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Co-Expression of Nogo-A in Dopaminergic Neurons of the Human Substantia Nigra Pars Compacta Is Reduced in Parkinson’s Disease. Cells 2021; 10:cells10123368. [PMID: 34943877 PMCID: PMC8699585 DOI: 10.3390/cells10123368] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2021] [Revised: 11/19/2021] [Accepted: 11/27/2021] [Indexed: 12/21/2022] Open
Abstract
Parkinson’s disease is mainly characterized by a progressive loss of dopaminergic neurons in the substantia nigra pars compacta. Together with the small number, the high vulnerability of the dopaminergic neurons is a major pathogenic culprit of Parkinson’s disease. Our previous findings of a higher survival of dopaminergic neurons in the substantia nigra co-expressing Nogo-A in an animal model of Parkinson’s disease suggested that Nogo-A may be associated with dopaminergic neurons resilience against Parkinson’s disease neurodegeneration. In the present study, we have addressed the expression of Nogo-A in the dopaminergic neurons in the substantia nigra in postmortem specimens of diseased and non-diseased subjects of different ages. For this purpose, in a collaborative effort we developed a tissue micro array (TMA) that allows for simultaneous staining of many samples in a single run. Interestingly, and in contrast to the observations gathered during normal aging and in the animal model of Parkinson’s disease, increasing age was significantly associated with a lower co-expression of Nogo-A in nigral dopaminergic neurons of patients with Parkinson’s disease. In sum, while Nogo-A expression in dopaminergic neurons is higher with increasing age, the opposite is the case in Parkinson’s disease. These observations suggest that Nogo-A might play a substantial role in the vulnerability of dopaminergic neurons in Parkinson’s disease.
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Luis-Ravelo D, Fumagallo-Reading F, Castro-Hernandez J, Barroso-Chinea P, Afonso-Oramas D, Febles-Casquero A, Cruz-Muros I, Salas-Hernandez J, Mesa-Infante V, Rodriguez-Nuñez J, Gonzalez-Hernandez T. Prolonged dopamine D 3 receptor stimulation promotes dopamine transporter ubiquitination and degradation through a PKC-dependent mechanism. Pharmacol Res 2021; 165:105434. [PMID: 33484816 DOI: 10.1016/j.phrs.2021.105434] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/22/2020] [Revised: 12/17/2020] [Accepted: 01/06/2021] [Indexed: 12/12/2022]
Abstract
The dopamine transporter (DAT) is a membrane glycoprotein in dopaminergic neurons, which modulates extracellular and intracellular dopamine levels. DAT is regulated by different presynaptic proteins, including dopamine D2 (D2R) and D3 (D3R) receptors. While D2R signalling enhances DAT activity, some data suggest that D3R has a biphasic effect. However, despite the extensive therapeutic use of D2R/D3R agonists in neuropsychiatric disorders, this phenomenon has been little studied. In order to shed light on this issue, DAT activity, expression and posttranslational modifications were studied in mice and DAT-D3R-transfected HEK cells. Consistent with previous reports, acute treatment with D2R/D3R agonists promoted DAT recruitment to the plasma membrane and an increase in DA uptake. However, when the treatment was prolonged, DA uptake and total striatal DAT protein declined below basal levels. These effects were inhibited in mice by genetic and pharmacological inactivation of D3R, but not D2R, indicating that they are D3R-dependent. No changes were detected in mesostriatal tyrosine hydroxylase (TH) protein expression and midbrain TH and DAT mRNAs, suggesting that the dopaminergic system is intact and DAT is posttranslationally regulated. The use of immunoprecipitation and cell surface biotinylation revealed that DAT is phosphorylated at serine residues, ubiquitinated and released into late endosomes through a PKCβ-dependent mechanism. In sum, the results indicate that long-term D3R activation promotes DAT down-regulation, an effect that may underlie neuroprotective and antidepressant actions described for some D2R/D3R agonists.
