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Wiprich MT, da Rosa Vasques R, Gusso D, Rübensam G, Kist LW, Bogo MR, Bonan CD. Locomotor Behavior and Memory Dysfunction Induced by 3-Nitropropionic Acid in Adult Zebrafish: Modulation of Dopaminergic Signaling. Mol Neurobiol 2024; 61:609-621. [PMID: 37648841 DOI: 10.1007/s12035-023-03584-5] [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: 12/23/2022] [Accepted: 08/15/2023] [Indexed: 09/01/2023]
Abstract
Huntington's disease (HD) is a progressive neurodegenerative disease characterized by neuropsychiatric disturbance, cognitive impairment, and locomotor dysfunction. In the early stage (chorea) of HD, expression of dopamine D2 receptors (D2R) is reduced, whereas dopamine (DA) levels are increased. Contrary, in the late stage (bradykinesia), DA levels and the expression of D2R and dopamine D1 receptors (D1R) are reduced. 3-Nitropropionic acid (3-NPA) is a toxin that may replicate HD behavioral phenotypes and biochemical aspects. This study assessed the neurotransmitter levels, dopamine receptor gene expression, and the effect of acute exposure to quinpirole (D2R agonist) and eticlopride (D2R antagonist) in an HD model induced by 3-NPA in adult zebrafish. Quinpirole and eticlopride were acutely applied by i.p. injection in adult zebrafish after chronic treatment of 3-NPA (60 mg/kg). 3-NPA treatment caused a reduction in DA, glutamate, and serotonin levels. Quinpirole reversed the bradykinesia and memory loss induced by 3-NPA. Together, these data showed that 3-NPA acts on the dopaminergic system and causes biochemical alterations similar to late-stage HD. These data reinforce the hypothesis that DA levels are linked with locomotor and memory deficits. Thus, these findings may suggest that the use of DA agonists could be a pharmacological strategy to improve the bradykinesia and memory deficits in the late-stage HD.
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Affiliation(s)
- Melissa Talita Wiprich
- Programa de Pós-Graduação Em Medicina E Ciências da Saúde, Escola de Medicina, Pontifícia Universidade Católica Do Rio Grande Do Sul, Porto Alegre, RS, Brazil
- Laboratório de Neuroquímica E Psicofarmacologia, Escola de Ciências da Saúde E da Vida, Pontifícia Universidade Católica Do Rio Grande Do Sul, Porto Alegre, RS, Brazil
- Instituto Nacional de Ciência E Tecnologia Em Doenças Cerebrais, Excitotoxicidade E Neuroproteção, Porto Alegre, RS, Brazil
| | - Rafaela da Rosa Vasques
- Laboratório de Neuroquímica E Psicofarmacologia, Escola de Ciências da Saúde E da Vida, Pontifícia Universidade Católica Do Rio Grande Do Sul, Porto Alegre, RS, Brazil
| | - Darlan Gusso
- Laboratório de Neuroquímica E Psicofarmacologia, Escola de Ciências da Saúde E da Vida, Pontifícia Universidade Católica Do Rio Grande Do Sul, Porto Alegre, RS, Brazil
| | - Gabriel Rübensam
- Centro de Pesquisa Em Toxicologia E Farmacologia, Escola de Ciências da Saúde E da Vida, Pontifícia Universidade Católica Do Rio Grande Do Sul, Porto Alegre, RS, Brazil
| | - Luiza Wilges Kist
- Programa de Pós-Graduação Em Biologia Celular E Molecular, Escola de Ciências da Saúde E da Vida, Pontifícia Universidade Católica Do Rio Grande Do Sul, Porto Alegre, RS, Brazil
- Laboratório de Biologia Genômica E Molecular, Escola de Ciências da Saúde E da Vida, Pontifícia Universidade Católica Do Rio Grande Do Sul, Porto Alegre, RS, Brazil
| | - Mauricio Reis Bogo
- Programa de Pós-Graduação Em Medicina E Ciências da Saúde, Escola de Medicina, Pontifícia Universidade Católica Do Rio Grande Do Sul, Porto Alegre, RS, Brazil
- Programa de Pós-Graduação Em Biologia Celular E Molecular, Escola de Ciências da Saúde E da Vida, Pontifícia Universidade Católica Do Rio Grande Do Sul, Porto Alegre, RS, Brazil
- Laboratório de Biologia Genômica E Molecular, Escola de Ciências da Saúde E da Vida, Pontifícia Universidade Católica Do Rio Grande Do Sul, Porto Alegre, RS, Brazil
| | - Carla Denise Bonan
- Programa de Pós-Graduação Em Medicina E Ciências da Saúde, Escola de Medicina, Pontifícia Universidade Católica Do Rio Grande Do Sul, Porto Alegre, RS, Brazil.
