hypothesis that intercellular communication may be critically involved. This hypothesis is supported by the finding that extracellular ATP hydrolysis, and activation of adenosine A2 receptors are required to induce the metaplastic state. Moreover, delivery of the priming stimulation in stratum oriens elicited astrocytic calcium responses in stratum radiatum. Both the astrocytic responses and the metaplasticity were blocked by gap junction inhibitors. Taken together, these findings support a novel intercellular communication system, possibly involving astrocytes, being required for this type of heterosynaptic metaplasticity.
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Affiliation(s)
- Sarah R Hulme
- Department of Psychology and Brain Health Research Centre, University of Otago, , PO Box 56, Dunedin 9054, New Zealand
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24
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Rapid stimulus-evoked astrocyte Ca2+ elevations and hemodynamic responses in mouse somatosensory cortex in vivo. Proc Natl Acad Sci U S A 2013; 110:E4678-87. [PMID: 24218625 DOI: 10.1073/pnas.1310065110] [Citation(s) in RCA: 142] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Increased neuron and astrocyte activity triggers increased brain blood flow, but controversy exists over whether stimulation-induced changes in astrocyte activity are rapid and widespread enough to contribute to brain blood flow control. Here, we provide evidence for stimulus-evoked Ca(2+) elevations with rapid onset and short duration in a large proportion of cortical astrocytes in the adult mouse somatosensory cortex. Our improved detection of the fast Ca(2+) signals is due to a signal-enhancing analysis of the Ca(2+) activity. The rapid stimulation-evoked Ca(2+) increases identified in astrocyte somas, processes, and end-feet preceded local vasodilatation. Fast Ca(2+) responses in both neurons and astrocytes correlated with synaptic activity, but only the astrocytic responses correlated with the hemodynamic shifts. These data establish that a large proportion of cortical astrocytes have brief Ca(2+) responses with a rapid onset in vivo, fast enough to initiate hemodynamic responses or influence synaptic activity.
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Abstract
There is no question about the fact that astrocytes and other glial cells release neurotransmitters that activate receptors on neurons, glia and vascular cells, and that calcium is an important second messenger regulating the release. This occurs in cell culture, tissue slice and in vivo. Negative results from informative experiments designed to test the mechanism of calcium-dependent neurotransmitter release from astrocytes and the ensuing effects on synaptic transmission, have been cited as evidence calling into question whether astrocytes release neurotransmitters under normal circumstances with effects on synaptic transmission. The special feature section in this issue of Neuron Glia Biology addresses these issues and other aspects of neurotransmitter release from astrocytes in communicating with neurons and glial cells. Together these studies suggest that application of vocabulary and concepts developed for synaptic communication between neurons can lead to confusion and apparent paradoxes with respect to communication by extracellular signaling molecules released from glia in response to functional activity.
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Cao Z, Hulsizer S, Cui Y, Pretto DL, Kim KH, Hagerman PJ, Tassone F, Pessah IN. Enhanced asynchronous Ca(2+) oscillations associated with impaired glutamate transport in cortical astrocytes expressing Fmr1 gene premutation expansion. J Biol Chem 2013; 288:13831-41. [PMID: 23553633 DOI: 10.1074/jbc.m112.441055] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
BACKGROUND FMR1 CGG expansion repeats in the premutation range have not been linked to astrocyte pathophysiology. RESULTS Premutation cortical astrocytes display decreased Glu transporter expression/activity and enhanced asynchronous Ca(2+) oscillations. CONCLUSION Glu transport and Ca(2+) signaling defects in premutation astrocytes could contribute to FXTAS neuropathology. SIGNIFICANCE Premutation astrocytes may have an etiological role in FXTAS neuropathology. Premutation CGG repeat expansions (55-200 CGG repeats; preCGG) within the fragile X mental retardation 1 (FMR1) gene can cause fragile X-associated tremor/ataxia syndrome. Defects in early neuronal migration and morphology, electrophysiological activity, and mitochondria trafficking have been described in a premutation mouse model, but whether preCGG mutations also affect astrocyte function remains unknown. PreCGG cortical astrocytes (∼170 CGG repeats) displayed 3-fold higher Fmr1 mRNA and 30% lower FMR1 protein (FMRP) when compared with WT. PreCGG astrocytes showed modest reductions in expression of glutamate (Glu) transporters GLT-1 and GLAST and attenuated Glu uptake (p < 0.01). Consistent with astrocyte cultures in vitro, aged preCGG mice cerebral cortex also displayed reduced GLAST and GLT-1 expression. Approximately 65% of the WT and preCGG cortical astrocytes displayed spontaneous asynchronous Ca(2+) oscillations. PreCGG astrocytes exhibited nearly 50% higher frequency of asynchronous Ca(2+) oscillations (p < 0.01) than WT, a difference mimicked by chronic exposure of WT astrocytes to l-trans-pyrrolidine-2,4-dicarboxylic acid (l-trans-PDC) or by partial suppression of GLAST using siRNA interference. Acute challenge with Glu augmented the frequency of Ca(2+) oscillations in both genotypes. Additionally, 10 μm Glu elicited a sustained intracellular Ca(2+) rise in a higher portion of preCGG astrocytes when compared with WT. Pharmacological studies showed that mGluR5, but not NMDA receptor, contributed to Glu hypersensitivity in preCGG astrocytes. These functional defects in preCGG astrocytes, especially in Glu signaling, may contribute to fragile X-associated tremor/ataxia syndrome neuropathology.
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Affiliation(s)
- Zhengyu Cao
- Department of Molecular Biosciences, School of Veterinary Medicine, University ofCalifornia, Davis, California 95616, USA.
