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Müller P, Draguhn A, Egorov AV. Persistent sodium currents in neurons: potential mechanisms and pharmacological blockers. Pflugers Arch 2024; 476:1445-1473. [PMID: 38967655 PMCID: PMC11381486 DOI: 10.1007/s00424-024-02980-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2024] [Revised: 06/07/2024] [Accepted: 06/11/2024] [Indexed: 07/06/2024]
Abstract
Persistent sodium current (INaP) is an important activity-dependent regulator of neuronal excitability. It is involved in a variety of physiological and pathological processes, including pacemaking, prolongation of sensory potentials, neuronal injury, chronic pain and diseases such as epilepsy and amyotrophic lateral sclerosis. Despite its importance, neither the molecular basis nor the regulation of INaP are sufficiently understood. Of particular significance is a solid knowledge and widely accepted consensus about pharmacological tools for analysing the function of INaP and for developing new therapeutic strategies. However, the literature on INaP is heterogeneous, with varying definitions and methodologies used across studies. To address these issues, we provide a systematic review of the current state of knowledge on INaP, with focus on mechanisms and effects of this current in the central nervous system. We provide an overview of the specificity and efficacy of the most widely used INaP blockers: amiodarone, cannabidiol, carbamazepine, cenobamate, eslicarbazepine, ethosuximide, gabapentin, GS967, lacosamide, lamotrigine, lidocaine, NBI-921352, oxcarbazepine, phenytoine, PRAX-562, propofol, ranolazine, riluzole, rufinamide, topiramate, valproaic acid and zonisamide. We conclude that there is strong variance in the pharmacological effects of these drugs, and in the available information. At present, GS967 and riluzole can be regarded bona fide INaP blockers, while phenytoin and lacosamide are blockers that only act on the slowly inactivating component of sodium currents.
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Affiliation(s)
- Peter Müller
- Department Neurology and Epileptology, Hertie Institute for Clinical Brain Research, University of Tuebingen , Hoppe-Seyler-Straße 3, 72076, Tübingen, Germany.
| | - Andreas Draguhn
- Institute for Physiology and Pathophysiology, Medical Faculty, Heidelberg University, Im Neuenheimer Feld 326, 69120, Heidelberg, Germany
| | - Alexei V Egorov
- Institute for Physiology and Pathophysiology, Medical Faculty, Heidelberg University, Im Neuenheimer Feld 326, 69120, Heidelberg, Germany
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2
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Chiu WH, Wattad N, Goldberg JA. Ion channel dysregulation and cellular adaptations to alpha-synuclein in stressful pacemakers of the parkinsonian brainstem. Pharmacol Ther 2024; 260:108683. [PMID: 38950869 DOI: 10.1016/j.pharmthera.2024.108683] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2024] [Revised: 06/21/2024] [Accepted: 06/28/2024] [Indexed: 07/03/2024]
Abstract
Parkinson's disease (PD) is diagnosed by its cardinal motor symptoms that are associated with the loss of dopamine neurons in the substantia nigra pars compacta (SNc). However, PD patients suffer from various non-motor symptoms years before diagnosis. These prodromal symptoms are thought to be associated with the appearance of Lewy body pathologies (LBP) in brainstem regions such as the dorsal motor nucleus of the vagus (DMV), the locus coeruleus (LC) and others. The neurons in these regions that are vulnerable to LBP are all slow autonomous pacemaker neurons that exhibit elevated oxidative stress due to their perpetual influx of Ca2+ ions. Aggregation of toxic α-Synuclein (aSyn) - the main constituent of LBP - during the long prodromal period challenges these vulnerable neurons, presumably altering their biophysics and physiology. In contrast to pathophysiology of late stage parkinsonism which is well-documented, little is known about the pathophysiology of the brainstem during prodromal PD. In this review, we discuss ion channel dysregulation associated with aSyn aggregation in brainstem pacemaker neurons and their cellular responses to them. While toxic aSyn elevates oxidative stress in SNc and LC pacemaker neurons and exacerbates their phenotype, DMV neurons mount an adaptive response that mitigates the oxidative stress. Ion channel dysregulation and cellular adaptations may be the drivers of the prodromal symptoms of PD. For example, selective targeting of toxic aSyn to DMV pacemakers, elevates the surface density of K+ channels, which slows their firing rate, resulting in reduced parasympathetic tone to the gastrointestinal tract, which resembles the prodromal PD symptoms of dysphagia and constipation. The divergent responses of SNc & LC vs. DMV pacemaker neurons may explain why the latter outlive the former despite presenting LBPs earlier. Elucidation the brainstem pathophysiology of prodromal PD could pave the way for physiological biomarkers, earlier diagnosis and novel neuroprotective therapies for PD.
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Affiliation(s)
- Wei-Hua Chiu
- Department of Neurology, New York University Grossman School of Medicine, New York, NY 10016, USA
| | - Nadine Wattad
- Department of Medical Neurobiology, Institute of Medical Research Israel - Canada, The Faculty of Medicine, The Hebrew University of Jerusalem, 9112102 Jerusalem, Israel
| | - Joshua A Goldberg
- Department of Medical Neurobiology, Institute of Medical Research Israel - Canada, The Faculty of Medicine, The Hebrew University of Jerusalem, 9112102 Jerusalem, Israel; Department of Neuroscience, Feinberg School of Medicine, Northwestern University, Chicago, IL, 60611, USA.
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3
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Higgs MH, Beckstead MJ. Impact of Unitary Synaptic Inhibition on Spike Timing in Ventral Tegmental Area Dopamine Neurons. eNeuro 2024; 11:ENEURO.0203-24.2024. [PMID: 38969500 PMCID: PMC11287791 DOI: 10.1523/eneuro.0203-24.2024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2024] [Revised: 06/25/2024] [Accepted: 06/28/2024] [Indexed: 07/07/2024] Open
Abstract
Midbrain dopamine neurons receive convergent synaptic input from multiple brain areas, which perturbs rhythmic pacemaking to produce the complex firing patterns observed in vivo. This study investigated the impact of single and multiple inhibitory inputs on ventral tegmental area (VTA) dopamine neuron firing in mice of both sexes using novel experimental measurements and modeling. We first measured unitary inhibitory postsynaptic currents produced by single axons using both minimal electrical stimulation and minimal optical stimulation of rostromedial tegmental nucleus and ventral pallidum afferents. We next determined the phase resetting curve, the reversal potential for GABAA receptor-mediated inhibitory postsynaptic currents (IPSCs), and the average interspike membrane potential trajectory during pacemaking. We combined these data in a phase oscillator model of a VTA dopamine neuron, simulating the effects of unitary inhibitory postsynaptic conductances (uIPSGs) on spike timing and rate. The effect of a uIPSG on spike timing was predicted to vary according to its timing within the interspike interval or phase. Simulations were performed to predict the pause duration resulting from the synchronous arrival of multiple uIPSGs and the changes in firing rate and regularity produced by asynchronous uIPSGs. The model data suggest that asynchronous inhibition is more effective than synchronous inhibition, because it tends to hold the neuron at membrane potentials well positive to the IPSC reversal potential. Our results indicate that small fluctuations in the inhibitory synaptic input arriving from the many afferents to each dopamine neuron are sufficient to produce highly variable firing patterns, including pauses that have been implicated in reinforcement.
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Affiliation(s)
- Matthew H Higgs
- Aging & Metabolism Research Program, Oklahoma Medical Research Foundation, Oklahoma City, OK 73104
| | - Michael J Beckstead
- Aging & Metabolism Research Program, Oklahoma Medical Research Foundation, Oklahoma City, OK 73104
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4
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Kelly AR, Glover DJ. Information Transmission through Biotic-Abiotic Interfaces to Restore or Enhance Human Function. ACS APPLIED BIO MATERIALS 2024; 7:3605-3628. [PMID: 38729914 DOI: 10.1021/acsabm.4c00435] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/12/2024]
Abstract
Advancements in reliable information transfer across biotic-abiotic interfaces have enabled the restoration of lost human function. For example, communication between neuronal cells and electrical devices restores the ability to walk to a tetraplegic patient and vision to patients blinded by retinal disease. These impactful medical achievements are aided by tailored biotic-abiotic interfaces that maximize information transfer fidelity by considering the physical properties of the underlying biological and synthetic components. This Review develops a modular framework to define and describe the engineering of biotic and abiotic components as well as the design of interfaces to facilitate biotic-abiotic information transfer using light or electricity. Delineating the properties of the biotic, interface, and abiotic components that enable communication can serve as a guide for future research in this highly interdisciplinary field. Application of synthetic biology to engineer light-sensitive proteins has facilitated the control of neural signaling and the restoration of rudimentary vision after retinal blindness. Electrophysiological methodologies that use brain-computer interfaces and stimulating implants to bypass spinal column injuries have led to the rehabilitation of limb movement and walking ability. Cellular interfacing methodologies and on-chip learning capability have been made possible by organic transistors that mimic the information processing capacity of neurons. The collaboration of molecular biologists, material scientists, and electrical engineers in the emerging field of biotic-abiotic interfacing will lead to the development of prosthetics capable of responding to thought and experiencing touch sensation via direct integration into the human nervous system. Further interdisciplinary research will improve electrical and optical interfacing technologies for the restoration of vision, offering greater visual acuity and potentially color vision in the near future.
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Affiliation(s)
- Alexander R Kelly
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, NSW 2052, Australia
| | - Dominic J Glover
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, NSW 2052, Australia
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Lau MYH, Gadiwalla S, Jones S, Galliano E. Different electrophysiological profiles of genetically labelled dopaminergic neurons in the mouse midbrain and olfactory bulb. Eur J Neurosci 2024; 59:1480-1499. [PMID: 38169095 DOI: 10.1111/ejn.16239] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2023] [Revised: 12/06/2023] [Accepted: 12/09/2023] [Indexed: 01/05/2024]
Abstract
Dopaminergic (DA) neurons play pivotal roles in diverse brain functions, spanning movement, reward processing and sensory perception. DA neurons are most abundant in the midbrain (Substantia Nigra pars compacta [SNC] and Ventral Tegmental Area [VTA]) and the olfactory bulb (OB) in the forebrain. Interestingly, a subtype of OB DA neurons is capable of regenerating throughout life, while a second class is exclusively born during embryonic development. Compelling evidence in SNC and VTA also indicates substantial heterogeneity in terms of morphology, connectivity and function. To further investigate this heterogeneity and directly compare form and function of midbrain and forebrain bulbar DA neurons, we performed immunohistochemistry and whole-cell patch-clamp recordings in ex vivo brain slices from juvenile DAT-tdTomato mice. After confirming the penetrance and specificity of the dopamine transporter (DAT) Cre line, we compared soma shape, passive membrane properties, voltage sags and action potential (AP) firing across midbrain and forebrain bulbar DA subtypes. We found that each DA subgroup within midbrain and OB was highly heterogeneous, and that DA neurons across the two brain areas are also substantially different. These findings complement previous work in rats as well as gene expression and in vivo datasets, further questioning the existence of a single "dopaminergic" neuronal phenotype.
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Affiliation(s)
- Maggy Yu Hei Lau
- Department of Physiology, Development and Neuroscience, University of Cambridge, UK
| | - Sana Gadiwalla
- Department of Physiology, Development and Neuroscience, University of Cambridge, UK
| | - Susan Jones
- Department of Physiology, Development and Neuroscience, University of Cambridge, UK
| | - Elisa Galliano
- Department of Physiology, Development and Neuroscience, University of Cambridge, UK
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Sang Y, Niu C, Xu J, Zhu T, You S, Wang J, Zhang L, Du X, Zhang H. PI4KIIIβ-Mediated Phosphoinositides Metabolism Regulates Function of the VTA Dopaminergic Neurons and Depression-Like Behavior. J Neurosci 2024; 44:e0555232024. [PMID: 38267258 PMCID: PMC10941068 DOI: 10.1523/jneurosci.0555-23.2024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2023] [Revised: 12/18/2023] [Accepted: 01/11/2024] [Indexed: 01/26/2024] Open
Abstract
Phosphoinositides, including phosphatidylinositol-4,5-bisphosphate (PIP2), play a crucial role in controlling key cellular functions such as membrane and vesicle trafficking, ion channel, and transporter activity. Phosphatidylinositol 4-kinases (PI4K) are essential enzymes in regulating the turnover of phosphoinositides. However, the functional role of PI4Ks and mediated phosphoinositide metabolism in the central nervous system has not been fully revealed. In this study, we demonstrated that PI4KIIIβ, one of the four members of PI4Ks, is an important regulator of VTA dopaminergic neuronal activity and related depression-like behavior of mice by controlling phosphoinositide turnover. Our findings provide new insights into possible mechanisms and potential drug targets for neuropsychiatric diseases, including depression. Both sexes were studied in basic behavior tests, but only male mice could be used in the social defeat depression model.
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Affiliation(s)
- Yuqi Sang
- Department of Pharmacology, Hebei Medical University, Shijiazhuang, Hebei 050011, China
- The Key Laboratory of Neural and Vascular Biology, Ministry of Education, Hebei Medical University, Shijiazhuang, Hebei 050011, China
- The Key Laboratory of New Drug Pharmacology and Toxicology, Hebei Medical University, Shijiazhuang, Hebei 050011, China
- Collaborative Innovation Center of Hebei Province for Mechanism, Diagnosis and Treatment of Neuropsychiatric Diseases, Hebei Medical University, Shijiazhuang, Hebei 050011, China
| | - Chenxu Niu
- Department of Pharmacology, Hebei Medical University, Shijiazhuang, Hebei 050011, China
- The Key Laboratory of Neural and Vascular Biology, Ministry of Education, Hebei Medical University, Shijiazhuang, Hebei 050011, China
- The Key Laboratory of New Drug Pharmacology and Toxicology, Hebei Medical University, Shijiazhuang, Hebei 050011, China
- Collaborative Innovation Center of Hebei Province for Mechanism, Diagnosis and Treatment of Neuropsychiatric Diseases, Hebei Medical University, Shijiazhuang, Hebei 050011, China
| | - Jiaxi Xu
- Department of Pharmacology, Hebei Medical University, Shijiazhuang, Hebei 050011, China
- Department of Physiology and Pathophysiology, Xi'an Jiaotong University Health Science Center, Xi'an, Shanxi 710061, China
| | - Tiantian Zhu
- Department of Pharmacology, Hebei Medical University, Shijiazhuang, Hebei 050011, China
- The Key Laboratory of Neural and Vascular Biology, Ministry of Education, Hebei Medical University, Shijiazhuang, Hebei 050011, China
- The Key Laboratory of New Drug Pharmacology and Toxicology, Hebei Medical University, Shijiazhuang, Hebei 050011, China
- Collaborative Innovation Center of Hebei Province for Mechanism, Diagnosis and Treatment of Neuropsychiatric Diseases, Hebei Medical University, Shijiazhuang, Hebei 050011, China
| | - Shuangzhu You
- Department of Pharmacology, Hebei Medical University, Shijiazhuang, Hebei 050011, China
- The Key Laboratory of Neural and Vascular Biology, Ministry of Education, Hebei Medical University, Shijiazhuang, Hebei 050011, China
- The Key Laboratory of New Drug Pharmacology and Toxicology, Hebei Medical University, Shijiazhuang, Hebei 050011, China
- Collaborative Innovation Center of Hebei Province for Mechanism, Diagnosis and Treatment of Neuropsychiatric Diseases, Hebei Medical University, Shijiazhuang, Hebei 050011, China
| | - Jing Wang
- Department of Pharmacology, Hebei Medical University, Shijiazhuang, Hebei 050011, China
- The Key Laboratory of Neural and Vascular Biology, Ministry of Education, Hebei Medical University, Shijiazhuang, Hebei 050011, China
- The Key Laboratory of New Drug Pharmacology and Toxicology, Hebei Medical University, Shijiazhuang, Hebei 050011, China
- Collaborative Innovation Center of Hebei Province for Mechanism, Diagnosis and Treatment of Neuropsychiatric Diseases, Hebei Medical University, Shijiazhuang, Hebei 050011, China
| | - Ludi Zhang
- Department of Pharmacology, Hebei Medical University, Shijiazhuang, Hebei 050011, China
- The Key Laboratory of Neural and Vascular Biology, Ministry of Education, Hebei Medical University, Shijiazhuang, Hebei 050011, China
- The Key Laboratory of New Drug Pharmacology and Toxicology, Hebei Medical University, Shijiazhuang, Hebei 050011, China
- Collaborative Innovation Center of Hebei Province for Mechanism, Diagnosis and Treatment of Neuropsychiatric Diseases, Hebei Medical University, Shijiazhuang, Hebei 050011, China
| | - Xiaona Du
- Department of Pharmacology, Hebei Medical University, Shijiazhuang, Hebei 050011, China
- The Key Laboratory of Neural and Vascular Biology, Ministry of Education, Hebei Medical University, Shijiazhuang, Hebei 050011, China
- The Key Laboratory of New Drug Pharmacology and Toxicology, Hebei Medical University, Shijiazhuang, Hebei 050011, China
- Collaborative Innovation Center of Hebei Province for Mechanism, Diagnosis and Treatment of Neuropsychiatric Diseases, Hebei Medical University, Shijiazhuang, Hebei 050011, China
| | - Hailin Zhang
- Department of Pharmacology, Hebei Medical University, Shijiazhuang, Hebei 050011, China
- The Key Laboratory of Neural and Vascular Biology, Ministry of Education, Hebei Medical University, Shijiazhuang, Hebei 050011, China
- The Key Laboratory of New Drug Pharmacology and Toxicology, Hebei Medical University, Shijiazhuang, Hebei 050011, China
- Collaborative Innovation Center of Hebei Province for Mechanism, Diagnosis and Treatment of Neuropsychiatric Diseases, Hebei Medical University, Shijiazhuang, Hebei 050011, China
- Department of Psychiatry, The First Hospital of Hebei Medical University, Mental Health Institute of Hebei Medical University, Shijiazhuang, Hebei 050000, China
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Khamis H, Cohen O. Coupled action potential and calcium dynamics underlie robust spontaneous firing in dopaminergic neurons. Phys Biol 2024; 21:026005. [PMID: 38382117 DOI: 10.1088/1478-3975/ad2bd4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2023] [Accepted: 02/21/2024] [Indexed: 02/23/2024]
Abstract
Dopaminergic neurons are specialized cells in the substantia nigra, tasked with dopamine secretion. This secretion relies on intracellular calcium signaling coupled to neuronal electrical activity. These neurons are known to display spontaneous calcium oscillationsin-vitroandin-vivo, even in synaptic isolation, controlling the basal dopamine levels. Here we outline a kinetic model for the ion exchange across the neuronal plasma membrane. Crucially, we relax the assumption of constant, cytoplasmic sodium and potassium concentration. We show that sodium-potassium dynamics are strongly coupled to calcium dynamics and are essential for the robustness of spontaneous firing frequency. The model predicts several regimes of electrical activity, including tonic and 'burst' oscillations, and predicts the switch between those in response to perturbations. 'Bursting' correlates with increased calcium amplitudes, while maintaining constant average, allowing for a vast change in the calcium signal responsible for dopamine secretion. All the above traits provide the flexibility to create rich action potential dynamics that are crucial for cellular function.
