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Meccariello R, Bellenchi GC, Pulcrano S, D’Addario SL, Tafuri D, Mercuri NB, Guatteo E. Neuronal dysfunction and gene modulation by non-coding RNA in Parkinson's disease and synucleinopathies. Front Cell Neurosci 2024; 17:1328269. [PMID: 38249528 PMCID: PMC10796818 DOI: 10.3389/fncel.2023.1328269] [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: 10/26/2023] [Accepted: 12/07/2023] [Indexed: 01/23/2024] Open
Abstract
Over the last few decades, emerging evidence suggests that non-coding RNAs (ncRNAs) including long-non-coding RNA (lncRNA), microRNA (miRNA) and circular-RNA (circRNA) contribute to the molecular events underlying progressive neuronal degeneration, and a plethora of ncRNAs have been identified significantly misregulated in many neurodegenerative diseases, including Parkinson's disease and synucleinopathy. Although a direct link between neuropathology and causative candidates has not been clearly established in many cases, the contribution of ncRNAs to the molecular processes leading to cellular dysfunction observed in neurodegenerative diseases has been addressed, suggesting that they may play a role in the pathophysiology of these diseases. Aim of the present Review is to overview and discuss recent literature focused on the role of RNA-based mechanisms involved in different aspects of neuronal pathology in Parkinson's disease and synucleinopathy models.
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Affiliation(s)
- Rosaria Meccariello
- Department of Medical and Movement Sciences and Wellness, University of Naples Parthenope, Naples, Italy
| | - Gian Carlo Bellenchi
- Institute of Genetics and Biophysics, CNR, Naples, Italy
- Experimental Neurology Laboratory, Santa Lucia Foundation IRCCS, Rome, Italy
| | | | - Sebastian Luca D’Addario
- Experimental Neurology Laboratory, Santa Lucia Foundation IRCCS, Rome, Italy
- Computational and Translational Neuroscience Laboratory, Institute of Cognitive Sciences and Technologies, CNR, Rome, Italy
- Aligning Science Across Parkinson’s (ASAP) Collaborative Research Network, Chevy Chase, MD, United States
| | - Domenico Tafuri
- Department of Medical and Movement Sciences and Wellness, University of Naples Parthenope, Naples, Italy
| | - Nicola B. Mercuri
- Experimental Neurology Laboratory, Santa Lucia Foundation IRCCS, Rome, Italy
- Aligning Science Across Parkinson’s (ASAP) Collaborative Research Network, Chevy Chase, MD, United States
- Department of Systems Medicine, University of Rome Tor Vergata, Rome, Italy
| | - Ezia Guatteo
- Department of Medical and Movement Sciences and Wellness, University of Naples Parthenope, Naples, Italy
- Experimental Neurology Laboratory, Santa Lucia Foundation IRCCS, Rome, Italy
- Aligning Science Across Parkinson’s (ASAP) Collaborative Research Network, Chevy Chase, MD, United States
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2
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Clark BC. Neural Mechanisms of Age-Related Loss of Muscle Performance and Physical Function. J Gerontol A Biol Sci Med Sci 2023; 78:8-13. [PMID: 36738253 PMCID: PMC10272985 DOI: 10.1093/gerona/glad029] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2022] [Indexed: 02/05/2023] Open
Abstract
BACKGROUND This article discusses the putative neural mechanisms of age-related muscle weakness within the broader context of the development of function-promoting therapies for sarcopenia and age-related mobility limitations. We discuss here the evolving definition of sarcopenia and its primary defining characteristic, weakness. METHODS This review explores the premise that impairments in the nervous system's ability to generate maximal force or power contribute to sarcopenia. RESULTS Impairments in neural activation are responsible for a substantial amount of age-related weakness. The neurophysiological mechanisms of weakness are multifactorial. The roles of supraspinal descending command mechanisms, spinal motor neuron firing responsivity, and neuromuscular junction transmission failure in sarcopenia are discussed. Research/clinical gaps and recommendations for future work are highlighted. CONCLUSION Further research is needed to map putative neural mechanisms, determine the clinical relevance of age-related changes in neural activation to sarcopenia, and evaluate the effectiveness of various neurotherapeutic approaches to enhancing physical function.