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Affiliation(s)
- Diego Luis-Ravelo
- Departamento de Ciencias Médicas Básicas, Facultad de Medicina, Universidad de La Laguna, Tenerife, Spain; Instituto de Tecnologías Biomédicas (ITB), Universidad de La Laguna, Tenerife, Spain
| | - Felipe Fumagallo-Reading
- Departamento de Ciencias Médicas Básicas, Facultad de Medicina, Universidad de La Laguna, Tenerife, Spain; Instituto de Tecnologías Biomédicas (ITB), Universidad de La Laguna, Tenerife, Spain
| | - Javier Castro-Hernandez
- Departamento de Ciencias Médicas Básicas, Facultad de Medicina, Universidad de La Laguna, Tenerife, Spain
| | - Pedro Barroso-Chinea
- Departamento de Ciencias Médicas Básicas, Facultad de Medicina, Universidad de La Laguna, Tenerife, Spain; Instituto de Tecnologías Biomédicas (ITB), Universidad de La Laguna, Tenerife, Spain
| | - Domingo Afonso-Oramas
- Departamento de Ciencias Médicas Básicas, Facultad de Medicina, Universidad de La Laguna, Tenerife, Spain; Instituto de Tecnologías Biomédicas (ITB), Universidad de La Laguna, Tenerife, Spain
| | - Alejandro Febles-Casquero
- Departamento de Ciencias Médicas Básicas, Facultad de Medicina, Universidad de La Laguna, Tenerife, Spain
| | - Ignacio Cruz-Muros
- Departamento de Ciencias Médicas Básicas, Facultad de Medicina, Universidad de La Laguna, Tenerife, Spain; Instituto de Tecnologías Biomédicas (ITB), Universidad de La Laguna, Tenerife, Spain
| | - Josmar Salas-Hernandez
- Departamento de Ciencias Médicas Básicas, Facultad de Medicina, Universidad de La Laguna, Tenerife, Spain; Instituto de Tecnologías Biomédicas (ITB), Universidad de La Laguna, Tenerife, Spain
| | - Virginia Mesa-Infante
- Departamento de Ciencias Médicas Básicas, Facultad de Medicina, Universidad de La Laguna, Tenerife, Spain
| | - Julia Rodriguez-Nuñez
- Departamento de Ciencias Médicas Básicas, Facultad de Medicina, Universidad de La Laguna, Tenerife, Spain
| | - Tomas Gonzalez-Hernandez
- Departamento de Ciencias Médicas Básicas, Facultad de Medicina, Universidad de La Laguna, Tenerife, Spain; Instituto de Tecnologías Biomédicas (ITB), Universidad de La Laguna, Tenerife, Spain.
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Tamtè M, Brys I, Richter U, Ivica N, Halje P, Petersson P. Systems-level neurophysiological state characteristics for drug evaluation in an animal model of levodopa-induced dyskinesia. J Neurophysiol 2016; 115:1713-29. [PMID: 26740532 DOI: 10.1152/jn.00868.2015] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2015] [Accepted: 12/30/2015] [Indexed: 01/13/2023] Open
Abstract
Disorders affecting the central nervous system have proven particularly hard to treat, and disappointingly few novel therapies have reached the clinics in recent decades. A better understanding of the physiological processes in the brain underlying various symptoms could therefore greatly improve the rate of progress in this field. We here show how systems-level descriptions of different brain states reliably can be obtained through a newly developed method based on large-scale recordings in distributed neural networks encompassing several different brain structures. Using this technology, we characterize the neurophysiological states associated with parkinsonism and levodopa-induced dyskinesia in a rodent model of Parkinson's disease together with pharmacological interventions aimed at reducing dyskinetic symptoms. Our results show that the obtained electrophysiological data add significant information to conventional behavioral evaluations and hereby elucidate the underlying effects of treatments in greater detail. Taken together, these results potentially open up for studies of neurophysiological mechanisms underlying symptoms in a wide range of neurological and psychiatric conditions that until now have been very hard to investigate in animal models of disease.
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Affiliation(s)
- Martin Tamtè
- Integrative Neurophysiology and Neurotechnology, Neuronano Research Center, Department of Experimental Medical Sciences, Lund University, Lund, Sweden
| | - Ivani Brys
- Integrative Neurophysiology and Neurotechnology, Neuronano Research Center, Department of Experimental Medical Sciences, Lund University, Lund, Sweden
| | - Ulrike Richter
- Integrative Neurophysiology and Neurotechnology, Neuronano Research Center, Department of Experimental Medical Sciences, Lund University, Lund, Sweden
| | - Nedjeljka Ivica
- Integrative Neurophysiology and Neurotechnology, Neuronano Research Center, Department of Experimental Medical Sciences, Lund University, Lund, Sweden
| | - Pär Halje
- Integrative Neurophysiology and Neurotechnology, Neuronano Research Center, Department of Experimental Medical Sciences, Lund University, Lund, Sweden
| | - Per Petersson
- Integrative Neurophysiology and Neurotechnology, Neuronano Research Center, Department of Experimental Medical Sciences, Lund University, Lund, Sweden
