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Wang J, Zhao J, Zhao K, Wu S, Chen X, Hu W. The Role of Calcium and Iron Homeostasis in Parkinson's Disease. Brain Sci 2024; 14:88. [PMID: 38248303 PMCID: PMC10813814 DOI: 10.3390/brainsci14010088] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2023] [Revised: 01/04/2024] [Accepted: 01/09/2024] [Indexed: 01/23/2024] Open
Abstract
Calcium and iron are essential elements that regulate many important processes of eukaryotic cells. Failure to maintain homeostasis of calcium and iron causes cell dysfunction or even death. PD (Parkinson's disease) is the second most common neurological disorder in humans, for which there are currently no viable treatment options or effective strategies to cure and delay progression. Pathological hallmarks of PD, such as dopaminergic neuronal death and intracellular α-synuclein deposition, are closely involved in perturbations of iron and calcium homeostasis and accumulation. Here, we summarize the mechanisms by which Ca2+ signaling influences or promotes PD progression and the main mechanisms involved in ferroptosis in Parkinson's disease. Understanding the mechanisms by which calcium and iron imbalances contribute to the progression of this disease is critical to developing effective treatments to combat this devastating neurological disorder.
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Affiliation(s)
- Ji Wang
- School of Chinese Materia Medica & Yunnan Key Laboratory of Southern Medicine Utilization, Yunnan University of Chinese Medicine, Kunming 650500, China;
- School of Pharmaceutical Science & Yunnan Key Laboratory of Pharmacology for Natural Products, Kunming Medical University, Kunming 650500, China; (J.Z.); (K.Z.); (S.W.)
| | - Jindong Zhao
- School of Pharmaceutical Science & Yunnan Key Laboratory of Pharmacology for Natural Products, Kunming Medical University, Kunming 650500, China; (J.Z.); (K.Z.); (S.W.)
| | - Kunying Zhao
- School of Pharmaceutical Science & Yunnan Key Laboratory of Pharmacology for Natural Products, Kunming Medical University, Kunming 650500, China; (J.Z.); (K.Z.); (S.W.)
| | - Shangpeng Wu
- School of Pharmaceutical Science & Yunnan Key Laboratory of Pharmacology for Natural Products, Kunming Medical University, Kunming 650500, China; (J.Z.); (K.Z.); (S.W.)
| | - Xinglong Chen
- School of Chinese Materia Medica & Yunnan Key Laboratory of Southern Medicine Utilization, Yunnan University of Chinese Medicine, Kunming 650500, China;
| | - Weiyan Hu
- School of Pharmaceutical Science & Yunnan Key Laboratory of Pharmacology for Natural Products, Kunming Medical University, Kunming 650500, China; (J.Z.); (K.Z.); (S.W.)
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Choudhury N, Chen L, Al-Harthi L, Hu XT. Hyperactivity of medial prefrontal cortex pyramidal neurons occurs in a mouse model of early-stage Alzheimer's disease without β-amyloid accumulation. Front Pharmacol 2023; 14:1194869. [PMID: 37465526 PMCID: PMC10350500 DOI: 10.3389/fphar.2023.1194869] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2023] [Accepted: 06/19/2023] [Indexed: 07/20/2023] Open
Abstract
The normal function of the medial prefrontal cortex (mPFC) is essential for regulating neurocognition, but it is disrupted in the early stages of Alzheimer's disease (AD) before the accumulation of Aβ and the appearance of symptoms. Despite this, little is known about how the functional activity of medial prefrontal cortex pyramidal neurons changes as Alzheimer's disease progresses during aging. We used electrophysiological techniques (patch-clamping) to assess the functional activity of medial prefrontal cortex pyramidal neurons in the brain of 3xTg-Alzheimer's disease mice modeling early-stage Alzheimer's disease without Aβ accumulation. Our results indicate that firing rate and the frequency of spontaneous excitatory postsynaptic currents (sEPSCs) were significantly increased in medial prefrontal cortex neurons from young Alzheimer's disease mice (4-5-month, equivalent of <30-year-old humans) compared to age-matched control mice. Blocking ionotropic glutamatergic NMDA receptors, which regulate neuronal excitability and Ca2+ homeostasis, abolished this neuronal hyperactivity. There were no changes in Ca2+ influx through the voltage-gated Ca2+ channels (VGCCs) or inhibitory postsynaptic activity in medial prefrontal cortex neurons from young Alzheimer's disease mice compared to controls. Additionally, acute exposure to Aβ42 potentiated medial prefrontal cortex neuronal hyperactivity in young Alzheimer's disease mice but had no effects on controls. These findings indicate that the hyperactivity of medial prefrontal cortex pyramidal neurons at early-stage Alzheimer's disease is induced by an abnormal increase in presynaptic glutamate release and postsynaptic NMDA receptor activity, which initiates neuronal Ca2+ dyshomeostasis. Additionally, because accumulated Aβ forms unconventional but functional Ca2+ channels in medial prefrontal cortex neurons in the late stage of Alzheimer's disease, our study also suggests an exacerbated Ca2+ dyshomeostasis in medial prefrontal cortex pyramidal neurons following overactivation of such VGCCs.