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Ben Achour S, Pascual O. Astrocyte-neuron communication: functional consequences. Neurochem Res 2012; 37:2464-73. [PMID: 22669630 DOI: 10.1007/s11064-012-0807-0] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2012] [Revised: 05/07/2012] [Accepted: 05/21/2012] [Indexed: 12/17/2022]
Abstract
Astrocyte-neuron communication has recently been proposed as a potential mechanism participating to synaptic transmission. With the development of this concept and accumulating evidences in favor of a modulation of synaptic transmission by astrocytes, has emerged the term gliotransmission. It refers to the capacity of astrocytes to release various transmitters, such as ATP, glutamate, D-serine, and GABA in the vicinity of synapses. While the cellular mechanisms involved in gliotransmission still need to be better described and, for some, identified, the aim of more and more studies is to determine the role of astrocytes from a functional point of view. This review will summarize the principal studies that have investigated a potential role of astrocytes in the various functions regulated by the brain (sleep, breathing, perception, learning and memory…). This will allow us to highlight the similarities and discrepancies in the signaling pathways involved in the different areas of the brain related to these functions.
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Affiliation(s)
- Sarrah Ben Achour
- Ecole Normale Supérieure, Institut de Biologie de l'ENS, IBENS, 75005 Paris, France
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Tewari SG, Majumdar KK. A mathematical model of the tripartite synapse: astrocyte-induced synaptic plasticity. J Biol Phys 2012; 38:465-96. [PMID: 23729909 DOI: 10.1007/s10867-012-9267-7] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2012] [Accepted: 03/12/2012] [Indexed: 01/09/2023] Open
Abstract
In this paper, we present a biologically detailed mathematical model of tripartite synapses, where astrocytes modulate short-term synaptic plasticity. The model consists of a pre-synaptic bouton, a post-synaptic dendritic spine-head, a synaptic cleft and a peri-synaptic astrocyte controlling Ca(2 + ) dynamics inside the synaptic bouton. This in turn controls glutamate release dynamics in the cleft. As a consequence of this, glutamate concentration in the cleft has been modeled, in which glutamate reuptake by astrocytes has also been incorporated. Finally, dendritic spine-head dynamics has been modeled. As an application, this model clearly shows synaptic potentiation in the hippocampal region, i.e., astrocyte Ca(2 + ) mediates synaptic plasticity, which is in conformity with the majority of the recent findings (Perea and Araque (Science 317, 1083-1086, 2007); Henneberger et al. (Nature 463, 232-236, 2010); Navarrete et al. (PLoS Biol. 10, e1001259, 2012)).
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Affiliation(s)
- Shivendra G Tewari
- Systems Science and Informatics Unit, Indian Statistical Institute, 8th Mile, Mysore Road, Bangalore, 560059 India ; Biotechnology & Bioengineering Center and Department of Physiology, Medical College of Wisconsin, 8701 Watertown Plank Road, Milwaukee, WI 53226 USA
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A mathematical model for astrocytes mediated LTP at single hippocampal synapses. J Comput Neurosci 2012; 33:341-70. [PMID: 22454034 DOI: 10.1007/s10827-012-0389-5] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2011] [Revised: 02/21/2012] [Accepted: 02/22/2012] [Indexed: 02/07/2023]
Abstract
Many contemporary studies have shown that astrocytes play a significant role in modulating both short and long form of synaptic plasticity. There are very few experimental models which elucidate the role of astrocyte over Long-term Potentiation (LTP). Recently, Perea and Araque (Science 317:1083-1086, 2007) demonstrated a role of astrocytes in induction of LTP at single hippocampal synapses. They suggested a purely pre-synaptic basis for induction of this N-methyl-D-Aspartate (NMDA) Receptor-independent LTP. Also, the mechanisms underlying this pre-synaptic induction were not investigated. Here, in this article, we propose a mathematical model for astrocyte modulated LTP which successfully imitates the experimental findings of Perea and Araque (Science 317:1083-1086, 2007). Our study suggests the role of retrograde messengers, possibly Nitric Oxide (NO), for this pre-synaptically modulated LTP.
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Dere E, Zlomuzica A. The role of gap junctions in the brain in health and disease. Neurosci Biobehav Rev 2011; 36:206-17. [PMID: 21664373 DOI: 10.1016/j.neubiorev.2011.05.015] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2010] [Revised: 05/25/2011] [Accepted: 05/27/2011] [Indexed: 11/19/2022]
Abstract
Gap junctions connect the cytosolic compartments of adjacent cells for direct electrotonic and metabolic cell-to-cell communication. Gap junctions between glial cells or neurons are ubiquitously expressed in the brain and play a role in brain development including cell differentiation, cell migration and survival, tissue homeostasis, as well as in human diseases including hearing loss, skin disease, neuropathies, epilepsy, brain trauma, and cardiovascular disease. Furthermore, gap junctions are involved in the synchronization and rhythmic oscillation of hippocampal and neocotical neuronal ensembles which might be important for memory formation and consolidation. In this review the accumulated evidence from mouse mutant and pharmacological studies using gap junction blockers is summarized and the progress made in dissecting the physiological, pathophysiological and behavioral roles of gap junction mediated intercellular communication in the brain is discussed.
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Affiliation(s)
- Ekrem Dere
- Université Pierre et Marie Curie, Paris 6, UFR des Sciences de la Vie, UMR 7102, Neurobiologie des Processus Adaptatifs, 9 quai St Bernard, 75005 Paris, France.
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