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Aumann TD. Environment- and activity-dependent dopamine neurotransmitter plasticity in the adult substantia nigra. J Chem Neuroanat 2015; 73:21-32. [PMID: 26718607 DOI: 10.1016/j.jchemneu.2015.12.009] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2015] [Revised: 12/15/2015] [Accepted: 12/16/2015] [Indexed: 01/10/2023]
Abstract
The ability of neurons to change the amount or type of neurotransmitter they use, or 'neurotransmitter plasticity', is an emerging new form of adult brain plasticity. For example, it has recently been shown that neurons in the adult rat hypothalamus up- or down-regulate dopamine (DA) neurotransmission in response to the amount of light the animal receives (photoperiod), and that this in turn affects anxiety- and depressive-like behaviors (Dulcis et al., 2013). In this Chapter I consolidate recent evidence from my laboratory suggesting neurons in the adult mouse substantia nigra pars compacta (SNc) also undergo DA neurotransmitter plasticity in response to persistent changes in their electrical activity, including that driven by the mouse's environment or behavior. Specifically, we have shown that the amounts of tyrosine hydroxylase (TH, the rate-limiting enzyme in DA synthesis) gene promoter activity, TH mRNA and TH protein in SNc neurons increases or decreases after ∼20h of altered electrical activity. Also, infusion of ion-channel agonists or antagonists into the midbrain for 2 weeks results in ∼10% (∼500 neurons) more or fewer TH immunoreactive (TH+) SNc neurons, with no change in the total number of SNc neurons (TH+ and TH-). Targeting ion-channels mediating cell-autonomous pacemaker activity in, or synaptic input and afferent pathways to, SNc neurons are equally effective in this regard. In addition, exposing mice to different environments (sex pairing or environment enrichment) for 1-2 weeks induces ∼10% more or fewer TH+ SNc (and ventral tegmental area or VTA) neurons and this is abolished by concurrent blockade of synaptic transmission in midbrain. Although further research is required to establish SNc (and VTA) DA neurotransmitter plasticity, and to determine whether it alters brain function and behavior, it is an exciting prospect because: (1) It may play important roles in movement, motor learning, reward, motivation, memory and cognition; and (2) Imbalances in midbrain DA cause symptoms associated with several prominent brain and behavioral disorders such as schizophrenia, addiction, obsessive-compulsive disorder, depression, Parkinson's disease and attention-deficit and hyperactivity disorder. Midbrain DA neurotransmitter plasticity may therefore play a role in the etiology of these symptoms, and might also offer new treatment options.
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Affiliation(s)
- Tim D Aumann
- Florey Institute of Neuroscience and Mental Health, The University of Melbourne, Parkville, Victoria 3010, Australia.
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Marin C, Bonastre M, Mengod G, Cortés R, Rodríguez-Oroz M. From unilateral to bilateral parkinsonism: Effects of lateralization on dyskinesias and associated molecular mechanisms. Neuropharmacology 2015; 97:365-75. [DOI: 10.1016/j.neuropharm.2015.06.004] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2015] [Revised: 06/02/2015] [Accepted: 06/09/2015] [Indexed: 01/15/2023]
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Rodriguez M, Rodriguez-Sabate C, Morales I, Sanchez A, Sabate M. Parkinson's disease as a result of aging. Aging Cell 2015; 14:293-308. [PMID: 25677794 PMCID: PMC4406659 DOI: 10.1111/acel.12312] [Citation(s) in RCA: 142] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/16/2014] [Indexed: 12/15/2022] Open
Abstract
It is generally considered that Parkinson's disease is induced by specific agents that degenerate a clearly defined population of dopaminergic neurons. Data commented in this review suggest that this assumption is not as clear as is often thought and that aging may be critical for Parkinson's disease. Neurons degenerating in Parkinson's disease also degenerate in normal aging, and the different agents involved in the etiology of this illness are also involved in aging. Senescence is a wider phenomenon affecting cells all over the body, whereas Parkinson's disease seems to be restricted to certain brain centers and cell populations. However, reviewed data suggest that Parkinson's disease may be a local expression of aging on cell populations which, by their characteristics (high number of synaptic terminals and mitochondria, unmyelinated axons, etc.), are highly vulnerable to the agents promoting aging. The development of new knowledge about Parkinson's disease could be accelerated if the research on aging and Parkinson's disease were planned together, and the perspective provided by gerontology gains relevance in this field.