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Affiliation(s)
| | | | | | - Xiu-Ti Hu
- Department of Microbial Pathogens and Immunity, Rush University Medical Centre, Chicago, IL, United States
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3
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Mahan VL. Effects of lactate and carbon monoxide interactions on neuroprotection and neuropreservation. Med Gas Res 2021; 11:158-173. [PMID: 34213499 PMCID: PMC8374456 DOI: 10.4103/2045-9912.318862] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2020] [Revised: 08/21/2020] [Accepted: 10/23/2020] [Indexed: 11/04/2022] Open
Abstract
Lactate, historically considered a waste product of anerobic metabolism, is a metabolite in whole-body metabolism needed for normal central nervous system (CNS) functions and a potent signaling molecule and hormone in the CNS. Neuronal activity signals normally induce its formation primarily in astrocytes and production is dependent on anerobic and aerobic metabolisms. Functions are dependent on normal dynamic, expansive, and evolving CNS functions. Levels can change under normal physiologic conditions and with CNS pathology. A readily combusted fuel that is sshuttled throughout the body, lactate is used as an energy source and is needed for CNS hemostasis, plasticity, memory, and excitability. Diffusion beyond the neuron active zone impacts activity of neurons and astrocytes in other areas of the brain. Barriergenesis, function of the blood-brain barrier, and buffering between oxidative metabolism and glycolysis and brain metabolism are affected by lactate. Important to neuroprotection, presence or absence is associated with L-lactate and heme oxygenase/carbon monoxide (a gasotransmitter) neuroprotective systems. Effects of carbon monoxide on L-lactate affect neuroprotection - interactions of the gasotransmitter with L-lactate are important to CNS stability, which will be reviewed in this article.
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Affiliation(s)
- Vicki L. Mahan
- Department of Surgery and Pediatrics, Drexel University College of Medicine, Philadelphia, PA, USA
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4
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Montalant A, Carlsen EMM, Perrier J. Role of astrocytes in rhythmic motor activity. Physiol Rep 2021; 9:e15029. [PMID: 34558208 PMCID: PMC8461027 DOI: 10.14814/phy2.15029] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2021] [Revised: 08/11/2021] [Accepted: 08/13/2021] [Indexed: 01/14/2023] Open
Abstract
Rhythmic motor activities such as breathing, locomotion, tremor, or mastication are organized by groups of interconnected neurons. Most synapses in the central nervous system are in close apposition with processes belonging to astrocytes. Neurotransmitters released from neurons bind to receptors expressed by astrocytes, activating a signaling pathway that leads to an increase in calcium concentration and the release of gliotransmitters that eventually modulate synaptic transmission. It is therefore likely that the activation of astrocytes impacts motor control. Here we review recent studies demonstrating that astrocytes inhibit, modulate, or trigger motor rhythmic behaviors.
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Affiliation(s)
- Alexia Montalant
- Department of NeuroscienceFaculty of Health and Medical SciencesUniversity of CopenhagenCopenhagenDenmark
| | - Eva M. M. Carlsen
- Department of NeuroscienceFaculty of Health and Medical SciencesUniversity of CopenhagenCopenhagenDenmark
| | - Jean‐François Perrier
- Department of NeuroscienceFaculty of Health and Medical SciencesUniversity of CopenhagenCopenhagenDenmark
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5
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Mazaud D, Capano A, Rouach N. The many ways astroglial connexins regulate neurotransmission and behavior. Glia 2021; 69:2527-2545. [PMID: 34101261 DOI: 10.1002/glia.24040] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2020] [Revised: 05/17/2021] [Accepted: 05/21/2021] [Indexed: 12/18/2022]
Abstract
Astrocytes have emerged as major players in the brain, contributing to many functions such as energy supply, neurotransmission, and behavior. They accomplish these functions in part via their capacity to form widespread intercellular networks and to release neuroactive factors, which can modulate neurotransmission at different levels, from individual synapses to neuronal networks. The extensive network communication of astrocytes is primarily mediated by gap junction channels composed of two connexins, Cx30 and Cx43, which present distinct temporal and spatial expression patterns. Yet, astroglial connexins are also involved in direct exchange with the extracellular space via hemichannels, as well as in adhesion and signaling processes via unconventional nonchannel functions. Accumulating evidence indicate that astrocytes modulate neurotransmission and behavior through these diverse connexin functions. We here review the many ways astroglial connexins regulate neuronal activity from the molecular level to behavior.
