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Reyner-Parra D, Bonet C, Seara TM, Huguet G. Traveling waves in a model for cortical spreading depolarization with slow-fast dynamics. CHAOS (WOODBURY, N.Y.) 2023; 33:083154. [PMID: 38060797 DOI: 10.1063/5.0160509] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/02/2023] [Accepted: 07/30/2023] [Indexed: 12/18/2023]
Abstract
Cortical spreading depression and spreading depolarization (CSD) are waves of neuronal depolarization that spread across the cortex, leading to a temporary saturation of brain activity. They are associated with various brain disorders such as migraine and ischemia. We consider a reduced version of a biophysical model of a neuron-astrocyte network for the initiation and propagation of CSD waves [Huguet et al., Biophys. J. 111(2), 452-462, 2016], consisting of reaction-diffusion equations. The reduced model considers only the dynamics of the neuronal and astrocytic membrane potentials and the extracellular potassium concentration, capturing the instigation process implicated in such waves. We present a computational and mathematical framework based on the parameterization method and singular perturbation theory to provide semi-analytical results on the existence of a wave solution and to compute it jointly with its velocity of propagation. The traveling wave solution can be seen as a heteroclinic connection of an associated system of ordinary differential equations with a slow-fast dynamics. The presence of distinct time scales within the system introduces numerical instabilities, which we successfully address through the identification of significant invariant manifolds and the implementation of the parameterization method. Our results provide a methodology that allows to identify efficiently and accurately the mechanisms responsible for the initiation of these waves and the wave propagation velocity.
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Affiliation(s)
- David Reyner-Parra
- Departament de Matemàtiques, Universitat Politècnica de Catalunya, Avda. Diagonal 647, 08028 Barcelona, Spain
| | - Carles Bonet
- Departament de Matemàtiques, Universitat Politècnica de Catalunya, Avda. Diagonal 647, 08028 Barcelona, Spain
| | - Teresa M Seara
- Departament de Matemàtiques, Universitat Politècnica de Catalunya, Avda. Diagonal 647, 08028 Barcelona, Spain
- Institut de Matemàtiques de la UPC - Barcelona Tech (IMTech), Pau Gargallo 14, 08028 Barcelona, Spain
- Centre de Recerca Matemàtica, Edifici C, Campus Bellaterra, 08193 Bellaterra, Spain
| | - Gemma Huguet
- Departament de Matemàtiques, Universitat Politècnica de Catalunya, Avda. Diagonal 647, 08028 Barcelona, Spain
- Institut de Matemàtiques de la UPC - Barcelona Tech (IMTech), Pau Gargallo 14, 08028 Barcelona, Spain
- Centre de Recerca Matemàtica, Edifici C, Campus Bellaterra, 08193 Bellaterra, Spain
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2
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Handy G, Borisyuk A. Investigating the ability of astrocytes to drive neural network synchrony. PLoS Comput Biol 2023; 19:e1011290. [PMID: 37556468 PMCID: PMC10441806 DOI: 10.1371/journal.pcbi.1011290] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2022] [Revised: 08/21/2023] [Accepted: 06/21/2023] [Indexed: 08/11/2023] Open
Abstract
Recent experimental works have implicated astrocytes as a significant cell type underlying several neuronal processes in the mammalian brain, from encoding sensory information to neurological disorders. Despite this progress, it is still unclear how astrocytes are communicating with and driving their neuronal neighbors. While previous computational modeling works have helped propose mechanisms responsible for driving these interactions, they have primarily focused on interactions at the synaptic level, with microscale models of calcium dynamics and neurotransmitter diffusion. Since it is computationally infeasible to include the intricate microscale details in a network-scale model, little computational work has been done to understand how astrocytes may be influencing spiking patterns and synchronization of large networks. We overcome this issue by first developing an "effective" astrocyte that can be easily implemented to already established network frameworks. We do this by showing that the astrocyte proximity to a synapse makes synaptic transmission faster, weaker, and less reliable. Thus, our "effective" astrocytes can be incorporated by considering heterogeneous synaptic time constants, which are parametrized only by the degree of astrocytic proximity at that synapse. We then apply our framework to large networks of exponential integrate-and-fire neurons with various spatial structures. Depending on key parameters, such as the number of synapses ensheathed and the strength of this ensheathment, we show that astrocytes can push the network to a synchronous state and exhibit spatially correlated patterns.