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Affiliation(s)
- Manuel Rodriguez
- Laboratory of Neurobiology and Experimental Neurology, Department of Physiology, Faculty of Medicine, University of La LagunaLa Laguna, Spain
- Center for Networked Biomedical Research in Neurodegenerative Diseases (CIBERNED)La Laguna, Spain
| | - Clara Rodriguez-Sabate
- Center for Networked Biomedical Research in Neurodegenerative Diseases (CIBERNED)La Laguna, Spain
| | - Ingrid Morales
- Laboratory of Neurobiology and Experimental Neurology, Department of Physiology, Faculty of Medicine, University of La LagunaLa Laguna, Spain
- Center for Networked Biomedical Research in Neurodegenerative Diseases (CIBERNED)La Laguna, Spain
| | - Alberto Sanchez
- Laboratory of Neurobiology and Experimental Neurology, Department of Physiology, Faculty of Medicine, University of La LagunaLa Laguna, Spain
| | - Magdalena Sabate
- Rehabilitation Service, Department of Pharmacology and Physical Medicine, Faculty of Medicine, University of La LagunaLa Laguna, Spain
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Molochnikov I, Cohen D. Hemispheric differences in the mesostriatal dopaminergic system. Front Syst Neurosci 2014; 8:110. [PMID: 24966817 PMCID: PMC4052732 DOI: 10.3389/fnsys.2014.00110] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2013] [Accepted: 05/24/2014] [Indexed: 11/20/2022] Open
Abstract
The mesostriatal dopaminergic system, which comprises the mesolimbic and the nigrostriatal pathways, plays a major role in neural processing underlying motor and limbic functions. Multiple reports suggest that these processes are influenced by hemispheric differences in striatal dopamine (DA) levels, DA turnover and its receptor activity. Here, we review studies which measured the concentration of DA and its metabolites to examine the relationship between DA imbalance and animal behavior under different conditions. Specifically, we assess evidence in support of endogenous, inter-hemispheric DA imbalance; determine whether the known anatomy provides a suitable substrate for this imbalance; examine the relationship between DA imbalance and animal behavior; and characterize the symmetry of the observed inter-hemispheric laterality in the nigrostriatal and the mesolimbic DA systems. We conclude that many studies provide supporting evidence for the occurrence of experience-dependent endogenous DA imbalance which is controlled by a dedicated regulatory/compensatory mechanism. Additionally, it seems that the link between DA imbalance and animal behavior is better characterized in the nigrostriatal than in the mesolimbic system. Nonetheless, a variety of brain and behavioral manipulations demonstrate that the nigrostriatal system displays symmetrical laterality whereas the mesolimbic system displays asymmetrical laterality which supports hemispheric specialization in rodents. The reciprocity of the relationship between DA imbalance and animal behavior (i.e., the capacity of animal training to alter DA imbalance for prolonged time periods) remains controversial, however, if confirmed, it may provide a valuable non-invasive therapeutic means for treating abnormal DA imbalance.
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Affiliation(s)
- Ilana Molochnikov
- The Leslie and Susan Gonda Multidisciplinary Brain Research Center, Bar-Ilan University Ramat-Gan, Israel
| | - Dana Cohen
- The Leslie and Susan Gonda Multidisciplinary Brain Research Center, Bar-Ilan University Ramat-Gan, Israel
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Tritsch NX, Oh WJ, Gu C, Sabatini BL. Midbrain dopamine neurons sustain inhibitory transmission using plasma membrane uptake of GABA, not synthesis. eLife 2014; 3:e01936. [PMID: 24843012 PMCID: PMC4001323 DOI: 10.7554/elife.01936] [Citation(s) in RCA: 134] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Synaptic transmission between midbrain dopamine neurons and target neurons in the striatum is essential for the selection and reinforcement of movements. Recent evidence indicates that nigrostriatal dopamine neurons inhibit striatal projection neurons by releasing a neurotransmitter that activates GABAA receptors. Here, we demonstrate that this phenomenon extends to mesolimbic afferents, and confirm that the released neurotransmitter is GABA. However, the GABA synthetic enzymes GAD65 and GAD67 are not detected in midbrain dopamine neurons. Instead, these cells express the membrane GABA transporters mGAT1 (Slc6a1) and mGAT4 (Slc6a11) and inhibition of these transporters prevents GABA co-release. These findings therefore indicate that GABA co-release is a general feature of midbrain dopaminergic neurons that relies on GABA uptake from the extracellular milieu as opposed to de novo synthesis. This atypical mechanism may confer dopaminergic neurons the flexibility to differentially control GABAergic transmission in a target-dependent manner across their extensive axonal arbors. DOI:http://dx.doi.org/10.7554/eLife.01936.001 The electrical signals that are fired along neurons cannot be transmitted across the small gaps, called synapses that are found between neurons. Instead, the neuron sending the signal releases chemicals called neurotransmitters into the synapse. These neurotransmitters bind to receptor proteins on the surface of the second neuron and control how it fires. A neurotransmitter called dopamine plays a key role in the circuits of the brain that control how we learn certain tasks involving movement. In particular, two populations of neurons from the midbrain that release dopamine target the striatum, an area of the brain that is responsible for motor control. These neurons also release other neurotransmitters, but the identity of these other chemicals is not known, and the details of the interaction between the neurons and the striatum are poorly understood. Previous research showed that some of the midbrain neurons activate receptors that normally respond to a neurotransmitter called gamma-aminobutyric acid (GABA). However, several different chemicals can trigger this receptor. Using a range of techniques, Tritsch et al. now confirm that dopamine neurons release GABA alongside dopamine, and that this applies to both sets of the dopamine-producing neurons that feed into the striatum. Some neurons can manufacture GABA from amino acids found in their internal fluid. However, Tritsch et al. could not detect the enzymes needed for this reaction in dopamine-producing neurons. Instead, these neurons contain proteins that can transport GABA across the cell membrane, which suggests that the neurons collect GABA from the extracellular fluid that surrounds them. DOI:http://dx.doi.org/10.7554/eLife.01936.002