- Laboratório de Neuroquímica E Psicofarmacologia, Escola de Ciências da Saúde E da Vida, Pontifícia Universidade Católica Do Rio Grande Do Sul, Porto Alegre, RS, Brazil.
- Instituto Nacional de Ciência E Tecnologia Em Doenças Cerebrais, Excitotoxicidade E Neuroproteção, Porto Alegre, RS, Brazil.
- Programa de Pós-Graduação Em Biologia Celular E Molecular, Escola de Ciências da Saúde E da Vida, Pontifícia Universidade Católica Do Rio Grande Do Sul, Porto Alegre, RS, Brazil.
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Martinez-Rojas VA, Juarez-Hernandez LJ, Musio C. Ion channels and neuronal excitability in polyglutamine neurodegenerative diseases. Biomol Concepts 2022; 13:183-199. [DOI: 10.1515/bmc-2022-0018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2022] [Accepted: 03/14/2022] [Indexed: 11/15/2022] Open
Abstract
Abstract
Polyglutamine (polyQ) diseases are a family composed of nine neurodegenerative inherited disorders (NDDs) caused by pathological expansions of cytosine-adenine-guanine (CAG) trinucleotide repeats which encode a polyQ tract in the corresponding proteins. CAG polyQ repeat expansions produce neurodegeneration via multiple downstream mechanisms; among those the neuronal activity underlying the ion channels is affected directly by specific channelopathies or indirectly by secondary dysregulation. In both cases, the altered excitability underlies to gain- or loss-of-function pathological effects. Here we summarize the repertoire of ion channels in polyQ NDDs emphasizing the biophysical features of neuronal excitability and their pathogenic role. The aim of this review is to point out the value of a deeper understanding of those functional mechanisms and processes as crucial elements for the designing and targeting of novel therapeutic avenues.
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Affiliation(s)
- Vladimir A. Martinez-Rojas
- Institute of Biophysics (IBF), Trento Unit, National Research Council (CNR) , Via Sommarive 18 , 38123 Trento , Italy
| | - Leon J. Juarez-Hernandez
- Institute of Biophysics (IBF), Trento Unit, National Research Council (CNR) , Via Sommarive 18 , 38123 Trento , Italy
| | - Carlo Musio
- Institute of Biophysics (IBF), Trento Unit, National Research Council (CNR) , Via Sommarive 18 , 38123 Trento , Italy
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Barry J, Bui MTN, Levine MS, Cepeda C. Synaptic pathology in Huntington's disease: Beyond the corticostriatal pathway. Neurobiol Dis 2021; 162:105574. [PMID: 34848336 PMCID: PMC9328779 DOI: 10.1016/j.nbd.2021.105574] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2021] [Revised: 11/22/2021] [Accepted: 11/26/2021] [Indexed: 12/12/2022] Open
Abstract
Huntington's disease (HD) is a heritable, fatal neurodegenerative disorder caused by a mutation in the Huntingtin gene. It is characterized by chorea, as well as cognitive and psychiatric symptoms. Histopathologically, there is a massive loss of striatal projection neurons and less but significant loss in other areas throughout the cortico-basal ganglia-thalamocortical (CBGTC) loop. The mutant huntingtin protein has been implicated in numerous functions, including an important role in synaptic transmission. Most studies on anatomical and physiological alterations in HD have focused on striatum and cerebral cortex. However, based on recent CBGTC projectome evidence, the need to study other pathways has become increasingly clear. In this review, we examine the current status of our knowledge of morphological and electrophysiological alterations of those pathways in animal models of HD. Based on recent studies, there is accumulating evidence that synaptic disconnection, particularly along excitatory pathways, is pervasive and almost universal in HD, thus supporting a critical role of the huntingtin protein in synaptic transmission.
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Affiliation(s)
- Joshua Barry
- IDDRC, Jane and Terry Semel Institute for Neuroscience and Human Behavior, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA, USA
| | - Minh T N Bui
- IDDRC, Jane and Terry Semel Institute for Neuroscience and Human Behavior, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA, USA
| | - Michael S Levine
- IDDRC, Jane and Terry Semel Institute for Neuroscience and Human Behavior, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA, USA
| | - Carlos Cepeda
- IDDRC, Jane and Terry Semel Institute for Neuroscience and Human Behavior, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA, USA.