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Affiliation(s)
- Gregory Handy
- Departments of Neurobiology and Statistics, University of Chicago, Chicago, Illinois, United States of America
- Grossman Center for Quantitative Biology and Human Behavior, University of Chicago, Chicago, Illinois, United States of America
| | - Alla Borisyuk
- Department of Mathematics, University of Utah, Salt Lake City, Utah, United States of America
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3
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Du Y, Brennan FH, Popovich PG, Zhou M. Microglia maintain the normal structure and function of the hippocampal astrocyte network. Glia 2022; 70:1359-1379. [PMID: 35394085 PMCID: PMC9324808 DOI: 10.1002/glia.24179] [Citation(s) in RCA: 24] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2021] [Revised: 03/09/2022] [Accepted: 03/28/2022] [Indexed: 12/14/2022]
Abstract
Microglial control of activity‐dependent plasticity and synaptic remodeling in neuronal networks has been the subject of intense research in the past several years. Although microglia–neuron interactions have been extensively studied, less is known about how microglia influence astrocyte‐dependent control over neuronal structure and function. Here, we explored a role for microglia in regulating the structure and function of the astrocyte syncytium in mouse hippocampus. After depleting microglia using a CSF1R antagonist (PLX5622, Plexxikon), we observed severe disruption of astrocyte syncytial isopotentiality and dye coupling. A decrease in astrocyte‐specific gap junction connexin (Cx) 30 and 43 expression, at least partially accounts for these microglia‐dependent changes in astrocytes. Because neuronal function requires intact astrocyte coupling, we also evaluated the effects of microglia depletion on synaptic transmission in the hippocampus. Without microglia, the strength of synaptic transmission was reduced at baseline and after long‐term potentiation (LTP). Conversely, priming microglia with systemic injections of lipopolysaccharide enhanced CA3‐CA1 synaptic transmission. This microglia‐induced scaling of synaptic transmission was associated with increased expression of post‐synaptic scaffold proteins (Homer1) in CA1. However, astrocyte network function was not affected by microglia priming, indicating that microglia‐dependent effects on astrocytes and neurons vary across functional states. Through manipulation of microglia in the brain, our results reveal the importance of microglia in homeostatic regulation of the astrocyte syncytium and scaling of synaptic transmission. These novel mechanisms uncover a new direction for future studies interrogating microglia function in various physiological and pathological contexts.
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Affiliation(s)
- Yixing Du
- Department of Neuroscience, The Ohio State University Wexner Medical Center, Columbus, Ohio, USA
| | - Faith H Brennan
- Department of Neuroscience, The Ohio State University Wexner Medical Center, Columbus, Ohio, USA.,Center for Brain and Spinal Cord Repair, The Ohio State University Wexner Medical Center, Columbus, Ohio, USA
| | - Phillip G Popovich
- Department of Neuroscience, The Ohio State University Wexner Medical Center, Columbus, Ohio, USA.,Center for Brain and Spinal Cord Repair, The Ohio State University Wexner Medical Center, Columbus, Ohio, USA
| | - Min Zhou
- Department of Neuroscience, The Ohio State University Wexner Medical Center, Columbus, Ohio, USA
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Parvez S, Kaushik M, Ali M, Alam MM, Ali J, Tabassum H, Kaushik P. Dodging blood brain barrier with "nano" warriors: Novel strategy against ischemic stroke. Theranostics 2022; 12:689-719. [PMID: 34976208 PMCID: PMC8692911 DOI: 10.7150/thno.64806] [Citation(s) in RCA: 21] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2021] [Accepted: 10/14/2021] [Indexed: 12/13/2022] Open
Abstract
Ischemic stroke (IS) is one of the leading causes of death and disability resulting in inevitable burden globally. Ischemic injury initiates cascade of pathological events comprising energy dwindling, failure of ionic gradients, failure of blood brain barrier (BBB), vasogenic edema, calcium over accumulation, excitotoxicity, increased oxidative stress, mitochondrial dysfunction, inflammation and eventually cell death. In spite of such complexity of the disease, the only treatment approved by US Food and Drug Administration (FDA) is tissue plasminogen activator (t-PA). This therapy overcome blood deficiency in the brain along with side effects of reperfusion which are responsible for considerable tissue injury. Therefore, there is urgent need of novel therapeutic perspectives that can protect the integrity of BBB and salvageable brain tissue. Advancement in nanomedicine is empowering new approaches that are potent to improve the understanding and treatment of the IS. Herein, we focus nanomaterial mediated drug delivery systems (DDSs) and their role to bypass and cross BBB especially via intranasal drug delivery. The various nanocarriers used in DDSs are also discussed. In a nut shell, the objective is to provide an overview of use of nanomedicine in the diagnosis and treatment of IS to facilitate the research from benchtop to bedside.
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5
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Modeling the effect of cerebral capillary blood flow on neuronal firing. J Theor Biol 2022; 537:111018. [DOI: 10.1016/j.jtbi.2022.111018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2021] [Revised: 11/19/2021] [Accepted: 01/05/2022] [Indexed: 11/18/2022]
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Chen W, Jiang L, Hu Y, Fang G, Yang B, Li J, Liang N, Wu L, Hussain Z. Nanomedicines, an emerging therapeutic regimen for treatment of ischemic cerebral stroke: A review. J Control Release 2021; 340:342-360. [PMID: 34695522 DOI: 10.1016/j.jconrel.2021.10.020] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2021] [Revised: 10/14/2021] [Accepted: 10/15/2021] [Indexed: 12/18/2022]
Abstract
Owing to its intricate pathophysiology, cerebral stroke is a serious medical condition caused by interruption or obstruction of blood supply (blockage of vasculature) to the brain tissues which results in diminished supply of essential nutrients and oxygen (hypoxia) and ultimate necrosis of neuronal tissues. A prompt risks assessment and immediate rational therapeutic plan with proficient neuroprotection play critically important role in the effective management of this neuronal emergency. Various conventional medications are being used for treatment of acute ischemic cerebral stroke but fibrinolytic agents, alone or in combination with other agents are considered the mainstay. These clot-busting agents effectively restore blood supply (reperfusion) to ischemic regions of the brain; however, their clinical significance is hampered due to various factors such as short plasma half-life, limited distribution to brain tissues due to the presence of highly efficient physiological barrier, blood brain barrier (BBB), and lacking of target-specific delivery to the ischemic brain regions. To alleviate these issues, various types of nanomedicines such as polymeric nanoparticles (NPs), liposomes, nanoemulsion, micelles and dendrimers have been designed and evaluated. The implication of these newer therapies (nanomedicines) have revolutionized the therapeutic outcomes by improving the plasma half-life, permeation across BBB, efficient distribution to ischemic cerebral tissues and neuroprotection. Furthermore, the adaptation of some diverse techniques including PEGylation, tethering of targeting ligands on the surfaces of nanomedicines, and pH responsive features have also been pondered. The implication of these emerging adaptations have shown remarkable potential in maximizing the targeting efficiency of drugs to ischemic brain tissues, simultaneous delivery of drugs and imaging agents (for early prognosis as well as monitoring of therapy), and therapeutic outcomes such as long-term neuroprotection.