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Affiliation(s)
- Brian C Clark
- Ohio Musculoskeletal and Neurological Institute (OMNI) and the Department of Biomedical Sciences, Heritage College of Osteopathic Medicine, Ohio University, Athens, Ohio, USA
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3
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Köksal Ersöz E, Wendling F. Canard solutions in neural mass models: consequences on critical regimes. JOURNAL OF MATHEMATICAL NEUROSCIENCE 2021; 11:11. [PMID: 34529192 PMCID: PMC8446153 DOI: 10.1186/s13408-021-00109-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/16/2020] [Accepted: 08/17/2021] [Indexed: 05/06/2023]
Abstract
Mathematical models at multiple temporal and spatial scales can unveil the fundamental mechanisms of critical transitions in brain activities. Neural mass models (NMMs) consider the average temporal dynamics of interconnected neuronal subpopulations without explicitly representing the underlying cellular activity. The mesoscopic level offered by the neural mass formulation has been used to model electroencephalographic (EEG) recordings and to investigate various cerebral mechanisms, such as the generation of physiological and pathological brain activities. In this work, we consider a NMM widely accepted in the context of epilepsy, which includes four interacting neuronal subpopulations with different synaptic kinetics. Due to the resulting three-time-scale structure, the model yields complex oscillations of relaxation and bursting types. By applying the principles of geometric singular perturbation theory, we unveil the existence of the canard solutions and detail how they organize the complex oscillations and excitability properties of the model. In particular, we show that boundaries between pathological epileptic discharges and physiological background activity are determined by the canard solutions. Finally we report the existence of canard-mediated small-amplitude frequency-specific oscillations in simulated local field potentials for decreased inhibition conditions. Interestingly, such oscillations are actually observed in intracerebral EEG signals recorded in epileptic patients during pre-ictal periods, close to seizure onsets.
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Affiliation(s)
- Elif Köksal Ersöz
- Univ Rennes, INSERM, LTSI-U1099, Campus de Beaulieu, F - 35000, Rennes, France
| | - Fabrice Wendling
- Univ Rennes, INSERM, LTSI-U1099, Campus de Beaulieu, F - 35000, Rennes, France.
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4
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Matos B, Publicover SJ, Castro LFC, Esteves PJ, Fardilha M. Brain and testis: more alike than previously thought? Open Biol 2021; 11:200322. [PMID: 34062096 PMCID: PMC8169208 DOI: 10.1098/rsob.200322] [Citation(s) in RCA: 34] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Several strands of evidence indicate the presence of marked similarities between human brain and testis. Understanding these similarities and their implications has become a topic of interest among the scientific community. Indeed, an association of intelligence with some semen quality parameters has been reported and a relation between dysfunctions of the human brain and testis has also been evident. Numerous common molecular features are evident when these tissues are compared, which is reflected in the huge number of common proteins. At the functional level, human neurons and sperm share a number of characteristics, including the importance of the exocytotic process and the presence of similar receptors and signalling pathways. The common proteins are mainly involved in exocytosis, tissue development and neuron/brain-associated biological processes. With this analysis, we conclude that human brain and testis share several biochemical characteristics which, in addition to their involvement in the speciation process, could, at least in part, be responsible for the expression of a huge number of common proteins. Nonetheless, this is an underexplored topic, and the connection between these tissues needs to be clarified, which could help to understand the dysfunctions affecting brain and testis, as well as to develop improved therapeutic strategies.
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Affiliation(s)
- Bárbara Matos
- Laboratory of Signal Transduction, Department of Medical Sciences, Institute of Biomedicine-iBiMED, University of Aveiro, 3810-193 Aveiro, Portugal
| | - Stephen J Publicover
- School of Biosciences, The University of Birmingham, Edgbaston, Birmingham B15 2TT, UK
| | - Luis Filipe C Castro
- CIIMAR/CIMAR-Interdisciplinary Centre of Marine and Environmental Research, University of Porto, Porto, Portugal.,Department of Biology, FCUP-Faculty of Sciences, University of Porto, Porto, Portugal
| | - Pedro J Esteves
- Department of Biology, FCUP-Faculty of Sciences, University of Porto, Porto, Portugal.,CIBIO-InBIO, Research Centre in Biodiversity and Genetic Resources, Campus Agrico de Vairão, University of Porto, 4485-661 Vairão, Portugal
| | - Margarida Fardilha
- Laboratory of Signal Transduction, Department of Medical Sciences, Institute of Biomedicine-iBiMED, University of Aveiro, 3810-193 Aveiro, Portugal
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5
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Clark BC, Carson RG. Sarcopenia and Neuroscience: Learning to Communicate. J Gerontol A Biol Sci Med Sci 2021; 76:1882-1890. [PMID: 33824986 DOI: 10.1093/gerona/glab098] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2020] [Indexed: 12/11/2022] Open
Abstract
In the 1990s and early 2000s, the common definition for sarcopenia was age-related loss of skeletal muscle, and low levels of muscle mass were central to sarcopenia diagnosis. In more recent consensus definitions, however, low muscle strength displaces low muscle mass as a defining feature of sarcopenia. The change stems from growing evidence that muscle weakness is a better predictor of adverse health outcomes (e.g., mobility limitations) than muscle mass. This evidence accompanies an emerging recognition that central neural mechanisms are critical determinants of age-related changes in strength and mobility that can occur independently of variations in muscle mass. However, strikingly little practical attention is typically given to the potential role of the central nervous system in the aetiology or remediation of sarcopenia (i.e., low muscle function). In this article, we provide an overview of some mechanisms that mediate neural regulation of muscle contraction and control, and highlight the specific contributions of neural hypoexcitability, dopaminergic dysfunction, and degradation of functional and structural brain connectivity in relation to sarcopenia. We aim to enhance the lines of communication between the domains of sarcopenia and neuroscience. We believe that appreciation of the neural regulation of muscle contraction and control is fundamental to understanding sarcopenia and to developing targeted therapeutic strategies for its treatment.