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Affiliation(s)
- Hadeel Khamis
- Gateway Institute for Brain Research, Fort Lauderdale, FL 33314, United States of America
| | - Ohad Cohen
- Gateway Institute for Brain Research, Fort Lauderdale, FL 33314, United States of America
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8
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Thompson AC, Aizenman CD. Characterization of Na + currents regulating intrinsic excitability of optic tectal neurons. Life Sci Alliance 2024; 7:e202302232. [PMID: 37918964 PMCID: PMC10622587 DOI: 10.26508/lsa.202302232] [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: 06/22/2023] [Revised: 10/20/2023] [Accepted: 10/23/2023] [Indexed: 11/04/2023] Open
Abstract
Developing neurons adapt their intrinsic excitability to maintain stable output despite changing synaptic input. The mechanisms behind this process remain unclear. In this study, we examined Xenopus optic tectal neurons and found that the expressions of Nav1.1 and Nav1.6 voltage-gated Na+ channels are regulated during changes in intrinsic excitability, both during development and becsuse of changes in visual experience. Using whole-cell electrophysiology, we demonstrate the existence of distinct, fast, persistent, and resurgent Na+ currents in the tectum, and show that these Na+ currents are co-regulated with changes in Nav channel expression. Using antisense RNA to suppress the expression of specific Nav subunits, we found that up-regulation of Nav1.6 expression, but not Nav1.1, was necessary for experience-dependent increases in Na+ currents and intrinsic excitability. Furthermore, this regulation was also necessary for normal development of sensory guided behaviors. These data suggest that the regulation of Na+ currents through the modulation of Nav1.6 expression, and to a lesser extent Nav1.1, plays a crucial role in controlling the intrinsic excitability of tectal neurons and guiding normal development of the tectal circuitry.
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Affiliation(s)
- Adrian C Thompson
- https://ror.org/05gq02987 Department of Neuroscience, Brown University, Providence, RI, USA
| | - Carlos D Aizenman
- https://ror.org/05gq02987 Department of Neuroscience, Brown University, Providence, RI, USA
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9
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Monteil A, Guérineau NC, Gil-Nagel A, Parra-Diaz P, Lory P, Senatore A. New insights into the physiology and pathophysiology of the atypical sodium leak channel NALCN. Physiol Rev 2024; 104:399-472. [PMID: 37615954 DOI: 10.1152/physrev.00014.2022] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2022] [Revised: 07/13/2023] [Accepted: 08/15/2023] [Indexed: 08/25/2023] Open
Abstract
Cell excitability and its modulation by hormones and neurotransmitters involve the concerted action of a large repertoire of membrane proteins, especially ion channels. Unique complements of coexpressed ion channels are exquisitely balanced against each other in different excitable cell types, establishing distinct electrical properties that are tailored for diverse physiological contributions, and dysfunction of any component may induce a disease state. A crucial parameter controlling cell excitability is the resting membrane potential (RMP) set by extra- and intracellular concentrations of ions, mainly Na+, K+, and Cl-, and their passive permeation across the cell membrane through leak ion channels. Indeed, dysregulation of RMP causes significant effects on cellular excitability. This review describes the molecular and physiological properties of the Na+ leak channel NALCN, which associates with its accessory subunits UNC-79, UNC-80, and NLF-1/FAM155 to conduct depolarizing background Na+ currents in various excitable cell types, especially neurons. Studies of animal models clearly demonstrate that NALCN contributes to fundamental physiological processes in the nervous system including the control of respiratory rhythm, circadian rhythm, sleep, and locomotor behavior. Furthermore, dysfunction of NALCN and its subunits is associated with severe pathological states in humans. The critical involvement of NALCN in physiology is now well established, but its study has been hampered by the lack of specific drugs that can block or agonize NALCN currents in vitro and in vivo. Molecular tools and animal models are now available to accelerate our understanding of how NALCN contributes to key physiological functions and the development of novel therapies for NALCN channelopathies.
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Affiliation(s)
- Arnaud Monteil
- Institut de Génomique Fonctionnelle, Université de Montpellier, CNRS, INSERM, Montpellier, France
- LabEx "Ion Channel Science and Therapeutics," Montpellier, France
- Department of Physiology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand
| | - Nathalie C Guérineau
- Institut de Génomique Fonctionnelle, Université de Montpellier, CNRS, INSERM, Montpellier, France
- LabEx "Ion Channel Science and Therapeutics," Montpellier, France
| | - Antonio Gil-Nagel
- Department of Neurology, Epilepsy Program, Hospital Ruber Internacional, Madrid, Spain
| | - Paloma Parra-Diaz
- Department of Neurology, Epilepsy Program, Hospital Ruber Internacional, Madrid, Spain
| | - Philippe Lory
- Institut de Génomique Fonctionnelle, Université de Montpellier, CNRS, INSERM, Montpellier, France
- LabEx "Ion Channel Science and Therapeutics," Montpellier, France
| | - Adriano Senatore
- Department of Biology, University of Toronto Mississauga, Mississauga, Ontario, Canada
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10
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Sharma T, Kumar R, Mukherjee S. Neuronal Vulnerability to Degeneration in Parkinson's Disease and Therapeutic Approaches. CNS & NEUROLOGICAL DISORDERS DRUG TARGETS 2024; 23:715-730. [PMID: 37185323 DOI: 10.2174/1871527322666230426155432] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/10/2022] [Revised: 02/15/2023] [Accepted: 02/17/2023] [Indexed: 05/17/2023]
Abstract
Parkinson's disease is the second most common neurodegenerative disease affecting millions of people worldwide. Despite the crucial threat it poses, currently, no specific therapy exists that can completely reverse or halt the progression of the disease. Parkinson's disease pathology is driven by neurodegeneration caused by the intraneuronal accumulation of alpha-synuclein (α-syn) aggregates in Lewy bodies in the substantia nigra region of the brain. Parkinson's disease is a multiorgan disease affecting the central nervous system (CNS) as well as the autonomic nervous system. A bidirectional route of spreading α-syn from the gut to CNS through the vagus nerve and vice versa has also been reported. Despite our understanding of the molecular and pathophysiological aspects of Parkinson's disease, many questions remain unanswered regarding the selective vulnerability of neuronal populations, the neuromodulatory role of the locus coeruleus, and alpha-synuclein aggregation. This review article aims to describe the probable factors that contribute to selective neuronal vulnerability in Parkinson's disease, such as genetic predisposition, bioenergetics, and the physiology of neurons, as well as the interplay of environmental and exogenous modulators. This review also highlights various therapeutic strategies with cell transplants, through viral gene delivery, by targeting α-synuclein and aquaporin protein or epidermal growth factor receptors for the treatment of Parkinson's disease. The application of regenerative medicine and patient-specific personalized approaches have also been explored as promising strategies in the treatment of Parkinson's disease.
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Affiliation(s)
- Tanushree Sharma
- Amity Institute of Biotechnology, Amity University Uttar Pradesh Lucknow Campus, Lucknow, Uttar Pradesh, India
- Molecular and Human Genetics, Banaras Hindu University Varanasi, Uttar Pradesh, India
| | - Rajnish Kumar
- Amity Institute of Biotechnology, Amity University Uttar Pradesh Lucknow Campus, Lucknow, Uttar Pradesh, India
- Department of Veterinary Medicine and Surgery, College of Veterinary Medicine, University of Missouri, Columbia, MO, USA
| | - Sayali Mukherjee
- Amity Institute of Biotechnology, Amity University Uttar Pradesh Lucknow Campus, Lucknow, Uttar Pradesh, India
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11
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Meerman JJ, Legler J, Piersma AH, Westerink RHS, Heusinkveld HJ. An adverse outcome pathway for chemical-induced Parkinson's disease: Calcium is key. Neurotoxicology 2023; 99:226-243. [PMID: 37926220 DOI: 10.1016/j.neuro.2023.11.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2023] [Revised: 10/25/2023] [Accepted: 11/01/2023] [Indexed: 11/07/2023]
Abstract
Exposure to pesticides is associated with an increased risk of developing Parkinson's disease (PD). Currently, rodent-based risk assessment studies cannot adequately capture neurodegenerative effects of pesticides due to a lack of human-relevant endpoints targeted at neurodegeneration. Thus, there is a need for improvement of the risk assessment guidelines. Specifically, a mechanistic assessment strategy, based on human physiology and (patho)biology is needed, which can be applied in next generation risk assessment. The Adverse Outcome Pathway (AOP) framework is particularly well-suited to provide the mechanistic basis for such a strategy. Here, we conducted a semi-systematic review in Embase and MEDLINE, focused on neurodegeneration and pesticides, to develop an AOP network for parkinsonian motor symptoms. Articles were labelled and included/excluded using the online platform Sysrev. Only primary articles, written in English, focused on effects of pesticides or PD model compounds in models for the brain were included. A total of 66 articles, out of the 1700 screened, was included. PD symptoms are caused by loss of function and ultimately death of dopaminergic neurons in the substantia nigra (SN). Our literature review highlights that a unique feature of these cells that increases their vulnerability is their reliance on continuous low-level influx of calcium. As such, excess intracellular calcium was identified as a central early Key Event (KE). This KE can lead to death of dopaminergic neurons of the SN, and eventually parkinsonian motor symptoms, via four distinct pathways: 1) activation of calpains, 2) endoplasmic reticulum stress, 3) impairment of protein degradation, and 4) oxidative damage. Several receptors have been identified that may serve as molecular initiating events (MIEs) to trigger one or more of these pathways. The proposed AOP network provides the biological basis that can be used to develop a mechanistic testing strategy that captures neurodegenerative effects of pesticides.
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Affiliation(s)
- Julia J Meerman
- Centre for Health Protection, Dutch National Institute for Public Health and the Environment (RIVM), Antonie van Leeuwenhoeklaan 9, 3721 MA Bilthoven, the Netherlands; Institute for Risk Assessment Sciences (IRAS), Faculty of Veterinary Medicine, Utrecht University, Utrecht, the Netherlands
| | - Juliette Legler
- Institute for Risk Assessment Sciences (IRAS), Faculty of Veterinary Medicine, Utrecht University, Utrecht, the Netherlands
| | - Aldert H Piersma
- Centre for Health Protection, Dutch National Institute for Public Health and the Environment (RIVM), Antonie van Leeuwenhoeklaan 9, 3721 MA Bilthoven, the Netherlands; Institute for Risk Assessment Sciences (IRAS), Faculty of Veterinary Medicine, Utrecht University, Utrecht, the Netherlands
| | - Remco H S Westerink
- Institute for Risk Assessment Sciences (IRAS), Faculty of Veterinary Medicine, Utrecht University, Utrecht, the Netherlands
| | - Harm J Heusinkveld
- Centre for Health Protection, Dutch National Institute for Public Health and the Environment (RIVM), Antonie van Leeuwenhoeklaan 9, 3721 MA Bilthoven, the Netherlands.
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12
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Blankenship HE, Carter KA, Cassidy NT, Markiewicz AN, Thellmann MI, Sharpe AL, Freeman WM, Beckstead MJ. VTA dopamine neurons are hyperexcitable in 3xTg-AD mice due to casein kinase 2-dependent SK channel dysfunction. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.11.16.567486. [PMID: 38014232 PMCID: PMC10680865 DOI: 10.1101/2023.11.16.567486] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/29/2023]
Abstract
Alzheimer's disease (AD) patients exhibit neuropsychiatric symptoms that extend beyond classical cognitive deficits, suggesting involvement of subcortical areas. Here, we investigated the role of midbrain dopamine (DA) neurons in AD using the amyloid + tau-driven 3xTg-AD mouse model. We found deficits in reward-based operant learning in AD mice, suggesting possible VTA DA neuron dysregulation. Physiological assessment revealed hyperexcitability and disrupted firing in DA neurons caused by reduced activity of small-conductance calcium-activated potassium (SK) channels. RNA sequencing from contents of single patch-clamped DA neurons (Patch-seq) identified up-regulation of the SK channel modulator casein kinase 2 (CK2). Pharmacological inhibition of CK2 restored SK channel activity and normal firing patterns in 3xTg-AD mice. These findings shed light on a complex interplay between neuropsychiatric symptoms and subcortical circuits in AD, paving the way for novel treatment strategies.
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13
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Stetsenko A, Koos T. Neuronal implementation of the temporal difference learning algorithm in the midbrain dopaminergic system. Proc Natl Acad Sci U S A 2023; 120:e2309015120. [PMID: 37903252 PMCID: PMC10636325 DOI: 10.1073/pnas.2309015120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2023] [Accepted: 09/29/2023] [Indexed: 11/01/2023] Open
Abstract
The temporal difference learning (TDL) algorithm has been essential to conceptualizing the role of dopamine in reinforcement learning (RL). Despite its theoretical importance, it remains unknown whether a neuronal implementation of this algorithm exists in the brain. Here, we provide an interpretation of the recently described signaling properties of ventral tegmental area (VTA) GABAergic neurons and show that a circuitry of these neurons implements the TDL algorithm. Specifically, we identified the neuronal mechanism of three key components of the TDL model: a sustained state value signal encoded by an afferent input to the VTA, a temporal differentiation circuit formed by two types of VTA GABAergic neurons the combined output of which computes momentary reward prediction (RP) as the derivative of the state value, and the computation of reward prediction errors (RPEs) in dopamine neurons utilizing the output of the differentiation circuit. Using computational methods, we also show that this mechanism is optimally adapted to the biophysics of RPE signaling in dopamine neurons, mechanistically links the emergence of conditioned reinforcement to RP, and can naturally account for the temporal discounting of reinforcement. Elucidating the implementation of the TDL algorithm may further the investigation of RL in biological and artificial systems.