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Affiliation(s)
- Wei Chen
- Department of Neurology, The First Affiliated Hospital of Guangxi, University of Chinese Medicine, Nanning, Guangxi 530023, China; Graduate School, Jiangxi University of Chinese Medicine, Nanchang, Jiangxi 330004, China
| | - Lingfei Jiang
- Graduate College, Guangxi University of Chinese Medicine, Nanning, Guangxi 530200, China
| | - Yueqiang Hu
- Department of Neurology, The First Affiliated Hospital of Guangxi, University of Chinese Medicine, Nanning, Guangxi 530023, China; Guangxi Key Laboratory of Chinese Medicine Foundation Research, Guangxi University of Chinese Medicine, Nanning, Guangxi 530200, China.
| | - Gang Fang
- Guangxi Zhuang and Yao Medicine Engineering Technology Research Center, Guangxi University of Chinese Medicine, Nanning, Guangxi 530200, China
| | - Bilin Yang
- Graduate College, Guangxi University of Chinese Medicine, Nanning, Guangxi 530200, China
| | - Junhong Li
- Department of Neurology, The First Affiliated Hospital of Guangxi, University of Chinese Medicine, Nanning, Guangxi 530023, China
| | - Ni Liang
- Department of Neurology, The First Affiliated Hospital of Guangxi, University of Chinese Medicine, Nanning, Guangxi 530023, China
| | - Lin Wu
- Department of Neurology, The First Affiliated Hospital of Guangxi, University of Chinese Medicine, Nanning, Guangxi 530023, China; Guangxi Key Laboratory of Chinese Medicine Foundation Research, Guangxi University of Chinese Medicine, Nanning, Guangxi 530200, China.
| | - Zahid Hussain
- Department of Pharmaceutics and Pharmaceutical Technology, College of Pharmacy, University of Sharjah, Sharjah 27272, United Arab Emirates; Research Institute for Medical & Health Sciences, University of Sharjah, Sharjah 27272, United Arab Emirates.
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Lemaire L, Desroches M, Krupa M, Pizzamiglio L, Scalmani P, Mantegazza M. Modeling NaV1.1/SCN1A sodium channel mutations in a microcircuit with realistic ion concentration dynamics suggests differential GABAergic mechanisms leading to hyperexcitability in epilepsy and hemiplegic migraine. PLoS Comput Biol 2021; 17:e1009239. [PMID: 34314446 PMCID: PMC8345895 DOI: 10.1371/journal.pcbi.1009239] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2021] [Revised: 08/06/2021] [Accepted: 07/02/2021] [Indexed: 11/19/2022] Open
Abstract
Loss of function mutations of SCN1A, the gene coding for the voltage-gated sodium channel NaV1.1, cause different types of epilepsy, whereas gain of function mutations cause sporadic and familial hemiplegic migraine type 3 (FHM-3). However, it is not clear yet how these opposite effects can induce paroxysmal pathological activities involving neuronal networks’ hyperexcitability that are specific of epilepsy (seizures) or migraine (cortical spreading depolarization, CSD). To better understand differential mechanisms leading to the initiation of these pathological activities, we used a two-neuron conductance-based model of interconnected GABAergic and pyramidal glutamatergic neurons, in which we incorporated ionic concentration dynamics in both neurons. We modeled FHM-3 mutations by increasing the persistent sodium current in the interneuron and epileptogenic mutations by decreasing the sodium conductance in the interneuron. Therefore, we studied both FHM-3 and epileptogenic mutations within the same framework, modifying only two parameters. In our model, the key effect of gain of function FHM-3 mutations is ion fluxes modification at each action potential (in particular the larger activation of voltage-gated potassium channels induced by the NaV1.1 gain of function), and the resulting CSD-triggering extracellular potassium accumulation, which is not caused only by modifications of firing frequency. Loss of function epileptogenic mutations, on the other hand, increase GABAergic neurons’ susceptibility to depolarization block, without major modifications of firing frequency before it. Our modeling results connect qualitatively to experimental data: potassium accumulation in the case of FHM-3 mutations and facilitated depolarization block of the GABAergic neuron in the case of epileptogenic mutations. Both these effects can lead to pyramidal neuron hyperexcitability, inducing in the migraine condition depolarization block of both the GABAergic and the pyramidal neuron. Overall, our findings suggest different mechanisms of network hyperexcitability for migraine and epileptogenic NaV1.1 mutations, implying that the modifications of firing frequency may not be the only relevant pathological mechanism. The voltage-gated sodium channel NaV1.1 is a major target of human mutations implicated in different pathologies. In particular, mutations identified in certain types of epilepsy cause loss of function of the channel, whereas mutations identified in certain types of migraine (in which spreading depolarizations of the cortical circuits of the brain are involved) cause instead gain of function. Here, we study dysfunctions induced by these differential effects in a two-neuron (GABAergic and pyramidal) conductance-based model with dynamic ion concentrations. We obtain results that can be related to experimental findings in both situations. Namely, extracellular potassium accumulation induced by the activity of the GABAergic neuron in the case of CSD, and higher propensity of the GABAergic neuron to depolarization block in the epileptogenic scenario, without significant modifications of its firing frequency prior to it. Both scenarios can induce hyperexcitability of the pyramidal neuron, leading in the migraine condition to depolarization block of both the GABAergic and the pyramidal neuron. Our results are successfully confronted to experimental data and suggest that modification of firing frequency is not the only key mechanism in these pathologies of neuronal excitability.