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Affiliation(s)
- David Mazaud
- Neuroglial Interactions in Cerebral Physiology and Pathologies, Center for Interdisciplinary Research in Biology, Collège de France, CNRS UMR 7241, INSERM U1050, Labex Memolife, PSL Research University, Paris, France
| | - Anna Capano
- Neuroglial Interactions in Cerebral Physiology and Pathologies, Center for Interdisciplinary Research in Biology, Collège de France, CNRS UMR 7241, INSERM U1050, Labex Memolife, PSL Research University, Paris, France.,Doctoral School N°158, Sorbonne University, Paris, France
| | - Nathalie Rouach
- Neuroglial Interactions in Cerebral Physiology and Pathologies, Center for Interdisciplinary Research in Biology, Collège de France, CNRS UMR 7241, INSERM U1050, Labex Memolife, PSL Research University, Paris, France
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6
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Calim A, Longtin A, Uzuntarla M. Vibrational resonance in a neuron-astrocyte coupled model. PHILOSOPHICAL TRANSACTIONS. SERIES A, MATHEMATICAL, PHYSICAL, AND ENGINEERING SCIENCES 2021; 379:20200267. [PMID: 33840211 DOI: 10.1098/rsta.2020.0267] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 10/28/2020] [Indexed: 05/22/2023]
Abstract
Recent findings have revealed that not only neurons but also astrocytes, a special type of glial cells, are major players of neuronal information processing. It is now widely accepted that they contribute to the regulation of their microenvironment by cross-talking with neurons via gliotransmitters. In this context, we here study the phenomenon of vibrational resonance in neurons by considering their interaction with astrocytes. Our analysis of a neuron-astrocyte pair reveals that intracellular dynamics of astrocytes can induce a double vibrational resonance effect in the weak signal detection performance of a neuron, exhibiting two distinct wells centred at different high-frequency driving amplitudes. We also identify the underlying mechanism of this behaviour, showing that the interaction of widely separated time scales of neurons, astrocytes and driving signals is the key factor for the emergence and control of double vibrational resonance. This article is part of the theme issue 'Vibrational and stochastic resonance in driven nonlinear systems (part 2)'.
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Affiliation(s)
- Ali Calim
- Department of Biomedical Engineering, Zonguldak Bulent Ecevit University, Zonguldak, Turkey
| | - Andre Longtin
- Department of Physics, University of Ottawa, Ottawa, Ontario, Canada
| | - Muhammet Uzuntarla
- Department of Biomedical Engineering, Zonguldak Bulent Ecevit University, Zonguldak, Turkey
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Broadhead MJ, Miles GB. A common role for astrocytes in rhythmic behaviours? Prog Neurobiol 2021; 202:102052. [PMID: 33894330 DOI: 10.1016/j.pneurobio.2021.102052] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2020] [Revised: 03/03/2021] [Accepted: 04/13/2021] [Indexed: 01/16/2023]
Abstract
Astrocytes are a functionally diverse form of glial cell involved in various aspects of nervous system infrastructure, from the metabolic and structural support of neurons to direct neuromodulation of synaptic activity. Investigating how astrocytes behave in functionally related circuits may help us understand whether there is any conserved logic to the role of astrocytes within neuronal networks. Astrocytes are implicated as key neuromodulatory cells within neural circuits that control a number of rhythmic behaviours such as breathing, locomotion and circadian sleep-wake cycles. In this review, we examine the evidence that astrocytes are directly involved in the regulation of the neural circuits underlying six different rhythmic behaviours: locomotion, breathing, chewing, gastrointestinal motility, circadian sleep-wake cycles and oscillatory feeding behaviour. We discuss how astrocytes are integrated into the neuronal networks that regulate these behaviours, and identify the potential gliotransmission signalling mechanisms involved. From reviewing the evidence of astrocytic involvement in a range of rhythmic behaviours, we reveal a heterogenous array of gliotransmission mechanisms, which help to regulate neuronal networks. However, we also observe an intriguing thread of commonality, in the form of purinergic gliotransmission, which is frequently utilised to facilitate feedback inhibition within rhythmic networks to constrain a given behaviour within its operational range.
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Affiliation(s)
- Matthew J Broadhead
- School of Psychology and Neuroscience, University of St Andrews, St Andrews, UK.