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Cepeda C, Levine MS. Synaptic Dysfunction in Huntington's Disease: Lessons from Genetic Animal Models. Neuroscientist 2020; 28:20-40. [PMID: 33198566 DOI: 10.1177/1073858420972662] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
The understanding of the functional and structural changes occurring in the cerebral cortex and basal ganglia in Huntington's disease (HD) has benefited considerably from the generation of genetic animal models. Most studies of synaptic alterations in HD models have focused on the striatum, but a more complete picture of synaptic dysfunction in the cortico-basal ganglia-cortical loop is emerging. Here, we provide a review and analysis of current developments in the study of synaptic alterations in these areas using HD rodent models. Recent evidence indicates that cortical maldevelopment plays a role in synaptic dysfunction along the corticostriatal pathway that may have its roots in the way mutant huntingtin interacts with synaptic proteins. Furthermore, a progressive disconnection in the corticostriatal pathway leads to abnormal function engaging extrasynaptic N-methyl-D-aspartate glutamate receptors that contribute to eventual cell degeneration. In addition, biphasic increases followed by decreases in glutamate and dopamine release in the striatum could explain contrasting symptomatology in early and late stages of the disease. Changes in striatal output regions also are beginning to be examined. Finally, we highlight some therapeutic avenues aimed at rescuing synaptic dysfunction.
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Affiliation(s)
- Carlos Cepeda
- IDDRC, Jane and Terry Semel Institute for Neuroscience & Human Behavior, David Geffen School of Medicine, University of California, Los Angeles, CA, USA
| | - Michael S Levine
- IDDRC, Jane and Terry Semel Institute for Neuroscience & Human Behavior, David Geffen School of Medicine, University of California, Los Angeles, CA, USA
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Maldonado O, Jenkins A, Belalcazar HM, Hernandez-Cuervo H, Hyman KM, Ladaga G, Padilla L, de Erausquin GA. Age-dependent neuroprotective effect of an SK3 channel agonist on excitotoxity to dopaminergic neurons in organotypic culture. PLoS One 2020; 15:e0223633. [PMID: 32701951 PMCID: PMC7377472 DOI: 10.1371/journal.pone.0223633] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2019] [Accepted: 07/06/2020] [Indexed: 11/19/2022] Open
Abstract
Background Small conductance, calcium-activated (SK3) potassium channels control the intrinsic excitability of dopaminergic neurons (DN) in the midbrain and modulate their susceptibility to toxic insults during development. Methods We evaluated the age-dependency of the neuroprotective effect of an SK3 agonist, 1-Ethyl-1,3-dihydro-2H-benzimidazol-2-one (1-EBIO), on Amino-3-hydroxy-5-methylisoxazole-4-propionic acid (AMPA) excitotoxicity to DN in ventral mesencephalon (VM) organotypic cultures. Results Most tyrosine hydroxylase (TH)+ neurons were also SK3+; SK3+/TH- cells (DN+) were common at each developmental stage but more prominently at day in vitro (DIV) 8. Young DN+ neurons were small bipolar and fusiform, whereas mature ones were large and multipolar. Exposure of organotypic cultures to AMPA (100 μm, 16 h) had no effect on the survival of DN+ at DIV 8, but caused significant toxicity at DIV 15 (n = 15, p = 0.005) and DIV 22 (n = 15, p<0.001). These results indicate that susceptibility of DN to AMPA excitotoxicity is developmental stage-dependent in embryonic VM organotypic cultures. Immature DN+ (small, bipolar) were increased after AMPA (100 μm, 16 h) at DIV 8, at the expense of the number of differentiated (large, multipolar) DN+ (p = 0.039). This effect was larger at DIV 15 (p<<<0.0001) and at DIV 22 (p<<<0.0001). At DIV 8, 30 μM 1-EBIO resulted in a large increase in DN+. At DIV 15, AMPA toxicity was prevented by exposure to 30 μM, but not 100 μM 1-EBIO. At DIV 22, excitotoxicity was unaffected by 30 μM 1-EBIO, and partially reduced by 100 μM 1-EBIO. Conclusion The effects of the SK3 channel agonist 1-EBIO on the survival of SK3-expressing dopaminergic neurons were concentration-dependent and influenced by neuronal developmental stage.