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Affiliation(s)
- Louisiane Lemaire
- Inria Sophia Antipolis Méditerranée Research Centre, MathNeuro Team, Valbonne-Sophia Antipolis, France
- Université Côte d’Azur, Nice, France
- * E-mail: (LL); (MM)
| | - Mathieu Desroches
- Inria Sophia Antipolis Méditerranée Research Centre, MathNeuro Team, Valbonne-Sophia Antipolis, France
- Université Côte d’Azur, Nice, France
| | - Martin Krupa
- Inria Sophia Antipolis Méditerranée Research Centre, MathNeuro Team, Valbonne-Sophia Antipolis, France
- Université Côte d’Azur, Laboratoire Jean-Alexandre Dieudonné, Nice, France
| | - Lara Pizzamiglio
- Université Côte d’Azur, Institute of Molecular and Cellular Pharmacology (IPMC), Valbonne-Sophia Antipolis, France
- CNRS UMR7275, Institute of Molecular and Cellular Pharmacology (IPMC), Valbonne-Sophia Antipolis, France
| | - Paolo Scalmani
- U.O. VII Clinical and Experimental Epileptology, Foundation IRCCS Neurological Institute Carlo Besta, Milan, Italy
| | - Massimo Mantegazza
- Université Côte d’Azur, Institute of Molecular and Cellular Pharmacology (IPMC), Valbonne-Sophia Antipolis, France
- CNRS UMR7275, Institute of Molecular and Cellular Pharmacology (IPMC), Valbonne-Sophia Antipolis, France
- Inserm, Valbonne-Sophia Antipolis, France
- * E-mail: (LL); (MM)
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8
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Astrocyte Networks as Therapeutic Targets in Glaucomatous Neurodegeneration. Cells 2021; 10:cells10061368. [PMID: 34199470 PMCID: PMC8228804 DOI: 10.3390/cells10061368] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2021] [Revised: 05/28/2021] [Accepted: 05/30/2021] [Indexed: 11/22/2022] Open
Abstract
Astrocytes are intimately involved in the response to neurodegenerative stress and have become an attractive target for the development of neuroprotective therapies. However, studies often focus on astrocytes as single-cell units. Astrocytes are densely interconnected by gap junctions that are composed primarily of the protein connexin-43 (Cx43) and can function as a broader network of cells. Such networks contribute to a number of important processes, including metabolite distribution and extracellular ionic buffering, and are likely to play an important role in the progression of neurodegenerative disease. This review will focus on the pro-degenerative and pro-survival influence of astrocyte Cx43 in disease progression, with a focus on the roles of gap junctions and hemichannels in the spread of degenerative stress. Finally, we will highlight the specific evidence for targeting these networks in the treatment of glaucomatous neurodegeneration and other optic neuropathies.
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Almalki WH, Alghamdi S, Alzahrani A, Zhang W. Emerging paradigms in treating cerebral infarction with nanotheranostics: opportunities and clinical challenges. Drug Discov Today 2020; 26:826-835. [PMID: 33383212 DOI: 10.1016/j.drudis.2020.12.018] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2020] [Revised: 10/10/2020] [Accepted: 12/21/2020] [Indexed: 12/28/2022]
Abstract
Interest is increasing in the use of nanotheranostics as diagnosis, imaging and therapeutic tools for stroke management, but movement to the clinic remains challenging.
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Affiliation(s)
- Waleed H Almalki
- Department of Pharmacology and Toxicology, College of Pharmacy, Umm al-qura University, Saudi Arabia.