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Affiliation(s)
- Brian C Clark
- Ohio Musculoskeletal & Neurological Institute and the Department of Biomedical Sciences, Ohio University, Athens, Ohio, USA
| | - Richard G Carson
- Trinity College Institute of Neuroscience and School of Psychology, Trinity College Dublin, Dublin, Ireland.,School of Psychology, Queen's University Belfast, Belfast, Northern Ireland, UK.,School of Human Movement and Nutrition Sciences, The University of Queensland, Australia
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6
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Clark LA, Manini TM, Wages NP, Simon JE, Russ DW, Clark BC. Reduced Neural Excitability and Activation Contribute to Clinically Meaningful Weakness in Older Adults. J Gerontol A Biol Sci Med Sci 2021; 76:692-702. [PMID: 32588058 PMCID: PMC8011705 DOI: 10.1093/gerona/glaa157] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2020] [Indexed: 12/19/2022] Open
Abstract
BACKGROUND Weakness is a risk factor for physical limitations and death in older adults (OAs). We sought to determine whether OAs with clinically meaningful leg extensor weakness exhibit differences in voluntary inactivation (VIA) and measures of corticospinal excitability when compared to young adults (YAs) and OAs without clinically meaningful weakness. We also sought to estimate the relative contribution of indices of neural excitability and thigh lean mass in explaining the between-subject variability in OAs leg extensor strength. METHODS In 66 OAs (75.1 ± 7.0 years) and 20 YAs (22.0 ± 1.9 years), we quantified leg extensor strength, thigh lean mass, VIA, and motor evoked potential (MEP) amplitude and silent period (SP) duration. OAs were classified into weakness groups based on previously established strength/body weight (BW) cut points (Weak, Modestly Weak, or Not Weak). RESULTS The OAs had 63% less strength/BW when compared to YAs. Weak OAs exhibited higher levels of leg extensor VIA than Not Weak OAs (14.2 ± 7.5% vs 6.1 ± 7.5%). Weak OAs exhibited 24% longer SPs compared to Not Weak OAs, although this difference was insignificant (p = .06). The Weak OAs MEPs were half the amplitude of the Not Weak OAs. Regression analysis indicated that MEP amplitude, SP duration, and thigh lean mass explained ~62% of the variance in strength, with the neural excitability variables explaining ~33% of the variance and thigh lean mass explaining ~29%. CONCLUSION These findings suggest that neurotherapeutic interventions targeting excitability could be a viable approach to increase muscle strength in order to reduce the risk of physical impairments in late life.
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Affiliation(s)
- Leatha A Clark
- Ohio Musculoskeletal and Neurological Institute (OMNI), Ohio University, Athens
- Department of Biomedical Sciences, Ohio University, Athens
| | - Todd M Manini
- Department of Aging and Geriatric Research, University of Florida, Gainesville
| | - Nathan P Wages
- Ohio Musculoskeletal and Neurological Institute (OMNI), Ohio University, Athens
- Department of Biomedical Sciences, Ohio University, Athens
| | - Janet E Simon
- Ohio Musculoskeletal and Neurological Institute (OMNI), Ohio University, Athens
- School of Applied Health Sciences and Wellness, Ohio University, Athens
| | - David W Russ
- School of Physical Therapy & Rehabilitation Sciences, University of South Florida, Tampa
| | - Brian C Clark
- Ohio Musculoskeletal and Neurological Institute (OMNI), Ohio University, Athens
- Department of Biomedical Sciences, Ohio University, Athens
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7
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Epigenomic Remodeling in Huntington's Disease-Master or Servant? EPIGENOMES 2020; 4:epigenomes4030015. [PMID: 34968288 PMCID: PMC8594700 DOI: 10.3390/epigenomes4030015] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2020] [Revised: 07/15/2020] [Accepted: 07/27/2020] [Indexed: 12/03/2022] Open
Abstract
In light of our aging population, neurodegenerative disorders are becoming a tremendous challenge, that modern societies have to face. They represent incurable, progressive conditions with diverse and complex pathological features, followed by catastrophic occurrences of massive neuronal loss at the later stages of the diseases. Some of these disorders, like Huntington’s disease (HD), rely on defined genetic factors. HD, as an incurable, fatal hereditary neurodegenerative disorder characterized by its mid-life onset, is caused by the expansion of CAG trinucleotide repeats coding for glutamine (Q) in exon 1 of the huntingtin gene. Apart from the genetic defect, environmental factors are thought to influence the risk, onset and progression of HD. As epigenetic mechanisms are known to readily respond to environmental stimuli, they are proposed to play a key role in HD pathogenesis. Indeed, dynamic epigenomic remodeling is observed in HD patients and in brains of HD animal models. Epigenetic signatures, such as DNA methylation, histone variants and modifications, are known to influence gene expression and to orchestrate various aspects of neuronal physiology. Hence, deciphering their implication in HD pathogenesis might open up new paths for novel therapeutic concepts, which are discussed in this review.
