751
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Yang XQ, Glizer D, Vo A, Seergobin KN, MacDonald PA. Pramipexole Increases Go Timeouts but Not No-go Errors in Healthy Volunteers. Front Hum Neurosci 2016; 10:523. [PMID: 27803657 PMCID: PMC5067488 DOI: 10.3389/fnhum.2016.00523] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2016] [Accepted: 10/03/2016] [Indexed: 12/03/2022] Open
Abstract
Parkinson's disease (PD) is characterized by motor symptoms, such as resting tremor, bradykinesia and rigidity, but also features non-motor complications. PD patients taking dopaminergic therapy, such as levodopa but especially dopamine agonists (DAs), evidence an increase in impulse control disorders (ICDs), suggesting a link between dopaminergic therapy and impulsive pursuit of pleasurable activities. However, impulsivity is a multifaceted construct. Motor impulsivity refers to the inability to overcome automatic responses or cancel pre-potent responses. Previous research has suggested that PD patients, on dopaminergic medications, have decreased motor impulsivity. Whether effects on impulsivity are main effects of dopaminergic therapies or are specific to PD is unclear. Using a Go No-go task, we investigated the effect of a single dose of the DA pramipexole on motor impulsivity in healthy participants. The Go No-go task consisted of Go trials, for which keystroke responses were made as quickly as possible, and lesser frequency No-go trials, on which motor responses were to be inhibited. We hypothesized that pramipexole would decrease motor impulsivity. This would manifest as: (a) fewer No-go errors (i.e., fewer responses on trials in which a response ought to have been inhibited); and (b) more timed-out Go trials (i.e., more trials on which the deadline elapsed before a decision to make a keystroke occurred). Healthy volunteers were treated with either 0.5 mg of pramipexole or a standard placebo (randomly determined). During the 2-h wait period, they completed demographic, cognitive, physiological and affective measures. The pramipexole group had significantly more Go timeouts (p < 0.05) compared to the placebo group though they did not differ in percent of No-go errors. In contrast to its effect on pursuit of pleasurable activities, pramipexole did not increase motor impulsivity. In fact, in line with findings in PD and addiction, dopaminergic therapy might increase motor impulse control. In these patient groups, by enhancing function of the dorsal striatum (DS) of the basal ganglia in contrast to its effect on impulsive pursuit of pleasurable activities. These findings have implications for use and effects of pramipexole in PD as well as in other conditions (e.g., restless leg, dystonia, depression, addiction-related problems).
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Affiliation(s)
- Xue Qing Yang
- MacDonald Lab, Brain and Mind Institute, University of Western OntarioLondon, ON, Canada
| | - Daniel Glizer
- MacDonald Lab, Brain and Mind Institute, University of Western OntarioLondon, ON, Canada
| | - Andrew Vo
- MacDonald Lab, Brain and Mind Institute, University of Western OntarioLondon, ON, Canada
| | - Ken N. Seergobin
- MacDonald Lab, Brain and Mind Institute, University of Western OntarioLondon, ON, Canada
| | - Penny A. MacDonald
- MacDonald Lab, Brain and Mind Institute, University of Western OntarioLondon, ON, Canada
- Clinical Neurological Sciences, Schulich School of Medicine and Dentistry, University of Western OntarioLondon, ON, Canada
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752
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Bagga P, Crescenzi R, Krishnamoorthy G, Verma G, Nanga RPR, Reddy D, Greenberg J, Detre JA, Hariharan H, Reddy R. Mapping the alterations in glutamate with GluCEST MRI in a mouse model of dopamine deficiency. J Neurochem 2016; 139:432-439. [PMID: 27529288 DOI: 10.1111/jnc.13771] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2016] [Revised: 06/21/2016] [Accepted: 08/05/2016] [Indexed: 11/30/2022]
Abstract
Glutamate chemical exchange saturation transfer (GluCEST) MRI was used to measure metabolic changes in mice treated with 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) by mapping regional cerebral glutamate. The GluCEST contrast following MPTP treatment was correlated with 1 H-MR spectroscopy, motor function, and immunohistochemical measures. The GluCEST contrast was found to be significantly higher in the striatum and motor cortex of mice treated with MPTP than in controls (p < 0.001), which was confirmed by localized 1 H-MR spectroscopy. Elevated striatal GluCEST was positively associated with local astrogliosis measured by immunohistochemistry for glial fibrillary acidic protein. Additionally, a negative correlation was found between motor function, measured by the four-limb grip strength test, and GluCEST of the striatum (R = -0.705, p < 0.001) and the motor cortex (R = -0.617, p < 0.01), suggesting a role of elevated glutamate in the abnormal cerebral motor function regulation. The GluCEST contrast and glial fibrillary acidic protein immunostaining were unaltered in the thalamus indicating glutamate elevation was localized to the striatum and the motor cortex. These findings suggest that in addition to measuring spatial changes in glutamate, GluCEST may serve as an in vivo biomarker of metabolic and functional changes that may be applied to the assessment of a broad range of neuropathologies. Read the Editorial Highlight for this article on page 346.
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Affiliation(s)
- Puneet Bagga
- Center for Magnetic Resonance and Optical Imaging (CMROI), Department of Radiology, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Rachelle Crescenzi
- Center for Magnetic Resonance and Optical Imaging (CMROI), Department of Radiology, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Guruprasad Krishnamoorthy
- Center for Magnetic Resonance and Optical Imaging (CMROI), Department of Radiology, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Gaurav Verma
- Center for Magnetic Resonance and Optical Imaging (CMROI), Department of Radiology, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Ravi Prakash Reddy Nanga
- Center for Magnetic Resonance and Optical Imaging (CMROI), Department of Radiology, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Damodar Reddy
- Center for Magnetic Resonance and Optical Imaging (CMROI), Department of Radiology, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Joel Greenberg
- Department of Neurology, University of Pennsylvania, Philadelphia, Pennsylvania
| | - John A Detre
- Center for Functional Neuroimaging, Department of Neurology, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Hari Hariharan
- Center for Magnetic Resonance and Optical Imaging (CMROI), Department of Radiology, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Ravinder Reddy
- Center for Magnetic Resonance and Optical Imaging (CMROI), Department of Radiology, University of Pennsylvania, Philadelphia, Pennsylvania.
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753
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Olanow CW, Bartus RT, Volpicelli-Daley LA, Kordower JH. Trophic factors for Parkinson's disease: To live or let die. Mov Disord 2016; 30:1715-24. [PMID: 26769457 DOI: 10.1002/mds.26426] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2015] [Revised: 08/06/2015] [Accepted: 08/19/2015] [Indexed: 12/23/2022] Open
Abstract
Trophic factors show great promise in laboratory studies as potential therapies for PD. However, multiple double-blind, clinical trials have failed to show benefits in comparison to a placebo control. This article will review the scientific rationale for testing trophic factors in PD, the results of the different clinical trials that have been performed to date, and the possible explanations for these failed outcomes. We will also consider future directions and the likelihood that trophic factors will become a viable therapy for patients with PD.