| | - Gareth B Miles
- School of Psychology and Neuroscience, University of St Andrews, St Andrews, UK
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Ryczko D, Hanini‐Daoud M, Condamine S, Bréant BJB, Fougère M, Araya R, Kolta A. S100β‐mediated astroglial control of firing and input processing in layer 5 pyramidal neurons of the mouse visual cortex. J Physiol 2020; 599:677-707. [DOI: 10.1113/jp280501] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2020] [Accepted: 11/23/2020] [Indexed: 12/18/2022] Open
Affiliation(s)
- Dimitri Ryczko
- Département de Neurosciences Université de Montréal Montréal QC Canada
- Département de Pharmacologie‐Physiologie Université de Sherbrooke Sherbrooke QC Canada
- Centre de recherche du CHUS Sherbrooke QC Canada
- Institut de Pharmacologie de Sherbrooke Sherbrooke QC Canada
- Centre d'excellence en neurosciences de l'Université de Sherbrooke Sherbrooke QC Canada
| | | | - Steven Condamine
- Département de Neurosciences Université de Montréal Montréal QC Canada
| | | | - Maxime Fougère
- Département de Pharmacologie‐Physiologie Université de Sherbrooke Sherbrooke QC Canada
| | - Roberto Araya
- Département de Neurosciences Université de Montréal Montréal QC Canada
| | - Arlette Kolta
- Département de Neurosciences Université de Montréal Montréal QC Canada
- Faculté de Médecine Dentaire Université de Montréal Montréal QC Canada
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Rasmussen R, O'Donnell J, Ding F, Nedergaard M. Interstitial ions: A key regulator of state-dependent neural activity? Prog Neurobiol 2020; 193:101802. [PMID: 32413398 PMCID: PMC7331944 DOI: 10.1016/j.pneurobio.2020.101802] [Citation(s) in RCA: 45] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2019] [Revised: 03/24/2020] [Accepted: 03/26/2020] [Indexed: 02/08/2023]
Abstract
Throughout the nervous system, ion gradients drive fundamental processes. Yet, the roles of interstitial ions in brain functioning is largely forgotten. Emerging literature is now revitalizing this area of neuroscience by showing that interstitial cations (K+, Ca2+ and Mg2+) are not static quantities but change dynamically across states such as sleep and locomotion. In turn, these state-dependent changes are capable of sculpting neuronal activity; for example, changing the local interstitial ion composition in the cortex is sufficient for modulating the prevalence of slow-frequency neuronal oscillations, or potentiating the gain of visually evoked responses. Disturbances in interstitial ionic homeostasis may also play a central role in the pathogenesis of central nervous system diseases. For example, impairments in K+ buffering occur in a number of neurodegenerative diseases, and abnormalities in neuronal activity in disease models disappear when interstitial K+ is normalized. Here we provide an overview of the roles of interstitial ions in physiology and pathology. We propose the brain uses interstitial ion signaling as a global mechanism to coordinate its complex activity patterns, and ion homeostasis failure contributes to central nervous system diseases affecting cognitive functions and behavior.
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Affiliation(s)
- Rune Rasmussen
- Center for Translational Neuromedicine, Faculty of Health and Medical Sciences, University of Copenhagen, 2200, Copenhagen, Denmark.
| | - John O'Donnell
- Center for Translational Neuromedicine, University of Rochester Medical Center, Rochester, NY, 14642, United States
| | - Fengfei Ding
- Center for Translational Neuromedicine, University of Rochester Medical Center, Rochester, NY, 14642, United States
| | - Maiken Nedergaard
- Center for Translational Neuromedicine, Faculty of Health and Medical Sciences, University of Copenhagen, 2200, Copenhagen, Denmark; Center for Translational Neuromedicine, University of Rochester Medical Center, Rochester, NY, 14642, United States.
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10
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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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11
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Hu XT. A Novel Concept is Needed for Combating Alzheimer's Disease and NeuroHIV. ACTA ACUST UNITED AC 2020; 4:85-91. [PMID: 32968718 PMCID: PMC7508468 DOI: 10.36959/734/377] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Both Alzheimer’s disease (AD) and HIV-associated neurocognitive disorders (HAND) could progress to dementia, a severe consequence of neurodegenerative diseases. Cumulating evidence suggests that the β-amyloid (Aβ) theory, currently thought to be the predominant mechanism underlying AD and AD-related dementia (ADRD), needs re-evaluation, considering all treatments and new drug trials based upon this theory have been unsuccessful. Similar intention for treating HAND, including HIV-associated dementia (HAD), has also failed. Thus, novel theory, hypothesis, and therapeutic strategies are desperately needed for future study and effective treatments of AD/ADRD and HAND. There are numerous potential upstream mechanisms that may cause AD and/or HAND; but it is unrealistic to identify all of them. However, it is realistic and feasible to intervene the downstream mechanism of these two devastating neurodegenerative diseases by blocking the final common path to neurotoxicity mediated by overactivation of NMDA receptors (NMDARs) and voltage-gated calcium channels (VGCCs). Such a combined pharmacological intervention will likely ameliorate neuronal Ca2+ homeostasis by diminishing overactivated NMDAR and VGCC-mediated Ca2+ dysregulation (i.e., by reducing excessive Ca2+ influx and intracellular levels, [Ca2+]in)-induced hyperactivity, injury, and death of neurons in the critical brain regions that regulate neurocognition in the context of AD/ADRD or HAND, especially during aging. Here we present a novel theoretical concept, hypothesis, and working model for switching the battlefield from searching-and-fighting the original mechanism that may cause AD or HAND, to abolishing AD- and neuroHIV-induced neurotoxicity mediated by NMDAR and VGCC over activation, which may ultimately improve the therapeutic strategies for treating AD and HAND.