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8
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Gunes ZI, Kan VWY, Ye X, Liebscher S. Exciting Complexity: The Role of Motor Circuit Elements in ALS Pathophysiology. Front Neurosci 2020; 14:573. [PMID: 32625051 PMCID: PMC7311855 DOI: 10.3389/fnins.2020.00573] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2020] [Accepted: 05/11/2020] [Indexed: 12/11/2022] Open
Abstract
Amyotrophic lateral sclerosis (ALS) is a fatal disease, characterized by the degeneration of both upper and lower motor neurons. Despite decades of research, we still to date lack a cure or disease modifying treatment, emphasizing the need for a much-improved insight into disease mechanisms and cell type vulnerability. Altered neuronal excitability is a common phenomenon reported in ALS patients, as well as in animal models of the disease, but the cellular and circuit processes involved, as well as the causal relevance of those observations to molecular alterations and final cell death, remain poorly understood. Here, we review evidence from clinical studies, cell type-specific electrophysiology, genetic manipulations and molecular characterizations in animal models and culture experiments, which argue for a causal involvement of complex alterations of structure, function and connectivity of different neuronal subtypes within the cortical and spinal cord motor circuitries. We also summarize the current knowledge regarding the detrimental role of astrocytes and reassess the frequently proposed hypothesis of glutamate-mediated excitotoxicity with respect to changes in neuronal excitability. Together, these findings suggest multifaceted cell type-, brain area- and disease stage- specific disturbances of the excitation/inhibition balance as a cardinal aspect of ALS pathophysiology.
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Affiliation(s)
- Zeynep I Gunes
- Institute of Clinical Neuroimmunology, Klinikum der Universität München, Ludwig Maximilians University Munich, Munich, Germany.,Graduate School of Systemic Neurosciences, Ludwig Maximilians University Munich, Munich, Germany.,Biomedical Center, Ludwig Maximilians University Munich, Munich, Germany
| | - Vanessa W Y Kan
- Institute of Clinical Neuroimmunology, Klinikum der Universität München, Ludwig Maximilians University Munich, Munich, Germany.,Graduate School of Systemic Neurosciences, Ludwig Maximilians University Munich, Munich, Germany.,Biomedical Center, Ludwig Maximilians University Munich, Munich, Germany
| | - XiaoQian Ye
- Institute of Clinical Neuroimmunology, Klinikum der Universität München, Ludwig Maximilians University Munich, Munich, Germany.,Biomedical Center, Ludwig Maximilians University Munich, Munich, Germany
| | - Sabine Liebscher
- Institute of Clinical Neuroimmunology, Klinikum der Universität München, Ludwig Maximilians University Munich, Munich, Germany.,Biomedical Center, Ludwig Maximilians University Munich, Munich, Germany.,Munich Cluster for Systems Neurology (SyNergy), Munich, Germany
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9
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Rhynchophylline Protects Against the Amyloid β-Induced Increase of Spontaneous Discharges in the Hippocampal CA1 Region of Rats. Neurochem Res 2015; 40:2365-73. [DOI: 10.1007/s11064-015-1730-y] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2015] [Revised: 09/07/2015] [Accepted: 09/26/2015] [Indexed: 12/14/2022]
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10
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Ren SC, Shao H, Ji WG, Jiang HH, Xu F, Chen PZ, Mi Z, Wen B, Zhu GX, Zhu ZR. Riluzole prevents soluble Aβ1-42 oligomers-induced perturbation of spontaneous discharge in the hippocampal CA1 region of rats. Amyloid 2015; 22:36-44. [PMID: 25472656 DOI: 10.3109/13506129.2014.990558] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Abnormal accumulation of soluble amyloid beta (Aβ) is believed to cause malfunction of neurons in Alzheimer's disease (AD). The hippocampus is one of the earliest affected brain regions in AD. However, little effort has been made to investigate the effects of soluble Aβ1-42 oligomers on discharge properties of hippocampal neurons in vivo. This study was designed to examine the effects of soluble Aβ1-42 oligomers on the discharge properties of hippocampal CA1 neurons using extracellular single-unit recordings in vivo. The protective effects of riluzole (RLZ) were also investigated for the prevention of soluble oligomers of Aβ1-42-induced alterations in the spontaneous discharge of hippocampal neurons. The results showed that (1) the mean frequency of spontaneous discharge was increased by the local application of 100 μM Aβ1-42 oligomers; (2) Aβ1-42 oligomers also induced alterations of the neuronal firing patterns in the hippocampal CA1 region; and (3) pretreatment with 20 μM RLZ effectively inhibited the Aβ1-42-induced enhancement of spontaneous discharge and alterations of neuronal firing patterns in CA1 neurons. Our study suggested that Aβ1-42 oligomers induced hyperactivity and perturbed the firing patterns in hippocampal neurons. RLZ may provide neuroprotective effects on the Aβ1-42-induced perturbation of neuronal activities in the hippocampal region of rats.