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Affiliation(s)
- Nicolas X Tritsch
- Department of Neurobiology, Howard Hughes Medical Institute, Harvard Medical School, Boston, United States
| | - Won-Jong Oh
- Department of Neurobiology, Harvard Medical School, Boston, United States
| | - Chenghua Gu
- Department of Neurobiology, Harvard Medical School, Boston, United States
| | - Bernardo L Sabatini
- Department of Neurobiology, Howard Hughes Medical Institute, Harvard Medical School, Boston, United States
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Walker MD, Dinelle K, Kornelsen R, Lee A, Farrer MJ, Stoessl AJ, Sossi V. Measuring dopaminergic function in the 6-OHDA-lesioned rat: a comparison of PET and microdialysis. EJNMMI Res 2013; 3:69. [PMID: 24088510 PMCID: PMC3875899 DOI: 10.1186/2191-219x-3-69] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2013] [Accepted: 09/23/2013] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND [18 F]fluorodopa (FDOPA) positron emission tomography (PET) allows assessment of levodopa (LDOPA) metabolism and is widely used to study Parkinson's disease. We examined how [18 F]FDOPA PET-derived kinetic parameters relate the dopamine (DA) and DA metabolite content of extracellular fluid measured by microdialysis to aid in the interpretation of data from both techniques. METHODS [18 F]FDOPA PET imaging and microdialysis measurements were performed in unilaterally 6-hydroxydopamine-lesioned rats (n = 8) and normal control rats (n = 3). Microdialysis testing included baseline measurements and measurements following acute administration of LDOPA. PET imaging was also performed using [11C]dihydrotetrabenazine (DTBZ), which is a ligand for the vesicular monoamine transporter marker and allowed assessment of denervation severity. RESULTS The different methods provided highly correlated data. Lesioned rats had reduced DA metabolite concentrations ipsilateral to the lesion (p < 0.05 compared to controls), with the concentration being correlated with FDOPA's effective distribution volume ratio (EDVR; r = 0.86, p < 0.01) and DTBZ's binding potential (BPND; r = 0.89, p < 0.01). The DA metabolite concentration in the contralateral striatum of severely (>80%) lesioned rats was lower (p < 0.05) than that of less severely lesioned rats (<80%) and was correlated with the ipsilateral PET measures (r = 0.89, p < 0.01 for BPND) but not with the contralateral PET measures. EDVR and BPND in the contralateral striatum were not different from controls and were not correlated with the denervation severity. CONCLUSIONS The demonstrated strong correlations between the PET and microdialysis measures can aid in the interpretation of [18 F]FDOPA-derived kinetic parameters and help compare results from different studies. The contralateral striatum was affected by the lesioning and so cannot always serve as an unaffected control.
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Affiliation(s)
- Matthew D Walker
- Department of Physics and Astronomy, University of British Columbia, 6224 Agricultural Road, Vancouver, British Columbia V6T 1Z1, Canada
| | - Katherine Dinelle
- Pacific Parkinson's Research Centre, University of British Columbia, 2221 Wesbrook Mall, Vancouver, British Columbia V6T 2B5, Canada
| | - Rick Kornelsen
- Pacific Parkinson's Research Centre, University of British Columbia, 2221 Wesbrook Mall, Vancouver, British Columbia V6T 2B5, Canada
| | - Anna Lee
- Pacific Parkinson's Research Centre, University of British Columbia, 2221 Wesbrook Mall, Vancouver, British Columbia V6T 2B5, Canada
| | - Matthew J Farrer
- Department of Medical Genetics, University of British Columbia, Vancouver, British Columbia V6H 3N1, Canada
| | - A Jon Stoessl
- Pacific Parkinson's Research Centre, University of British Columbia, 2221 Wesbrook Mall, Vancouver, British Columbia V6T 2B5, Canada
| | - Vesna Sossi
- Department of Physics and Astronomy, University of British Columbia, 6224 Agricultural Road, Vancouver, British Columbia V6T 1Z1, Canada
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Castaño JG, González C, Obeso JA, Rodriguez M. Molecular Pathogenesis and Pathophysiology of Parkinson’s Disease: New Targets for New Therapies. EMERGING DRUGS AND TARGETS FOR PARKINSON’S DISEASE 2013. [DOI: 10.1039/9781849737357-00026] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Parkinson’s disease (PD) is a complex chronic neurodegenerative disease of unknown etiology. A conceptual framework for all chronic diseases involves a series of channels or pathways (aging, genetic, environment, oxidative stress, mitochondrial damage, protein aggregation, etc.) and their interactions. Those channels with specificities may explain the ‘developmental’ program that through transcriptional reprogramming results in stressed dopamine neurons that eventually become dysfunctional or die, giving rise to the clinical manifestations of PD. In Chapter 2 we review the molecular mechanisms of those channels that may be implicated in the pathogenesis of PD and the pathophysiology of the disease based on the anatomo‐physiological complexity of the basal ganglia. This illustrates that understanding the molecular mechanisms of a disease may not be enough, or we have to reach an adequate system level to understand the disease process. Finally, we suggest that common therapies used for the treatment of other chronic diseases may be useful for the treatment (or help to advance the understanding) of PD, as well as new targets for new therapies that may be useful in the prevention of, or to stop the progression of, PD and other synucleinopathies.