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Affiliation(s)
- Xiu-Ti Hu
- Department of Microbial Pathogens and Immunity, Rush University Medical Center, USA
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12
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Slaoui Hasnaoui M, Arsenault I, Verdier D, Obeid S, Kolta A. Functional Connectivity Between the Trigeminal Main Sensory Nucleus and the Trigeminal Motor Nucleus. Front Cell Neurosci 2020; 14:167. [PMID: 32655373 PMCID: PMC7324845 DOI: 10.3389/fncel.2020.00167] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2020] [Accepted: 05/19/2020] [Indexed: 11/24/2022] Open
Abstract
The present study shows new evidence of functional connectivity between the trigeminal main sensory (NVsnpr) and motor (NVmt) nuclei in rats and mice. NVsnpr neurons projecting to NVmt are most highly concentrated in its dorsal half. Their electrical stimulation induced multiphasic excitatory synaptic responses in trigeminal MNs and evoked calcium responses mainly in the jaw-closing region of NVmt. Induction of rhythmic bursting in NVsnpr neurons by local applications of BAPTA also elicited rhythmic firing or clustering of postsynaptic potentials in trigeminal motoneurons, further emphasizing the functional relationship between these two nuclei in terms of rhythm transmission. Biocytin injections in both nuclei and calcium-imaging in one of the two nuclei during electrical stimulation of the other revealed a specific pattern of connectivity between the two nuclei, which organization seemed to critically depend on the dorsoventral location of the stimulation site within NVsnpr with the most dorsal areas of NVsnpr projecting to the dorsolateral region of NVmt and intermediate areas projecting to ventromedial NVmt. This study confirms and develops earlier experiments by exploring the physiological nature and functional topography of the connectivity between NVsnpr and NVmt that was demonstrated in the past with neuroanatomical techniques.
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Affiliation(s)
- Mohammed Slaoui Hasnaoui
- Groupe de Recherche sur le Systéme Nerveux Central, Département de Neurosciences, Faculté de Médecine, Université de Montréal, Montréeal, QC, Canada
| | - Isabel Arsenault
- Groupe de Recherche sur le Systéme Nerveux Central, Département de Neurosciences, Faculté de Médecine, Université de Montréal, Montréeal, QC, Canada
| | - Dorly Verdier
- Groupe de Recherche sur le Systéme Nerveux Central, Département de Neurosciences, Faculté de Médecine, Université de Montréal, Montréeal, QC, Canada
| | - Sami Obeid
- Groupe de Recherche sur le Systéme Nerveux Central, Département de Neurosciences, Faculté de Médecine, Université de Montréal, Montréeal, QC, Canada
| | - Arlette Kolta
- Groupe de Recherche sur le Systéme Nerveux Central, Département de Neurosciences, Faculté de Médecine, Université de Montréal, Montréeal, QC, Canada.,Département de Stomatologie, Faculté de Médecine Dentaire, Université de Montreal, Montreal, QC, Canada
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13
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Abstract
The contribution of an impaired astrocytic K+ regulation system to epileptic neuronal hyperexcitability has been increasingly recognized in the last decade. A defective K+ regulation leads to an elevated extracellular K+ concentration ([K+]o). When [K+]o reaches peaks of 10-12 mM, it is strongly associated with seizure initiation during hypersynchronous neuronal activities. On the other hand, reactive astrocytes during a seizure attack restrict influx of K+ across the membrane both passively and actively. In addition to decreased K+ buffering, aberrant Ca2+ signaling and declined glutamate transport have also been observed in astrogliosis in epileptic specimens, precipitating an increased neuronal discharge and induction of seizures. This review aims to provide an overview of experimental findings that implicated astrocytic modulation of extracellular K+ in the mechanism of epileptogenesis.