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Affiliation(s)
- Anya Stetsenko
- Center for Molecular and Behavioral Neuroscience, Rutgers University, Newark, NJ07102
| | - Tibor Koos
- Center for Molecular and Behavioral Neuroscience, Rutgers University, Newark, NJ07102
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14
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Cobb-Lewis DE, Sansalone L, Khaliq ZM. Contributions of the Sodium Leak Channel NALCN to Pacemaking of Medial Ventral Tegmental Area and Substantia Nigra Dopaminergic Neurons. J Neurosci 2023; 43:6841-6853. [PMID: 37640554 PMCID: PMC10573758 DOI: 10.1523/jneurosci.0930-22.2023] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2022] [Revised: 08/04/2023] [Accepted: 08/10/2023] [Indexed: 08/31/2023] Open
Abstract
We tested the role of the sodium leak channel, NALCN, in pacemaking of dopaminergic neuron (DAN) subpopulations from adult male and female mice. In situ hybridization revealed NALCN RNA in all DANs, with lower abundance in medial ventral tegmental area (VTA) relative to substantia nigra pars compacta (SNc). Despite lower relative abundance of NALCN, we found that acute pharmacological blockade of NALCN in medial VTA DANs slowed pacemaking by 49.08%. We also examined the electrophysiological properties of projection-defined VTA DAN subpopulations identified by retrograde labeling. Inhibition of NALCN reduced pacemaking in DANs projecting to medial nucleus accumbens (NAc) and others projecting to lateral NAc by 70.74% and 31.98%, respectively, suggesting that NALCN is a primary driver of pacemaking in VTA DANs. In SNc DANs, potentiating NALCN by lowering extracellular calcium concentration speeded pacemaking in wildtype but not NALCN conditional knockout mice, demonstrating functional presence of NALCN. In contrast to VTA DANs, however, pacemaking in SNc DANs was unaffected by inhibition of NALCN. Instead, we found that inhibition of NALCN increased the gain of frequency-current plots at firing frequencies slower than spontaneous firing. Similarly, inhibition of the hyperpolarization-activated cyclic nucleotide-gated (HCN) conductance increased gain but had little effect on pacemaking. Interestingly, simultaneous inhibition of NALCN and HCN resulted in significant reduction in pacemaker rate. Thus, we found NALCN makes substantial contributions to driving pacemaking in VTA DAN subpopulations. In SNc DANs, NALCN is not critical for pacemaking but inhibition of NALCN makes cells more sensitive to hyperpolarizing stimuli.SIGNIFICANCE STATEMENT Pacemaking in midbrain dopaminergic neurons (DAN) relies on multiple subthreshold conductances, including a sodium leak. Whether the sodium leak channel, NALCN, contributes to pacemaking in DANs located in the VTA and the SNc has not yet been determined. Using electrophysiology and pharmacology, we show that NALCN plays a prominent role in driving pacemaking in projection-defined VTA DAN subpopulations. By contrast, pacemaking in SNc neurons does not rely on NALCN. Instead, the presence of NALCN regulates the excitability of SNc DANs by reducing the gain of the neuron's response to inhibitory stimuli. Together, these findings will inform future efforts to obtain DAN subpopulation-specific treatments for use in neuropsychiatric disorders.
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Affiliation(s)
- Dana E Cobb-Lewis
- Cellular Neurophysiology Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland 20892
- Institute for Neuroscience, George Washington University School of Medicine and Health Sciences, Washington, DC 20037
| | - Lorenzo Sansalone
- Cellular Neurophysiology Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland 20892
| | - Zayd M Khaliq
- Cellular Neurophysiology Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland 20892
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15
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Jomova K, Raptova R, Alomar SY, Alwasel SH, Nepovimova E, Kuca K, Valko M. Reactive oxygen species, toxicity, oxidative stress, and antioxidants: chronic diseases and aging. Arch Toxicol 2023; 97:2499-2574. [PMID: 37597078 PMCID: PMC10475008 DOI: 10.1007/s00204-023-03562-9] [Citation(s) in RCA: 208] [Impact Index Per Article: 208.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2023] [Accepted: 07/24/2023] [Indexed: 08/21/2023]
Abstract
A physiological level of oxygen/nitrogen free radicals and non-radical reactive species (collectively known as ROS/RNS) is termed oxidative eustress or "good stress" and is characterized by low to mild levels of oxidants involved in the regulation of various biochemical transformations such as carboxylation, hydroxylation, peroxidation, or modulation of signal transduction pathways such as Nuclear factor-κB (NF-κB), Mitogen-activated protein kinase (MAPK) cascade, phosphoinositide-3-kinase, nuclear factor erythroid 2-related factor 2 (Nrf2) and other processes. Increased levels of ROS/RNS, generated from both endogenous (mitochondria, NADPH oxidases) and/or exogenous sources (radiation, certain drugs, foods, cigarette smoking, pollution) result in a harmful condition termed oxidative stress ("bad stress"). Although it is widely accepted, that many chronic diseases are multifactorial in origin, they share oxidative stress as a common denominator. Here we review the importance of oxidative stress and the mechanisms through which oxidative stress contributes to the pathological states of an organism. Attention is focused on the chemistry of ROS and RNS (e.g. superoxide radical, hydrogen peroxide, hydroxyl radicals, peroxyl radicals, nitric oxide, peroxynitrite), and their role in oxidative damage of DNA, proteins, and membrane lipids. Quantitative and qualitative assessment of oxidative stress biomarkers is also discussed. Oxidative stress contributes to the pathology of cancer, cardiovascular diseases, diabetes, neurological disorders (Alzheimer's and Parkinson's diseases, Down syndrome), psychiatric diseases (depression, schizophrenia, bipolar disorder), renal disease, lung disease (chronic pulmonary obstruction, lung cancer), and aging. The concerted action of antioxidants to ameliorate the harmful effect of oxidative stress is achieved by antioxidant enzymes (Superoxide dismutases-SODs, catalase, glutathione peroxidase-GPx), and small molecular weight antioxidants (vitamins C and E, flavonoids, carotenoids, melatonin, ergothioneine, and others). Perhaps one of the most effective low molecular weight antioxidants is vitamin E, the first line of defense against the peroxidation of lipids. A promising approach appears to be the use of certain antioxidants (e.g. flavonoids), showing weak prooxidant properties that may boost cellular antioxidant systems and thus act as preventive anticancer agents. Redox metal-based enzyme mimetic compounds as potential pharmaceutical interventions and sirtuins as promising therapeutic targets for age-related diseases and anti-aging strategies are discussed.
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Affiliation(s)
- Klaudia Jomova
- Department of Chemistry, Faculty of Natural Sciences, Constantine the Philosopher University in Nitra, Nitra, 949 74, Slovakia
| | - Renata Raptova
- Faculty of Chemical and Food Technology, Slovak University of Technology, Bratislava, 812 37, Slovakia
| | - Suliman Y Alomar
- Zoology Department, College of Science, King Saud University, 11451, Riyadh, Saudi Arabia
| | - Saleh H Alwasel
- Zoology Department, College of Science, King Saud University, 11451, Riyadh, Saudi Arabia
| | - Eugenie Nepovimova
- Department of Chemistry, Faculty of Sciences, University of Hradec Kralove, 50005, Hradec Kralove, Czech Republic
| | - Kamil Kuca
- Department of Chemistry, Faculty of Sciences, University of Hradec Kralove, 50005, Hradec Kralove, Czech Republic
| | - Marian Valko
- Faculty of Chemical and Food Technology, Slovak University of Technology, Bratislava, 812 37, Slovakia.
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16
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Parkkinen I, Their A, Asghar MY, Sree S, Jokitalo E, Airavaara M. Pharmacological Regulation of Endoplasmic Reticulum Structure and Calcium Dynamics: Importance for Neurodegenerative Diseases. Pharmacol Rev 2023; 75:959-978. [PMID: 37127349 DOI: 10.1124/pharmrev.122.000701] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2022] [Revised: 03/27/2023] [Accepted: 04/04/2023] [Indexed: 05/03/2023] Open
Abstract
The endoplasmic reticulum (ER) is the largest organelle of the cell, composed of a continuous network of sheets and tubules, and is involved in protein, calcium (Ca2+), and lipid homeostasis. In neurons, the ER extends throughout the cell, both somal and axodendritic compartments, and is highly important for neuronal functions. A third of the proteome of a cell, secreted and membrane-bound proteins, are processed within the ER lumen and most of these proteins are vital for neuronal activity. The brain itself is high in lipid content, and many structural lipids are produced, in part, by the ER. Cholesterol and steroid synthesis are strictly regulated in the ER of the blood-brain barrier protected brain cells. The high Ca2+ level in the ER lumen and low cytosolic concentration is needed for Ca2+-based intracellular signaling, for synaptic signaling and Ca2+ waves, and for preparing proteins for correct folding in the presence of high Ca2+ concentrations to cope with the high concentrations of extracellular milieu. Particularly, ER Ca2+ is controlled in axodendritic areas for proper neurito- and synaptogenesis and synaptic plasticity and remodeling. In this review, we cover the physiologic functions of the neuronal ER and discuss it in context of common neurodegenerative diseases, focusing on pharmacological regulation of ER Ca2+ Furthermore, we postulate that heterogeneity of the ER, its protein folding capacity, and ensuring Ca2+ regulation are crucial factors for the aging and selective vulnerability of neurons in various neurodegenerative diseases. SIGNIFICANCE STATEMENT: Endoplasmic reticulum (ER) Ca2+ regulators are promising therapeutic targets for degenerative diseases for which efficacious drug therapies do not exist. The use of pharmacological probes targeting maintenance and restoration of ER Ca2+ can provide restoration of protein homeostasis (e.g., folding of complex plasma membrane signaling receptors) and slow down the degeneration process of neurons.
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Affiliation(s)
- Ilmari Parkkinen
- Neuroscience Center (I.P., A.T., M.A.), Division of Pharmacology and Pharmacotherapy, Faculty of Pharmacy (I.P., M.A.), Cell and Tissue Dynamics Research Program, Institute of Biotechnology, Helsinki Institute of Life Sciences (M.Y.A., S.S., E.J.), and Electron Microscopy Unit, Institute of Biotechnology, Helsinki Institute of Life Sciences (E.J.), University of Helsinki, Helsinki, Finland
| | - Anna Their
- Neuroscience Center (I.P., A.T., M.A.), Division of Pharmacology and Pharmacotherapy, Faculty of Pharmacy (I.P., M.A.), Cell and Tissue Dynamics Research Program, Institute of Biotechnology, Helsinki Institute of Life Sciences (M.Y.A., S.S., E.J.), and Electron Microscopy Unit, Institute of Biotechnology, Helsinki Institute of Life Sciences (E.J.), University of Helsinki, Helsinki, Finland
| | - Muhammad Yasir Asghar
- Neuroscience Center (I.P., A.T., M.A.), Division of Pharmacology and Pharmacotherapy, Faculty of Pharmacy (I.P., M.A.), Cell and Tissue Dynamics Research Program, Institute of Biotechnology, Helsinki Institute of Life Sciences (M.Y.A., S.S., E.J.), and Electron Microscopy Unit, Institute of Biotechnology, Helsinki Institute of Life Sciences (E.J.), University of Helsinki, Helsinki, Finland
| | - Sreesha Sree
- Neuroscience Center (I.P., A.T., M.A.), Division of Pharmacology and Pharmacotherapy, Faculty of Pharmacy (I.P., M.A.), Cell and Tissue Dynamics Research Program, Institute of Biotechnology, Helsinki Institute of Life Sciences (M.Y.A., S.S., E.J.), and Electron Microscopy Unit, Institute of Biotechnology, Helsinki Institute of Life Sciences (E.J.), University of Helsinki, Helsinki, Finland
| | - Eija Jokitalo
- Neuroscience Center (I.P., A.T., M.A.), Division of Pharmacology and Pharmacotherapy, Faculty of Pharmacy (I.P., M.A.), Cell and Tissue Dynamics Research Program, Institute of Biotechnology, Helsinki Institute of Life Sciences (M.Y.A., S.S., E.J.), and Electron Microscopy Unit, Institute of Biotechnology, Helsinki Institute of Life Sciences (E.J.), University of Helsinki, Helsinki, Finland
| | - Mikko Airavaara
- Neuroscience Center (I.P., A.T., M.A.), Division of Pharmacology and Pharmacotherapy, Faculty of Pharmacy (I.P., M.A.), Cell and Tissue Dynamics Research Program, Institute of Biotechnology, Helsinki Institute of Life Sciences (M.Y.A., S.S., E.J.), and Electron Microscopy Unit, Institute of Biotechnology, Helsinki Institute of Life Sciences (E.J.), University of Helsinki, Helsinki, Finland
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17
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Ham SJ, Yoo H, Woo D, Lee DH, Park KS, Chung J. PINK1 and Parkin regulate IP 3R-mediated ER calcium release. Nat Commun 2023; 14:5202. [PMID: 37626046 PMCID: PMC10457342 DOI: 10.1038/s41467-023-40929-z] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2022] [Accepted: 08/16/2023] [Indexed: 08/27/2023] Open
Abstract
Although defects in intracellular calcium homeostasis are known to play a role in the pathogenesis of Parkinson's disease (PD), the underlying molecular mechanisms remain unclear. Here, we show that loss of PTEN-induced kinase 1 (PINK1) and Parkin leads to dysregulation of inositol 1,4,5-trisphosphate receptor (IP3R) activity, robustly increasing ER calcium release. In addition, we identify that CDGSH iron sulfur domain 1 (CISD1, also known as mitoNEET) functions downstream of Parkin to directly control IP3R. Both genetic and pharmacologic suppression of CISD1 and its Drosophila homolog CISD (also known as Dosmit) restore the increased ER calcium release in PINK1 and Parkin null mammalian cells and flies, respectively, demonstrating the evolutionarily conserved regulatory mechanism of intracellular calcium homeostasis by the PINK1-Parkin pathway. More importantly, suppression of CISD in PINK1 and Parkin null flies rescues PD-related phenotypes including defective locomotor activity and dopaminergic neuronal degeneration. Based on these data, we propose that the regulation of ER calcium release by PINK1 and Parkin through CISD1 and IP3R is a feasible target for treating PD pathogenesis.
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Affiliation(s)
- Su Jin Ham
- Institute of Molecular Biology and Genetics, Seoul National University, Seoul, 08826, Republic of Korea
- Interdisciplinary Graduate Program in Genetic Engineering, Seoul National University, Seoul, 08826, Republic of Korea
- School of Biological Sciences, Seoul National University, Seoul, 08826, Republic of Korea
| | - Heesuk Yoo
- Institute of Molecular Biology and Genetics, Seoul National University, Seoul, 08826, Republic of Korea
- Interdisciplinary Graduate Program in Genetic Engineering, Seoul National University, Seoul, 08826, Republic of Korea
- School of Biological Sciences, Seoul National University, Seoul, 08826, Republic of Korea
| | - Daihn Woo
- Institute of Molecular Biology and Genetics, Seoul National University, Seoul, 08826, Republic of Korea
| | - Da Hyun Lee
- Institute of Molecular Biology and Genetics, Seoul National University, Seoul, 08826, Republic of Korea
- School of Biological Sciences, Seoul National University, Seoul, 08826, Republic of Korea
| | - Kyu-Sang Park
- Department of Physiology, Yonsei University Wonju College of Medicine, Wonju, 26426, Republic of Korea
- Mitohormesis Research Center, Yonsei University Wonju College of Medicine, Wonju, 26426, Republic of Korea
| | - Jongkyeong Chung
- Institute of Molecular Biology and Genetics, Seoul National University, Seoul, 08826, Republic of Korea.
- Interdisciplinary Graduate Program in Genetic Engineering, Seoul National University, Seoul, 08826, Republic of Korea.
- School of Biological Sciences, Seoul National University, Seoul, 08826, Republic of Korea.