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Affiliation(s)
- José G. Castaño
- Departamento de Bioquímica, Instituto de Investigaciones Biomédicas “Alberto Sols”, Facultad de Medicina Universidad Autónoma de Madrid Spain
- Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas Madrid Spain
| | - Carmen González
- Departamento de Farmacologia, Facultad de Medicina Universidad de Castilla‐La Mancha Albacete Spain
| | - José A. Obeso
- Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas Madrid Spain
- Laboratorio de Trastornos del Movimiento, Centro de Investigación Médica Aplicada University of Navarra Pamplona Spain
| | - Manuel Rodriguez
- Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas Madrid Spain
- Laboratory of Neurobiology and Experimental Neurology, Department of Physiology, Faculty of Medicine University of La Laguna Tenerife Canary Islands
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Dopaminergic neurons inhibit striatal output through non-canonical release of GABA. Nature 2012; 490:262-6. [PMID: 23034651 PMCID: PMC3944587 DOI: 10.1038/nature11466] [Citation(s) in RCA: 400] [Impact Index Per Article: 33.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2012] [Accepted: 07/27/2012] [Indexed: 12/19/2022]
Abstract
The substantia nigra pars compacta (SNc) and ventral tegmental area (VTA) contain the two largest populations of dopamine (DA)-releasing neurons in the mammalian brain. These neurons extend elaborate projections in striatum, a large subcortical structure implicated in motor planning and reward-based learning. Phasic activation of dopaminergic neurons in response to salient or reward-predicting stimuli is thought to modulate striatal output via the release of DA to promote and reinforce motor action1–4. Here we show that activation of DA neurons in striatal slices rapidly inhibits action potential firing in both direct-and indirect-pathway striatal projection neurons (SPNs) through vesicular release of the inhibitory transmitter γ-aminobutyric acid (GABA). GABA is released directly from dopaminergic axons but in a manner that is independent of the vesicular GABA transporter VGAT. Instead GABA release requires activity of the vesicular monoamine transporter VMAT2, which is the vesicular transporter for DA. Furthermore, VMAT2 expression in GABAergic neurons lacking VGAT is sufficient to sustain GABA release. Thus, these findings expand the repertoire of synaptic mechanisms employed by DA neurons to influence basal ganglia circuits, reveal a novel substrate whose transport is dependent on VMAT2, and demonstrate that GABA can function as a bona fide co-transmitter in monoaminergic neurons.
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Riederer P, Sian-Hülsmann J. The significance of neuronal lateralisation in Parkinson's disease. J Neural Transm (Vienna) 2012; 119:953-62. [PMID: 22367437 DOI: 10.1007/s00702-012-0775-1] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2011] [Accepted: 02/04/2012] [Indexed: 12/29/2022]
Abstract
The destruction of the dopaminergic neurons in the substantia nigra (SN) and consequent depletion of striatal dopamine elicits the main movement deficits related to Parkinson's disease (PD). In the early stages of the illness, the motor symptoms are often exhibited asymmetrically. Thus, the onset of PD features starts on either the right or left side. The side of onset appears to determine the prognosis of the disorder and other features, such as right-side tremor dominance has a better prognosis in contrast to left-side dominant bradykinesia-rigidity. In addition, left-side onset of motor features is associated with cognitive decline. Therefore, an intricate relation appears to exist between the side of disease onset and progression/severity and other non-motor symptoms. Unilateral PD in turn corresponds to neuronal nigrostriatal degeneration in the contralateral hemisphere. Indeed positron emission tomography has demonstrated a positive correlation between symptom asymmetry and brain function (Hoorn et al. Parkinsonism Relat Disord 17:58-60, 2011), which corresponds to a unilateral pattern of degeneration. This phenomenon appears to be exclusive to PD. Additionally, the variation in motor symptom(s) dominance exhibited in the disorder conforms to the notion that PD is a spectrum disease with many sub-groups. Thus, clinical and post mortem studies on "lateralisation" may serve as a vital tool in understanding the mechanism(s) eliciting the characteristic destruction of the SN neurons. Additionally, it may be employed as a predictive indicator for the symptomology and prognosis of the illness thus allowing selective treatment strategies targeted at the pronounced hemispheric degeneration.