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Affiliation(s)
- C Warren Olanow
- Department of Neurology, Mount Sinai School of Medicine, New York, New York, USA
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754
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Fischer DL, Gombash SE, Kemp CJ, Manfredsson FP, Polinski NK, Duffy MF, Sortwell CE. Viral Vector-Based Modeling of Neurodegenerative Disorders: Parkinson's Disease. Methods Mol Biol 2016; 1382:367-82. [PMID: 26611600 DOI: 10.1007/978-1-4939-3271-9_26] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Gene therapy methods are increasingly used to model Parkinson's disease (PD) in animals in an effort to test experimental therapeutics within a more relevant context to disease pathophysiology and neuropathology. We have detailed several criteria that are critical or advantageous to accurately modeling PD in a murine model or in a nonhuman primate. Using these criteria, we then evaluate approaches made to model PD using viral vectors to date, including both adeno-associated viruses and lentiviruses. Lastly, we comment on the consideration of aging as a critical factor for modeling PD.
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Affiliation(s)
- D Luke Fischer
- Department of Translational Science & Molecular Medicine, Michigan State University, 333 Bostwick Ave., NE, Grand Rapids, MI, 49503-2532, USA
- MD/PhD Program, Michigan State University, Grand Rapids, MI, USA
- Neuroscience Graduate Program, Michigan State University, Grand Rapids, MI, USA
| | - Sara E Gombash
- Department of Translational Science & Molecular Medicine, Michigan State University, 333 Bostwick Ave., NE, Grand Rapids, MI, 49503-2532, USA
- Neuroscience Graduate Program, University of Cincinnati, Cincinnati, OH, USA
| | - Christopher J Kemp
- Department of Translational Science & Molecular Medicine, Michigan State University, 333 Bostwick Ave., NE, Grand Rapids, MI, 49503-2532, USA
| | - Fredric P Manfredsson
- Translational Science and Molecular Medicine, Michigan State University, College of Human Science, 333 Bostwick Ave., NE, Grand Rapids, MI, 49503-2532, USA
| | - Nicole K Polinski
- Department of Translational Science & Molecular Medicine, Michigan State University, 333 Bostwick Ave., NE, Grand Rapids, MI, 49503-2532, USA
- Neuroscience Graduate Program, Michigan State University, Grand Rapids, MI, USA
| | - Megan F Duffy
- Department of Translational Science & Molecular Medicine, Michigan State University, 333 Bostwick Ave., NE, Grand Rapids, MI, 49503-2532, USA
- Neuroscience Graduate Program, Michigan State University, Grand Rapids, MI, USA
| | - Caryl E Sortwell
- Department of Translational Science & Molecular Medicine, Michigan State University, 333 Bostwick Ave., NE, Grand Rapids, MI, 49503-2532, USA.
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755
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Abstract
The dream that trophic factors could be effectively delivered and potently forestall and reverse the symptoms of Parkinson's disease (PD) has yet to be realized. Research in this area has been active for 20 years, but after much work, the prospects for utilizing trophic factors in the treatment of PD are currently dim. Millions of dollars have been spent, numerous academic, foundation, and government resources have been invested, and hundreds of patient research volunteers have contributed their time and hope to this effort without a therapeutic breakthrough. As a scientist who has journeyed these events from the beginning and participated in many of the decisions that navigated this field, I consider it important for the movement disorder scientific community to reflect on the evolution of thought and to participate in the dialog over whether the investments were worthwhile.The most studied group of trophic factor for PD is the glial cell derived family of ligands, of which glial cell derived neurotrophic factor (GDNF) and neurturin are members, and are the best studied. I trace the development of these factors chronologically with commentary on the key decision-making points. Before we collectively invest further, I offer this scientific reflection on the past and offer my own view on the next steps of research in the field of neurotrophins as potential therapeutic agents in PD.
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756
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Bez F, Francardo V, Cenci MA. Dramatic differences in susceptibility to l-DOPA-induced dyskinesia between mice that are aged before or after a nigrostriatal dopamine lesion. Neurobiol Dis 2016; 94:213-25. [DOI: 10.1016/j.nbd.2016.06.005] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2016] [Revised: 06/08/2016] [Accepted: 06/11/2016] [Indexed: 12/26/2022] Open
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757
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Abstract
Parkinson's disease psychosis (PDP) is theoretically a serotonin-dopamine imbalance syndrome due to disruption of the normal balance between the serotonergic and dopaminergic neurotransmitter systems in key brain circuits.
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758
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Vogt Weisenhorn DM, Giesert F, Wurst W. Diversity matters - heterogeneity of dopaminergic neurons in the ventral mesencephalon and its relation to Parkinson's Disease. J Neurochem 2016; 139 Suppl 1:8-26. [PMID: 27206718 PMCID: PMC5096020 DOI: 10.1111/jnc.13670] [Citation(s) in RCA: 49] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2016] [Revised: 04/25/2016] [Accepted: 05/17/2016] [Indexed: 12/25/2022]
Abstract
Dopaminergic neurons in the ventral mesencephalon (the ventral mesencephalic dopaminergic complex) are known for their role in a multitude of behaviors, including cognition, reward, addiction and voluntary movement. Dysfunctions of these neurons are the underlying cause of various neuropsychiatric disorders, such as depression, addiction and schizophrenia. In addition, Parkinson's disease (PD), which is the second most common degenerative disease in developed countries, is characterized by the degeneration of dopaminergic neurons, leading to the core motor symptoms of the disease. However, only a subset of dopaminergic neurons in the ventral mesencephalon is highly vulnerable to the disease process. Indeed, research over several decades revealed that the neurons in the ventral mesencephalic dopaminergic complex do not form a homogeneous group with respect to anatomy, physiology, function, molecular identity or vulnerability/dysfunction in different diseases. Here, we review how the concept of dopaminergic neuron diversity, assisted by the advent and application of new technologies, evolved and was refined over time and how it shaped our understanding of PD pathogenesis. Understanding this diversity of neurons in the ventral mesencephalic dopaminergic complex at all levels is imperative for the development of new and more selective drugs for both PD and various other neuropsychiatric diseases. Several decades of research revealed that the neurons in the ventral mesencephalic dopaminergic complex do not form a homogeneous group in respect to anatomy, physiology, function, molecular identity or vulnerability/dysfunction in diseases like Parkinson's disease (PD). Here, we review how this concept evolved and was refined over time and how it shaped our understanding of the pathogenesis of PD. Source of the midbrain image: www.wikimd.org/wiki/index.php/The_Midbrain_or_Mesencephalon; downloaded 28.01.2016. See also Figures and of the paper. This article is part of a special issue on Parkinson disease.
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Affiliation(s)
- Daniela Maria Vogt Weisenhorn
- Helmholtz Zentrum München, German Research Center for Environmental Health, Institute of Developmental Genetics, Neuherberg, Germany
- Technische Universität München-Weihenstephan, Lehrstuhl für Entwicklungsgenetik, c/o Helmholtz Zentrum München, Neuherberg, Germany
| | - Florian Giesert
- Helmholtz Zentrum München, German Research Center for Environmental Health, Institute of Developmental Genetics, Neuherberg, Germany
- Technische Universität München-Weihenstephan, Lehrstuhl für Entwicklungsgenetik, c/o Helmholtz Zentrum München, Neuherberg, Germany
| | - Wolfgang Wurst
- Helmholtz Zentrum München, German Research Center for Environmental Health, Institute of Developmental Genetics, Neuherberg, Germany.