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18
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Ramesh S, Arachchige ASPM. Depletion of dopamine in Parkinson's disease and relevant therapeutic options: A review of the literature. AIMS Neurosci 2023; 10:200-231. [PMID: 37841347 PMCID: PMC10567584 DOI: 10.3934/neuroscience.2023017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2023] [Revised: 07/27/2023] [Accepted: 08/02/2023] [Indexed: 10/17/2023] Open
Abstract
Parkinson's disease (PD) is a progressive neurodegenerative disorder that affects motor and cognition functions. The etiology of Parkinson's disease remains largely unknown, but genetic and environmental factors are believed to play a role. The neurotransmitter dopamine is implicated in regulating movement, motivation, memory, and other physiological processes. In individuals with Parkinson's disease, the loss of dopaminergic neurons leads to a reduction in dopamine levels, which causes motor impairment and may also contribute to the cognitive deficits observed in some patients. Therefore, it is important to understand the pathophysiology that leads to the loss of dopaminergic neurons, along with reliable biomarkers that may help distinguish PD from other conditions, monitor its progression, or indicate a positive response to a therapeutic intervention. Important advances in the treatment, etiology, and pathogenesis of Parkinson's disease have been made in the past 50 years. Therefore, this review tries to explain the different possible mechanisms behind the depletion of dopamine in PD patients such as alpha-synuclein abnormalities, mitochondrial dysfunction, and 3,4-dihydroxyphenylacetaldehyde (DOPAL) toxicity, along with the current therapies we have and the ones that are in development. The clinical aspect of Parkinson's disease such as the manifestation of both motor and non-motor symptoms, and the differential diagnosis with similar neurodegenerative disease are also discussed.
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19
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Juarez B, Kong MS, Jo YS, Elum JE, Yee JX, Ng-Evans S, Cline M, Hunker AC, Quinlan MA, Baird MA, Elerding AJ, Johnson M, Ban D, Mendez A, Goodwin NL, Soden ME, Zweifel LS. Temporal scaling of dopamine neuron firing and dopamine release by distinct ion channels shape behavior. SCIENCE ADVANCES 2023; 9:eadg8869. [PMID: 37566654 PMCID: PMC10421029 DOI: 10.1126/sciadv.adg8869] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/27/2023] [Accepted: 07/10/2023] [Indexed: 08/13/2023]
Abstract
Dopamine is broadly implicated in reinforcement learning, but how patterns of dopamine activity are generated is poorly resolved. Here, we demonstrate that two ion channels, Kv4.3 and BKCa1.1, regulate the pattern of dopamine neuron firing and dopamine release on different time scales to influence separate phases of reinforced behavior in mice. Inactivation of Kv4.3 in VTA dopamine neurons increases ex vivo pacemaker activity and excitability that is associated with increased in vivo firing rate and ramping dynamics before lever press in a learned instrumental paradigm. Loss of Kv4.3 enhances performance of the learned response and facilitates extinction. In contrast, loss of BKCa1.1 increases burst firing and phasic dopamine release that enhances learning of an instrumental response and enhances extinction burst lever pressing in early extinction that is associated with a greater change in activity between reinforced and unreinforced actions. These data demonstrate that disruption of intrinsic regulators of neuronal activity differentially affects dopamine dynamics during reinforcement and extinction learning.
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Affiliation(s)
- Barbara Juarez
- Department of Psychiatry and Behavioral Sciences, University of Washington, Seattle, WA, USA
- Department of Pharmacology, University of Washington, Seattle, WA, USA
| | - Mi-Seon Kong
- Department of Psychiatry and Behavioral Sciences, University of Washington, Seattle, WA, USA
| | - Yong S. Jo
- Department of Psychiatry and Behavioral Sciences, University of Washington, Seattle, WA, USA
| | - Jordan E. Elum
- Department of Psychiatry and Behavioral Sciences, University of Washington, Seattle, WA, USA
| | - Joshua X. Yee
- Department of Psychiatry and Behavioral Sciences, University of Washington, Seattle, WA, USA
| | - Scott Ng-Evans
- Department of Psychiatry and Behavioral Sciences, University of Washington, Seattle, WA, USA
| | - Marcella Cline
- Department of Psychiatry and Behavioral Sciences, University of Washington, Seattle, WA, USA
| | - Avery C. Hunker
- Department of Pharmacology, University of Washington, Seattle, WA, USA
| | - Meagan A. Quinlan
- Department of Psychiatry and Behavioral Sciences, University of Washington, Seattle, WA, USA
| | - Madison A. Baird
- Department of Pharmacology, University of Washington, Seattle, WA, USA
| | | | - Mia Johnson
- Department of Psychiatry and Behavioral Sciences, University of Washington, Seattle, WA, USA
| | - Derek Ban
- Department of Psychiatry and Behavioral Sciences, University of Washington, Seattle, WA, USA
| | - Adriana Mendez
- Department of Psychiatry and Behavioral Sciences, University of Washington, Seattle, WA, USA
| | | | - Marta E. Soden
- Department of Pharmacology, University of Washington, Seattle, WA, USA
| | - Larry S. Zweifel
- Department of Psychiatry and Behavioral Sciences, University of Washington, Seattle, WA, USA
- Department of Pharmacology, University of Washington, Seattle, WA, USA
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20
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Suri D, Zanni G, Mahadevia D, Chuhma N, Saha R, Spivack S, Pini N, Stevens GS, Ziolkowski-Blake A, Simpson EH, Balsam P, Rayport S, Ansorge MS. Dopamine transporter blockade during adolescence increases adult dopamine function, impulsivity, and aggression. Mol Psychiatry 2023; 28:3512-3523. [PMID: 37532798 PMCID: PMC10618097 DOI: 10.1038/s41380-023-02194-w] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/16/2022] [Revised: 07/11/2023] [Accepted: 07/17/2023] [Indexed: 08/04/2023]
Abstract
Sensitive developmental periods shape neural circuits and enable adaptation. However, they also engender vulnerability to factors that can perturb developmental trajectories. An understanding of sensitive period phenomena and mechanisms separate from sensory system development is still lacking, yet critical to understanding disease etiology and risk. The dopamine system is pivotal in controlling and shaping adolescent behaviors, and it undergoes heightened plasticity during that time, such that interference with dopamine signaling can have long-lasting behavioral consequences. Here we sought to gain mechanistic insight into this dopamine-sensitive period and its impact on behavior. In mice, dopamine transporter (DAT) blockade from postnatal (P) day 22 to 41 increases aggression and sensitivity to amphetamine (AMPH) behavioral stimulation in adulthood. Here, we refined this sensitive window to P32-41 and identified increased firing of dopaminergic neurons in vitro and in vivo as a neural correlate to altered adult behavior. Aggression can result from enhanced impulsivity and cognitive dysfunction, and dopamine regulates working memory and motivated behavior. Hence, we assessed these behavioral domains and found that P32-41 DAT blockade increases impulsivity but has no effect on cognition, working memory, or motivation in adulthood. Lastly, using optogenetics to drive dopamine neurons, we find that increased VTA but not SNc dopaminergic activity mimics the increase in impulsive behavior in the Go/NoGo task observed after adolescent DAT blockade. Together our data provide insight into the developmental origins of aggression and impulsivity that may ultimately improve diagnosis, prevention, and treatment strategies for related neuropsychiatric disorders.
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Affiliation(s)
- Deepika Suri
- Department of Psychiatry, Columbia University, New York, NY, 10032, USA
- Department of Developmental Neuroscience, New York State Psychiatric Institute, New York, NY, 10032, USA
| | - Giulia Zanni
- Department of Psychiatry, Columbia University, New York, NY, 10032, USA
- Department of Developmental Neuroscience, New York State Psychiatric Institute, New York, NY, 10032, USA
| | - Darshini Mahadevia
- Department of Psychiatry, Columbia University, New York, NY, 10032, USA
- Department of Developmental Neuroscience, New York State Psychiatric Institute, New York, NY, 10032, USA
| | - Nao Chuhma
- Department of Psychiatry, Columbia University, New York, NY, 10032, USA
- Department of Molecular Therapeutics, New York State Psychiatric Institute, New York, NY, 10032, USA
| | - Rinki Saha
- Department of Psychiatry, Columbia University, New York, NY, 10032, USA
- Department of Developmental Neuroscience, New York State Psychiatric Institute, New York, NY, 10032, USA
| | - Stephen Spivack
- Department of Psychiatry, Columbia University, New York, NY, 10032, USA
- Department of Developmental Neuroscience, New York State Psychiatric Institute, New York, NY, 10032, USA
| | - Nicolò Pini
- Department of Psychiatry, Columbia University, New York, NY, 10032, USA
- Department of Developmental Neuroscience, New York State Psychiatric Institute, New York, NY, 10032, USA
| | - Gregory S Stevens
- Department of Psychiatry, Columbia University, New York, NY, 10032, USA
- Department of Developmental Neuroscience, New York State Psychiatric Institute, New York, NY, 10032, USA
| | - Annette Ziolkowski-Blake
- Department of Developmental Neuroscience, New York State Psychiatric Institute, New York, NY, 10032, USA
| | - Eleanor H Simpson
- Department of Psychiatry, Columbia University, New York, NY, 10032, USA
- Department of Developmental Neuroscience, New York State Psychiatric Institute, New York, NY, 10032, USA
| | - Peter Balsam
- Department of Psychiatry, Columbia University, New York, NY, 10032, USA
- Department of Developmental Neuroscience, New York State Psychiatric Institute, New York, NY, 10032, USA
- Department of Neuroscience and Behavior, Barnard College, Columbia University, New York, NY, 10032, USA
| | - Stephen Rayport
- Department of Psychiatry, Columbia University, New York, NY, 10032, USA
- Department of Molecular Therapeutics, New York State Psychiatric Institute, New York, NY, 10032, USA
| | - Mark S Ansorge
- Department of Psychiatry, Columbia University, New York, NY, 10032, USA.
- Department of Developmental Neuroscience, New York State Psychiatric Institute, New York, NY, 10032, USA.
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21
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Beccano-Kelly DA, Cherubini M, Mousba Y, Cramb KM, Giussani S, Caiazza MC, Rai P, Vingill S, Bengoa-Vergniory N, Ng B, Corda G, Banerjee A, Vowles J, Cowley S, Wade-Martins R. Calcium dysregulation combined with mitochondrial failure and electrophysiological maturity converge in Parkinson's iPSC-dopamine neurons. iScience 2023; 26:107044. [PMID: 37426342 PMCID: PMC10329047 DOI: 10.1016/j.isci.2023.107044] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2022] [Revised: 11/30/2022] [Accepted: 06/01/2023] [Indexed: 07/11/2023] Open
Abstract
Parkinson's disease (PD) is characterized by a progressive deterioration of motor and cognitive functions. Although death of dopamine neurons is the hallmark pathology of PD, this is a late-stage disease process preceded by neuronal dysfunction. Here we describe early physiological perturbations in patient-derived induced pluripotent stem cell (iPSC)-dopamine neurons carrying the GBA-N370S mutation, a strong genetic risk factor for PD. GBA-N370S iPSC-dopamine neurons show an early and persistent calcium dysregulation notably at the mitochondria, followed by reduced mitochondrial membrane potential and oxygen consumption rate, indicating mitochondrial failure. With increased neuronal maturity, we observed decreased synaptic function in PD iPSC-dopamine neurons, consistent with the requirement for ATP and calcium to support the increase in electrophysiological activity over time. Our work demonstrates that calcium dyshomeostasis and mitochondrial failure impair the higher electrophysiological activity of mature neurons and may underlie the vulnerability of dopamine neurons in PD.
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Affiliation(s)
- Dayne A. Beccano-Kelly
- Oxford Parkinson’s Disease Centre, University of Oxford, Oxford, United Kingdom
- Department of Physiology, Anatomy and Genetics, University of Oxford, South Parks Road, Oxford OX3 7BN, UK
| | - Marta Cherubini
- Oxford Parkinson’s Disease Centre, University of Oxford, Oxford, United Kingdom
- Department of Physiology, Anatomy and Genetics, University of Oxford, South Parks Road, Oxford OX3 7BN, UK
| | - Yassine Mousba
- Oxford Parkinson’s Disease Centre, University of Oxford, Oxford, United Kingdom
- Department of Physiology, Anatomy and Genetics, University of Oxford, South Parks Road, Oxford OX3 7BN, UK
| | - Kaitlyn M.L. Cramb
- Oxford Parkinson’s Disease Centre, University of Oxford, Oxford, United Kingdom
- Department of Physiology, Anatomy and Genetics, University of Oxford, South Parks Road, Oxford OX3 7BN, UK
- Kavli Institute for Nanoscience Discovery, University of Oxford, Dorothy Crowfoot Hodgkin Building, South Parks Road, Oxford OX1 3QU, UK
| | - Stefania Giussani
- Oxford Parkinson’s Disease Centre, University of Oxford, Oxford, United Kingdom
- Department of Physiology, Anatomy and Genetics, University of Oxford, South Parks Road, Oxford OX3 7BN, UK
| | - Maria Claudia Caiazza
- Oxford Parkinson’s Disease Centre, University of Oxford, Oxford, United Kingdom
- Department of Physiology, Anatomy and Genetics, University of Oxford, South Parks Road, Oxford OX3 7BN, UK
- Kavli Institute for Nanoscience Discovery, University of Oxford, Dorothy Crowfoot Hodgkin Building, South Parks Road, Oxford OX1 3QU, UK
| | - Pavandeep Rai
- Oxford Parkinson’s Disease Centre, University of Oxford, Oxford, United Kingdom
- Department of Physiology, Anatomy and Genetics, University of Oxford, South Parks Road, Oxford OX3 7BN, UK
| | - Siv Vingill
- Oxford Parkinson’s Disease Centre, University of Oxford, Oxford, United Kingdom
- Department of Physiology, Anatomy and Genetics, University of Oxford, South Parks Road, Oxford OX3 7BN, UK
| | - Nora Bengoa-Vergniory
- Oxford Parkinson’s Disease Centre, University of Oxford, Oxford, United Kingdom
- Department of Physiology, Anatomy and Genetics, University of Oxford, South Parks Road, Oxford OX3 7BN, UK
- Kavli Institute for Nanoscience Discovery, University of Oxford, Dorothy Crowfoot Hodgkin Building, South Parks Road, Oxford OX1 3QU, UK
| | - Bryan Ng
- Department of Physiology, Anatomy and Genetics, University of Oxford, South Parks Road, Oxford OX3 7BN, UK
- Kavli Institute for Nanoscience Discovery, University of Oxford, Dorothy Crowfoot Hodgkin Building, South Parks Road, Oxford OX1 3QU, UK
| | - Gabriele Corda
- Department of Physiology, Anatomy and Genetics, University of Oxford, South Parks Road, Oxford OX3 7BN, UK
| | - Abhirup Banerjee
- Radcliffe Department of Medicine, Division of Cardiovascular Medicine, University of Oxford, Oxford OX3 9DU, UK
- Department of Engineering Science, Institute of Biomedical Engineering, University of Oxford, Oxford OX3 7DQ, UK
| | - Jane Vowles
- Oxford Parkinson’s Disease Centre, University of Oxford, Oxford, United Kingdom
- The James Martin Stem Cell Facility, Sir William Dunn School of Pathology, University of Oxford, South Parks Road, Oxford OX1 3RE, UK
| | - Sally Cowley
- Oxford Parkinson’s Disease Centre, University of Oxford, Oxford, United Kingdom
- The James Martin Stem Cell Facility, Sir William Dunn School of Pathology, University of Oxford, South Parks Road, Oxford OX1 3RE, UK
| | - Richard Wade-Martins
- Oxford Parkinson’s Disease Centre, University of Oxford, Oxford, United Kingdom
- Department of Physiology, Anatomy and Genetics, University of Oxford, South Parks Road, Oxford OX3 7BN, UK
- Kavli Institute for Nanoscience Discovery, University of Oxford, Dorothy Crowfoot Hodgkin Building, South Parks Road, Oxford OX1 3QU, UK
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22
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Kwon YJ, Kwon OI, Hwang HJ, Shin HC, Yang S. Therapeutic effects of phlorotannins in the treatment of neurodegenerative disorders. Front Mol Neurosci 2023; 16:1193590. [PMID: 37305552 PMCID: PMC10249478 DOI: 10.3389/fnmol.2023.1193590] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2023] [Accepted: 04/27/2023] [Indexed: 06/13/2023] Open
Abstract
Phlorotannins are natural polyphenolic compounds produced by brown marine algae and are currently found in nutritional supplements. Although they are known to cross the blood-brain barrier, their neuropharmacological actions remain unclear. Here we review the potential therapeutic benefits of phlorotannins in the treatment of neurodegenerative diseases. In mouse models of Alzheimer's disease, ethanol intoxication and fear stress, the phlorotannin monomer phloroglucinol and the compounds eckol, dieckol and phlorofucofuroeckol A have been shown to improve cognitive function. In a mouse model of Parkinson's disease, phloroglucinol treatment led to improved motor performance. Additional neurological benefits associated with phlorotannin intake have been demonstrated in stroke, sleep disorders, and pain response. These effects may stem from the inhibition of disease-inducing plaque synthesis and aggregation, suppression of microglial activation, modulation of pro-inflammatory signaling, reduction of glutamate-induced excitotoxicity, and scavenging of reactive oxygen species. Clinical trials of phlorotannins have not reported significant adverse effects, suggesting these compounds to be promising bioactive agents in the treatment of neurological diseases. We therefore propose a putative biophysical mechanism of phlorotannin action in addition to future directions for phlorotannin research.