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Affiliation(s)
- P Riederer
- Clinical Neurochemistry, National Parkinson's Foundation Centre of Excellence Laboratories, Department of Psychiatry, Psychosomatics and Psychotherapy, University Hospital Würzburg, Fuechsleinstrasse 15, Würzburg, Germany.
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Blesa J, Juri C, García-Cabezas MÁ, Adánez R, Sánchez-González MÁ, Cavada C, Obeso JA. Inter-hemispheric asymmetry of nigrostriatal dopaminergic lesion: a possible compensatory mechanism in Parkinson's disease. Front Syst Neurosci 2011; 5:92. [PMID: 22287944 PMCID: PMC3258666 DOI: 10.3389/fnsys.2011.00092] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2011] [Accepted: 10/25/2011] [Indexed: 11/15/2022] Open
Abstract
The onset of Parkinson’s disease (PD) is characterized by focal motor features in one body part, which are usually correlated with greater dopaminergic depletion in the contralateral posterior putamen. The role of dopamine (DA) hemispheric differences in the onset and progression of motor symptoms of PD, however, remains undefined. Previous studies have demonstrated that unilateral manipulations of one nigrostriatal system affect contralateral DA turnover, indicating a functional and compensatory inter-dependence of the two nigrostriatal systems. In preliminary data obtained by our group from asymmetric PD patients, a higher asymmetry index as measured by 6-[18F]fluoro-L-dopa (18 F-DOPA) positron emission tomography (PET) was associated with a higher threshold (i.e., greater dopaminergic loss) for the onset of motor symptoms in the less-affected side. To further elucidate the underlying basis for this, we carried out a complementary study in monkeys using PET to assess and correlate the degree of dopaminergic striatal depletion with motor activity. Control and 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-intoxicated monkeys with symmetrical lesions were characterized behaviorally and with 18F-DOPA PET. In parallel, an acute lesion was inflicted in the nigrostriatal projection unilaterally in one monkey, generating a 30% dopaminergic depletion in the ipsilateral striatum, which was not associated with any noticeable parkinsonian feature or deficit. The monkey remained asymptomatic for several months. Subsequently, this monkey received systemic MPTP, following which motor behavior and PET were repeatedly evaluated during progression of parkinsonian signs. The brains of all monkeys were processed using immunohistochemical methods. Our results suggest that the onset of motor signs is related to and influenced by the dopaminergic status of the less-affected, contralateral striatum. Although this work is still preliminary, the study agrees with our general hypothesis of hemispheric inter-dependence in the compensation of striatal DA deficit in PD.
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Affiliation(s)
- Javier Blesa
- *Correspondence: Javier Blesa, Centro de Investigación Médica Aplicada-Neurociencias, Universidad de Navarra, Pio XII 35, Pamplona 31008, Spain. e-mail:
| | - Carlos Juri
- Laboratorio deTrastornos del Movimiento, Neurociencias, Centro de Investigación Médica Aplicada, Departamento de Neurología y Neurocirugía, Clínica Universidad de Navarra, Pamplona, Spain
| | - Miguel Á. García-Cabezas
- Departamento de Anatomía, Histología y Neurociencia, Facultad de Medicina, Universidad Autónoma de Madrid, Madrid, Spain
| | - Rebeca Adánez
- Laboratorio deTrastornos del Movimiento, Neurociencias, Centro de Investigación Médica Aplicada, Departamento de Neurología y Neurocirugía, Clínica Universidad de Navarra, Pamplona, Spain
| | - Miguel Á. Sánchez-González
- Departamento de Anatomía, Histología y Neurociencia, Facultad de Medicina, Universidad Autónoma de Madrid, Madrid, Spain
| | - Carmen Cavada
- Departamento de Anatomía, Histología y Neurociencia, Facultad de Medicina, Universidad Autónoma de Madrid, Madrid, Spain
| | - José A. Obeso
- Laboratorio deTrastornos del Movimiento, Neurociencias, Centro de Investigación Médica Aplicada, Departamento de Neurología y Neurocirugía, Clínica Universidad de Navarra, Pamplona, Spain
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Altered expression of neuronal nitric oxide synthase in weaver mutant mice. Brain Res 2010; 1326:40-50. [PMID: 20219442 DOI: 10.1016/j.brainres.2010.02.056] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2009] [Revised: 02/08/2010] [Accepted: 02/19/2010] [Indexed: 01/06/2023]
Abstract
The weaver mouse represents the only genetic animal model of gradual nigrostriatal dopaminergic neurodegeneration which is proposed as a pathophysiological phenotype of Parkinson's disease. The aim of the present study was to analyze the nitric oxide and dopaminergic systems in selected brain regions of homozygous weaver mice at different postnatal ages corresponding to specific stages of the dopamine loss. Structural deficits were evaluated by quantification of tyrosine hydroxylase and neuronal nitric oxide synthase-immunostaining in the cortex, striatum, accumbens nuclei, subthalamic nuclei, ventral tegmental area, and substantia nigra compacta of 10-day, 1- and 2-month-old wild-type and weaver mutant mice. The results confirmed the progressive loss of dopamine during the postnatal development in the adult weaver mainly affecting the substantia nigra pars compacta, striatum, and subthalamic nucleus and slightly affecting the accumbens nuclei and ventral tegmental area. A general decrease in neuronal nitric oxide synthase-immunostaining with age was revealed in both the weaver and wild-type mice, with the decrease being most pronounced in the weaver. In contrast, there was an increase in the substantia nigra pars compacta nitric oxide synthase-immunostaining and a decrease mainly in the subthalamic and accumbens nuclei of the 2-month-old weaver mutant. The decrease in the expression of nNOS may bear functional significance related to the process of aging. DA neurons from the substantia nigra directly modulate the activity of subthalamic nucleus neurons, and their loss may contribute to the abnormal activity of subthalamic nucleus neurons. Although the functional significance of these changes is not clear, it may represent plastic compensating adjustments resulting from the loss of dopamine innervation, highlighting a possible role of nitric oxide in this process.