| | - Saad Alghamdi
- Laboratory Medicine Department, Faculty of Applied Medical Sciences, Umm Al-qura University, Makkah, Saudi Arabia
| | - Abdulaziz Alzahrani
- Department of Pharmacology, College of Clinical Pharmacy, Albaha University, Saudi Arabia
| | - Wenzhi Zhang
- Senior Research Scientist, Inn Research Sdn. Bhd., Subang Jaya, Selangor, Malaysia
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10
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Verhoog QP, Holtman L, Aronica E, van Vliet EA. Astrocytes as Guardians of Neuronal Excitability: Mechanisms Underlying Epileptogenesis. Front Neurol 2020; 11:591690. [PMID: 33324329 PMCID: PMC7726323 DOI: 10.3389/fneur.2020.591690] [Citation(s) in RCA: 73] [Impact Index Per Article: 18.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2020] [Accepted: 10/26/2020] [Indexed: 12/11/2022] Open
Abstract
Astrocytes are key homeostatic regulators in the central nervous system and play important roles in physiology. After brain damage caused by e.g., status epilepticus, traumatic brain injury, or stroke, astrocytes may adopt a reactive phenotype. This process of reactive astrogliosis is important to restore brain homeostasis. However, persistent reactive astrogliosis can be detrimental for the brain and contributes to the development of epilepsy. In this review, we will focus on physiological functions of astrocytes in the normal brain as well as pathophysiological functions in the epileptogenic brain, with a focus on acquired epilepsy. We will discuss the role of astrocyte-related processes in epileptogenesis, including reactive astrogliosis, disturbances in energy supply and metabolism, gliotransmission, and extracellular ion concentrations, as well as blood-brain barrier dysfunction and dysregulation of blood flow. Since dysfunction of astrocytes can contribute to epilepsy, we will also discuss their role as potential targets for new therapeutic strategies.
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Affiliation(s)
- Quirijn P. Verhoog
- Leiden Academic Center for Drug Research, Leiden University, Leiden, Netherlands
- Department of Neuropathology, Amsterdam Neuroscience, Amsterdam UMC, University of Amsterdam, Amsterdam, Netherlands
| | - Linda Holtman
- Leiden Academic Center for Drug Research, Leiden University, Leiden, Netherlands
| | - Eleonora Aronica
- Department of Neuropathology, Amsterdam Neuroscience, Amsterdam UMC, University of Amsterdam, Amsterdam, Netherlands
- Stichting Epilepsie Instellingen Nederland (SEIN), Heemstede, Netherlands
| | - Erwin A. van Vliet
- Department of Neuropathology, Amsterdam Neuroscience, Amsterdam UMC, University of Amsterdam, Amsterdam, Netherlands
- Center for Neuroscience, Swammerdam Institute for Life Sciences, University of Amsterdam, Amsterdam, Netherlands
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Dai WL, Zhang L, Han L, Yang X, Hu L, Miao C, Song L, Xiao H, Liu JH, Liu WT. Regulation of the K ATP-JNK gap junction signaling pathway by immunomodulator astragaloside IV attenuates neuropathic pain. Reg Anesth Pain Med 2020; 45:955-963. [PMID: 32963077 DOI: 10.1136/rapm-2020-101411] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2020] [Revised: 07/29/2020] [Accepted: 08/03/2020] [Indexed: 12/30/2022]
Abstract
BACKGROUND AND OBJECTIVES Gap junctions play a pivotal role in contributing to the formation of astroglial networks and in chronic pain. However, the mechanisms underlying the dysfunction of astroglial gap junctions in chronic pain have not been fully elucidated. METHODS Chronic constriction injury (CCI) of the sciatic nerve was used to establish rat neuropathic pain model. C6 cells were used to perform experiments in vitro. Von Frey hairs and Hargreave's method were used to determine the withdrawal threshold of rats. Protein expression was detected by immunofluorescence and western blotting. RESULTS Astragaloside IV (AST IV) significantly attenuated neuropathic pain and suppressed the excitation of spinal astrocytes in rats with CCI. The antinociceptive effect of AST IV was reversed by the gap junction decoupler carbenoxolone (CBX). AST IV inhibited the high expression of phosphorylated connexin 43 (p-Cx43) and p-c-Jun N-terminal kinase (p-JNK) in spinal cord of rats with CCI. JNK inhibitor alleviated neuropathic pain, which was reversed by CBX. JNK inhibitor decreased the high expression of p-Cx43 in both rats with CCI and tumor necrosis factor-alpha (TNF-α)-treated C6 cells. Additionally, the analgesic effect of AST IV was reversed by the adenosine triphosphate-sensitive potassium (KATP) channel blocker, glibenclamide (Glib). Glib abolished the inhibitory effects of AST IV on p-JNK and p-Cx43 both in vivo and in vitro. KATP channel opener (KCO) mimicked the inhibitory effects of AST IV on p-JNK and p-Cx43 in TNF-α-treated C6 cells. CONCLUSION Our results indicate that the sciatic nerve CCI induces the dysfunction of gap junctions in the spinal cord by activating KATP/JNK signaling to contribute to neuropathic pain. AST IV attenuates neuropathic pain via regulating the KATP-JNK gap junction axis.