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Affiliation(s)
- Yoon Ji Kwon
- Department of Neuroscience, City University of Hong Kong, Kowloon, Hong Kong SAR, China
| | - Oh Ig Kwon
- Botamedi Brain Health and Medical Care Company Limited, Central, Hong Kong SAR, China
| | - Hye Jeong Hwang
- Center for Molecular Intelligence, SUNY Korea, Incheon, Republic of Korea
| | - Hyeon-Cheol Shin
- Botamedi Brain Health and Medical Care Company Limited, Central, Hong Kong SAR, China
- Center for Molecular Intelligence, SUNY Korea, Incheon, Republic of Korea
| | - Sungchil Yang
- Department of Neuroscience, City University of Hong Kong, Kowloon, Hong Kong SAR, China
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23
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Copeland DS, Gugel A, Gantz SC. Potentiation of neuronal activity by tonic GluD1 current in brain slices. EMBO Rep 2023:e56801. [PMID: 37154294 DOI: 10.15252/embr.202356801] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2023] [Revised: 04/19/2023] [Accepted: 04/24/2023] [Indexed: 05/10/2023] Open
Abstract
Ion channel function of native delta glutamate receptors (GluDR ) is incompletely understood. Previously, we and others have shown that activation of Gαq protein-coupled receptors (GqPCR) produces a slow inward current carried by GluD1R . GluD1R also carries a tonic cation current of unknown cause. Here, using voltage-clamp electrophysiological recordings from adult mouse brain slices containing the dorsal raphe nucleus, we find no role of ongoing G-protein-coupled receptor activity in generating or sustaining tonic GluD1R currents. Neither augmentation nor disruption of G protein activity affects tonic GluD1R currents, suggesting that ongoing G-protein-coupled receptor activity does not give rise to tonic GluD1R currents. Further, the tonic GluD1R current is unaffected by the addition of external glycine or D-serine, which influences GluD2R current at millimolar concentrations. Instead, GqPCR-stimulated and tonic GluD1R currents are regulated by physiological levels of external calcium. In current-clamp recordings, block of GluD1R channels hyperpolarizes the membrane by ~7 mV at subthreshold potentials, reducing excitability. Thus, GluD1R carries a G-protein-independent tonic current that contributes to subthreshold neuronal excitation in the dorsal raphe nucleus.
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Affiliation(s)
- Daniel S Copeland
- Department of Molecular Physiology and Biophysics, University of Iowa, Iowa City, IA, USA
| | - Aleigha Gugel
- Department of Molecular Physiology and Biophysics, University of Iowa, Iowa City, IA, USA
| | - Stephanie C Gantz
- Department of Molecular Physiology and Biophysics, University of Iowa, Iowa City, IA, USA
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24
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Kuan W, Alfaidi M, Horne CB, Vallin B, Fox S, Fazal SV, Williams‐Gray CH, Barker RA. Selective neurodegeneration generated by intravenous α-synuclein pre-formed fibril administration is not associated with endogenous α-synuclein levels in the rat brain. Brain Pathol 2023; 33:e13128. [PMID: 36321260 PMCID: PMC10154377 DOI: 10.1111/bpa.13128] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2022] [Accepted: 10/11/2022] [Indexed: 03/02/2023] Open
Abstract
Selective loss of discrete neuronal populations is a prominent feature of many neurodegenerative conditions, but the molecular basis of this is poorly understood. A central role of α-synuclein in the selective neurodegeneration of Parkinson's disease has been speculated, as its level of expression critically determines the propensity of this protein to misfold. To investigate whether the propensity of neuronal cell loss is associated with the level of endogenous α-synuclein expression, non-transgenic rats were given a single intravenous administration of α-synuclein pre-formed fibrils (PFFs) reversibly complexed with the rabies virus glycoprotein peptide (RVG9R). The number of surviving cells in different neuronal populations was systematically quantified using unbiased stereology. Our data demonstrated that a non-selective, transvascular delivery of α-synuclein PFFs led to a time-dependent loss of specific populations of midbrain (but not olfactory) dopaminergic neurons, medullary (but not pontine) cholinergic neurons, and brainstem serotonergic neurons. Contrary to the central role of endogenous α-synuclein expression in determining the seeding and aggregation propensity of pathological α-synuclein, we did not observe an association between the levels of α-synuclein expression in different regions of the rodent brain (although did not ascertain this at the individual cell level) and neurodegenerative propensity. The results from our study highlight the complexity of the neurodegenerative process generated by α-synuclein seeding. Further investigations are therefore required to elucidate the molecular basis of neurodegeneration driven by exogenous pathogenic α-synuclein spread.
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Affiliation(s)
- Wei‐Li Kuan
- John van Geest Centre for Brain Repair, Department of Clinical NeuroscienceUniversity of CambridgeCambridgeUK
| | - Maha Alfaidi
- John van Geest Centre for Brain Repair, Department of Clinical NeuroscienceUniversity of CambridgeCambridgeUK
| | - Catherine B. Horne
- John van Geest Centre for Brain Repair, Department of Clinical NeuroscienceUniversity of CambridgeCambridgeUK
| | - Benjamin Vallin
- John van Geest Centre for Brain Repair, Department of Clinical NeuroscienceUniversity of CambridgeCambridgeUK
| | - Sarah Fox
- John van Geest Centre for Brain Repair, Department of Clinical NeuroscienceUniversity of CambridgeCambridgeUK
| | - Shaline V. Fazal
- John van Geest Centre for Brain Repair, Department of Clinical NeuroscienceUniversity of CambridgeCambridgeUK
| | - Caroline H. Williams‐Gray
- John van Geest Centre for Brain Repair, Department of Clinical NeuroscienceUniversity of CambridgeCambridgeUK
| | - Roger A. Barker
- John van Geest Centre for Brain Repair, Department of Clinical NeuroscienceUniversity of CambridgeCambridgeUK
- Department of NeurologyAddenbrooke's HospitalCambridgeUK
- Wellcome Trust MRC Cambridge Stem Cell CentreCambridgeUK
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25
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Rizzello E, Pimpinella D, Pignataro A, Titta G, Merenda E, Saviana M, Porcheddu G, Paolantoni C, Malerba F, Giorgi C, Curia G, Middei S, Marchetti C. Lamotrigine rescues neuronal alterations and prevents seizure-induced memory decline in an Alzheimer's disease mouse model. Neurobiol Dis 2023; 181:106106. [PMID: 37001613 DOI: 10.1016/j.nbd.2023.106106] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2023] [Revised: 03/17/2023] [Accepted: 03/25/2023] [Indexed: 03/31/2023] Open
Abstract
Epilepsy is a comorbidity associated with Alzheimer's disease (AD), often starting many years earlier than memory decline. Investigating this association in the early pre-symptomatic stages of AD can unveil new mechanisms of the pathology as well as guide the use of antiepileptic drugs to prevent or delay hyperexcitability-related pathological effects of AD. We investigated the impact of repeated seizures on hippocampal memory and amyloid-β (Aβ) load in pre-symptomatic Tg2576 mice, a transgenic model of AD. Seizure induction caused memory deficits and an increase in oligomeric Aβ42 and fibrillary species selectively in pre-symptomatic transgenic mice, and not in their wildtype littermates. Electrophysiological patch-clamp recordings in ex vivo CA1 pyramidal neurons and immunoblots were carried out to investigate the neuronal alterations associated with the behavioral outcomes of Tg2576 mice. CA1 pyramidal neurons exhibited increased intrinsic excitability and lower hyperpolarization-activated Ih current. CA1 also displayed lower expression of the hyperpolarization-activated cyclic nucleotide-gated HCN1 subunit, a protein already identified as downregulated in the AD human proteome. The antiepileptic drug lamotrigine restored electrophysiological alterations and prevented both memory deficits and the increase in extracellular Aβ induced by seizures. Thus our study provides evidence of pre-symptomatic hippocampal neuronal alterations leading to hyperexcitability and associated with both higher susceptibility to seizures and to AD-specific seizure-induced memory impairment. Our findings also provide a basis for the use of the antiepileptic drug lamotrigine as a way to counteract acceleration of AD induced by seizures in the early phases of the pathology.
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26
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Gonzalez-Rodriguez P, Zampese E, Surmeier DJ. Disease mechanisms as Subtypes: Mitochondrial and bioenergetic dysfunction. HANDBOOK OF CLINICAL NEUROLOGY 2023; 193:53-66. [PMID: 36803823 DOI: 10.1016/b978-0-323-85555-6.00007-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/18/2023]
Abstract
Parkinson disease (PD) is the second most common neurodegenerative disease in the world. Despite its enormous human and societal cost, there is no disease-modifying therapy for PD. This unmet medical need reflects our limited understanding of PD pathogenesis. One of the most important clues comes from the recognition that PD motor symptoms arises from the dysfunction and degeneration of a very select group of neurons in the brain. These neurons have a distinctive set of anatomic and physiologic traits that reflect their role in brain function. These traits elevate mitochondrial stress, potentially making them particularly vulnerable to age, as well as to genetic mutations and environmental toxins linked to PD incidence. In this chapter, the literature supporting this model is outlined, along with gaps in our knowledge base. The translational implications of this hypothesis are then discussed, with a focus on why disease-modification trials have failed to date and what this means for the development of new strategies for altering disease course.
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Affiliation(s)
- Patricia Gonzalez-Rodriguez
- Instituto de Biomedicina de Sevilla, Hospital Universitario Virgen del Rocío/CSIC/Universidad de Sevilla and CIBERNED, Seville, Spain
| | - Enrico Zampese
- Department of Neuroscience, Feinberg School of Medicine, Northwestern University, Chicago, IL, United States
| | - D James Surmeier
- Department of Neuroscience, Feinberg School of Medicine, Northwestern University, Chicago, IL, United States.
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27
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Inhibition of Voltage-Gated Na + Currents Exerted by KB-R7943 (2-[2-[4-(4-nitrobenzyloxy)phenyl]ethyl]isothiourea), an Inhibitor of Na +-Ca 2+ Exchanging Process. Int J Mol Sci 2023; 24:ijms24021805. [PMID: 36675319 PMCID: PMC9864174 DOI: 10.3390/ijms24021805] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2022] [Revised: 12/21/2022] [Accepted: 01/13/2023] [Indexed: 01/18/2023] Open
Abstract
KB-R7943, an isothiourea derivative, has been recognized as an inhibitor in the reverse mode of the Na+-Ca2+ exchanging process. This compound was demonstrated to prevent intracellular Na+-dependent Ca2+ uptake in intact cells; however, it is much less effective at preventing extracellular Na+-dependent Ca2+ efflux. Therefore, whether or how this compound may produce any perturbations on other types of ionic currents, particularly on voltage-gated Na+ current (INa), needs to be further studied. In this study, the whole-cell current recordings demonstrated that upon abrupt depolarization in pituitary GH3 cells, the exposure to KB-R7943 concentration-dependently depressed the transient (INa(T)) or late component (INa(L)) of INa with an IC50 value of 11 or 0.9 μM, respectively. Likewise, the dissociation constant for the KB-R7943-mediated block of INa on the basis of a minimum reaction scheme was estimated to be 0.97 μM. The presence of benzamil or amiloride could suppress the INa(L) magnitude. The instantaneous window Na+ current (INa(W)) activated by abrupt ascending ramp voltage (Vramp) was suppressed by adding KB-R7943; however, subsequent addition of deltamethrin or tefluthrin (Tef) effectively reversed KB-R7943-inhibted INa(W). With prolonged duration of depolarizing pulses, the INa(L) amplitude became exponentially decreased; moreover, KB-R7943 diminished INa(L) magnitude. The resurgent Na+ current (INa(R)) evoked by a repolarizing Vramp was also suppressed by adding this compound; moreover, subsequent addition of ranolazine or Tef further diminished or reversed, respectively, its reduction in INa(R) magnitude. The persistent Na+ current (INa(P)) activated by sinusoidal voltage waveform became enhanced by Tef; however, subsequent application of KB-R7943 counteracted Tef-stimulated INa(P). The docking prediction reflected that there seem to be molecular interactions of this molecule with the hNaV1.2 or hNaV1.7 channels. Collectively, this study highlights evidence showing that KB-R7943 has the propensity to perturb the magnitude and gating kinetics of INa (e.g., INa(T), INa(L), INa(W), INa(R), and INa(P)) and that the NaV channels appear to be important targets for the in vivo actions of KB-R7943 or other relevant compounds.
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28
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Guo QB, Zhan L, Xu HY, Gao ZB, Zheng YM. SCN8A epileptic encephalopathy mutations display a gain-of-function phenotype and divergent sensitivity to antiepileptic drugs. Acta Pharmacol Sin 2022; 43:3139-3148. [PMID: 35902765 PMCID: PMC9712530 DOI: 10.1038/s41401-022-00955-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2022] [Accepted: 07/05/2022] [Indexed: 11/09/2022] Open
Abstract
De novo missense mutations in SCN8A gene encoding voltage-gated sodium channel NaV1.6 are linked to a severe form of early infantile epileptic encephalopathy named early infantile epileptic encephalopathy type13 (EIEE13). The majority of the patients with EIEE13 does not respond favorably to the antiepileptic drugs (AEDs) in clinic and has a significantly increased risk of death. Although more than 60 EIEE13-associated mutations have been discovered, only few mutations have been functionally analyzed. In this study we investigated the functional influences of mutations N1466T and N1466K, two EIEE13-associated mutations located in the inactivation gate, on sodium channel properties. Sodium currents were recorded from CHO cells expressing the mutant and wide-type (WT) channels using the whole-cell patch-clamp technique. We found that, in comparison with WT channels, both the mutant channels exhibited increased window currents, persistent currents (INaP) and ramp currents, suggesting that N1466T and N1466K were gain-of-function (GoF) mutations. Sodium channel inhibition is one common mechanism of currently available AEDs, in which topiramate (TPM) was effective in controlling seizures of patients carrying either of the two mutations. We found that TPM (100 µM) preferentially inhibited INaP and ramp currents but did not affect transient currents (INaT) mediated by N1466T or N1466K. Among the other 6 sodium channel-inhibiting AEDs tested, phenytoin and carbamazepine displayed greater efficacy than TPM in suppressing both INaP and ramp currents. Functional characterization of mutants N1466T and N1466K is beneficial for understanding the pathogenesis of EIEE13. The divergent effects of sodium channel-inhibiting AEDs on INaP and ramp currents provide insight into the development of therapeutic strategies for the N1466T and N1466K-associated EIEE13.
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Affiliation(s)
- Qian-Bei Guo
- Center for Neurological and Psychiatric Research and Drug Discovery, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, 201203, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Li Zhan
- Center for Neurological and Psychiatric Research and Drug Discovery, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, 201203, China
| | - Hai-Yan Xu
- Center for Neurological and Psychiatric Research and Drug Discovery, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, 201203, China
| | - Zhao-Bing Gao
- Center for Neurological and Psychiatric Research and Drug Discovery, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, 201203, China.
- University of Chinese Academy of Sciences, Beijing, 100049, China.
- Zhongshan Institute for Drug Discovery, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Zhongshan, 528437, China.
| | - Yue-Ming Zheng
- Center for Neurological and Psychiatric Research and Drug Discovery, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, 201203, China.