- Technische Universität München-Weihenstephan, Lehrstuhl für Entwicklungsgenetik, c/o Helmholtz Zentrum München, Neuherberg, Germany.
- Deutsches Zentrum für Neurodegenerative Erkrankungen e. V. (DZNE), Standort München, München, Germany.
- Munich Cluster for Systems Neurology (SyNergy), Adolf-Butenandt-Institut, Ludwig-Maximilians-Universität München, München, Germany.
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759
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Hood RL, Liguore WA, Moore C, Pflibsen L, Meshul CK. Exercise intervention increases spontaneous locomotion but fails to attenuate dopaminergic system loss in a progressive MPTP model in aged mice. Brain Res 2016; 1646:535-542. [DOI: 10.1016/j.brainres.2016.06.032] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2016] [Revised: 06/06/2016] [Accepted: 06/21/2016] [Indexed: 02/04/2023]
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760
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Surmeier DJ, Schumacker PT, Guzman JD, Ilijic E, Yang B, Zampese E. Calcium and Parkinson's disease. Biochem Biophys Res Commun 2016; 483:1013-1019. [PMID: 27590583 DOI: 10.1016/j.bbrc.2016.08.168] [Citation(s) in RCA: 143] [Impact Index Per Article: 15.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2016] [Revised: 08/18/2016] [Accepted: 08/29/2016] [Indexed: 01/07/2023]
Abstract
Parkinson's disease (PD) is the second most common neurodegenerative disease in the world. Its causes are poorly understood and there is no proven therapeutic strategy for slowing disease progression. The core motor symptoms of PD are caused by the death of dopaminergic neurons in the substantia nigra pars compacta (SNc). In these neurons, Ca2+entry through plasma membrane Cav1 channels drives a sustained feed-forward stimulation of mitochondrial oxidative phosphorylation. Although this design helps prevent bioenergetic failure when activity needs to be sustained, it leads to basal mitochondrial oxidant stress. Over decades, this basal oxidant stress could compromise mitochondrial function and increase mitophagy, resulting in increased vulnerability to other proteostatic stressors, like elevated alpha synuclein expression. Because this feedforward mechanism is no longer demanded by our lifestyle, it could be dispensed with. Indeed, use of dihydropyridines - negative allosteric modulators of Cav1 Ca2+ channels - comes with little or no effect on brain function but is associated with decreased risk and progression of PD. An ongoing, NIH sponsored, Phase 3 clinical trial in North America is testing the ability of one member of the dihydropyridine class (isradipine) to slow PD progression in early stage patients. The review summarizes the rationale for the trial and outlines some unanswered questions.
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Affiliation(s)
- D James Surmeier
- Department of Physiology, Feinberg School of Medicine, Northwestern University, Chicago, 60611, Illinois, USA.
| | - Paul T Schumacker
- Department of Pediatrics, Feinberg School of Medicine, Northwestern University, Chicago, 60611, Illinois, USA
| | - Jaime D Guzman
- Department of Physiology, Feinberg School of Medicine, Northwestern University, Chicago, 60611, Illinois, USA
| | - Ema Ilijic
- Department of Physiology, Feinberg School of Medicine, Northwestern University, Chicago, 60611, Illinois, USA
| | - Ben Yang
- Department of Physiology, Feinberg School of Medicine, Northwestern University, Chicago, 60611, Illinois, USA
| | - Enrico Zampese
- Department of Physiology, Feinberg School of Medicine, Northwestern University, Chicago, 60611, Illinois, USA
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761
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Identification of Multiple QTLs Linked to Neuropathology in the Engrailed-1 Heterozygous Mouse Model of Parkinson's Disease. Sci Rep 2016; 6:31701. [PMID: 27550741 PMCID: PMC4994027 DOI: 10.1038/srep31701] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2016] [Accepted: 07/27/2016] [Indexed: 12/28/2022] Open
Abstract
Motor symptoms in Parkinson’s disease are attributed to degeneration of midbrain dopaminergic neurons (DNs). Heterozygosity for Engrailed-1 (En1), one of the key factors for programming and maintenance of DNs, results in a parkinsonian phenotype featuring progressive degeneration of DNs in substantia nigra pars compacta (SNpc), decreased striatal dopamine levels and swellings of nigro-striatal axons in the SwissOF1-En1+/− mouse strain. In contrast, C57Bl/6-En1+/− mice do not display this neurodegenerative phenotype, suggesting that susceptibility to En1 heterozygosity is genetically regulated. Our goal was to identify quantitative trait loci (QTLs) that regulate the susceptibility to PD-like neurodegenerative changes in response to loss of one En1 allele. We intercrossed SwissOF1-En1+/− and C57Bl/6 mice to obtain F2 mice with mixed genomes and analyzed number of DNs in SNpc and striatal axonal swellings in 120 F2-En1+/− 17 week-old male mice. Linkage analyses revealed 8 QTLs linked to number of DNs (p = 2.4e-09, variance explained = 74%), 7 QTLs linked to load of axonal swellings (p = 1.7e-12, variance explained = 80%) and 8 QTLs linked to size of axonal swellings (p = 7.0e-11, variance explained = 74%). These loci should be of prime interest for studies of susceptibility to Parkinson’s disease-like damage in rodent disease models and considered in clinical association studies in PD.
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762
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Gallant H, Vo A, Seergobin KN, MacDonald PA. Pramipexole Impairs Stimulus-Response Learning in Healthy Young Adults. Front Neurosci 2016; 10:374. [PMID: 27594823 PMCID: PMC4990534 DOI: 10.3389/fnins.2016.00374] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2016] [Accepted: 08/02/2016] [Indexed: 01/31/2023] Open
Abstract
Dopaminergic therapy has paradoxical effects on cognition in Parkinson's disease (PD) patients, with some functions worsened and others improved. The dopamine overdose hypothesis is proposed as an explanation for these opposing effects of medication taking into account the varying levels of dopamine within different brain regions in PD. The detrimental effects of medication on cognition have been attributed to exogenous dopamine overdose in brain regions with spared dopamine levels in PD. It has been demonstrated that learning is most commonly worsened by dopaminergic medication. The current study aimed to investigate whether the medication-related learning impairment exhibited in PD patients is due to a main effect of medication by evaluating the dopamine overdose hypothesis in healthy young adults. Using a randomized, double-blind, placebo-controlled design, 40 healthy young undergraduate students completed a stimulus-response learning task. Half of the participants were treated with 0.5 mg of pramipexole, a dopamine agonist, whereas the other half were treated with a placebo. We found that stimulus-response learning was significantly impaired in participants on pramipexole relative to placebo controls. These findings are consistent with the dopamine overdose hypothesis and suggest that dopaminergic medication impairs learning independent of PD pathology. Our results have important clinical implications for conditions treated with pramipexole, particularly PD, restless leg syndrome, some forms of dystonia, and potentially depression.