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Affiliation(s)
- Wen-Ling Dai
- Jiangsu Key Laboratory of TCM Evaluation and Translational Research, School of Traditional Chinese Pharmacy, China Pharmaceutical University, Nanjing, Jiangsu, China
| | - Li Zhang
- Department of Anesthesiology, Children's Hospital of Nanjing Medical University, Nanjing, Jiangsu, China
| | - Liu Han
- Department of Anesthesiology, Nanjing Hospital Affiliated to Nanjing Medical University, Nanjing, Jiangsu, China
| | - Xing Yang
- Jiangsu Key Laboratory of Neurodegeneration, Department of Pharmacology, Nanjing Medical University, Nanjing, Jiangsu, China
| | - Liang Hu
- Jiangsu Key Laboratory of Neurodegeneration, Department of Pharmacology, Nanjing Medical University, Nanjing, Jiangsu, China
| | - Chen Miao
- Department of pathology, The First Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu, China
| | - Ling Song
- Jiangsu Key Laboratory of Neurodegeneration, Department of Pharmacology, Nanjing Medical University, Nanjing, Jiangsu, China
| | - Hang Xiao
- Key Lab of Modern Toxicology (NJMU), Ministry of Education; Department of Toxicology, School of Public Health, Nanjing Medical University, Nanjing, Jiangsu, China
| | - Ji-Hua Liu
- Jiangsu Key Laboratory of TCM Evaluation and Translational Research, School of Traditional Chinese Pharmacy, China Pharmaceutical University, Nanjing, Jiangsu, China
| | - Wen-Tao Liu
- Jiangsu Key Laboratory of Neurodegeneration, Department of Pharmacology, Nanjing Medical University, Nanjing, Jiangsu, China .,Institute of Translational Medicine, Nanjing Medical University, Nanjing, Jiangsu, China
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12
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Stevenson R, Samokhina E, Rossetti I, Morley JW, Buskila Y. Neuromodulation of Glial Function During Neurodegeneration. Front Cell Neurosci 2020; 14:278. [PMID: 32973460 PMCID: PMC7473408 DOI: 10.3389/fncel.2020.00278] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2020] [Accepted: 08/05/2020] [Indexed: 12/12/2022] Open
Abstract
Glia, a non-excitable cell type once considered merely as the connective tissue between neurons, is nowadays acknowledged for its essential contribution to multiple physiological processes including learning, memory formation, excitability, synaptic plasticity, ion homeostasis, and energy metabolism. Moreover, as glia are key players in the brain immune system and provide structural and nutritional support for neurons, they are intimately involved in multiple neurological disorders. Recent advances have demonstrated that glial cells, specifically microglia and astroglia, are involved in several neurodegenerative diseases including Amyotrophic lateral sclerosis (ALS), Epilepsy, Parkinson's disease (PD), Alzheimer's disease (AD), and frontotemporal dementia (FTD). While there is compelling evidence for glial modulation of synaptic formation and regulation that affect neuronal signal processing and activity, in this manuscript we will review recent findings on neuronal activity that affect glial function, specifically during neurodegenerative disorders. We will discuss the nature of each glial malfunction, its specificity to each disorder, overall contribution to the disease progression and assess its potential as a future therapeutic target.
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Affiliation(s)
- Rebecca Stevenson
- School of Medicine, Western Sydney University, Campbelltown, NSW, Australia
| | - Evgeniia Samokhina
- School of Medicine, Western Sydney University, Campbelltown, NSW, Australia
| | - Ilaria Rossetti
- School of Medicine, Western Sydney University, Campbelltown, NSW, Australia
| | - John W. Morley
- School of Medicine, Western Sydney University, Campbelltown, NSW, Australia
| | - Yossi Buskila
- School of Medicine, Western Sydney University, Campbelltown, NSW, Australia
- International Centre for Neuromorphic Systems, The MARCS Institute for Brain, Behaviour and Development, Penrith, NSW, Australia
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13
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Kenny A, Plank MJ, David T. The effects of cerebral curvature on cortical spreading depression. J Theor Biol 2019; 472:11-26. [PMID: 30978351 DOI: 10.1016/j.jtbi.2019.04.006] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2019] [Revised: 04/05/2019] [Accepted: 04/08/2019] [Indexed: 10/27/2022]
Abstract
Neuronal activity evokes a localised increase in cerebral blood flow through neurovascular coupling (NVC), a communication system between a group of cells known as a neurovascular unit (NVU). Dysfunctional NVC can lead to pathologies such as cortical spreading depression (CSD), characterised by a slowly propagating wave of neuronal depolarisation and high extracellular potassium (K+) levels. CSD is associated with several neurological disorders such as migraine, stroke, and traumatic brain injury. Insight into the spatial dynamics of CSD in humans is mainly deduced from animal experiments on the smooth lissencephalic brain (in particular murine experiments), however the human cortex is gyrencephalic (highly folded) and is considered likely to exhibit different and more complex patterns of CSD. In this study a large scale numerical NVC model of multiple NVUs is coupled to a vascular tree simulating a two-dimensional cerebral tissue slice. This model is extended with a spatial Gaussian curvature mapping that can simulate the highly folded nature of the human cortex. For a flat surface comparable to a lissencephalic cortex the model can simulate propagating waves of high extracellular K+ travelling radially outwards from a stimulated area at approximately 6.7 mm/min, corresponding well with multiple experimental results. The high K+ concentration induces a corresponding wave of vasoconstriction (with decreased blood flow) then slight vasodilation, achieved through cellular communication within the NVU. The BOLD response decreases below baseline by approximately 10% followed by an increase of 1%. For a surface with spatially varied curvature comparable to a section of gyrencephalic cortex, areas of positive Gaussian curvature inhibit wave propagation due to decreased extracellular diffusion rate. Whereas areas of negative curvature promote propagation. Consequently extracellular K+ is observed travelling as wave segments (as opposed to radial waves) through flat or negatively curved "valleys" corresponding to folds (sulci) in the cortex. If the wave size (defined as the activated area of high K+ concentration) is too small or diffusion rate too low then wave segments can cease propagation. If the diffusion rate is high enough the wave segments can grow from open ends forming loose spiral waves. These results may provide some insight into the differences seen between human and animal experiments.