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29
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Characterization in Inhibitory Effectiveness of Carbamazepine in Voltage-Gated Na + and Erg-Mediated K + Currents in a Mouse Neural Crest-Derived (Neuro-2a) Cell Line. Int J Mol Sci 2022; 23:ijms23147892. [PMID: 35887240 PMCID: PMC9321339 DOI: 10.3390/ijms23147892] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2022] [Revised: 07/15/2022] [Accepted: 07/15/2022] [Indexed: 12/18/2022] Open
Abstract
Carbamazepine (CBZ, Tegretol®) is an anticonvulsant used in the treatment of epilepsy and neuropathic pain; however, several unwanted effects of this drug have been noticed. Therefore, the regulatory actions of CBZ on ionic currents in electrically excitable cells need to be reappraised, although its efficacy in suppressing voltage-gated Na+ current (INa) has been disclosed. This study was undertaken to explore the modifications produced by CBZ on ionic currents (e.g., INa and erg-mediated K+ current [IK(erg)]) measured from Neuro-2a (N2a) cells. In these cells, we found that this drug differentially suppressed the peak (transient, INa(T)) and sustained (late, INa(L)) components of INa in a concentration-dependent manner with effective IC50 of 56 and 18 μM, respectively. The overall current–voltage relationship of INa(T) with or without the addition of CBZ remained unchanged; however, the strength (i.e., ∆area) in the window component of INa (INa(W)) evoked by the short ascending ramp pulse (Vramp) was overly lessened in the CBZ presence. Tefluthrin (Tef), a synthetic pyrethroid, known to stimulate INa, augmented the strength of the voltage-dependent hysteresis (Hys(V)) of persistent INa (INa(P)) in response to the isosceles-triangular Vramp; moreover, further application of CBZ attenuated Tef-mediated accentuation of INa(P)’s Hys(V). With a two-step voltage protocol, the recovery of INa(T) inactivation seen in Neuro-2a cells became progressively slowed by adding CBZ; however, the cumulative inhibition of INa(T) evoked by pulse train stimulation was enhanced during exposure to this drug. Neuro-2a-cell exposure to CBZ (100 μM), the magnitude of erg-mediated K+ current measured throughout the entire voltage-clamp steps applied was mildly inhibited. The docking results regarding the interaction of CBZ and voltage-gate Na+ (NaV) channel predicted the ability of CBZ to bind to some amino-acid residues in NaV due to the existence of a hydrogen bond or hydrophobic contact. It is conceivable from the current investigations that the INa (INa(T), INa(L), INa(W), and INa(P)) residing in Neuro-2a cells are susceptible to being suppressed by CBZ, and that its block on INa(L) is larger than that on INa(T). Collectively, the magnitude and gating of NaV channels produced by the CBZ presence might have an impact on its anticonvulsant and analgesic effects occurring in vivo.
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30
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Yee JX, Rastani A, Soden ME. The potassium channel auxiliary subunit Kvβ2 ( Kcnab2) regulates Kv1 channels and dopamine neuron firing. J Neurophysiol 2022; 128:62-72. [PMID: 35788155 PMCID: PMC9273274 DOI: 10.1152/jn.00194.2022] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Ion channel complexes typically consist of both pore-forming subunits and auxiliary subunits that do not directly conduct current but can regulate trafficking or alter channel properties. Isolating the role of these auxiliary subunits in neurons has proved difficult due to a lack of specific pharmacological agents and the potential for developmental compensation in constitutive knockout models. Here, we use cell-type-specific viral-mediated CRISPR/Cas9 mutagenesis to target the potassium channel auxiliary subunit Kvβ2 (Kcnab2) in dopamine neurons in the adult mouse brain. We find that mutagenesis of Kcnab2 reduces surface expression of Kv1.2, the primary Kv1 pore-forming subunit expressed in dopamine neurons, and shifts the voltage dependence of inactivation of potassium channel currents toward more hyperpolarized potentials. Loss of Kcnab2 broadens the action potential waveform in spontaneously firing dopamine neurons recorded in slice, reduces the afterhyperpolarization amplitude, and increases spike timing irregularity and excitability, all of which is consistent with a reduction in potassium channel current. Similar effects were observed with mutagenesis of the pore-forming subunit Kv1.2 (Kcna2). These results identify Kv1 currents as important contributors to dopamine neuron firing and demonstrate a role for Kvβ2 subunits in regulating the trafficking and gating properties of these ion channels. Furthermore, they demonstrate the utility of CRISPR-mediated mutagenesis in the study of previously difficult to isolate ion channel subunits.NEW & NOTEWORTHY Here, we utilize CRISPR/Cas9-mediated mutagenesis in dopamine neurons in mice to target the gene encoding Kvβ2, an auxiliary subunit that forms a part of Kv1 channel complexes. We find that the absence of Kvβ2 alters action potential properties by reducing surface expression of pore-forming subunits and shifting the voltage dependence of channel inactivation. This work establishes a new function for Kvβ2 subunits and Kv1 complexes in regulating dopamine neuron activity.
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Affiliation(s)
- Joshua X. Yee
- Department of Pharmacology, University of Washington, Seattle, Washington
| | - Ariana Rastani
- Department of Pharmacology, University of Washington, Seattle, Washington
| | - Marta E. Soden
- Department of Pharmacology, University of Washington, Seattle, Washington
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31
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Contribution of tetrodotoxin-resistant persistent Na + currents to the excitability of C-type dural afferent neurons in rats. J Headache Pain 2022; 23:73. [PMID: 35764917 PMCID: PMC9238149 DOI: 10.1186/s10194-022-01443-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2022] [Accepted: 06/20/2022] [Indexed: 01/12/2023] Open
Abstract
BACKGROUND Growing evidence supports the important role of persistent sodium currents (INaP) in the neuronal excitability of various central neurons. However, the role of tetrodotoxin-resistant (TTX-R) Na+ channel-mediated INaP in the neuronal excitability of nociceptive neurons remains poorly understood. METHODS We investigated the functional role of TTX-R INaP in the excitability of C-type nociceptive dural afferent neurons, which was identified using a fluorescent dye, 1,1'-dioctadecyl-3,3,3',3'-tetramethylindocarbocyanine perchloride (DiI), and a whole-cell patch-clamp technique. RESULTS TTX-R INaP were found in most DiI-positive neurons, but their density was proportional to neuronal size. Although the voltage dependence of TTX-R Na+ channels did not differ among DiI-positive neurons, the extent of the onset of slow inactivation, recovery from inactivation, and use-dependent inhibition of these channels was highly correlated with neuronal size and, to a great extent, the density of TTX-R INaP. In the presence of TTX, treatment with a specific INaP inhibitor, riluzole, substantially decreased the number of action potentials generated by depolarizing current injection, suggesting that TTX-R INaP are related to the excitability of dural afferent neurons. In animals treated chronically with inflammatory mediators, the density of TTX-R INaP was significantly increased, and it was difficult to inactivate TTX-R Na+ channels. CONCLUSIONS TTX-R INaP apparently contributes to the differential properties of TTX-R Na+ channels and neuronal excitability. Consequently, the selective modulation of TTX-R INaP could be, at least in part, a new approach for the treatment of migraine headaches.
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Guzmán-Ramos K, Osorio-Gómez D, Bermúdez-Rattoni F. Cognitive impairment in alzheimer’s and metabolic diseases: A catecholaminergic hypothesis. Neuroscience 2022; 497:308-323. [DOI: 10.1016/j.neuroscience.2022.05.031] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2021] [Revised: 05/19/2022] [Accepted: 05/24/2022] [Indexed: 12/16/2022]
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Sharifi P, Bae H, Gveric D, Gentleman SM, Smith PJS, Tierney TS, Alavian KN. CAV2.3 expression is upregulated in the substantia nigra pars compacta of humans with Parkinson's disease. BRAIN DISORDERS 2022. [DOI: 10.1016/j.dscb.2022.100031] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022] Open
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Radulovic J, Ivkovic S, Adzic M. From chronic stress and anxiety to neurodegeneration: Focus on neuromodulation of the axon initial segment. HANDBOOK OF CLINICAL NEUROLOGY 2022; 184:481-495. [PMID: 35034756 DOI: 10.1016/b978-0-12-819410-2.00025-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
To adapt to the sustained demands of chronic stress, discrete brain circuits undergo structural and functional changes often resulting in anxiety disorders. In some individuals, anxiety disorders precede the development of motor symptoms of Parkinson's disease (PD) caused by degeneration of neurons in the substantia nigra (SN). Here, we present a circuit framework for probing a causal link between chronic stress, anxiety, and PD, which postulates a central role of abnormal neuromodulation of the SN's axon initial segment by brainstem inputs. It is grounded in findings demonstrating that the earliest PD pathologies occur in the stress-responsive, emotion regulation network of the brainstem, which provides the SN with dense aminergic and cholinergic innervation. SN's axon initial segment (AIS) has unique features that support the sustained and bidirectional propagation of activity in response to synaptic inputs. It is therefore, especially sensitive to circuit-mediated stress-induced imbalance of neuromodulation, and thus a plausible initiating site of neurodegeneration. This could explain why, although secondary to pathophysiologies in other brainstem nuclei, SN degeneration is the most extensive. Consequently, the cardinal symptom of PD, severe motor deficits, arise from degeneration of the nigrostriatal pathway rather than other brainstem nuclei. Understanding when and how circuit dysfunctions underlying anxiety can progress to neurodegeneration, raises the prospect of timed interventions for reversing, or at least impeding, the early pathophysiologies that lead to PD and possibly other neurodegenerative disorders.
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Affiliation(s)
- Jelena Radulovic
- Department of Neuroscience, Albert Einstein Medical College, Bronx, NY, United States; Department of Psychiatry and Behavioral Sciences, Albert Einstein Medical College, Bronx, NY, United States.
| | - Sanja Ivkovic
- Department of Molecular Biology and Endocrinology, Vinca Institute of Nuclear Sciences, National Institute of the Republic of Serbia, University of Belgrade, Belgrade, Serbia
| | - Miroslav Adzic
- Department of Molecular Biology and Endocrinology, Vinca Institute of Nuclear Sciences, National Institute of the Republic of Serbia, University of Belgrade, Belgrade, Serbia
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Mitochondrial Phenotypes in Parkinson's Diseases-A Focus on Human iPSC-Derived Dopaminergic Neurons. Cells 2021; 10:cells10123436. [PMID: 34943944 PMCID: PMC8699816 DOI: 10.3390/cells10123436] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2021] [Revised: 11/29/2021] [Accepted: 12/02/2021] [Indexed: 12/18/2022] Open
Abstract
Established disease models have helped unravel the mechanistic underpinnings of pathological phenotypes in Parkinson’s disease (PD), the second most common neurodegenerative disorder. However, these discoveries have been limited to relatively simple cellular systems and animal models, which typically manifest with incomplete or imperfect recapitulation of disease phenotypes. The advent of induced pluripotent stem cells (iPSCs) has provided a powerful scientific tool for investigating the underlying molecular mechanisms of both familial and sporadic PD within disease-relevant cell types and patient-specific genetic backgrounds. Overwhelming evidence supports mitochondrial dysfunction as a central feature in PD pathophysiology, and iPSC-based neuronal models have expanded our understanding of mitochondrial dynamics in the development and progression of this devastating disorder. The present review provides a comprehensive assessment of mitochondrial phenotypes reported in iPSC-derived neurons generated from PD patients’ somatic cells, with an emphasis on the role of mitochondrial respiration, morphology, and trafficking, as well as mitophagy and calcium handling in health and disease. Furthermore, we summarize the distinguishing characteristics of vulnerable midbrain dopaminergic neurons in PD and report the unique advantages and challenges of iPSC disease modeling at present, and for future mechanistic and therapeutic applications.
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Ferreira JJ, Amazu C, Puga-Molina LC, Ma X, England SK, Santi CM. SLO2.1/NALCN a sodium signaling complex that regulates uterine activity. iScience 2021; 24:103210. [PMID: 34746693 PMCID: PMC8551532 DOI: 10.1016/j.isci.2021.103210] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2021] [Revised: 07/29/2021] [Accepted: 09/29/2021] [Indexed: 01/05/2023] Open
Abstract
Depolarization of the myometrial smooth muscle cell (MSMC) resting membrane potential is necessary for the uterus to transition from a quiescent state to a contractile state. The molecular mechanisms involved in this transition are not completely understood. Here, we report that a coupled system between the Na+-activated K+ channel (SLO2.1) and the non-selective Na+ leak channel (NALCN) determines the MSMC membrane potential. Our data indicate that Na+ entering through NALCN acts as an intracellular signaling molecule that activates SLO2.1. Potassium efflux through SLO2.1 hyperpolarizes the membrane. A decrease in SLO2.1/NALCN activity induces membrane depolarization, triggering Ca2+ entry through voltage-dependent Ca2+ channels and promoting contraction. Consistent with functional coupling, our data show that NALCN and SLO2.1 are in close proximity in human MSMCs. We propose that these arrangements of SLO2.1 and NALCN permit these channels to functionally regulate MSMC membrane potential and cell excitability and modulate uterine contractility.
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Affiliation(s)
- Juan J. Ferreira
- Department of Obstetrics and Gynecology, Center for Reproductive Health Sciences, Washington University in St. Louis, School of Medicine, 425 S. Euclid Avenue, CB 8064, St. Louis, MO 63110, USA
- Department of Neuroscience, Washington University in St. Louis, School of Medicine, St. Louis, MO 63110, USA
| | - Chinwendu Amazu
- Department of Obstetrics and Gynecology, Center for Reproductive Health Sciences, Washington University in St. Louis, School of Medicine, 425 S. Euclid Avenue, CB 8064, St. Louis, MO 63110, USA
| | - Lis C. Puga-Molina
- Department of Obstetrics and Gynecology, Center for Reproductive Health Sciences, Washington University in St. Louis, School of Medicine, 425 S. Euclid Avenue, CB 8064, St. Louis, MO 63110, USA
| | - Xiaofeng Ma
- Department of Obstetrics and Gynecology, Center for Reproductive Health Sciences, Washington University in St. Louis, School of Medicine, 425 S. Euclid Avenue, CB 8064, St. Louis, MO 63110, USA
| | - Sarah K. England
- Department of Obstetrics and Gynecology, Center for Reproductive Health Sciences, Washington University in St. Louis, School of Medicine, 425 S. Euclid Avenue, CB 8064, St. Louis, MO 63110, USA
| | - Celia M. Santi
- Department of Obstetrics and Gynecology, Center for Reproductive Health Sciences, Washington University in St. Louis, School of Medicine, 425 S. Euclid Avenue, CB 8064, St. Louis, MO 63110, USA
- Department of Neuroscience, Washington University in St. Louis, School of Medicine, St. Louis, MO 63110, USA
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Nakamura M, Jang IS. Propranolol modulation of tetrodotoxin-resistant Na + channels in dural afferent neurons. Eur J Pharmacol 2021; 910:174449. [PMID: 34454925 DOI: 10.1016/j.ejphar.2021.174449] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2021] [Revised: 08/25/2021] [Accepted: 08/25/2021] [Indexed: 10/20/2022]
Abstract
Propranolol, a representative adrenergic β-receptor antagonist, is widely used to prevent migraine attacks. Although propranolol is well known to inhibit tetrodotoxin-resistant (TTX-R) Na+ channels in cardiac myocytes, it is unclear whether the drug modulates these channels expressed in dural afferent neurons. In this study, we examined the effects of propranolol on TTX-R Na+ channels in medium-sized dural afferent neurons identified by the fluorescent dye DiI. The TTX-R Na+ currents (INa) were recorded from acutely isolated DiI-positive neurons using a whole-cell patch clamp technique under voltage-clamp conditions. Propranolol inhibited the noninactivating steady-state component more potently than the peak component of transient TTX-R INa. Propranolol also potently inhibited the slow voltage ramp-induced TTX-R INa in a concentration-dependent manner, suggesting that it preferentially inhibited the noninactivating or persistent INa in DiI-positive neurons. Propranolol had little effect on voltage dependence, but it increased the extent of the use-dependent inhibition of TTX-R Na+ channels. Propranolol also accelerated the onset of inactivation and retarded recovery from inactivation in these channels. Under current-clamp conditions, propranolol decreased the number of action potentials elicited by depolarizing current stimuli. In conclusion, the propranolol-mediated preferential inhibition of persistent INa and modulation of the inactivation kinetics of TTX-R Na+ channels might represent additional mechanisms for migraine prophylaxis.
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Affiliation(s)
- Michiko Nakamura
- Department of Pharmacology, School of Dentistry, Kyungpook National University, Daegu, 41940, Republic of Korea; Brain Science & Engineering Institute, Kyungpook National University, Daegu, 41940, Republic of Korea
| | - Il-Sung Jang
- Department of Pharmacology, School of Dentistry, Kyungpook National University, Daegu, 41940, Republic of Korea; Brain Science & Engineering Institute, Kyungpook National University, Daegu, 41940, Republic of Korea.