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Affiliation(s)
- Oscar Maldonado
- Laboratory of Brain Development, and Repair, Biggs Institute for Alzheimer and Neurodegenerative Diseases, University of Texas Health San Antonio, San Antonio, Texas, United States of America
| | - Alexandra Jenkins
- Department of Molecular Medicine, University of South Florida, Tampa, Florida, United States of America
| | - Helen M. Belalcazar
- Department of Genetics, Albert Einstein College of Medicine, New York City, New York, United States of America
| | - Helena Hernandez-Cuervo
- Department of Molecular Medicine, University of South Florida, Tampa, Florida, United States of America
| | - Katelynn M. Hyman
- Department of Molecular Medicine, University of South Florida, Tampa, Florida, United States of America
| | - Giannina Ladaga
- Laboratory of Brain Development, and Repair, Biggs Institute for Alzheimer and Neurodegenerative Diseases, University of Texas Health San Antonio, San Antonio, Texas, United States of America
| | - Lucia Padilla
- Laboratory of Brain Development, and Repair, Biggs Institute for Alzheimer and Neurodegenerative Diseases, University of Texas Health San Antonio, San Antonio, Texas, United States of America
| | - Gabriel A. de Erausquin
- Laboratory of Brain Development, and Repair, Biggs Institute for Alzheimer and Neurodegenerative Diseases, University of Texas Health San Antonio, San Antonio, Texas, United States of America
- * E-mail:
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Creus-Muncunill J, Ehrlich ME. Cell-Autonomous and Non-cell-Autonomous Pathogenic Mechanisms in Huntington's Disease: Insights from In Vitro and In Vivo Models. Neurotherapeutics 2019; 16:957-978. [PMID: 31529216 PMCID: PMC6985401 DOI: 10.1007/s13311-019-00782-9] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
Huntington's disease (HD) is an autosomal dominant disorder caused by an expansion in the trinucleotide CAG repeat in exon-1 in the huntingtin gene, located on chromosome 4. When the number of trinucleotide CAG exceeds 40 repeats, disease invariably is manifested, characterized by motor, cognitive, and psychiatric symptoms. The huntingtin (Htt) protein and its mutant form (mutant huntingtin, mHtt) are ubiquitously expressed but although multiple brain regions are affected, the most vulnerable brain region is the striatum. Striatal medium-sized spiny neurons (MSNs) preferentially degenerate, followed by the cortical pyramidal neurons located in layers V and VI. Proposed HD pathogenic mechanisms include, but are not restricted to, excitotoxicity, neurotrophic support deficits, collapse of the protein degradation mechanisms, mitochondrial dysfunction, transcriptional alterations, and disorders of myelin. Studies performed in cell type-specific and regionally selective HD mouse models implicate both MSN cell-autonomous properties and cell-cell interactions, particularly corticostriatal but also with non-neuronal cell types. Here, we review the intrinsic properties of MSNs that contribute to their selective vulnerability and in addition, we discuss how astrocytes, microglia, and oligodendrocytes, together with aberrant corticostriatal connectivity, contribute to HD pathophysiology. In addition, mHtt causes cell-autonomous dysfunction in cell types other than MSNs. These findings have implications in terms of therapeutic strategies aimed at preventing neuronal dysfunction and degeneration.
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Affiliation(s)
- Jordi Creus-Muncunill
- Department of Neurology, Icahn School of Medicine at Mount Sinai, 1468 Madison Avenue, New York, NY, 10029, USA
| | - Michelle E Ehrlich
- Department of Neurology, Icahn School of Medicine at Mount Sinai, 1468 Madison Avenue, New York, NY, 10029, USA.
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Kuljis D, Kudo T, Tahara Y, Ghiani CA, Colwell CS. Pathophysiology in the suprachiasmatic nucleus in mouse models of Huntington's disease. J Neurosci Res 2018; 96:1862-1875. [PMID: 30168855 DOI: 10.1002/jnr.24320] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2018] [Revised: 08/04/2018] [Accepted: 08/07/2018] [Indexed: 12/30/2022]
Abstract
Disturbances in sleep/wake cycle are a common complaint of individuals with Huntington's disease (HD) and are displayed by HD mouse models. The underlying mechanisms, including the possible role of the circadian timing system, are not well established. The BACHD mouse model of HD exhibits disrupted behavioral and physiological rhythms, including decreased electrical activity in the central circadian clock (suprachiasmatic nucleus, SCN). In this study, electrophysiological techniques were used to explore the ionic underpinning of the reduced spontaneous neural activity in male mice. We found that SCN neural activity rhythms were lost early in the disease progression and was accompanied by loss of the normal daily variation in resting membrane potential in the mutant SCN neurons. The low neural activity could be transiently reversed by direct current injection or application of exogenous N-methyl-d-aspartate (NMDA) thus demonstrating that the neurons have the capacity to discharge at WT levels. Exploring the potassium currents known to regulate the electrical activity of SCN neurons, our most striking finding was that these cells in the mutants exhibited an enhancement in the large-conductance calcium activated K+ (BK) currents. The expression of the pore forming subunit (Kcnma1) of the BK channel was higher in the mutant SCN. We found a similar decrease in daytime electrical activity and enhancement in the magnitude of the BK currents early in disease in another HD mouse model (Q175). These findings suggest that SCN neurons of both HD models exhibit early pathophysiology and that dysregulation of BK current may be responsible.