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Affiliation(s)
- Allanah Kenny
- Department of Mechanical Engineering, University of Canterbury, New Zealand.
| | - Michael J Plank
- School of Mathematics and Statistics and Te Punaha Matatini, University of Canterbury, New Zealand
| | - Tim David
- Department of Mechanical Engineering, University of Canterbury, New Zealand
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Cervera J, Pai VP, Levin M, Mafe S. From non-excitable single-cell to multicellular bioelectrical states supported by ion channels and gap junction proteins: Electrical potentials as distributed controllers. PROGRESS IN BIOPHYSICS AND MOLECULAR BIOLOGY 2019; 149:39-53. [PMID: 31255702 DOI: 10.1016/j.pbiomolbio.2019.06.004] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/24/2019] [Accepted: 06/26/2019] [Indexed: 12/18/2022]
Abstract
Endogenous bioelectric patterns within tissues are an important driver of morphogenesis and a tractable component of a number of disease states. Developing system-level understanding of the dynamics by which non-neural bioelectric circuits regulate complex downstream cascades is a key step towards both, an evolutionary understanding of ion channel genes, and novel strategies in regenerative medicine. An important capability gap is deriving rational modulation strategies targeting individual cells' bioelectric states to achieve global (tissue- or organ-level) outcomes. Here, we develop an ion channel-based model that describes multicellular states on the basis of spatio-temporal patterns of electrical potentials in aggregates of non-excitable cells. The model is of biological interest because modern techniques allow to associate bioelectrical signals with specific ion channel proteins in the cell membrane that are central to embryogenesis, regeneration, and tumorigenesis. As a complementary approach to the usual biochemical description, we have studied four biophysical questions: (i) how can single-cell bioelectrical states be established; (ii) how can a change in the cell potential caused by a transient perturbation of the cell state be maintained after the stimulus is gone (bioelectrical memory); (iii) how can a single-cell contribute to the control of multicellular ensembles based on the spatio-temporal pattern of electrical potentials; and (iv) how can oscillatory patterns arise from the single-cell bioelectrical dynamics. Experimentally, endogenous bioelectric gradients have emerged as instructive agents for morphogenetic processes. In this context, the simulations can guide new procedures that may allow a distributed control of the multicellular ensemble.
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Affiliation(s)
- Javier Cervera
- Dept. Termodinàmica, Universitat de València, E-46100, Burjassot, Spain.
| | - Vaibhav P Pai
- Dept. of Biology and Allen Discovery Center at Tufts University, Medford, MA, 02155-4243, USA
| | - Michael Levin
- Dept. of Biology and Allen Discovery Center at Tufts University, Medford, MA, 02155-4243, USA
| | - Salvador Mafe
- Dept. Termodinàmica, Universitat de València, E-46100, Burjassot, Spain
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15
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Fairless R, Williams SK, Diem R. Calcium-Binding Proteins as Determinants of Central Nervous System Neuronal Vulnerability to Disease. Int J Mol Sci 2019; 20:ijms20092146. [PMID: 31052285 PMCID: PMC6539299 DOI: 10.3390/ijms20092146] [Citation(s) in RCA: 63] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2019] [Revised: 04/26/2019] [Accepted: 04/27/2019] [Indexed: 12/14/2022] Open
Abstract
Neuronal subpopulations display differential vulnerabilities to disease, but the factors that determine their susceptibility are poorly understood. Toxic increases in intracellular calcium are a key factor in several neurodegenerative processes, with calcium-binding proteins providing an important first line of defense through their ability to buffer incoming calcium, allowing the neuron to quickly achieve homeostasis. Since neurons expressing different calcium-binding proteins have been reported to be differentially susceptible to degeneration, it can be hypothesized that rather than just serving as markers of different neuronal subpopulations, they might actually be a key determinant of survival. In this review, we will summarize some of the evidence that expression of the EF-hand calcium-binding proteins, calbindin, calretinin and parvalbumin, may influence the susceptibility of distinct neuronal subpopulations to disease processes.
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Affiliation(s)
- Richard Fairless
- Department of Neurology, University Clinic Heidelberg, 69120 Heidelberg, Germany.
- Clinical Cooperation Unit (CCU) Neurooncology, German Cancer Consortium (DKTK), German Cancer Research Center (DFKZ), 69120 Heidelberg, Germany.
| | - Sarah K Williams
- Department of Neurology, University Clinic Heidelberg, 69120 Heidelberg, Germany.
- Clinical Cooperation Unit (CCU) Neurooncology, German Cancer Consortium (DKTK), German Cancer Research Center (DFKZ), 69120 Heidelberg, Germany.
| | - Ricarda Diem
- Department of Neurology, University Clinic Heidelberg, 69120 Heidelberg, Germany.
- Clinical Cooperation Unit (CCU) Neurooncology, German Cancer Consortium (DKTK), German Cancer Research Center (DFKZ), 69120 Heidelberg, Germany.