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Affiliation(s)
- Haley Gallant
- The Brain and Mind Institute, University of Western Ontario London, ON, Canada
| | - Andrew Vo
- The Brain and Mind Institute, University of Western OntarioLondon, ON, Canada; Department of Psychology, University of Western OntarioLondon, ON, Canada
| | - Ken N Seergobin
- The Brain and Mind Institute, University of Western Ontario London, ON, Canada
| | - Penny A MacDonald
- The Brain and Mind Institute, University of Western OntarioLondon, ON, Canada; Department of Psychology, University of Western OntarioLondon, ON, Canada; Department of Clinical Neurological Sciences, University of Western OntarioLondon, ON, Canada
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763
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Newland B, Dunnett SB, Dowd E. Targeting delivery in Parkinson's disease. Drug Discov Today 2016; 21:1313-20. [DOI: 10.1016/j.drudis.2016.06.003] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2015] [Revised: 05/23/2016] [Accepted: 06/06/2016] [Indexed: 01/24/2023]
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764
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Mechanism of action of pimavanserin in Parkinson's disease psychosis: targeting serotonin 5HT2A and 5HT2C receptors. CNS Spectr 2016; 21:271-5. [PMID: 27503570 DOI: 10.1017/s1092852916000407] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Pimavanserin, a novel agent approved for the treatment of Parkinson's disease psychosis, has potent actions as an antagonist/inverse agonist at serotonin 5HT2A receptors and less potent antagonist/inverse agonist actions at 5HT2C receptors.
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765
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Enrichment of risk SNPs in regulatory regions implicate diverse tissues in Parkinson's disease etiology. Sci Rep 2016; 6:30509. [PMID: 27461410 PMCID: PMC4962314 DOI: 10.1038/srep30509] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2016] [Accepted: 07/04/2016] [Indexed: 12/15/2022] Open
Abstract
Recent genome-wide association studies (GWAS) of Parkinson’s disease (PD) revealed at least 26 risk loci, with associated single nucleotide polymorphisms (SNPs) located in non-coding DNA having unknown functions in risk. In order to explore in which cell types these SNPs (and their correlated surrogates at r2 ≥ 0.8) could alter cellular function, we assessed their location overlap with histone modification regions that indicate transcription regulation in 77 diverse cell types. We found statistically significant enrichment of risk SNPs at 12 loci in active enhancers or promoters. We investigated 4 risk loci in depth that were most significantly enriched (−logeP > 14) and contained 8 putative enhancers in the different cell types. These enriched loci, along with eQTL associations, were unexpectedly present in non-neuronal cell types. These included lymphocytes, mesendoderm, liver- and fat-cells, indicating that cell types outside the brain are involved in the genetic predisposition to PD. Annotating regulatory risk regions within specific cell types may unravel new putative risk mechanisms and molecular pathways that contribute to PD development.
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766
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Salvatore MF, Calipari ES, Jones SR. Regulation of Tyrosine Hydroxylase Expression and Phosphorylation in Dopamine Transporter-Deficient Mice. ACS Chem Neurosci 2016; 7:941-51. [PMID: 27124386 DOI: 10.1021/acschemneuro.6b00064] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
Tyrosine hydroxylase (TH) and dopamine transporters (DATs) regulate dopamine (DA) neurotransmission at the biosynthesis and reuptake steps, respectively. Dysfunction or loss of these proteins occurs in impaired locomotor or addictive behavior, but little is known about the influence of DAT expression on TH function. Differences in TH phosphorylation, DA tissue content, l-DOPA biosynthesis, and DA turnover exist between the somatodendritic and terminal field compartments of nigrostriatal and mesoaccumbens pathways. We examined whether differential DAT expression affects these compartmental differences in DA regulation by comparing TH expression and phosphorylation at ser31 and ser40. In heterozygous DAT knockout (KO) (+/-) mice, DA tissue content and DA turnover were unchanged relative to wild-type mice, despite a 40% reduction in DAT protein expression. In DAT KO (-/-) mice, DA turnover increased in all DA compartments, but DA tissue content decreased (90-96%) only in terminal fields. TH protein expression and phosphorylation were differentially affected within DA pathway compartments by relative expression of DAT. TH protein decreased (∼74%), though to a significantly lesser extent than DA, in striatum and nucleus accumbens (NAc) in DAT -/- mice, with no decrease in substantia nigra or ventral tegmental area. Striatal ser31 TH phosphorylation and recovery of DA relative to TH protein expression in DAT +/- and DAT -/- mice decreased, whereas ser40 TH phosphorylation increased ∼2- to 3-fold in striatum and NAc of DAT -/- mice. These results suggest that DAT expression affects TH expression and phosphorylation largely in DA terminal field compartments, further corroborating evidence for dichotomous regulation of TH between somatodendritic and terminal field compartments of the nigrostriatal and mesoaccumbens pathways.
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Affiliation(s)
- Michael F. Salvatore
- Department
of Pharmacology, Toxicology and Neuroscience, Louisiana State University Health Sciences Center, Shreveport, Louisiana 71130, United States
| | - Erin S. Calipari
- Department
of Physiology and Pharmacology, Wake Forest School of Medicine, Winston-Salem, North Carolina 27157, United States
| | - Sara R. Jones
- Department
of Physiology and Pharmacology, Wake Forest School of Medicine, Winston-Salem, North Carolina 27157, United States
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767
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Martínez-Fernández R, Schmitt E, Martinez-Martin P, Krack P. The hidden sister of motor fluctuations in Parkinson's disease: A review on nonmotor fluctuations. Mov Disord 2016; 31:1080-94. [PMID: 27431515 DOI: 10.1002/mds.26731] [Citation(s) in RCA: 117] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2015] [Revised: 06/13/2016] [Accepted: 06/19/2016] [Indexed: 12/29/2022] Open
Abstract
Only a few years after the introduction of levodopa, the first descriptions of motor fluctuations and dyskinesia related to dopaminergic therapy appeared. In PD, attention turned to their management, that had dampened the euphoria of the "levodopa miracle." It soon became clear that neuropsychiatric, autonomic, and sensory features also tend to develop fluctuations after chronic exposure to l-dopa. The diversity of fluctuating nonmotor symptoms, their largely subjective nature, coupled with a frequent lack of insight led to difficulties in identification and quantification. This may explain why, despite the high impact of nonmotor symptoms on patient autonomy and quality of life, evaluation of nonmotor fluctuations is not part of clinical routine. In view of the lack of specific validated assessment tools, detailed anamnesis should ideally be coupled with an evaluation in both ON and OFF drug conditions. The mechanisms of nonmotor fluctuations are not well understood. It is thought that they share dopaminergic presynaptic pharmacokinetic and postsynaptic pharmacodynamic mechanisms with the classical motor complications, but involve different neural pathways. Although symptoms fluctuate with dopaminergic treatment, serotonine and norepinephrine denervation, as well as interactions between neurotransmitter systems, probably contribute to their diversity. The lack of validated tools for assessment of these phenomena explains the almost complete absence of treatment studies. Management, largely resulting from expert opinion, includes psychiatric follow-up, nondopaminergic drugs, and advanced dopaminergic treatment, including drug delivery pumps and DBS. This review aims to provide a starting point for the understanding, diagnosis, and management of nonmotor fluctuations. © 2016 International Parkinson and Movement Disorder Society.