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Affiliation(s)
- Dika Kuljis
- Department of Neurobiology, University of California Los Angeles, Los Angeles, California.,Department of Biological Sciences, Mellon Institute, Carnegie Mellon University, Pittsburgh, Pennsylvania
| | - Takashi Kudo
- Department of Psychiatry & Biobehavioral Sciences, University of California Los Angeles, Los Angeles, California.,Okinawa Institute of Science and Technology Graduate University, Onna-son, Japan
| | - Yu Tahara
- Department of Psychiatry & Biobehavioral Sciences, University of California Los Angeles, Los Angeles, California
| | - Cristina A Ghiani
- Department of Psychiatry & Biobehavioral Sciences, University of California Los Angeles, Los Angeles, California.,Department of Pathology and Laboratory Medicine, University of California Los Angeles, Los Angeles, California
| | - Christopher S Colwell
- Department of Psychiatry & Biobehavioral Sciences, University of California Los Angeles, Los Angeles, California
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Striatal Direct and Indirect Pathway Output Structures Are Differentially Altered in Mouse Models of Huntington's Disease. J Neurosci 2018; 38:4678-4694. [PMID: 29691329 DOI: 10.1523/jneurosci.0434-18.2018] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2018] [Revised: 04/02/2018] [Accepted: 04/18/2018] [Indexed: 11/21/2022] Open
Abstract
The present study examined synaptic communication between direct and indirect output pathway striatal medium-sized spiny neurons (MSNs) and their target structures, the substantia nigra pars reticulata (SNr) and the external globus pallidus (GPe) in two mouse models of Huntington's disease (HD). Cre recombination, optogenetics, and whole-cell patch-clamp recordings were used to determine alterations in intrinsic and synaptic properties of SNr and GPe neurons from both male and female symptomatic R6/2 (>60 d) and presymptomatic (2 months) or symptomatic (10-12 months) YAC128 mice. Cell membrane capacitance was decreased, whereas input resistance was increased in SNr neurons from R6/2, but not YAC128 mice. The amplitude of GABAergic responses evoked by optogenetic stimulation of direct pathway terminals was reduced in SNr neurons of symptomatic mice of both models. A decrease in spontaneous GABA synaptic activity, in particular large-amplitude events, in SNr neurons also was observed. Passive membrane properties of GPe neurons were not different between R6/2 or YAC128 mice and their control littermates. Similarly, the amplitude of GABA responses evoked by activation of indirect pathway MSN terminals and the frequency of spontaneous GABA synaptic activity were similar in HD and control animals. In contrast, the decay time of the evoked GABA response was significantly longer in cells from HD mice. Interestingly, activation of indirect pathway MSNs within the striatum evoked larger-amplitude responses in direct pathway MSNs. Together, these results demonstrate differential alterations in responses evoked by direct and indirect pathway terminals in SNr and GPe leading to striatal output imbalance and motor dysfunction.SIGNIFICANCE STATEMENT Previous work on Huntington's disease (HD) focused on striatal medium-sized spiny neurons (MSNs) almost exclusively. Little is known about the effects that alterations in the striatum have on output structures of the direct and indirect pathways, the substantia nigra pars reticulata (SNr) and the external segment of the globus pallidus (GPe), respectively. We combined electrophysiological and optogenetic methods to examine responses evoked by selective activation of terminals of direct and indirect pathway MSNs in SNr and GPe neurons in two mouse models of HD. We show a differential disruption of synaptic communication between the direct and indirect output pathways of the striatum with their target regions leading to an imbalance of striatal output, which will contribute to motor dysfunction.
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Zhang X, Wan JQ, Tong XP. Potassium channel dysfunction in neurons and astrocytes in Huntington's disease. CNS Neurosci Ther 2018; 24:311-318. [PMID: 29377621 DOI: 10.1111/cns.12804] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2017] [Revised: 12/24/2017] [Accepted: 12/25/2017] [Indexed: 01/09/2023] Open
Abstract
Huntington's disease (HD) is a late-onset fatal neurodegenerative disease, characterized by progressive movement disorders, psychiatric symptoms, and cognitive impairment. The cytosine-adenine-guanine (CAG) triplet expansion encoding glutamine present in the protein huntingtin (Htt), produces widespread neuronal and glial pathology. Mutant huntingtin (mHtt) nuclear aggregates are the primary cause of cortical and striatal neuron degeneration, neuronal inflammation, apoptosis and eventual cell loss. The precise mechanisms underlying the pathogenesis of neurodegeneration in HD remain poorly understood and HD patients have no current cure. Potassium channels are widely expressed in most cell types. In neurons, they play a crucial role in setting the resting membrane potential, mediating the rapid repolarization phase of the action potential and controlling sub-threshold oscillations of membrane potentials. In glial cells, their major contributions are maintaining the resting membrane potential and buffering extracellular K+ . Thus, potassium channels have an essential function in both physiological and pathological brain conditions. This review summarizes recent progress on potassium channels involved in the pathology of HD by using different HD mouse models. Exploring the dysfunction of potassium channels in the brain illustrates new approaches for targeting this channel for the treatment of HD.