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Pirooznia SK, Rosenthal LS, Dawson VL, Dawson TM. Parkinson Disease: Translating Insights from Molecular Mechanisms to Neuroprotection. Pharmacol Rev 2021; 73:33-97. [PMID: 34663684 DOI: 10.1124/pharmrev.120.000189] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Parkinson disease (PD) used to be considered a nongenetic condition. However, the identification of several autosomal dominant and recessive mutations linked to monogenic PD has changed this view. Clinically manifest PD is then thought to occur through a complex interplay between genetic mutations, many of which have incomplete penetrance, and environmental factors, both neuroprotective and increasing susceptibility, which variably interact to reach a threshold over which PD becomes clinically manifested. Functional studies of PD gene products have identified many cellular and molecular pathways, providing crucial insights into the nature and causes of PD. PD originates from multiple causes and a range of pathogenic processes at play, ultimately culminating in nigral dopaminergic loss and motor dysfunction. An in-depth understanding of these complex and possibly convergent pathways will pave the way for therapeutic approaches to alleviate the disease symptoms and neuroprotective strategies to prevent disease manifestations. This review is aimed at providing a comprehensive understanding of advances made in PD research based on leveraging genetic insights into the pathogenesis of PD. It further discusses novel perspectives to facilitate identification of critical molecular pathways that are central to neurodegeneration that hold the potential to develop neuroprotective and/or neurorestorative therapeutic strategies for PD. SIGNIFICANCE STATEMENT: A comprehensive review of PD pathophysiology is provided on the complex interplay of genetic and environmental factors and biologic processes that contribute to PD pathogenesis. This knowledge identifies new targets that could be leveraged into disease-modifying therapies to prevent or slow neurodegeneration in PD.
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Affiliation(s)
- Sheila K Pirooznia
- Neuroregeneration and Stem Cell Programs, Institute for Cell Engineering (S.K.P., V.L.D., T.M.D.), Departments of Neurology (S.K.P., L.S.R., V.L.D., T.M.D.), Departments of Physiology (V.L.D.), Solomon H. Snyder Department of Neuroscience (V.L.D., T.M.D.), Department of Pharmacology and Molecular Sciences (T.M.D.), Johns Hopkins University School of Medicine, Baltimore, Maryland; Adrienne Helis Malvin Medical Research Foundation, New Orleans, Louisiana (S.K.P., V.L.D., T.M.D.); and Diana Helis Henry Medical Research Foundation, New Orleans, Louisiana (S.K.P., V.L.D., T.M.D.)
| | - Liana S Rosenthal
- Neuroregeneration and Stem Cell Programs, Institute for Cell Engineering (S.K.P., V.L.D., T.M.D.), Departments of Neurology (S.K.P., L.S.R., V.L.D., T.M.D.), Departments of Physiology (V.L.D.), Solomon H. Snyder Department of Neuroscience (V.L.D., T.M.D.), Department of Pharmacology and Molecular Sciences (T.M.D.), Johns Hopkins University School of Medicine, Baltimore, Maryland; Adrienne Helis Malvin Medical Research Foundation, New Orleans, Louisiana (S.K.P., V.L.D., T.M.D.); and Diana Helis Henry Medical Research Foundation, New Orleans, Louisiana (S.K.P., V.L.D., T.M.D.)
| | - Valina L Dawson
- Neuroregeneration and Stem Cell Programs, Institute for Cell Engineering (S.K.P., V.L.D., T.M.D.), Departments of Neurology (S.K.P., L.S.R., V.L.D., T.M.D.), Departments of Physiology (V.L.D.), Solomon H. Snyder Department of Neuroscience (V.L.D., T.M.D.), Department of Pharmacology and Molecular Sciences (T.M.D.), Johns Hopkins University School of Medicine, Baltimore, Maryland; Adrienne Helis Malvin Medical Research Foundation, New Orleans, Louisiana (S.K.P., V.L.D., T.M.D.); and Diana Helis Henry Medical Research Foundation, New Orleans, Louisiana (S.K.P., V.L.D., T.M.D.)
| | - Ted M Dawson
- Neuroregeneration and Stem Cell Programs, Institute for Cell Engineering (S.K.P., V.L.D., T.M.D.), Departments of Neurology (S.K.P., L.S.R., V.L.D., T.M.D.), Departments of Physiology (V.L.D.), Solomon H. Snyder Department of Neuroscience (V.L.D., T.M.D.), Department of Pharmacology and Molecular Sciences (T.M.D.), Johns Hopkins University School of Medicine, Baltimore, Maryland; Adrienne Helis Malvin Medical Research Foundation, New Orleans, Louisiana (S.K.P., V.L.D., T.M.D.); and Diana Helis Henry Medical Research Foundation, New Orleans, Louisiana (S.K.P., V.L.D., T.M.D.)
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Sodium background currents in endocrine/neuroendocrine cells: Towards unraveling channel identity and contribution in hormone secretion. Front Neuroendocrinol 2021; 63:100947. [PMID: 34592201 DOI: 10.1016/j.yfrne.2021.100947] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/16/2021] [Revised: 09/03/2021] [Accepted: 09/23/2021] [Indexed: 02/04/2023]
Abstract
In endocrine/neuroendocrine tissues, excitability of secretory cells is patterned by the repertoire of ion channels and there is clear evidence that extracellular sodium (Na+) ions contribute to hormone secretion. While voltage-gated channels involved in action potential generation are well-described, the background 'leak' channels operating near the resting membrane potential are much less known, and in particular the channels supporting a background entry of Na+ ions. These background Na+ currents (called here 'INab') have the ability to modulate the resting membrane potential and subsequently affect action potential firing. Here we compile and analyze the data collected from three endocrine/neuroendocrine tissues: the anterior pituitary gland, the adrenal medulla and the endocrine pancreas. We also model how INab can be functionally involved in cellular excitability. Finally, towards deciphering the physiological role of INab in endocrine/neuroendocrine cells, its implication in hormone release is also discussed.
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40
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Prieto ML, Firouzi K, Khuri-Yakub BT, Madison DV, Maduke M. Spike frequency-dependent inhibition and excitation of neural activity by high-frequency ultrasound. J Gen Physiol 2021; 152:182190. [PMID: 33074301 PMCID: PMC7534904 DOI: 10.1085/jgp.202012672] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2020] [Accepted: 09/14/2020] [Indexed: 01/09/2023] Open
Abstract
Ultrasound can modulate action potential firing in vivo and in vitro, but the mechanistic basis of this phenomenon is not well understood. To address this problem, we used patch-clamp recording to quantify the effects of focused, high-frequency (43 MHz) ultrasound on evoked action potential firing in CA1 pyramidal neurons in acute rodent hippocampal brain slices. We find that ultrasound can either inhibit or potentiate firing in a spike frequency–dependent manner: at low (near-threshold) input currents and low firing frequencies, ultrasound inhibits firing, while at higher input currents and higher firing frequencies, ultrasound potentiates firing. The net result of these two competing effects is that ultrasound increases the threshold current for action potential firing, the slope of frequency-input curves, and the maximum firing frequency. In addition, ultrasound slightly hyperpolarizes the resting membrane potential, decreases action potential width, and increases the depth of the after-hyperpolarization. All of these results can be explained by the hypothesis that ultrasound activates a sustained potassium conductance. According to this hypothesis, increased outward potassium currents hyperpolarize the resting membrane potential and inhibit firing at near-threshold input currents but potentiate firing in response to higher-input currents by limiting inactivation of voltage-dependent sodium channels during the action potential. This latter effect is a consequence of faster action potential repolarization, which limits inactivation of voltage-dependent sodium channels, and deeper (more negative) after-hyperpolarization, which increases the rate of recovery from inactivation. Based on these results, we propose that ultrasound activates thermosensitive and mechanosensitive two-pore-domain potassium (K2P) channels through heating or mechanical effects of acoustic radiation force. Finite-element modeling of the effects of ultrasound on brain tissue suggests that the effects of ultrasound on firing frequency are caused by a small (<2°C) increase in temperature, with possible additional contributions from mechanical effects.
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Affiliation(s)
- Martin Loynaz Prieto
- Department of Molecular and Cellular Physiology, Stanford University, Stanford, CA
| | - Kamyar Firouzi
- E.L. Ginzton Laboratory, Stanford University, Stanford, CA
| | | | - Daniel V Madison
- Department of Molecular and Cellular Physiology, Stanford University, Stanford, CA
| | - Merritt Maduke
- Department of Molecular and Cellular Physiology, Stanford University, Stanford, CA
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Um KB, Hahn S, Kim SW, Lee YJ, Birnbaumer L, Kim HJ, Park MK. TRPC3 and NALCN channels drive pacemaking in substantia nigra dopaminergic neurons. eLife 2021; 10:70920. [PMID: 34409942 PMCID: PMC8456572 DOI: 10.7554/elife.70920] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2021] [Accepted: 08/18/2021] [Indexed: 01/16/2023] Open
Abstract
Midbrain dopamine (DA) neurons are slow pacemakers that maintain extracellular DA levels. During the interspike intervals, subthreshold slow depolarization underlies autonomous pacemaking and determines its rate. However, the ion channels that determine slow depolarization are unknown. Here we show that TRPC3 and NALCN channels together form sustained inward currents responsible for the slow depolarization of nigral DA neurons. Specific TRPC3 channel blockade completely blocked DA neuron pacemaking, but the pacemaking activity in TRPC3 knock-out (KO) mice was perfectly normal, suggesting the presence of compensating ion channels. Blocking NALCN channels abolished pacemaking in both TRPC3 KO and wild-type mice. The NALCN current and mRNA and protein expression are increased in TRPC3 KO mice, indicating that NALCN compensates for TRPC3 currents. In normal conditions, TRPC3 and NALCN contribute equally to slow depolarization. Therefore, we conclude that TRPC3 and NALCN are two major leak channels that drive robust pacemaking in nigral DA neurons.
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Affiliation(s)
- Ki Bum Um
- Department of physiology, Sungkyunkwan University School of Medicine, Suwon, Republic of Korea
| | - Suyun Hahn
- Department of physiology, Sungkyunkwan University School of Medicine, Suwon, Republic of Korea
| | - So Woon Kim
- Department of physiology, Sungkyunkwan University School of Medicine, Suwon, Republic of Korea
| | - Yoon Je Lee
- Department of physiology, Sungkyunkwan University School of Medicine, Suwon, Republic of Korea
| | - Lutz Birnbaumer
- Neurobiology Laboratory. National Institute of Environmental Health Sciences, North Carolina 27709, USA; and Institute of Biomedical Research (BIOMED), Catholic University of Argentina, Buenos Aires, Argentina
| | - Hyun Jin Kim
- Department of physiology, Sungkyunkwan University School of Medicine, Suwon, Republic of Korea.,Samsung Biomedical Research Institute, Samsung Medical Center, Seoul, Republic of Korea
| | - Myoung Kyu Park
- Department of physiology, Sungkyunkwan University School of Medicine, Suwon, Republic of Korea.,Samsung Biomedical Research Institute, Samsung Medical Center, Seoul, Republic of Korea
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Jan A, Gonçalves NP, Vaegter CB, Jensen PH, Ferreira N. The Prion-Like Spreading of Alpha-Synuclein in Parkinson's Disease: Update on Models and Hypotheses. Int J Mol Sci 2021; 22:8338. [PMID: 34361100 PMCID: PMC8347623 DOI: 10.3390/ijms22158338] [Citation(s) in RCA: 43] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2021] [Revised: 07/29/2021] [Accepted: 07/30/2021] [Indexed: 12/11/2022] Open
Abstract
The pathological aggregation of the presynaptic protein α-synuclein (α-syn) and propagation through synaptically coupled neuroanatomical tracts is increasingly thought to underlie the pathophysiological progression of Parkinson's disease (PD) and related synucleinopathies. Although the precise molecular mechanisms responsible for the spreading of pathological α-syn accumulation in the CNS are not fully understood, growing evidence suggests that de novo α-syn misfolding and/or neuronal internalization of aggregated α-syn facilitates conformational templating of endogenous α-syn monomers in a mechanism reminiscent of prions. A refined understanding of the biochemical and cellular factors mediating the pathological neuron-to-neuron propagation of misfolded α-syn will potentially elucidate the etiology of PD and unravel novel targets for therapeutic intervention. Here, we discuss recent developments on the hypothesis regarding trans-synaptic propagation of α-syn pathology in the context of neuronal vulnerability and highlight the potential utility of novel experimental models of synucleinopathies.
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Affiliation(s)
- Asad Jan
- Danish Research Institute of Translational Neuroscience (DANDRITE), Nordic EMBL Partnership for Molecular Medicine, Department of Biomedicine, Aarhus University, 8000 Aarhus, Denmark; (N.P.G.); (C.B.V.); (P.H.J.)
| | - Nádia Pereira Gonçalves
- Danish Research Institute of Translational Neuroscience (DANDRITE), Nordic EMBL Partnership for Molecular Medicine, Department of Biomedicine, Aarhus University, 8000 Aarhus, Denmark; (N.P.G.); (C.B.V.); (P.H.J.)
- International Diabetic Neuropathy Consortium (IDNC), Aarhus University Hospital, 8200 Aarhus, Denmark
| | - Christian Bjerggaard Vaegter
- Danish Research Institute of Translational Neuroscience (DANDRITE), Nordic EMBL Partnership for Molecular Medicine, Department of Biomedicine, Aarhus University, 8000 Aarhus, Denmark; (N.P.G.); (C.B.V.); (P.H.J.)
- International Diabetic Neuropathy Consortium (IDNC), Aarhus University Hospital, 8200 Aarhus, Denmark
| | - Poul Henning Jensen
- Danish Research Institute of Translational Neuroscience (DANDRITE), Nordic EMBL Partnership for Molecular Medicine, Department of Biomedicine, Aarhus University, 8000 Aarhus, Denmark; (N.P.G.); (C.B.V.); (P.H.J.)
| | - Nelson Ferreira
- Danish Research Institute of Translational Neuroscience (DANDRITE), Nordic EMBL Partnership for Molecular Medicine, Department of Biomedicine, Aarhus University, 8000 Aarhus, Denmark; (N.P.G.); (C.B.V.); (P.H.J.)
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The gating pore blocker 1-(2,4-xylyl)guanidinium selectively inhibits pacemaking of midbrain dopaminergic neurons. Neuropharmacology 2021; 197:108722. [PMID: 34273387 DOI: 10.1016/j.neuropharm.2021.108722] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2021] [Revised: 07/08/2021] [Accepted: 07/13/2021] [Indexed: 11/22/2022]
Abstract
Although several ionic mechanisms are known to control rate and regularity of the slow pacemaker in dopamine (DA) neurons, the core mechanism of pacing is controversial. Here we tested the hypothesis that pacemaking of SNc DA neurons is enabled by an unconventional conductance. We found that 1-(2,4-xylyl)guanidinium (XG), an established blocker of gating pore currents, selectively inhibits pacemaking of DA neurons. The compound inhibited all slow pacemaking DA neurons that were tested, both in the substantia nigra pars compacta, and in the ventral tegmental area. Interestingly, bursting behavior was not affected by XG. Furthermore, the drug did not affect fast pacemaking of GABAergic neurons from substantia nigra pars reticulata neurons or slow pacemaking of noradrenergic neurons. In DA neurons, current-clamp analysis revealed that XG did not appear to affect ion channels involved in the action potential. Its inhibitory effect persisted during blockade of all ion channels previously suggested to contribute to pacemaking. RNA sequencing and voltage-clamp recordings yielded no evidence for a gating pore current to underlie the conductance. However, we could isolate a small subthreshold XG-sensitive current, which was carried by both Na+ and Cl- ions. Although the molecular target of XG remains to be defined, these observations represent a step towards understanding pacemaking in DA neurons.