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Affiliation(s)
| | - Emmanuelle Schmitt
- Movement Disorders Unit, Department of Psychiatry and Neurology, CHU de Grenoble, Université de Grenoble Alpes and Grenoble Institut des Neurosciences, INSERM U386, Grenoble, France
| | - Pablo Martinez-Martin
- National Center of Epidemiology, Carlos III Institute of Health and CIBERNED, Madrid, Spain
| | - Paul Krack
- Neurology Division, Department of Clinical Neurosciences, University Hospital of Geneva, Geneva, Switzerland
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768
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Martella G, Madeo G, Maltese M, Vanni V, Puglisi F, Ferraro E, Schirinzi T, Valente E, Bonanni L, Shen J, Mandolesi G, Mercuri N, Bonsi P, Pisani A. Exposure to low-dose rotenone precipitates synaptic plasticity alterations in PINK1 heterozygous knockout mice. Neurobiol Dis 2016; 91:21-36. [DOI: 10.1016/j.nbd.2015.12.020] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2015] [Revised: 12/22/2015] [Accepted: 12/25/2015] [Indexed: 12/21/2022] Open
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769
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Venuto CS, Potter NB, Dorsey ER, Kieburtz K. A review of disease progression models of Parkinson's disease and applications in clinical trials. Mov Disord 2016; 31:947-956. [PMID: 27226141 PMCID: PMC4931998 DOI: 10.1002/mds.26644] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2015] [Revised: 02/19/2016] [Accepted: 03/04/2016] [Indexed: 12/31/2022] Open
Abstract
Quantitative disease progression models for neurodegenerative disorders are gaining recognition as important tools for drug development and evaluation. In Parkinson's disease (PD), several models have described longitudinal changes in the Unified Parkinson's Disease Rating Scale (UPDRS), one of the most utilized outcome measures for PD trials assessing disease progression. We conducted a literature review to examine the methods and applications of quantitative disease progression modeling for PD using a combination of key words including "Parkinson disease," "progression," and "model." For this review, we focused on models of PD progression quantifying changes in the total UPDRS scores against time. Four different models reporting equations and parameters have been published using linear and nonlinear functions. The reasons for constructing disease progression models of PD thus far have been to quantify disease trajectories of PD patients in active and inactive treatment arms of clinical trials, to quantify and discern symptomatic and disease-modifying treatment effects, and to demonstrate how model-based methods may be used to design clinical trials. The historical lack of efficiency of PD clinical trials begs for model-based simulations in planning for studies that result in more informative conclusions, particularly around disease modification. © 2016 International Parkinson and Movement Disorder Society.
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Affiliation(s)
- Charles S. Venuto
- Center for Human Experimental Therapeutics, University of Rochester, Rochester, NY, USA
- Department of Neurology, University of Rochester, Rochester NY USA
| | - Nicholas B. Potter
- Center for Human Experimental Therapeutics, University of Rochester, Rochester, NY, USA
| | - E. Ray Dorsey
- Center for Human Experimental Therapeutics, University of Rochester, Rochester, NY, USA
- Department of Neurology, University of Rochester, Rochester NY USA
| | - Karl Kieburtz
- Center for Human Experimental Therapeutics, University of Rochester, Rochester, NY, USA
- Department of Neurology, University of Rochester, Rochester NY USA
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770
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The role of environmental constraints in walking: Effects of steering and sharp turns on gait dynamics. Sci Rep 2016; 6:28374. [PMID: 27345577 PMCID: PMC4937443 DOI: 10.1038/srep28374] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2015] [Accepted: 06/02/2016] [Indexed: 01/31/2023] Open
Abstract
Stride durations in gait exhibit long-range correlation (LRC) which tends to disappear with certain movement disorders. The loss of LRC has been hypothesized to result from a reduction of functional degrees of freedom of the neuromuscular apparatus. A consequence of this theory is that environmental constraints such as the ones induced during constant steering may also reduce LRC. Furthermore, obstacles may perturb control of the gait cycle and also reduce LRC. To test these predictions, seven healthy participants walked freely overground in three conditions: unconstrained, constrained (constant steering), and perturbed (frequent 90° turns). Both steering and sharp turning reduced LRC with the latter having a stronger effect. Competing theories explain LRC in gait by positing fractal CPGs or a biomechanical process of kinetic energy reuse. Mediation analysis showed that the effect of the experimental manipulation in the current experiment depends partly on a reduction in walking speed. This supports the biomechanical theory. We also found that the local Hurst exponent did not reflect the frequent changes of heading direction. This suggests that the recovery from the sharp turn perturbation, a kind of relaxation time, takes longer than the four to seven meters between successive turns in the present study.
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771
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Chouhan AK, Guo C, Hsieh YC, Ye H, Senturk M, Zuo Z, Li Y, Chatterjee S, Botas J, Jackson GR, Bellen HJ, Shulman JM. Uncoupling neuronal death and dysfunction in Drosophila models of neurodegenerative disease. Acta Neuropathol Commun 2016; 4:62. [PMID: 27338814 PMCID: PMC4918017 DOI: 10.1186/s40478-016-0333-4] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2016] [Accepted: 06/07/2016] [Indexed: 02/04/2023] Open
Abstract
Common neurodegenerative proteinopathies, such as Alzheimer's disease (AD) and Parkinson's disease (PD), are characterized by the misfolding and aggregation of toxic protein species, including the amyloid beta (Aß) peptide, microtubule-associated protein Tau (Tau), and alpha-synuclein (αSyn) protein. These factors also show toxicity in Drosophila; however, potential limitations of prior studies include poor discrimination between effects on the adult versus developing nervous system and neuronal versus glial cell types. In addition, variable expression paradigms and outcomes hinder systematic comparison of toxicity profiles. Using standardized conditions and medium-throughput assays, we express human Tau, Aß or αSyn selectively in neurons of the adult Drosophila retina and monitor age-dependent changes in both structure and function, based on tissue histology and recordings of the electroretinogram (ERG), respectively. We find that each protein causes a unique profile of neurodegenerative pathology, demonstrating distinct and separable impacts on neuronal death and dysfunction. Strikingly, expression of Tau leads to progressive loss of ERG responses whereas retinal architecture and neuronal numbers are largely preserved. By contrast, Aß induces modest, age-dependent neuronal loss without degrading the retinal ERG. αSyn expression, using a codon-optimized transgene, is characterized by marked retinal vacuolar change, progressive photoreceptor cell death, and delayed-onset but modest ERG changes. Lastly, to address potential mechanisms, we perform transmission electron microscopy (TEM) to reveal potential degenerative changes at the ultrastructural level. Surprisingly, Tau and αSyn each cause prominent but distinct synaptotoxic profiles, including disorganization or enlargement of photoreceptor terminals, respectively. Our findings highlight variable and dynamic properties of neurodegeneration triggered by these disease-relevant proteins in vivo, and suggest that Drosophila may be useful for revealing determinants of neuronal dysfunction that precede cell loss, including synaptic changes, in the adult nervous system.