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Affiliation(s)
- Xiao Zhang
- Discipline of Neuroscience and Department of Anatomy and Physiology, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Jie-Qing Wan
- Department of Neurological Surgery, Ren Ji Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Xiao-Ping Tong
- Discipline of Neuroscience and Department of Anatomy and Physiology, Shanghai Jiao Tong University School of Medicine, Shanghai, China
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Rangel-Barajas C, Rebec GV. Dysregulation of Corticostriatal Connectivity in Huntington's Disease: A Role for Dopamine Modulation. J Huntingtons Dis 2017; 5:303-331. [PMID: 27983564 PMCID: PMC5181679 DOI: 10.3233/jhd-160221] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Aberrant communication between striatum, the main information processing unit of the basal ganglia, and cerebral cortex plays a critical role in the emergence of Huntington’s disease (HD), a fatal monogenetic condition that typically strikes in the prime of life. Although both striatum and cortex undergo substantial cell loss over the course of HD, corticostriatal circuits become dysfunctional long before neurons die. Understanding the dysfunction is key to developing effective strategies for treating a progressively worsening triad of motor, cognitive, and psychiatric symptoms. Cortical output neurons drive striatal activity through the release of glutamate, an excitatory amino acid. Striatal outputs, in turn, release γ-amino butyric acid (GABA) and exert inhibitory control over downstream basal ganglia targets. Ample evidence from transgenic rodent models points to dysregulation of corticostriatal glutamate transmission along with corresponding changes in striatal GABA release as underlying factors in the HD behavioral phenotype. Another contributor is dysregulation of dopamine (DA), a modulator of both glutamate and GABA transmission. In fact, pharmacological manipulation of DA is the only currently available treatment for HD symptoms. Here, we review data from animal models and human patients to evaluate the role of DA in HD, including DA interactions with glutamate and GABA within the context of dysfunctional corticostriatal circuitry.
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Affiliation(s)
| | - George V. Rebec
- Correspondence to: George V. Rebec, PhD, Department of Psychological and Brain Sciences, Program in
Neuroscience, Indiana University, 1101 E. 10th Street, Bloomington, IN 47405-7007, USA. Tel.: +1 812 855 4832;
Fax: +1 812 855 4520; E-mail:
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11
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Bunner KD, Rebec GV. Corticostriatal Dysfunction in Huntington's Disease: The Basics. Front Hum Neurosci 2016; 10:317. [PMID: 27445757 PMCID: PMC4924423 DOI: 10.3389/fnhum.2016.00317] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2016] [Accepted: 06/13/2016] [Indexed: 11/23/2022] Open
Abstract
The main input to the basal ganglia, the corticostriatal pathway, shows some of the earliest signs of neuropathology in Huntington’s disease (HD), an inherited neurodegenerative condition that typically strikes in mid-life with progressively deteriorating cognitive, emotional, and motor symptoms. Although an effective treatment remains elusive, research on transgenic animal models has implicated dysregulation of glutamate (Glu), the excitatory amino acid released by corticostriatal neurons, in HD onset. Abnormalities in the control of Glu transmission at the level of postsynaptic receptors and Glu transport proteins play a critical role in the loss of information flow through downstream circuits that set the stage for the HD behavioral phenotype. Parallel but less-well characterized changes in dopamine (DA), a key modulator of Glu activation, ensure further deficits in neuronal communication throughout the basal ganglia. Continued analysis of corticostriatal Glu transmission and its modulation by DA, including analysis at the neurobehavioral level in transgenic models, is likely to be an effective strategy in the pursuit of HD therapeutics.
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Affiliation(s)
- Kendra D Bunner
- Department of Psychological and Brain Sciences, Program in Neuroscience, Indiana University Bloomington, IN, USA
| | - George V Rebec
- Department of Psychological and Brain Sciences, Program in Neuroscience, Indiana University Bloomington, IN, USA
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12
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Martin S, Lazzarini M, Dullin C, Balakrishnan S, Gomes FV, Ninkovic M, El Hady A, Pardo LA, Stühmer W, Del-Bel E. SK3 Channel Overexpression in Mice Causes Hippocampal Shrinkage Associated with Cognitive Impairments. Mol Neurobiol 2016; 54:1078-1091. [PMID: 26803493 PMCID: PMC5310555 DOI: 10.1007/s12035-015-9680-6] [Citation(s) in RCA: 18] [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: 07/08/2015] [Accepted: 12/23/2015] [Indexed: 12/11/2022]
Abstract
The dysfunction of the small-conductance calcium-activated K+ channel SK3 has been described as one of the factors responsible for the progress of psychoneurological diseases, but the molecular basis of this is largely unknown. This report reveals through use of immunohistochemistry and computational tomography that long-term increased expression of the SK3 small-conductance calcium-activated potassium channel (SK3-T/T) in mice induces a notable bilateral reduction of the hippocampal area (more than 50 %). Histological analysis showed that SK3-T/T mice have cellular disarrangements and neuron discontinuities in the hippocampal formation CA1 and CA3 neuronal layer. SK3 overexpression resulted in cognitive loss as determined by the object recognition test. Electrophysiological examination of hippocampal slices revealed that SK3 channel overexpression induced deficiency of long-term potentiation in hippocampal microcircuits. In association with these results, there were changes at the mRNA levels of some genes involved in Alzheimer’s disease and/or linked to schizophrenia, epilepsy, and autism. Taken together, these features suggest that augmenting the function of SK3 ion channel in mice may present a unique opportunity to investigate the neural basis of central nervous system dysfunctions associated with schizophrenia, Alzheimer’s disease, or other neuropsychiatric/neurodegenerative disorders in this model system. As a more detailed understanding of the role of the SK3 channel in brain disorders is limited by the lack of specific SK3 antagonists and agonists, the results observed in this study are of significant interest; they suggest a new approach for the development of neuroprotective strategies in neuropsychiatric/neurodegenerative diseases with SK3 representing a potential drug target.