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11
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Pourbadie HG, Naderi N, Mehranfard N, Janahmadi M, Khodagholi F, Motamedi F. Preventing effect of L-type calcium channel blockade on electrophysiological alterations in dentate gyrus granule cells induced by entorhinal amyloid pathology. PLoS One 2015; 10:e0117555. [PMID: 25689857 PMCID: PMC4331091 DOI: 10.1371/journal.pone.0117555] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2014] [Accepted: 12/26/2014] [Indexed: 12/12/2022] Open
Abstract
The entorhinal cortex (EC) is one of the earliest affected brain regions in Alzheimer's disease (AD). EC-amyloid pathology induces synaptic failure in the dentate gyrus (DG) with resultant behavioral impairment, but there is little known about its impact on neuronal properties in the DG. It is believed that calcium dyshomeostasis plays a pivotal role in the etiology of AD. Here, the effect of the EC amyloid pathogenesis on cellular properties of DG granule cells and also possible neuroprotective role of L-type calcium channel blockers (CCBs), nimodipine and isradipine, were investigated. The amyloid beta (Aβ) 1-42 was injected bilaterally into the EC of male rats and one week later, electrophysiological properties of DG granule cells were assessed. Voltage clamp recording revealed appearance of giant sIPSC in combination with a decrease in sEPSC frequency which was partially reversed by CCBs in granule cells from Aβ treated rats. EC amyloid pathogenesis induced a significant reduction of input resistance (Rin) accompanied by a profound decreased excitability in the DG granule cells. However, daily administration of CCBs, isradipine or nimodipine (i.c.v. for 6 days), almost preserved the normal excitability against Aβ. In conclusion, lower tendency to fire AP along with reduced Rin suggest that DG granule cells might undergo an alteration in the membrane ion channel activities which finally lead to the behavioral deficits observed in animal models and patients with early-stage Alzheimer's disease.
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Affiliation(s)
- Hamid Gholami Pourbadie
- Department of Physiology and Pharmacology, Pasteur Institute of Iran, Tehran, Iran
- Neuroscience Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran
- Department of Physiology, Faculty of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Nima Naderi
- Neuroscience Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran
- Department of Pharmacology and Toxicology, School of Pharmacy, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Nasrin Mehranfard
- Neuroscience Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran
- Department of Physiology, Faculty of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Mahyar Janahmadi
- Neurophysiology Research Center, Faculty of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Fariba Khodagholi
- Neurobiology Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Fereshteh Motamedi
- Neuroscience Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran
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12
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Lin WH, Baines RA. Regulation of membrane excitability: a convergence on voltage-gated sodium conductance. Mol Neurobiol 2014; 51:57-67. [PMID: 24677068 PMCID: PMC4309913 DOI: 10.1007/s12035-014-8674-0] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2014] [Accepted: 03/11/2014] [Indexed: 11/30/2022]
Abstract
The voltage-gated sodium channel (Nav) plays a key role in regulation of neuronal excitability. Aberrant regulation of Nav expression and/or function can result in an imbalance in neuronal activity which can progress to epilepsy. Regulation of Nav activity is achieved by coordination of a multitude of mechanisms including RNA alternative splicing and translational repression. Understanding of these regulatory mechanisms is complicated by extensive genetic redundancy: the mammalian genome encodes ten Navs. By contrast, the genome of the fruitfly, Drosophila melanogaster, contains just one Nav homologue, encoded by paralytic (DmNa v ). Analysis of splicing in DmNa v shows variants exhibit distinct gating properties including varying magnitudes of persistent sodium current (INaP). Splicing by Pasilla, an identified RNA splicing factor, alters INaP magnitude as part of an activity-dependent mechanism. Enhanced INaP promotes membrane hyperexcitability that is associated with seizure-like behaviour in Drosophila. Nova-2, a mammalian Pasilla homologue, has also been linked to splicing of Navs and, moreover, mouse gene knockouts display seizure-like behaviour.Expression level of Navs is also regulated through a mechanism of translational repression in both flies and mammals. The translational repressor Pumilio (Pum) can bind to Na v transcripts and repress the normal process of translation, thus regulating sodium current (INa) density in neurons. Pum2-deficient mice exhibit spontaneous EEG abnormalities. Taken together, aberrant regulation of Nav function and/or expression is often epileptogenic. As such, a better understanding of regulation of membrane excitability through RNA alternative splicing and translational repression of Navs should provide new leads to treat epilepsy.