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772
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Pearlstein E, Michel FJ, Save L, Ferrari DC, Hammond C. Abnormal Development of Glutamatergic Synapses Afferent to Dopaminergic Neurons of the Pink1(-/-) Mouse Model of Parkinson's Disease. Front Cell Neurosci 2016; 10:168. [PMID: 27445695 PMCID: PMC4917553 DOI: 10.3389/fncel.2016.00168] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2016] [Accepted: 06/09/2016] [Indexed: 11/13/2022] Open
Abstract
In a preceding study, we showed that in adult pink1−/− mice, a monogenic animal model of Parkinson’s disease (PD), striatal neurons display aberrant electrical activities that precede the onset of overt clinical manifestations. Here, we tested the hypothesis that the maturation of dopaminergic (DA) neurons of the pink1−/− substantia nigra compacta (SNc) follows, from early stages on, a different developmental trajectory from age-matched wild type (wt) SNc DA neurons. We used immature (postnatal days P2–P10) and young adult (P30–P90) midbrain slices of pink1−/− mice expressing the green fluorescent protein in tyrosine hydroxylase (TH)-positive neurons. We report that the developmental sequence of N-Methyl-D-aspartic acid (NMDA) spontaneous excitatory postsynaptic currents (sEPSCs) is altered in pink1−/− SNc DA neurons, starting from shortly after birth. They lack the transient episode of high NMDA receptor-mediated neuronal activity characteristic of the immature stage of wt SNc DA neurons. The maturation of the membrane resistance of pink1−/− SNc DA neurons is also altered. Collectively, these observations suggest that electrical manifestations occurring shortly after birth in SNc DA neurons might lead to dysfunction in dopamine release and constitute an early pathogenic mechanism of PD.
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Affiliation(s)
- Edouard Pearlstein
- UMR901, Aix-Marseille UniversitéMarseille, France; Institut de Neurobiologie de la Méditerranée (INMED), Inserm UMR 901Marseille, France
| | - François J Michel
- UMR901, Aix-Marseille UniversitéMarseille, France; Institut de Neurobiologie de la Méditerranée (INMED), Inserm UMR 901Marseille, France
| | - Laurène Save
- UMR901, Aix-Marseille UniversitéMarseille, France; Institut de Neurobiologie de la Méditerranée (INMED), Inserm UMR 901Marseille, France
| | - Diana C Ferrari
- UMR901, Aix-Marseille UniversitéMarseille, France; Institut de Neurobiologie de la Méditerranée (INMED), Inserm UMR 901Marseille, France
| | - Constance Hammond
- UMR901, Aix-Marseille UniversitéMarseille, France; Institut de Neurobiologie de la Méditerranée (INMED), Inserm UMR 901Marseille, France
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773
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Morales I, Sanchez A, Rodriguez-Sabate C, Rodriguez M. The astrocytic response to the dopaminergic denervation of the striatum. J Neurochem 2016; 139:81-95. [DOI: 10.1111/jnc.13684] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2016] [Revised: 05/19/2016] [Accepted: 05/23/2016] [Indexed: 01/01/2023]
Affiliation(s)
- Ingrid Morales
- Laboratory of Neurobiology and Experimental Neurology; Department of Physiology; Faculty of Medicine; University of La Laguna, La Laguna; Tenerife, Canary Islands Spain
- Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED); Madrid Spain
| | - Alberto Sanchez
- Laboratory of Neurobiology and Experimental Neurology; Department of Physiology; Faculty of Medicine; University of La Laguna, La Laguna; Tenerife, Canary Islands Spain
| | - Clara Rodriguez-Sabate
- Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED); Madrid Spain
| | - Manuel Rodriguez
- Laboratory of Neurobiology and Experimental Neurology; Department of Physiology; Faculty of Medicine; University of La Laguna, La Laguna; Tenerife, Canary Islands Spain
- Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED); Madrid Spain
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774
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Padel T, Özen I, Boix J, Barbariga M, Gaceb A, Roth M, Paul G. Platelet-derived growth factor-BB has neurorestorative effects and modulates the pericyte response in a partial 6-hydroxydopamine lesion mouse model of Parkinson's disease. Neurobiol Dis 2016; 94:95-105. [PMID: 27288154 DOI: 10.1016/j.nbd.2016.06.002] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2016] [Revised: 05/24/2016] [Accepted: 06/05/2016] [Indexed: 12/28/2022] Open
Abstract
Parkinson's disease (PD) is a neurodegenerative disease where the degeneration of the nigrostriatal pathway leads to specific motor deficits. There is an unmet medical need for regenerative treatments that stop or reverse disease progression. Several growth factors have been investigated in clinical trials to restore the dopaminergic nigrostriatal pathway damaged in PD. Platelet-derived growth factor-BB (PDGF-BB), a molecule that recruits pericytes to stabilize microvessels, was recently investigated in a phase-1 clinical trial, showing a dose-dependent increase in dopamine transporter binding in the putamen of PD patients. Interestingly, evidence is accumulating that PD is paralleled by microvascular changes, however, whether PDGF-BB modifies pericytes in PD is not known. Using a pericyte reporter mouse strain, we investigate the functional and restorative effect of PDGF-BB in a partial 6-hydroxydopamine medial forebrain bundle lesion mouse model of PD, and whether this restorative effect is accompanied by changes in pericyte features. We demonstrate that a 2-week treatment with PDGF-BB leads to behavioural recovery using several behavioural tests, and partially restores the nigrostriatal pathway. Interestingly, we find that pericytes are activated in the striatum of PD lesioned mice and that these changes are reversed by PDGF-BB treatment. The modulation of brain pericytes may contribute to the PDGF-BB-induced neurorestorative effects, PDGF-BB allowing for vascular stabilization in PD. Pericytes might be a new cell target of interest for future regenerative therapies.
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Affiliation(s)
- Thomas Padel
- Translational Neurology Group, Department of Clinical Science, Wallenberg Neuroscience Center, Lund University, 22184 Lund, Sweden
| | - Ilknur Özen
- Translational Neurology Group, Department of Clinical Science, Wallenberg Neuroscience Center, Lund University, 22184 Lund, Sweden
| | - Jordi Boix
- Translational Neurology Group, Department of Clinical Science, Wallenberg Neuroscience Center, Lund University, 22184 Lund, Sweden
| | - Marco Barbariga
- Translational Neurology Group, Department of Clinical Science, Wallenberg Neuroscience Center, Lund University, 22184 Lund, Sweden
| | - Abderahim Gaceb
- Translational Neurology Group, Department of Clinical Science, Wallenberg Neuroscience Center, Lund University, 22184 Lund, Sweden
| | - Michaela Roth
- Translational Neurology Group, Department of Clinical Science, Wallenberg Neuroscience Center, Lund University, 22184 Lund, Sweden
| | - Gesine Paul
- Translational Neurology Group, Department of Clinical Science, Wallenberg Neuroscience Center, Lund University, 22184 Lund, Sweden; Department of Neurology, Scania University Hospital, 22185 Lund, Sweden.