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Galvan A, Kuwajima M, Smith Y. Glutamate and GABA receptors and transporters in the basal ganglia: what does their subsynaptic localization reveal about their function? Neuroscience 2006; 143:351-75. [PMID: 17059868 PMCID: PMC2039707 DOI: 10.1016/j.neuroscience.2006.09.019] [Citation(s) in RCA: 84] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2006] [Revised: 09/10/2006] [Accepted: 09/13/2006] [Indexed: 01/29/2023]
Abstract
GABA and glutamate, the main transmitters in the basal ganglia, exert their effects through ionotropic and metabotropic receptors. The dynamic activation of these receptors in response to released neurotransmitter depends, among other factors, on their precise localization in relation to corresponding synapses. The use of high resolution quantitative electron microscope immunocytochemical techniques has provided in-depth description of the subcellular and subsynaptic localization of these receptors in the CNS. In this article, we review recent findings on the ultrastructural localization of GABA and glutamate receptors and transporters in monkey and rat basal ganglia, at synaptic, extrasynaptic and presynaptic sites. The anatomical evidence supports numerous potential locations for receptor-neurotransmitter interactions, and raises important questions regarding mechanisms of activation and function of synaptic versus extrasynaptic receptors in the basal ganglia.
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Affiliation(s)
- A Galvan
- Yerkes National Primate Research Center, Emory University, Atlanta, GA 30322, USA.
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Ducray A, Krebs SH, Schaller B, Seiler RW, Meyer M, Widmer HR. GDNF family ligands display distinct action profiles on cultured GABAergic and serotonergic neurons of rat ventral mesencephalon. Brain Res 2006; 1069:104-12. [PMID: 16380100 DOI: 10.1016/j.brainres.2005.11.056] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2005] [Revised: 11/08/2005] [Accepted: 11/11/2005] [Indexed: 12/29/2022]
Abstract
Glial-cell-line-derived neurotrophic factor (GDNF), neurturin (NRTN), artemin (ARTN) and persephin (PSPN), known as the GDNF family ligands (GFLs), influence the development, survival and differentiation of cultured dopaminergic neurons from ventral mesencephalon (VM). Detailed knowledge about the effects of GFLs on other neuronal populations in the VM is essential for their potential application as therapeutic molecules for Parkinson's disease. Hence, in a comparative study, we investigated the effects of GFLs on cell densities and morphological differentiation of gamma-aminobutyric acid-immunoreactive (GABA-ir) and serotonin-ir (5-HT-ir) neurons in primary cultures of E14 rat VM. We observed that all GFLs [10 ng/ml] significantly increased GABA-ir cell densities (1.6-fold) as well as neurite length/neuron. However, only GDNF significantly increased the number of primary neurites/neuron, and none of the GFLs affected soma size of GABA-ir neurons. In contrast, only NRTN treatment significantly increased 5-HT-ir cells densities at 10 ng/ml (1.3-fold), while an augmentation was seen for GDNF and PSPN at 100 ng/ml (2.4-fold and 1.7-fold, respectively). ARTN had no effect on 5-HT-ir cell densities. Morphological analysis of 5-HT-ir neurons revealed a significant increase of soma size, number of primary neurites/neuron and neurite length/neuron after GDNF exposure, while PSPN only affected soma size, and NRTN and ARTN failed to exert any effect. In conclusion, we identified GFLs as effective neurotrophic factors for VM GABAergic and serotonergic neurons, demonstrating characteristic individual action profiles emphasizing their important and distinct roles during brain development.
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Affiliation(s)
- Angélique Ducray
- Department of Neurosurgery, University of Bern, CH-3010 Bern, Switzerland
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