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Affiliation(s)
- Fushun Wang
- Department of Neurosurgery, Baylor Scott & White Health, Temple, TX, USA; Institute of Brain and Psychological Science, Sichuan Normal University, Chengdu, Sichuan Province, China
| | - Xiaoming Qi
- Department of Neurosurgery, Baylor Scott & White Health, Temple, TX, USA
| | - Jun Zhang
- Department of Neurosurgery, PLA General Hospital, Beijing, China
| | - Jason H Huang
- Department of Neurosurgery, Baylor Scott & White Health; Department of Surgery, Texas A&M University College of Medicine, Temple, TX, USA
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Circuit-Specific Early Impairment of Proprioceptive Sensory Neurons in the SOD1 G93A Mouse Model for ALS. J Neurosci 2019; 39:8798-8815. [PMID: 31530644 DOI: 10.1523/jneurosci.1214-19.2019] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2019] [Revised: 07/24/2019] [Accepted: 09/02/2019] [Indexed: 12/12/2022] Open
Abstract
Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease in which motor neurons degenerate, resulting in muscle atrophy, paralysis, and fatality. Studies using mouse models of ALS indicate a protracted period of disease development with progressive motor neuron pathology, evident as early as embryonic and postnatal stages. Key missing information includes concomitant alterations in the sensorimotor circuit essential for normal development and function of the neuromuscular system. Leveraging unique brainstem circuitry, we show in vitro evidence for reflex circuit-specific postnatal abnormalities in the jaw proprioceptive sensory neurons in the well-studied SOD1G93A mouse. These include impaired and arrhythmic action potential burst discharge associated with a deficit in Nav1.6 Na+ channels. However, the mechanoreceptive and nociceptive trigeminal ganglion neurons and the visual sensory retinal ganglion neurons were resistant to excitability changes in age-matched SOD1G93A mice. Computational modeling of the observed disruption in sensory patterns predicted asynchronous self-sustained motor neuron discharge suggestive of imminent reflexive defects, such as muscle fasciculations in ALS. These results demonstrate a novel reflex circuit-specific proprioceptive sensory abnormality in ALS.SIGNIFICANCE STATEMENT Neurodegenerative diseases have prolonged periods of disease development and progression. Identifying early markers of vulnerability can therefore help devise better diagnostic and treatment strategies. In this study, we examined postnatal abnormalities in the electrical excitability of muscle spindle afferent proprioceptive neurons in the well-studied SOD1G93A mouse model for neurodegenerative motor neuron disease, amyotrophic lateral sclerosis. Our findings suggest that these proprioceptive sensory neurons are exclusively afflicted early in the disease process relative to sensory neurons of other modalities. Moreover, they presented Nav1.6 Na+ channel deficiency, which contributed to arrhythmic burst discharge. Such sensory arrhythmia could initiate reflexive defects, such as muscle fasciculations in amyotrophic lateral sclerosis, as suggested by our computational model.
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15
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Steuer I, Guertin PA. Central pattern generators in the brainstem and spinal cord: an overview of basic principles, similarities and differences. Rev Neurosci 2019; 30:107-164. [PMID: 30543520 DOI: 10.1515/revneuro-2017-0102] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2017] [Accepted: 03/30/2018] [Indexed: 12/11/2022]
Abstract
Central pattern generators (CPGs) are generally defined as networks of neurons capable of enabling the production of central commands, specifically controlling stereotyped, rhythmic motor behaviors. Several CPGs localized in brainstem and spinal cord areas have been shown to underlie the expression of complex behaviors such as deglutition, mastication, respiration, defecation, micturition, ejaculation, and locomotion. Their pivotal roles have clearly been demonstrated although their organization and cellular properties remain incompletely characterized. In recent years, insightful findings about CPGs have been made mainly because (1) several complementary animal models were developed; (2) these models enabled a wide variety of techniques to be used and, hence, a plethora of characteristics to be discovered; and (3) organizations, functions, and cell properties across all models and species studied thus far were generally found to be well-preserved phylogenetically. This article aims at providing an overview for non-experts of the most important findings made on CPGs in in vivo animal models, in vitro preparations from invertebrate and vertebrate species as well as in primates. Data about CPG functions, adaptation, organization, and cellular properties will be summarized with a special attention paid to the network for locomotion given its advanced level of characterization compared with some of the other CPGs. Similarities and differences between these networks will also be highlighted.
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Affiliation(s)
- Inge Steuer
- Neuroscience Unit, Laval University Medical Center (CHUL - CHU de Québec), 2705 Laurier Blvd, Quebec City, Quebec G1V 4G2, Canada
| | - Pierre A Guertin
- Neuroscience Unit, Laval University Medical Center (CHUL - CHU de Québec), 2705 Laurier Blvd, Quebec City, Quebec G1V 4G2, Canada
- Faculty of Medicine, Department of Psychiatry and Neurosciences, Laval University, Quebec City, Quebec G1V 0A6, Canada
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Ashhad S, Narayanan R. Stores, Channels, Glue, and Trees: Active Glial and Active Dendritic Physiology. Mol Neurobiol 2019; 56:2278-2299. [PMID: 30014322 PMCID: PMC6394607 DOI: 10.1007/s12035-018-1223-5] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2017] [Accepted: 07/03/2018] [Indexed: 02/07/2023]
Abstract
Glial cells and neuronal dendrites were historically assumed to be passive structures that play only supportive physiological roles, with no active contribution to information processing in the central nervous system. Research spanning the past few decades has clearly established this assumption to be far from physiological realities. Whereas the discovery of active channel conductances and their localized plasticity was the turning point for dendritic structures, the demonstration that glial cells release transmitter molecules and communicate across the neuroglia syncytium through calcium wave propagation constituted path-breaking discoveries for glial cell physiology. An additional commonality between these two structures is the ability of calcium stores within their endoplasmic reticulum (ER) to support active propagation of calcium waves, which play crucial roles in the spatiotemporal integration of information within and across cells. Although there have been several demonstrations of regulatory roles of glial cells and dendritic structures in achieving common physiological goals such as information propagation and adaptability through plasticity, studies assessing physiological interactions between these two active structures have been few and far. This lacuna is especially striking given the strong connectivity that is known to exist between these two structures through several complex and tightly intercoupled mechanisms that also recruit their respective ER structures. In this review, we present brief overviews of the parallel literatures on active dendrites and active glial physiology and make a strong case for future studies to directly assess the strong interactions between these two structures in regulating physiology and pathophysiology of the brain.