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775
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Ling H, Kearney S, Yip HLK, Silveira-Moriyama L, Revesz T, Holton JL, Strand C, Davey K, Mok KY, Polke JM, Lees AJ. Parkinson's disease without nigral degeneration: a pathological correlate of scans without evidence of dopaminergic deficit (SWEDD)? J Neurol Neurosurg Psychiatry 2016. [PMID: 26209716 DOI: 10.1136/jnnp-2015-310756] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
OBJECTIVE To describe 5 cases of Parkinson's disease lacking any detectable histopathology. BACKGROUND The diagnosis of Parkinson's disease is supported histologically by the findings of α-synuclein immunopositive Lewy bodies and neurites and severe substantia nigra cell loss. Bradykinesia as defined by slowness of initiation of movement and a progressive reduction in speed and amplitude on finger tapping is a clinical correlate of pars compacta nigral degeneration. There are very few published cases of Parkinson's disease in which no pathological abnormality was found, and some of these cases were in hindsight thought to have probably been cases of indeterminate senile tremor or dystonic tremor. METHODS Retrospective case notes review of the Queen Square Brain Bank archival collection and detailed neuropathological analysis of the selected cases. RESULTS 5 cases considered to have Parkinson's disease by neurologists throughout the entirety of their illness that lacked any histopathological findings known to be associated with Parkinson's syndromes were identified out of a total number of 773 brains with a final clinical diagnosis of Parkinson's disease in the Queen Square Brain Bank. Retrospective case note analysis did not suggest dystonic tremor or indeterminate tremor in any of them. There was a reduction in tyrosine hydroxylase (TH) density in the striatum in these cases when compared with healthy controls, but not in the substantia nigra. CONCLUSIONS Striatal dopamine deficiency without nigral cell loss is the most likely explanation for the clinical findings; other possible explanations include slowness due to comorbidities misinterpreted as bradykinesia, a tardive syndrome related to undisclosed previous neuroleptic exposure, or 'soft age-related' parkinsonian signs. These cases emphasise the need to regularly review the diagnosis in cases of suspected Parkinson's disease and highlight the need for precision in the neurological examination particularly of elderly patients. These cases may represent a distinct entity of diagnostic exclusion and may be considered one explanation for the radiological phenomenon of SWEDD (scans without evidence of dopaminergic deficit).
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Affiliation(s)
- Helen Ling
- Reta Lila Weston Institute of Neurological Studies, UCL Institute of Neurology, London, UK Queen Square Brain Bank for Neurological Disorders, UCL Institute of Neurology, London, UK
| | - Seamus Kearney
- Reta Lila Weston Institute of Neurological Studies, UCL Institute of Neurology, London, UK Belfast Health and Social Care Trust, Belfast, Ireland
| | - Helen Lai Kuen Yip
- Department of Rehabilitation and Extended Care, Wong Tai Sin Hospital TWGHs, Hong Kong, Hong Kong Neuro-medical Unit, Department of Medicine and Geriatrics, Kwong Wah Hospital TWGHs, Hong Kong, Hong Kong
| | - Laura Silveira-Moriyama
- Reta Lila Weston Institute of Neurological Studies, UCL Institute of Neurology, London, UK Postgraduate Program in Medicine, Universidade Nove de Julho, UNINOVE, São Paulo, Brazil
| | - Tamas Revesz
- Reta Lila Weston Institute of Neurological Studies, UCL Institute of Neurology, London, UK Queen Square Brain Bank for Neurological Disorders, UCL Institute of Neurology, London, UK
| | - Janice L Holton
- Reta Lila Weston Institute of Neurological Studies, UCL Institute of Neurology, London, UK Queen Square Brain Bank for Neurological Disorders, UCL Institute of Neurology, London, UK
| | - Catherine Strand
- Queen Square Brain Bank for Neurological Disorders, UCL Institute of Neurology, London, UK
| | - Karen Davey
- Queen Square Brain Bank for Neurological Disorders, UCL Institute of Neurology, London, UK
| | - Kin Ying Mok
- Department of Molecular Neuroscience, UCL Institute of Neurology, London, UK Division of Life Science, Hong Kong University of Science and Technology, Hong Kong, Hong Kong
| | - James M Polke
- Department of Molecular Neuroscience, UCL Institute of Neurology, London, UK
| | - Andrew J Lees
- Reta Lila Weston Institute of Neurological Studies, UCL Institute of Neurology, London, UK Queen Square Brain Bank for Neurological Disorders, UCL Institute of Neurology, London, UK
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776
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Hansen AK, Knudsen K, Lillethorup TP, Landau AM, Parbo P, Fedorova T, Audrain H, Bender D, Østergaard K, Brooks DJ, Borghammer P. In vivo imaging of neuromelanin in Parkinson's disease using 18F-AV-1451 PET. Brain 2016; 139:2039-49. [PMID: 27190023 DOI: 10.1093/brain/aww098] [Citation(s) in RCA: 100] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2016] [Accepted: 03/14/2016] [Indexed: 11/13/2022] Open
Abstract
The tau tangle ligand (18)F-AV-1451 ((18)F-T807) binds to neuromelanin in the midbrain, and may therefore be a measure of the pigmented dopaminergic neuronal count in the substantia nigra. Parkinson's disease is characterized by progressive loss of dopaminergic neurons. Extrapolation of post-mortem data predicts that a ∼30% decline of nigral dopamine neurons is necessary to cause motor symptoms in Parkinson's disease. Putamen dopamine terminal loss at disease onset most likely exceeds that of the nigral cell bodies and has been estimated to be of the order of 50-70%. We investigated the utility of (18)F-AV-1451 positron emission tomography to visualize the concentration of nigral neuromelanin in Parkinson's disease and correlated the findings to dopamine transporter density, measured by (123)I-FP-CIT single photon emission computed tomography. A total of 17 patients with idiopathic Parkinson's disease and 16 age- and sex-matched control subjects had (18)F-AV-1451 positron emission tomography using a Siemens high-resolution research tomograph. Twelve patients with Parkinson's disease also received a standardized (123)I-FP-CIT single photon emission computed tomography scan at our imaging facility. Many of the patients with Parkinson's disease displayed visually apparent decreased (18)F-AV-1451 signal in the midbrain. On quantitation, patients showed a 30% mean decrease in total nigral (18)F-AV-1451 volume of distribution compared with controls (P = 0.004), but there was an overlap of the individual ranges. We saw no significant correlation between symptom dominant side and contralateral nigral volume of distribution. There was no correlation between nigral (18)F-AV-1451 volume of distribution and age or time since diagnosis. In the subset of 12 patients, who also had a (123)I-FP-CIT scan, the mean total striatal dopamine transporter signal was decreased by 45% and the mean total (18)F-AV-1451 substantia nigra volume of distribution was decreased by 33% after median disease duration of 4.7 years (0.5-12.4 years). (18)F-AV-1451 positron emission tomography may be the first radiotracer to reflect the loss of pigmented neurons in the substantia nigra of parkinsonian patients. The magnitude of the nigral signal loss was smaller than the decrease in striatal dopamine transporter signal measured by dopamine transporter single photon emission computed tomography. These findings suggest a more severe loss of striatal nerve terminal function compared with neuronal cell bodies, in accordance with the post-mortem literature.