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Paß T, Wiesner RJ, Pla-Martín D. Selective Neuron Vulnerability in Common and Rare Diseases-Mitochondria in the Focus. Front Mol Biosci 2021; 8:676187. [PMID: 34295920 PMCID: PMC8290884 DOI: 10.3389/fmolb.2021.676187] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2021] [Accepted: 06/08/2021] [Indexed: 12/12/2022] Open
Abstract
Mitochondrial dysfunction is a central feature of neurodegeneration within the central and peripheral nervous system, highlighting a strong dependence on proper mitochondrial function of neurons with especially high energy consumptions. The fitness of mitochondria critically depends on preservation of distinct processes, including the maintenance of their own genome, mitochondrial dynamics, quality control, and Ca2+ handling. These processes appear to be differently affected in common neurodegenerative diseases, such as Alzheimer’s and Parkinson’s disease, as well as in rare neurological disorders, including Huntington’s disease, Amyotrophic Lateral Sclerosis and peripheral neuropathies. Strikingly, particular neuron populations of different morphology and function perish in these diseases, suggesting that cell-type specific factors contribute to the vulnerability to distinct mitochondrial defects. Here we review the disruption of mitochondrial processes in common as well as in rare neurological disorders and its impact on selective neurodegeneration. Understanding discrepancies and commonalities regarding mitochondrial dysfunction as well as individual neuronal demands will help to design new targets and to make use of already established treatments in order to improve treatment of these diseases.
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Affiliation(s)
- Thomas Paß
- Center for Physiology and Pathophysiology, Institute of Vegetative Physiology, University of Cologne, Cologne, Germany
| | - Rudolf J Wiesner
- Center for Physiology and Pathophysiology, Institute of Vegetative Physiology, University of Cologne, Cologne, Germany.,Cologne Excellence Cluster on Cellular Stress Responses in Aging Associated Diseases (CECAD), University of Cologne, Cologne, Germany
| | - David Pla-Martín
- Center for Physiology and Pathophysiology, Institute of Vegetative Physiology, University of Cologne, Cologne, Germany
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Behl T, Kaur I, Sehgal A, Singh S, Bhatia S, Al-Harrasi A, Zengin G, Bumbu AG, Andronie-Cioara FL, Nechifor AC, Gitea D, Bungau AF, Toma MM, Bungau SG. The Footprint of Kynurenine Pathway in Neurodegeneration: Janus-Faced Role in Parkinson's Disorder and Therapeutic Implications. Int J Mol Sci 2021; 22:6737. [PMID: 34201647 PMCID: PMC8268239 DOI: 10.3390/ijms22136737] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2021] [Revised: 06/17/2021] [Accepted: 06/21/2021] [Indexed: 02/06/2023] Open
Abstract
Progressive degeneration of neurons and aggravation of dopaminergic neurons in the substantia nigra pars compacta results in the loss of dopamine in the brain of Parkinson's disease (PD) patients. Numerous therapies, exhibiting transient efficacy have been developed; however, they are mostly accompanied by side effects and limited reliability, therefore instigating the need to develop novel optimistic treatment targets. Significant therapeutic targets have been identified, namely: chaperones, protein Abelson, glucocerebrosidase-1, calcium, neuromelanin, ubiquitin-proteasome system, neuroinflammation, mitochondrial dysfunction, and the kynurenine pathway (KP). The role of KP and its metabolites and enzymes in PD, namely quinolinic acid (QUIN), kynurenic acid (KYNA), 3-hydroxykynurenine (3-HK), 3-hydroxyanthranillic acid (3-HAA), kunurenine-3-monooxygenase (KMO), etc. has been reported. The neurotoxic QUIN, N-methyl-D-aspartate (NMDA) receptor agonist, and neuroprotective KYNA-which antagonizes QUIN actions-primarily justify the Janus-faced role of KP in PD. Moreover, KP has been reported to play a biomarker role in PD detection. Therefore, the authors detail the neurotoxic, neuroprotective, and immunomodulatory neuroactive components, alongside the upstream and downstream metabolic pathways of KP, forming a basis for a therapeutic paradigm of the disease while recognizing KP as a potential biomarker in PD, thus facilitating the development of a suitable target in PD management.
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Affiliation(s)
- Tapan Behl
- Department of Pharmacology, Chitkara College of Pharmacy, Chitkara University, Punjab 140401, India; (I.K.); (A.S.); (S.S.)
| | - Ishnoor Kaur
- Department of Pharmacology, Chitkara College of Pharmacy, Chitkara University, Punjab 140401, India; (I.K.); (A.S.); (S.S.)
| | - Aayush Sehgal
- Department of Pharmacology, Chitkara College of Pharmacy, Chitkara University, Punjab 140401, India; (I.K.); (A.S.); (S.S.)
| | - Sukhbir Singh
- Department of Pharmacology, Chitkara College of Pharmacy, Chitkara University, Punjab 140401, India; (I.K.); (A.S.); (S.S.)
| | - Saurabh Bhatia
- Amity Institute of Pharmacy, Amity University, Gurugram, Haryana 122412, India;
- Natural and Medical Sciences Research Centre, University of Nizwa, P.O. Box 33, PC 616 Birkat Al Mouz, Nizwa 611, Oman;
| | - Ahmed Al-Harrasi
- Natural and Medical Sciences Research Centre, University of Nizwa, P.O. Box 33, PC 616 Birkat Al Mouz, Nizwa 611, Oman;
| | - Gokhan Zengin
- Department of Biology, Faculty of Science, Selcuk University Campus, Konya 42130, Turkey;
| | - Adrian Gheorghe Bumbu
- Department of Surgical Disciplines, Faculty of Medicine and Pharmacy, University of Oradea, 410073 Oradea, Romania;
| | - Felicia Liana Andronie-Cioara
- Department of Psycho-Neuroscience and Recovery, Faculty of Medicine and Pharmacy, University of Oradea, 410073 Oradea, Romania;
| | - Aurelia Cristina Nechifor
- Analytical Chemistry and Environmental Engineering Department, Polytechnic University of Bucharest, 011061 Bucharest, Romania;
| | - Daniela Gitea
- Department of Pharmacy, Faculty of Medicine and Pharmacy, University of Oradea, 410028 Oradea, Romania; (D.G.); (M.M.T.)
| | | | - Mirela Marioara Toma
- Department of Pharmacy, Faculty of Medicine and Pharmacy, University of Oradea, 410028 Oradea, Romania; (D.G.); (M.M.T.)
- Doctoral School of Biomedical Sciences, University of Oradea, 410087 Oradea, Romania
| | - Simona Gabriela Bungau
- Department of Pharmacy, Faculty of Medicine and Pharmacy, University of Oradea, 410028 Oradea, Romania; (D.G.); (M.M.T.)
- Doctoral School of Biomedical Sciences, University of Oradea, 410087 Oradea, Romania
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Liu C, Goel P, Kaeser PS. Spatial and temporal scales of dopamine transmission. Nat Rev Neurosci 2021; 22:345-358. [PMID: 33837376 PMCID: PMC8220193 DOI: 10.1038/s41583-021-00455-7] [Citation(s) in RCA: 101] [Impact Index Per Article: 33.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/04/2021] [Indexed: 02/02/2023]
Abstract
Dopamine is a prototypical neuromodulator that controls circuit function through G protein-coupled receptor signalling. Neuromodulators are volume transmitters, with release followed by diffusion for widespread receptor activation on many target cells. Yet, we are only beginning to understand the specific organization of dopamine transmission in space and time. Although some roles of dopamine are mediated by slow and diffuse signalling, recent studies suggest that certain dopamine functions necessitate spatiotemporal precision. Here, we review the literature describing dopamine signalling in the striatum, including its release mechanisms and receptor organization. We then propose the domain-overlap model, in which release and receptors are arranged relative to one another in micrometre-scale structures. This architecture is different from both point-to-point synaptic transmission and the widespread organization that is often proposed for neuromodulation. It enables the activation of receptor subsets that are within micrometre-scale domains of release sites during baseline activity and broader receptor activation with domain overlap when firing is synchronized across dopamine neuron populations. This signalling structure, together with the properties of dopamine release, may explain how switches in firing modes support broad and dynamic roles for dopamine and may lead to distinct pathway modulation.
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Affiliation(s)
- Changliang Liu
- Department of Neurobiology, Harvard Medical School, Boston, MA, USA
| | - Pragya Goel
- Department of Neurobiology, Harvard Medical School, Boston, MA, USA
| | - Pascal S Kaeser
- Department of Neurobiology, Harvard Medical School, Boston, MA, USA.
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Sevoflurane excites nociceptive sensory neurons by inhibiting K + conductances in rats. Neurosci Lett 2021; 756:135951. [PMID: 33984431 DOI: 10.1016/j.neulet.2021.135951] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2021] [Revised: 05/05/2021] [Accepted: 05/07/2021] [Indexed: 11/23/2022]
Abstract
Sevoflurane, which is preferentially used as a day-case anesthetic based on its low blood solubility, acts on the central nervous system and exerts analgesic effects. However, it still remains unknown whether sevoflurane affects the excitability of nociceptive sensory neurons. Therefore, we conducted this study to examine the effects of sevoflurane on the excitability of small-sized dorsal root ganglion (DRG) neurons of rats using the whole-cell patch-clamp technique. In a voltage-clamp condition, sevoflurane elicited the membrane current in a concentration-dependent manner, in which the reversal potential was similar to the equilibrium potential of K+. In a current-clamp condition, sevoflurane directly depolarized the membrane potentials in a concentration-dependent manner. Moreover, at a clinically relevant concentration, sevoflurane decreased the threshold for action potential generation. These findings suggest that sevoflurane acts on the leak K+ channels to increase the excitability of DRG neurons. Sevoflurane increased the half-width of single action potentials, which resulted from the inhibition of voltage-gated K+ currents, including the fast inactivating A-type and non-inactivating delayed rectifier K+ currents. Our study indicates that sevoflurane could exhibit pronociceptive effects on nociceptive sensory neurons by inhibiting K+ conductances.
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Na + leak-current channel (NALCN) at the junction of motor and neuropsychiatric symptoms in Parkinson's disease. J Neural Transm (Vienna) 2021; 128:749-762. [PMID: 33961117 DOI: 10.1007/s00702-021-02348-6] [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: 02/10/2021] [Accepted: 04/30/2021] [Indexed: 12/27/2022]
Abstract
Parkinson's disease (PD) is a debilitating movement disorder often accompanied by neuropsychiatric symptoms that stem from the loss of dopaminergic function in the basal ganglia and altered neurotransmission more generally. Akinesia, postural instability, tremors and frozen gait constitute the major motor disturbances, whereas neuropsychiatric symptoms include altered circadian rhythms, disordered sleep, depression, psychosis and cognitive impairment. Evidence is emerging that the motor and neuropsychiatric symptoms may share etiologic factors. Calcium/ion channels (CACNA1C, NALCN), synaptic proteins (SYNJ1) and neuronal RNA-binding proteins (RBFOX1) are among the risk genes that are common to PD and various psychiatric disorders. The Na+ leak-current channel (NALCN) is the focus of this review because it has been implicated in dystonia, regulation of movement, cognitive impairment, sleep and circadian rhythms. It regulates the resting membrane potential in neurons, mediates pace-making activity, participates in synaptic vesicle recycling and is functionally co-localized to the endoplasmic reticulum (ER)-several of the major processes adversely affected in PD. Here, we summarize the literature on mechanisms and pathways that connect the motor and neuropsychiatric symptoms of PD with a focus on recurring relationships to the NALCN. It is hoped that the various connections outlined here will stimulate further discussion, suggest additional areas for exploration and ultimately inspire novel treatment strategies.
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Mechanism of Pacemaker Activity in Zebrafish DC2/4 Dopaminergic Neurons. J Neurosci 2021; 41:4141-4157. [PMID: 33731451 DOI: 10.1523/jneurosci.2124-20.2021] [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: 08/12/2020] [Revised: 02/02/2021] [Accepted: 02/07/2021] [Indexed: 11/21/2022] Open
Abstract
Zebrafish models are used increasingly to study the molecular pathogenesis of Parkinson's disease (PD), owing to the extensive array of techniques available for their experimental manipulation and analysis. The ascending dopaminergic projection from the posterior tuberculum (TPp; diencephalic populations DC2 and DC4) to the subpallium is considered the zebrafish correlate of the mammalian nigrostriatal projection, but little is known about the neurophysiology of zebrafish DC2/4 neurons. This is an important knowledge gap, because autonomous activity in mammalian substantia nigra (SNc) dopaminergic neurons contributes to their vulnerability in PD models. Using a new transgenic zebrafish line to label living dopaminergic neurons, and a novel brain slice preparation, we conducted whole-cell patch clamp recordings of DC2/4 neurons from adult zebrafish of both sexes. Zebrafish DC2/4 neurons share many physiological properties with mammalian dopaminergic neurons, including the cell-autonomous generation of action potentials. However, in contrast to mammalian dopaminergic neurons, the pacemaker driving intrinsic rhythmic activity in zebrafish DC2/4 neurons does not involve calcium conductances, hyperpolarization-activated cyclic nucleotide-gated (HCN) channels, or sodium leak currents. Instead, voltage clamp recordings and computational models show that interactions between three components - a small, predominantly potassium, leak conductance, voltage-gated sodium channels, and voltage-gated potassium channels - are sufficient for pacemaker activity in zebrafish DC2/4 neurons. These results contribute to understanding the comparative physiology of the dopaminergic system and provide a conceptual basis for interpreting data derived from zebrafish PD models. The findings further suggest new experimental opportunities to address the role of dopaminergic pacemaker activity in the pathogenesis of PD.SIGNIFICANCE STATEMENT Posterior tuberculum (TPp) DC2/4 dopaminergic neurons are considered the zebrafish correlate of mammalian substantia nigra (SNc) neurons, whose degeneration causes the motor signs of Parkinson's disease (PD). Our study shows that DC2/4 and SNc neurons share a number of electrophysiological properties, including depolarized membrane potential, high input resistance, and continual, cell-autonomous pacemaker activity, that strengthen the basis for the increasing use of zebrafish models to study the molecular pathogenesis of PD. The mechanisms driving pacemaker activity differ between DC2/4 and SNc neurons, providing: (1) experimental opportunities to dissociate the contributions of intrinsic activity and underlying pacemaker currents to pathogenesis; and (2) essential information for the design and interpretation of studies using zebrafish PD models.
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Hikima T, Lee CR, Witkovsky P, Chesler J, Ichtchenko K, Rice ME. Activity-dependent somatodendritic dopamine release in the substantia nigra autoinhibits the releasing neuron. Cell Rep 2021; 35:108951. [PMID: 33826884 PMCID: PMC8189326 DOI: 10.1016/j.celrep.2021.108951] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2019] [Revised: 11/20/2020] [Accepted: 03/15/2021] [Indexed: 12/12/2022] Open
Abstract
Somatodendritic dopamine (DA) release from midbrain DA neurons activates D2 autoreceptors on these cells to regulate their activity. However, the source of autoregulatory DA remains controversial. Here, we test the hypothesis that D2 autoreceptors on a given DA neuron in the substantia nigra pars compacta (SNc) are activated primarily by DA released from that same cell, rather than from its neighbors. Voltage-clamp recording allows monitoring of evoked D2-receptor-mediated inhibitory currents (D2ICs) in SNc DA neurons as an index of DA release. Single-cell application of antibodies to Na+ channels via the recording pipette decreases spontaneous activity of recorded neurons and attenuates evoked D2ICs; antibodies to SNAP-25, a soluble N-ethylmaleimide-sensitive factor attachment protein receptor (SNARE) protein, also decrease D2IC amplitude. Evoked D2ICs are nearly abolished by the light chain of botulinum neurotoxin A, which cleaves SNAP-25, whereas synaptically activated GABAB-receptor-mediated currents are unaffected. Thus, somatodendritic DA release in the SNc autoinhibits the neuron that releases it.
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Affiliation(s)
- Takuya Hikima
- Department of Neurosurgery, New York University Grossman School of Medicine, New York, NY 10016, USA
| | - Christian R Lee
- Department of Neurosurgery, New York University Grossman School of Medicine, New York, NY 10016, USA
| | - Paul Witkovsky
- Department of Neurosurgery, New York University Grossman School of Medicine, New York, NY 10016, USA
| | - Julia Chesler
- Department of Neurosurgery, New York University Grossman School of Medicine, New York, NY 10016, USA
| | - Konstantin Ichtchenko
- Department of Biochemistry & Molecular Pharmacology, New York University Grossman School of Medicine, New York, NY 10016, USA
| | - Margaret E Rice
- Department of Neurosurgery, New York University Grossman School of Medicine, New York, NY 10016, USA; Department of Neuroscience & Physiology, New York University Grossman School of Medicine, New York, NY 10016, USA.
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