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Affiliation(s)
- Sabine Martin
- Department of Molecular Biology of Neuronal Signals, Max Planck Institute of Experimental Medicine, Hermann-Rein-Strasse 3, 37075, Göttingen, Germany
- Center Nanoscale Microscopy and Molecular Physiology of the Brain (CNMPB), Göttingen, Germany
| | - Marcio Lazzarini
- Department of Molecular Biology of Neuronal Signals, Max Planck Institute of Experimental Medicine, Hermann-Rein-Strasse 3, 37075, Göttingen, Germany
| | - Christian Dullin
- Department of Diagnostic and Interventional Radiology, Georg-August University Medical Center, 37075, Göttingen, Germany
| | - Saju Balakrishnan
- Center Nanoscale Microscopy and Molecular Physiology of the Brain (CNMPB), Göttingen, Germany
- Department of Neuro- and Sensory Physiology, Georg-August University Medical Center, 37073, Göttingen, Germany
| | - Felipe V Gomes
- Department of Pharmacology, Medical School of Ribeirão Preto, University of São Paulo, 14040-900, Ribeirão Preto, Brazil
| | - Milena Ninkovic
- Department of Neurosurgery, Georg-August University Medical Center, 37075, Göttingen, Germany
| | - Ahmed El Hady
- Department of Molecular Biology of Neuronal Signals, Max Planck Institute of Experimental Medicine, Hermann-Rein-Strasse 3, 37075, Göttingen, Germany
- Bernstein Focus for Neurotechnology and Bernstein Center for Computational Neuroscience, Göttingen, Germany
- Theoretical Neurophysics, Department of Non-linear Dynamics, Max Planck Institute for Dynamics and Self-Organization, 37077, Göttingen, Germany
- The Interdisciplinary Collaborative Research Center 889 "Cellular Mechanisms of Sensory Processing", Göttingen, Germany
| | - Luis A Pardo
- Oncophysiology Group, Max Planck Institute of Experimental Medicine, 37075, Göttingen, Germany
| | - Walter Stühmer
- Department of Molecular Biology of Neuronal Signals, Max Planck Institute of Experimental Medicine, Hermann-Rein-Strasse 3, 37075, Göttingen, Germany.
- Center Nanoscale Microscopy and Molecular Physiology of the Brain (CNMPB), Göttingen, Germany.
- Bernstein Focus for Neurotechnology and Bernstein Center for Computational Neuroscience, Göttingen, Germany.
| | - Elaine Del-Bel
- Department of Morphology, Physiology and Pathology, CNPQ Research 1B (Biophysics, Biochemistry, Pharmacology and Neuroscience), University of São Paulo Dental School of Ribeirão Preto, Avenida do Café 3400, 14040-904, Ribeirão Preto, Brazil.
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Dallérac GM, Cummings DM, Hirst MC, Milnerwood AJ, Murphy KPSJ. Changes in Dopamine Signalling Do Not Underlie Aberrant Hippocampal Plasticity in a Mouse Model of Huntington's Disease. Neuromolecular Med 2016; 18:146-53. [PMID: 26782175 DOI: 10.1007/s12017-016-8384-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2015] [Accepted: 01/06/2016] [Indexed: 12/13/2022]
Abstract
Altered dopamine receptor labelling has been demonstrated in presymptomatic and symptomatic Huntington's disease (HD) gene carriers, indicating that alterations in dopaminergic signalling are an early event in HD. We have previously described early alterations in synaptic transmission and plasticity in both the cortex and hippocampus of the R6/1 mouse model of Huntington's disease. Deficits in cortical synaptic plasticity were associated with altered dopaminergic signalling and could be reversed by D1- or D2-like dopamine receptor activation. In light of these findings we here investigated whether defects in dopamine signalling could also contribute to the marked alteration in hippocampal synaptic function. To this end we performed dopamine receptor labelling and pharmacology in the R6/1 hippocampus and report a marked, age-dependent elevation of hippocampal D1 and D2 receptor labelling in R6/1 hippocampal subfields. Yet, pharmacological inhibition or activation of D1- or D2-like receptors did not modify the aberrant synaptic plasticity observed in R6/1 mice. These findings demonstrate that global perturbations to dopamine receptor expression do occur in HD transgenic mice, similarly in HD gene carriers and patients. However, the direction of change and the lack of effect of dopaminergic pharmacological agents on synaptic function demonstrate that the perturbations are heterogeneous and region-specific, a finding that may explain the mixed results of dopamine therapy in HD.