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Affiliation(s)
- Sufyan Ashhad
- Department of Neurobiology, University of California at Los Angeles, Los Angeles, CA, 90095, USA
| | - Rishikesh Narayanan
- Cellular Neurophysiology Laboratory, Molecular Biophysics Unit, Indian Institute of Science, Bangalore, 560012, India.
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Dave S, Chen L, Yu C, Seaton M, Khodr CE, Al-Harthi L, Hu XT. Methamphetamine decreases K + channel function in human fetal astrocytes by activating the trace amine-associated receptor type-1. J Neurochem 2018; 148:29-45. [PMID: 30295919 DOI: 10.1111/jnc.14606] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2017] [Revised: 09/28/2018] [Accepted: 10/03/2018] [Indexed: 12/22/2022]
Abstract
Methamphetamine (Meth) is a potent and commonly abused psychostimulant. Meth alters neuron and astrocyte activity; yet the underlying mechanism(s) is not fully understood. Here we assessed the impact of acute Meth on human fetal astrocytes (HFAs) using whole-cell patch-clamping. We found that HFAs displayed a large voltage-gated K+ efflux (IKv ) through Kv /Kv -like channels during membrane depolarization, and a smaller K+ influx (Ikir ) via inward-rectifying Kir /Kir -like channels during membrane hyperpolarization. Meth at a 'recreational' (20 μM) or toxic/fatal (100 μM) concentration depolarized resting membrane potential (RMP) and suppressed IKv/Kv-like . These changes were associated with a decreased time constant (Ƭ), and mimicked by blocking the two-pore domain K+ (K2P )/K2P -like and Kv /Kv -like channels, respectively. Meth also diminished IKir/Kir-like , but only at toxic/fatal levels. Given that Meth is a potent agonist for the trace amine-associated receptor type-1 (TAAR1), and TAAR1-coupled cAMP/cAMP-activated protein kinase (PKA) cascade, we further evaluated whether the Meth impact on K+ efflux was mediated by this pathway. We found that antagonizing TAAR1 with N-(3-Ethoxyphenyl)-4-(1-pyrrolidinyl)-3-(trifluoromethyl)benzamide (EPPTB) reversed Meth-induced suppression of IKv/Kv-like ; and inhibiting PKA activity by H89 abolished Meth effects on suppressing IKv/Kv-like . Antagonizing TAAR1 might also attenuate Meth-induced RMP depolarization. Voltage-gated Ca2+ currents were not detected in HFAs. These novel findings demonstrate that Meth suppresses IKv/Kv-like by facilitating the TAAR1/Gs /cAMP/PKA cascade and altering the kinetics of Kv /Kv -like channel gating, but reduces K2P /K2P -like channel activity through other pathway(s), in HFAs. Given that Meth-induced decrease in astrocytic K+ efflux through K2P /K2P -like and Kv /Kv -like channels reduces extracellular K+ levels, such reduction could consequently contribute to a decreased excitability of surrounding neurons. OPEN SCIENCE BADGES: This article has received a badge for *Open Materials* because it provided all relevant information to reproduce the study in the manuscript. The complete Open Science Disclosure form for this article can be found at the end of the article. More information about the Open Practices badges can be found at https://cos.io/our-services/open-science-badges/.
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Affiliation(s)
- Sonya Dave
- Department of Microbial Pathogens and Immunity, Rush University Medical Center, Chicago, Illinois, USA
| | - Lihua Chen
- Department of Microbial Pathogens and Immunity, Rush University Medical Center, Chicago, Illinois, USA
| | - Chunjiang Yu
- Department of Microbial Pathogens and Immunity, Rush University Medical Center, Chicago, Illinois, USA
| | - Melanie Seaton
- Department of Microbial Pathogens and Immunity, Rush University Medical Center, Chicago, Illinois, USA
| | - Christina E Khodr
- Department of Microbial Pathogens and Immunity, Rush University Medical Center, Chicago, Illinois, USA
| | - Lena Al-Harthi
- Department of Microbial Pathogens and Immunity, Rush University Medical Center, Chicago, Illinois, USA
| | - Xiu-Ti Hu
- Department of Microbial Pathogens and Immunity, Rush University Medical Center, Chicago, Illinois, USA
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Lucas-Romero J, Rivera-Arconada I, Roza C, Lopez-Garcia JA. Origin and classification of spontaneous discharges in mouse superficial dorsal horn neurons. Sci Rep 2018; 8:9735. [PMID: 29950700 PMCID: PMC6021406 DOI: 10.1038/s41598-018-27993-y] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2018] [Accepted: 06/13/2018] [Indexed: 12/24/2022] Open
Abstract
Superficial laminae of the spinal cord possess a considerable number of neurons with spontaneous activity as reported in vivo and in vitro preparations of several species. Such neurons may play a role in the development of the nociceptive system and/or in the spinal coding of somatosensory signals. We have used electrophysiological techniques in a horizontal spinal cord slice preparation from adult mice to investigate how this activity is generated and what are the main patterns of activity that can be found. The results show the existence of neurons that fire regularly and irregularly. Within each of these main types, it was possible to distinguish patterns of spontaneous activity formed by single action potentials and different types of bursts according to intra-burst firing frequency. Activity in neurons with irregular patterns was blocked by a mixture of antagonists of the main neurotransmitter receptors present in the cord. Approximately 82% of neurons with a regular firing pattern were insensitive to synaptic antagonists but their activity was inhibited by specific ion channel blockers. It is suggested that these neurons generate endogenous activity due to the functional expression of hyperpolarisation-activated and persistent sodium currents driving the activity of irregular neurons.