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Affiliation(s)
- Wei-Hsiang Lin
- Faculty of Life Sciences, University of Manchester, Oxford Road, Manchester, UK
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13
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Jung S, Bang M, Kim BS, Lee S, Kotov NA, Kim B, Jeon D. Intracellular gold nanoparticles increase neuronal excitability and aggravate seizure activity in the mouse brain. PLoS One 2014; 9:e91360. [PMID: 24625829 PMCID: PMC3953378 DOI: 10.1371/journal.pone.0091360] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2013] [Accepted: 02/10/2014] [Indexed: 12/16/2022] Open
Abstract
Due to their inert property, gold nanoparticles (AuNPs) have drawn considerable attention; their biological application has recently expanded to include nanomedicine and neuroscience. However, the effect of AuNPs on the bioelectrical properties of a single neuron remains unknown. Here we present the effect of AuNPs on a single neuron under physiological and pathological conditions in vitro. AuNPs were intracellularly applied to hippocampal CA1 neurons from the mouse brain. The electrophysiological property of CA1 neurons treated with 5- or 40-nm AuNPs was assessed using the whole-cell patch-clamp technique. Intracellular application of AuNPs increased both the number of action potentials (APs) and input resistance. The threshold and duration of APs and the after hyperpolarization (AHP) were decreased by the intracellular AuNPs. In addition, intracellular AuNPs elicited paroxysmal depolarizing shift-like firing patterns during sustained repetitive firings (SRF) induced by prolonged depolarization (10 sec). Furthermore, low Mg2+-induced epileptiform activity was aggravated by the intracellular AuNPs. In this study, we demonstrated that intracellular AuNPs alter the intrinsic properties of neurons toward increasing their excitability, and may have deleterious effects on neurons under pathological conditions, such as seizure. These results provide some considerable direction on application of AuNPs into central nervous system (CNS).
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Affiliation(s)
- Seungmoon Jung
- Department of Bio and Brain Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, Republic of Korea
| | - Minji Bang
- Department of Bio and Brain Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, Republic of Korea
| | - Byung Sun Kim
- Department of Bio and Brain Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, Republic of Korea
| | - Sungmun Lee
- Department of Biomedical Engineering, Khalifa University of Science, Technology, and Research, Abu Dhabi, United Arab Emirates
| | - Nicholas A. Kotov
- Department of Chemical Engineering, University of Michigan, Ann Arbor, Michigan, United States of America
| | - Bongsoo Kim
- Department of Chemistry, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, Republic of Korea
| | - Daejong Jeon
- Department of Bio and Brain Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, Republic of Korea
- * E-mail:
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14
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Razavinasab M, Moazzami K, Shabani M. Maternal mobile phone exposure alters intrinsic electrophysiological properties of CA1 pyramidal neurons in rat offspring. Toxicol Ind Health 2014; 32:968-79. [PMID: 24604340 DOI: 10.1177/0748233714525497] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Some studies have shown that exposure to electromagnetic field (EMF) may result in structural damage to neurons. In this study, we have elucidated the alteration in the hippocampal function of offspring Wistar rats (n = 8 rats in each group) that were chronically exposed to mobile phones during their gestational period by applying behavioral, histological, and electrophysiological tests. Rats in the EMF group were exposed to 900 MHz pulsed-EMF irradiation for 6 h/day. Whole cell recordings in hippocampal pyramidal cells in the mobile phone groups did show a decrease in neuronal excitability. Mobile phone exposure was mostly associated with a decrease in the number of action potentials fired in spontaneous activity and in response to current injection in both male and female groups. There was an increase in the amplitude of the afterhyperpolarization (AHP) in mobile phone rats compared with the control. The results of the passive avoidance and Morris water maze assessment of learning and memory performance showed that phone exposure significantly altered learning acquisition and memory retention in male and female rats compared with the control rats. Light microscopy study of brain sections of the control and mobile phone-exposed rats showed normal morphology.Our results suggest that exposure to mobile phones adversely affects the cognitive performance of both female and male offspring rats using behavioral and electrophysiological techniques.
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Affiliation(s)
- Moazamehosadat Razavinasab
- Kerman Neuroscience Research Center, Institute of Neuropharmacology, Kerman University of Medical Sciences, Kerman, Islamic Republic of Iran
| | - Kasra Moazzami
- Cardiovascular Research Center, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | - Mohammad Shabani
- Kerman Neuroscience Research Center, Institute of Neuropharmacology, Kerman University of Medical Sciences, Kerman, Islamic Republic of Iran
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Romer SH, Dominguez KM, Gelpi MW, Deardorff AS, Tracy RC, Fyffe REW. Redistribution of Kv2.1 ion channels on spinal motoneurons following peripheral nerve injury. Brain Res 2013; 1547:1-15. [PMID: 24355600 DOI: 10.1016/j.brainres.2013.12.012] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2013] [Revised: 12/09/2013] [Accepted: 12/10/2013] [Indexed: 01/01/2023]
Abstract
Pathophysiological responses to peripheral nerve injury include alterations in the activity, intrinsic membrane properties and excitability of spinal neurons. The intrinsic excitability of α-motoneurons is controlled in part by the expression, regulation, and distribution of membrane-bound ion channels. Ion channels, such as Kv2.1 and SK, which underlie delayed rectifier potassium currents and afterhyperpolarization respectively, are localized in high-density clusters at specific postsynaptic sites (Deardorff et al., 2013; Muennich and Fyffe, 2004). Previous work has indicated that Kv2.1 channel clustering and kinetics are regulated by a variety of stimuli including ischemia, hypoxia, neuromodulator action and increased activity. Regulation occurs via channel dephosphorylation leading to both declustering and alterations in channel kinetics, thus normalizing activity (Misonou et al., 2004; Misonou et al., 2005; Misonou et al., 2008; Mohapatra et al., 2009; Park et al., 2006). Here we demonstrate using immunohistochemistry that peripheral nerve injury is also sufficient to alter the surface distribution of Kv2.1 channels on motoneurons. The dynamic changes in channel localization include a rapid progressive decline in cluster size, beginning immediately after axotomy, and reaching maximum within one week. With reinnervation, the organization and size of Kv2.1 clusters do not fully recover. However, in the absence of reinnervation Kv2.1 cluster sizes fully recover. Moreover, unilateral peripheral nerve injury evokes parallel, but smaller effects bilaterally. These results suggest that homeostatic regulation of motoneuron Kv2.1 membrane distribution after axon injury is largely independent of axon reinnervation.