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Affiliation(s)
- Glenn M Dallérac
- Huntington's Disease Research Forum, Department of Life, Health and Chemical Sciences, The Open University, Milton Keynes, MK76AA, UK.
- CIRB, CNRS UMR 7241, INSERM U1050, Collège de France, 75005, Paris, France.
| | - Damian M Cummings
- Huntington's Disease Research Forum, Department of Life, Health and Chemical Sciences, The Open University, Milton Keynes, MK76AA, UK
- University College London, Neuroscience, Physiology and Pharmacology, Gower Street, London, WC1E 6BT, UK
| | - Mark C Hirst
- Huntington's Disease Research Forum, Department of Life, Health and Chemical Sciences, The Open University, Milton Keynes, MK76AA, UK
| | - Austen J Milnerwood
- Huntington's Disease Research Forum, Department of Life, Health and Chemical Sciences, The Open University, Milton Keynes, MK76AA, UK
- Department of Neurology & Centre for Applied Neurogenetics, Djavad Mowafaghian Centre for Brain Health, University of British Columbia, 2255, Wesbrook Mall, Vancouver, V6T 1Z3, Canada
| | - Kerry P S J Murphy
- Huntington's Disease Research Forum, Department of Life, Health and Chemical Sciences, The Open University, Milton Keynes, MK76AA, UK.
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Rothe T, Deliano M, Wójtowicz AM, Dvorzhak A, Harnack D, Paul S, Vagner T, Melnick I, Stark H, Grantyn R. Pathological gamma oscillations, impaired dopamine release, synapse loss and reduced dynamic range of unitary glutamatergic synaptic transmission in the striatum of hypokinetic Q175 Huntington mice. Neuroscience 2015; 311:519-38. [PMID: 26546830 DOI: 10.1016/j.neuroscience.2015.10.039] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2015] [Revised: 10/20/2015] [Accepted: 10/21/2015] [Indexed: 11/28/2022]
Abstract
Huntington's disease (HD) is a severe genetically inherited neurodegenerative disorder. Patients present with three principal phenotypes of motor symptoms: choreatic, hypokinetic-rigid and mixed. The Q175 mouse model of disease offers an opportunity to investigate the cellular basis of the hypokinetic-rigid form of HD. At the age of 1 year homozygote Q175 mice exhibited the following signs of hypokinesia: Reduced frequency of spontaneous movements on a precision balance at daytime (-55%), increased total time spent without movement in an open field (+42%), failures in the execution of unconditioned avoidance reactions (+32%), reduced ability for conditioned avoidance (-96%) and increased reaction times (+65%) in a shuttle box. Local field potential recordings revealed low-frequency gamma oscillations in the striatum as a characteristic feature of HD mice at rest. There was no significant loss of DARPP-32 immunolabeled striatal projection neurons (SPNs) although the level of DARPP-32 immunoreactivity was lower in HD. As a potential cause of hypokinesia, HD mice revealed a strong reduction in striatal KCl-induced dopamine release, accompanied by a decrease in the number of tyrosine hydroxylase-(TH)- and VMAT2-positive synaptic varicosities. The presynaptic TH fluorescence level was also reduced. Patch-clamp experiments were performed in slices from 1-year-old mice to record unitary EPSCs (uEPSCs) of presumed cortical origin in the absence of G-protein-mediated modulation. In HD mice, the maximal amplitudes of uEPSCs amounted to 69% of the WT level which matches the loss of VGluT1+/SYP+ synaptic terminals in immunostained sections. These results identify impairment of cortico-striatal synaptic transmission and dopamine release as a potential basis of hypokinesia in HD.
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Affiliation(s)
- T Rothe
- Leibniz Institute for Neurobiology Magdeburg, Germany
| | - M Deliano
- Leibniz Institute for Neurobiology Magdeburg, Germany
| | | | - A Dvorzhak
- Cluster of Excellence NeuroCure, Berlin, Germany
| | - D Harnack
- Department of Experimental Neurology, University Medicine Charité, Berlin, Germany
| | - S Paul
- Cluster of Excellence NeuroCure, Berlin, Germany
| | - T Vagner
- Cluster of Excellence NeuroCure, Berlin, Germany
| | - I Melnick
- Cluster of Excellence NeuroCure, Berlin, Germany; Bogomoletz Institute of Physiology, Kiev, Ukraine
| | - H Stark
- Leibniz Institute for Neurobiology Magdeburg, Germany
| | - R Grantyn
- Cluster of Excellence NeuroCure, Berlin, Germany; Department of Experimental Neurology, University Medicine Charité, Berlin, Germany.
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