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16
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Kaviarasi S, Yuba E, Harada A, Krishnan UM. Emerging paradigms in nanotechnology for imaging and treatment of cerebral ischemia. J Control Release 2019; 300:22-45. [DOI: 10.1016/j.jconrel.2019.02.031] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2019] [Revised: 02/20/2019] [Accepted: 02/21/2019] [Indexed: 02/07/2023]
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17
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Macro scale modelling of cortical spreading depression and the role of astrocytic gap junctions. J Theor Biol 2018; 458:78-91. [DOI: 10.1016/j.jtbi.2018.09.006] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2018] [Revised: 08/08/2018] [Accepted: 09/07/2018] [Indexed: 12/22/2022]
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18
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Li Q, Li QQ, Jia JN, Liu ZQ, Zhou HH, Mao XY. Targeting gap junction in epilepsy: Perspectives and challenges. Biomed Pharmacother 2018; 109:57-65. [PMID: 30396092 DOI: 10.1016/j.biopha.2018.10.068] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2018] [Revised: 10/08/2018] [Accepted: 10/12/2018] [Indexed: 12/21/2022] Open
Abstract
Gap junctions (GJs) are multiple cellular intercellular connections that allow ions to pass directly into the cytoplasm of neighboring cells. Electrical coupling mediated by GJs plays a role in the generation of highly synchronous electrical activity. Accumulative investigations show that GJs in the brain are involved in the generation, synchronization and maintenance of seizure events. At the same time, GJ blockers exert potent curative potential on epilepsy in vivo or in vitro. This review aims to shed light on the role of GJs in epileptogenesis. Targeting GJs is likely to be served as a novel therapeutic approach on epileptic patients.
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Affiliation(s)
- Qin Li
- Department of Clinical Pharmacology, Xiangya Hospital, Central South University, Changsha 410008, China; Institute of Clinical Pharmacology, Hunan Key Laboratory of Pharmacogenetics, Central South University, Changsha 410078, Hunan, China
| | - Qiu-Qi Li
- Department of Clinical Pharmacology, Xiangya Hospital, Central South University, Changsha 410008, China; Institute of Clinical Pharmacology, Hunan Key Laboratory of Pharmacogenetics, Central South University, Changsha 410078, Hunan, China
| | - Ji-Ning Jia
- Department of Clinical Pharmacology, Xiangya Hospital, Central South University, Changsha 410008, China; Institute of Clinical Pharmacology, Hunan Key Laboratory of Pharmacogenetics, Central South University, Changsha 410078, Hunan, China
| | - Zhao-Qian Liu
- Department of Clinical Pharmacology, Xiangya Hospital, Central South University, Changsha 410008, China; Institute of Clinical Pharmacology, Hunan Key Laboratory of Pharmacogenetics, Central South University, Changsha 410078, Hunan, China
| | - Hong-Hao Zhou
- Department of Clinical Pharmacology, Xiangya Hospital, Central South University, Changsha 410008, China; Institute of Clinical Pharmacology, Hunan Key Laboratory of Pharmacogenetics, Central South University, Changsha 410078, Hunan, China
| | - Xiao-Yuan Mao
- Department of Clinical Pharmacology, Xiangya Hospital, Central South University, Changsha 410008, China; Institute of Clinical Pharmacology, Hunan Key Laboratory of Pharmacogenetics, Central South University, Changsha 410078, Hunan, China.
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19
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Conte C, Lee R, Sarkar M, Terman D. A mathematical model of recurrent spreading depolarizations. J Comput Neurosci 2017; 44:203-217. [PMID: 29210004 DOI: 10.1007/s10827-017-0675-3] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2017] [Revised: 11/17/2017] [Accepted: 11/20/2017] [Indexed: 12/24/2022]
Abstract
A detailed biophysical model for a neuron/astrocyte network is developed in order to explore mechanisms responsible for the initiation and propagation of recurrent cortical spreading depolarizations. The model incorporates biophysical processes not considered in the earlier models. This includes a model for the Na+-glutamate transporter, which allows for a detailed description of reverse glutamate uptake. In particular, we consider the specific roles of elevated extracellular glutamate and K+ in the initiation, propagation and recurrence of spreading depolarizations.
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Affiliation(s)
- Cameron Conte
- Department of Mathematics, Ohio State University, Columbus, OH, USA
| | - Ray Lee
- Department of Mathematics, Ohio State University, Columbus, OH, USA
| | - Monica Sarkar
- Department of Mathematics, Ohio State University, Columbus, OH, USA
| | - David Terman
- Department of Mathematics, Ohio State University, Columbus, OH, USA.
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20
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Role of Connexin and Pannexin containing channels in HIV infection and NeuroAIDS. Neurosci Lett 2017; 695:86-90. [PMID: 28886986 DOI: 10.1016/j.neulet.2017.09.005] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2017] [Revised: 07/27/2017] [Accepted: 09/01/2017] [Indexed: 01/31/2023]
Abstract
Neuron-Glia crosstalk is essential for efficient synaptic communication, cell growth and differentiation, neuronal activity, neurotransmitter recycling, and brain immune response. The master regulators of this neuron-glia communication are connexin containing Gap Junctions (GJs) and Hemichannels (HCs) as well as pannexin HCs. However, the role of these channels under pathological conditions, especially in infectious diseases is still in exploratory stages. Human Immunodeficiency Virus-1 (HIV) is one such infectious agent that takes advantage of the host intercellular communication systems, GJs and HCs, to exacerbate viral pathogenesis in the brain in spite of the antiretroviral therapy effectively controlling viral replication in the periphery. Although most infectious agents lead to total "shutdown" of gap junctional communication in parenchymal cells, HIV infection maintains and "hijacks" GJs and HCs to enable few infected cells to spread toxic intracellular agents to neighboring uninfected cells aggravating viral neuropathology even in the absence of viral replication. In this mini-review, we present a comprehensive overview of the role of GJs and HCs in augmenting HIV neuropathogenesis.
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