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Affiliation(s)
- Shannon H Romer
- Department of Neuroscience, Cell Biology and Physiology, 202 University Hall, Wright State University, 3640 Colonel Glenn Hwy, Dayton, OH 45435, USA.
| | - Kathleen M Dominguez
- Department of Surgery Boonshoft School of Medicine, Wright State University, 3640 Colonel Glenn Hwy, Dayton, OH 45435, USA.
| | - Marc W Gelpi
- Department of Neuroscience, Cell Biology and Physiology, 202 University Hall, Wright State University, 3640 Colonel Glenn Hwy, Dayton, OH 45435, USA.
| | - Adam S Deardorff
- Department of Neuroscience, Cell Biology and Physiology, 202 University Hall, Wright State University, 3640 Colonel Glenn Hwy, Dayton, OH 45435, USA.
| | - Robert C Tracy
- Department of Neuroscience, Cell Biology and Physiology, 202 University Hall, Wright State University, 3640 Colonel Glenn Hwy, Dayton, OH 45435, USA.
| | - Robert E W Fyffe
- Department of Neuroscience, Cell Biology and Physiology, 202 University Hall, Wright State University, 3640 Colonel Glenn Hwy, Dayton, OH 45435, USA.
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Blurring the boundaries: developmental and activity-dependent determinants of neural circuits. Trends Neurosci 2013; 36:610-9. [PMID: 23876426 PMCID: PMC3794160 DOI: 10.1016/j.tins.2013.06.006] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2013] [Revised: 06/24/2013] [Accepted: 06/26/2013] [Indexed: 11/22/2022]
Abstract
The human brain comprises approximately 100 billion neurons that express a diverse, and often subtype-specific, set of neurotransmitters and voltage-gated ion channels. Given this enormous complexity, a fundamental question is how is this achieved? The acquisition of neurotransmitter phenotype was viewed as being set by developmental programs 'hard wired' into the genome. By contrast, the expression of neuron-specific ion channels was considered to be highly dynamic (i.e., 'soft wired') and shaped largely by activity-dependent mechanisms. Recent evidence blurs this distinction by showing that neurotransmitter phenotype can be altered by activity and that neuron type-specific ion channel expression can be set, and perhaps limited by, developmental programs. Better understanding of these early regulatory mechanisms may offer new avenues to avert the behavioral changes that are characteristic of many mental illnesses.
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Rapid homeostatic plasticity of intrinsic excitability in a central pattern generator network stabilizes functional neural network output. J Neurosci 2012; 32:9649-58. [PMID: 22787050 DOI: 10.1523/jneurosci.1945-12.2012] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Neurons and networks undergo a process of homeostatic plasticity that stabilizes output by integrating activity levels with network and cellular properties to counter longer-term perturbations. Here we describe a rapid compensatory interaction among a pair of potassium currents, I(A) and I(KCa), that stabilizes both intrinsic excitability and network function in the cardiac ganglion of the crab, Cancer borealis. We determined that mRNA levels in single identified neurons for the channels which encode I(A) and I(KCa) are positively correlated, yet the ionic currents themselves are negatively correlated, across a population of motor neurons. We then determined that these currents are functionally coupled; decreasing levels of either current within a neuron causes a rapid increase in the other. This functional interdependence results in homeostatic stabilization of both the individual neuronal and the network output. Furthermore, these compensatory increases are mechanistically independent, suggesting robustness in the maintenance of neural network output that is critical for survival. Together, we generate a complete model for homeostatic plasticity from mRNA to network output where rapid post-translational compensatory mechanisms acting on a reservoir of channels proteins regulated at the level of gene expression provide homeostatic stabilization of both cellular and network activity.
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Misonou H. Homeostatic regulation of neuronal excitability by K(+) channels in normal and diseased brains. Neuroscientist 2010; 16:51-64. [PMID: 20236949 DOI: 10.1177/1073858409341085] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
K(+)-selective ion channels are critical determinants of membrane excitability in neuronal cells. Like many other cells in our body, neuronal cells have a propensity to maintain their homeostasis. Action potential firing is the most important function to maintain in brain neurons, as they are the elements of neural networks. If one element fires action potentials at an abnormally high rate, the entire network could become epileptic. Therefore, brain neurons adjust their intrinsic membrane excitability to maintain the firing rate within their own optimal operational range. When a neuron receives an enormous input, it will reduce the membrane excitability to prevent overshooting. When it is deprived of stimulus, the membrane becomes more excitable to avoid total quiescence. The homeostatic regulation of intrinsic excitability provides stability to the neural network in the face of dynamic and plastic synaptic inputs. In the past decade, we have learned that neurons achieve this type of homeostatic regulation through a variety of ion channels, including K(+) channels. It has also become clear that under certain pathological conditions, these homeostatic mechanisms provide neuroprotection. In this article, I will review recent advances in our understanding of K(+) channel-mediated homeostatic regulation of neuronal excitability and discuss involvement of these channels in hyperexcitable diseases where they provide neuroprotection.