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Affiliation(s)
- Javier Lucas-Romero
- Department of Systems Biology, Universidad de Alcala, Alcala de Henares, 28871, Madrid, Spain
| | - Ivan Rivera-Arconada
- Department of Systems Biology, Universidad de Alcala, Alcala de Henares, 28871, Madrid, Spain
| | - Carolina Roza
- Department of Systems Biology, Universidad de Alcala, Alcala de Henares, 28871, Madrid, Spain
| | - Jose A Lopez-Garcia
- Department of Systems Biology, Universidad de Alcala, Alcala de Henares, 28871, Madrid, Spain.
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Choi M, Ahn S, Yang EJ, Kim H, Chong YH, Kim HS. Hippocampus-based contextual memory alters the morphological characteristics of astrocytes in the dentate gyrus. Mol Brain 2016; 9:72. [PMID: 27460927 PMCID: PMC4962445 DOI: 10.1186/s13041-016-0253-z] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2016] [Accepted: 07/22/2016] [Indexed: 12/31/2022] Open
Abstract
Astrocytes have been reported to exist in two states, the resting and the reactive states. Morphological changes in the reactive state of astrocytes include an increase in thickness and number of processes, and an increase in the size of the cell body. Molecular changes also occur, such as an increase in the expression of glial fibrillary acidic protein (GFAP). However, the morphological and molecular changes during the process of learning and memory have not been elucidated. In the current study, we subjected Fvb/n mice to contextual fear conditioning, and checked for morphological and molecular changes in astrocytes. 1 h after fear conditioning, type II and type III astrocytes exhibited a unique status with an increased number of processes and decreased GFAP expression which differed from the typical resting or reactive state. In addition, the protein level of excitatory excitatory amino acid transporter 2 (EAAT2) was increased 1 h to 24 h after contextual fear conditioning while EAAT1 did not show any alterations. Connexin 43 (Cx43) protein was found to be increased at 24 h after fear conditioning. These data suggest that hippocampus-based contextual memory process induces changes in the status of astrocytes towards a novel status different from typical resting or reactive states. These morphological and molecular changes may be in line with functional changes.
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Affiliation(s)
- Moonseok Choi
- Department of Pharmacology and Biomedical Sciences, College of Medicine, Seoul National University, 103 Daehakro, Jongro-gu, 110-799, Seoul, Republic of Korea
| | - Sangzin Ahn
- Department of Pharmacology and Biomedical Sciences, College of Medicine, Seoul National University, 103 Daehakro, Jongro-gu, 110-799, Seoul, Republic of Korea
| | - Eun-Jeong Yang
- Department of Pharmacology and Biomedical Sciences, College of Medicine, Seoul National University, 103 Daehakro, Jongro-gu, 110-799, Seoul, Republic of Korea
| | - Hyunju Kim
- Department of Pharmacology and Biomedical Sciences, College of Medicine, Seoul National University, 103 Daehakro, Jongro-gu, 110-799, Seoul, Republic of Korea
| | - Young Hae Chong
- Department of Microbiology, School of Medicine, Ewha Womans University, 911-1, Mok-6-dong, Yangcheonku, Seoul, 158-710, Republic of Korea
| | - Hye-Sun Kim
- Department of Pharmacology and Biomedical Sciences, College of Medicine, Seoul National University, 103 Daehakro, Jongro-gu, 110-799, Seoul, Republic of Korea. .,Seoul National University College of Medicine, Seoul National University Bundang Hospital, Sungnam, 463-707, Republic of Korea. .,Seoul National University College of Medicine, Bundang Hospital, Sungnam, Bundang-Gu, Republic of Korea. .,Neuroscience Research Institute, College of Medicine, Seoul National University, 103 Daehakro, Jongro-gu, Seoul, Republic of Korea.
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Sieck GC. Physiology in Perspective: The Air We Breathe: Providing O2 for Survival. Physiology (Bethesda) 2015; 30:338-9. [PMID: 26328878 DOI: 10.1152/physiol.00032.2015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
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