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Affiliation(s)
- Hiroaki Misonou
- Department of Neural and Pain Sciences, Program in Neuroscience, Dental School, University of Maryland, Baltimore, Maryland 21201, USA.
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19
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Liss B, Roeper J. Individual dopamine midbrain neurons: Functional diversity and flexibility in health and disease. ACTA ACUST UNITED AC 2008; 58:314-21. [DOI: 10.1016/j.brainresrev.2007.10.004] [Citation(s) in RCA: 68] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2007] [Revised: 10/03/2007] [Accepted: 10/15/2007] [Indexed: 11/30/2022]
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20
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Gründemann J, Schlaudraff F, Haeckel O, Liss B. Elevated alpha-synuclein mRNA levels in individual UV-laser-microdissected dopaminergic substantia nigra neurons in idiopathic Parkinson's disease. Nucleic Acids Res 2008; 36:e38. [PMID: 18332041 PMCID: PMC2367701 DOI: 10.1093/nar/gkn084] [Citation(s) in RCA: 133] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
The presynaptic protein α-synuclein is involved in several neurodegenerative diseases, including Parkinson's disease (PD). In rare familial forms of PD, causal mutations (PARK1) as well as multiplications (PARK4) of the α-synuclein gene have been identified. In sporadic, idiopathic PD, abnormal accumulation and deposition of α-synuclein might also cause degeneration of dopaminergic midbrain neurons, the clinically most relevant neuronal population in PD. Thus, cell-specific quantification of α-synuclein expression-levels in dopaminergic neurons from idiopathic PD patients in comparison to controls would provide essential information about contributions of α-synuclein to the etiology of PD. However, a number of previous studies addressing this question at the tissue-level yielded varying results regarding α-synuclein expression. To increase specificity, we developed a cell-specific approach for mRNA quantification that also took into account the important issue of variable RNA integrities of the individual human postmortem brain samples. We demonstrate that PCR –amplicon size can confound quantitative gene-expression analysis, in particular of partly degraded RNA. By combining optimized UV-laser microdissection- and quantitative RT–PCR-techniques with suitable PCR assays, we detected significantly elevated α-synuclein mRNA levels in individual, surviving neuromelanin- and tyrosine hydroxylase-positive substantia nigra dopaminergic neurons from idiopathic PD brains compared to controls. These results strengthen the pathophysiologic role of transcriptional dysregulation of the α-synuclein gene in sporadic PD.
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Affiliation(s)
- Jan Gründemann
- Molecular Neurobiology, Department of Physiology, Philipps-University Marburg, Deutschhausstrasse 2, 35037 Marburg, Germany
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Crow T, Xue-Bian JJ. One-trial in vitro conditioning of hermissenda regulates phosphorylation of ser-122 of csp24. Ann N Y Acad Sci 2007; 1112:189-200. [PMID: 17468234 DOI: 10.1196/annals.1415.012] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
The regulation of the intrinsic excitability of a neuron is an important aspect of cellular and synaptic plasticity underlying learning and memory. Various voltage-dependent K(+) channels have been shown to be critical for the modification of membrane excitability. Components of the cytoskeleton have been proposed to contribute to the location, distribution, and function of diverse K(+) channels. However, the mechanisms underlying the regulation of the cytoskeleton by signaling pathways and the role of the cytoskeleton in the induction of intrinsic excitability is not understood. Hermissenda Csp24 is a beta-thymosin-like protein containing multiple actin-binding domains that contributes to intrinsic enhanced excitability produced by Pavlovian conditioning. One-trial in vitro conditioning produces a significant reduction in the A-type transient K(+) current (I(A)) and a depolarized shift in the steady-state activation curve of I(A). Intermediate and long-term enhanced excitability produced by one-trial conditioning is also dependent on the expression and phosphorylation of Csp24. Blocking the expression of Csp24 with an antisense oligonucleotide inhibits the development of intermediate-term enhanced excitability and the concomitant reduction in I(A) normally produced by one-trial in vitro conditioning. In this report using two-dimensional gel PAGE and electrospray mass spectrometry, we have identified two phosphorylation sites on Csp24. Using phospho-specific antibodies with Western blot analysis and immunoprecipitation procedures we show that one-trial in vitro conditioning results in an increase in the phosphorylation of Ser-122, but not Ser-49 of Csp24.
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Affiliation(s)
- Terry Crow
- Department of Neurobiology and Anatomy, University of Texas Medical School, P.O. Box 20708, Houston, TX 77225, USA.
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