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Affiliation(s)
- Allan K Hansen
- 1 Department of Nuclear Medicine and PET-Centre, Aarhus University Hospital, Denmark
| | - Karoline Knudsen
- 1 Department of Nuclear Medicine and PET-Centre, Aarhus University Hospital, Denmark
| | - Thea P Lillethorup
- 1 Department of Nuclear Medicine and PET-Centre, Aarhus University Hospital, Denmark
| | - Anne M Landau
- 1 Department of Nuclear Medicine and PET-Centre, Aarhus University Hospital, Denmark 2 Translational Neuropsychiatry Unit, Institute of Clinical Medicine, Aarhus University, Denmark
| | - Peter Parbo
- 1 Department of Nuclear Medicine and PET-Centre, Aarhus University Hospital, Denmark
| | - Tatyana Fedorova
- 1 Department of Nuclear Medicine and PET-Centre, Aarhus University Hospital, Denmark
| | - Hélène Audrain
- 1 Department of Nuclear Medicine and PET-Centre, Aarhus University Hospital, Denmark
| | - Dirk Bender
- 1 Department of Nuclear Medicine and PET-Centre, Aarhus University Hospital, Denmark
| | - Karen Østergaard
- 3 Department of Neurology, Institute of Clinical Medicine, Aarhus University, Denmark
| | - David J Brooks
- 1 Department of Nuclear Medicine and PET-Centre, Aarhus University Hospital, Denmark 4 Division of Neuroscience, Department of Medicine, Imperial College London, UK 5 Division of Neuroscience, Newcastle University, UK
| | - Per Borghammer
- 1 Department of Nuclear Medicine and PET-Centre, Aarhus University Hospital, Denmark
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777
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Volpicelli-Daley LA, Kirik D, Stoyka LE, Standaert DG, Harms AS. How can rAAV-α-synuclein and the fibril α-synuclein models advance our understanding of Parkinson's disease? J Neurochem 2016; 139 Suppl 1:131-155. [PMID: 27018978 DOI: 10.1111/jnc.13627] [Citation(s) in RCA: 72] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2015] [Revised: 02/29/2016] [Accepted: 03/16/2016] [Indexed: 12/23/2022]
Abstract
Animal models of Parkinson's disease (PD) are important for understanding the mechanisms of the disease and can contribute to developing and validating novel therapeutics. Ideally, these models should replicate the cardinal features of PD, such as progressive neurodegeneration of catecholaminergic neurons and motor defects. Many current PD models emphasize pathological forms of α-synuclein, based on findings that autosomal dominant mutations in α-synuclein and duplications/triplications of the SNCA gene cause PD. In addition, Lewy bodies and Lewy neurites, primarily composed of α-synuclein, represent the predominant pathological characteristics of PD. These inclusions have defined features, such as insolubility in non-ionic detergent, hyperphosphorylation, proteinase K sensitivity, a filamentous appearance by electron microscopy, and β-sheet structure. Furthermore, it has become clear that Lewy bodies and Lewy neurites are found throughout the peripheral and central nervous system, and could account not only for motor symptoms, but also for non-motor symptoms of the disease. The goal of this review is to describe two new α-synuclein-based models: the recombinant adeno-associated viral vector-α-synuclein model and the α-synuclein fibril model. An advantage of both models is that they do not require extensive crossbreeding of rodents transgenic for α-synuclein with other rodents transgenic for genes of interest to study the impact of such genes on PD-related pathology and phenotypes. In addition, abnormal α-synuclein can be expressed in brain regions relevant for disease. Here, we discuss the features of each model, how each model has contributed thus far to our understanding of PD, and the advantages and potential caveats of each model. This review describes two α-synuclein-based rodent models of Parkinson's disease: the rAAV-α-synuclein model and the α-synuclein fibril model. The key features of these models are described, and the extent to which they recapitulate features of PD, such as α-synuclein inclusion formation, loss of dopaminergic synapses in the striatum, motor defects, inflammation, and dopamine neuron death. This article is part of a special issue on Parkinson disease.
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Affiliation(s)
- Laura A Volpicelli-Daley
- From the Center for Neurodegeneration and Experimental Therapeutics, Department of Neurology, The University of Alabama at Birmingham, Birmingham, Alabama.
| | - Deniz Kirik
- Brain Repair and Imaging in Neural Systems, Department of Experimental Medical Science, Lund University, Lund, Sweden
| | - Lindsay E Stoyka
- From the Center for Neurodegeneration and Experimental Therapeutics, Department of Neurology, The University of Alabama at Birmingham, Birmingham, Alabama
| | - David G Standaert
- From the Center for Neurodegeneration and Experimental Therapeutics, Department of Neurology, The University of Alabama at Birmingham, Birmingham, Alabama
| | - Ashley S Harms
- From the Center for Neurodegeneration and Experimental Therapeutics, Department of Neurology, The University of Alabama at Birmingham, Birmingham, Alabama
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778
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Benskey MJ, Perez RG, Manfredsson FP. The contribution of alpha synuclein to neuronal survival and function - Implications for Parkinson's disease. J Neurochem 2016; 137:331-59. [PMID: 26852372 PMCID: PMC5021132 DOI: 10.1111/jnc.13570] [Citation(s) in RCA: 159] [Impact Index Per Article: 17.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2016] [Accepted: 01/29/2016] [Indexed: 02/06/2023]
Abstract
The aggregation of alpha synuclein (α-syn) is a neuropathological feature that defines a spectrum of disorders collectively termed synucleinopathies, and of these, Parkinson's disease (PD) is arguably the best characterized. Aggregated α-syn is the primary component of Lewy bodies, the defining pathological feature of PD, while mutations or multiplications in the α-syn gene result in familial PD. The high correlation between α-syn burden and PD has led to the hypothesis that α-syn aggregation produces toxicity through a gain-of-function mechanism. However, α-syn has been implicated to function in a diverse range of essential cellular processes such as the regulation of neurotransmission and response to cellular stress. As such, an alternative hypothesis with equal explanatory power is that the aggregation of α-syn results in toxicity because of a toxic loss of necessary α-syn function, following sequestration of functional forms α-syn into insoluble protein aggregates. Within this review, we will provide an overview of the literature linking α-syn to PD and the knowledge gained from current α-syn-based animal models of PD. We will then interpret these data from the viewpoint of the α-syn loss-of-function hypothesis and provide a potential mechanistic model by which loss of α-syn function could result in at least some of the neurodegeneration observed in PD. By providing an alternative perspective on the etiopathogenesis of PD and synucleinopathies, this may reveal alternative avenues of research in order to identify potential novel therapeutic targets for disease modifying strategies. The correlation between α-synuclein burden and Parkinson's disease pathology has led to the hypothesis that α-synuclein aggregation produces toxicity through a gain-of-function mechanism. However, in this review, we discuss data supporting the alternative hypothesis that the aggregation of α-synuclein results in toxicity because of loss of necessary α-synuclein function at the presynaptic terminal, following sequestration of functional forms of α-synuclein into aggregates.
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Affiliation(s)
- Matthew J Benskey
- Department of Translational Science and Molecular Medicine, College of Human Medicine, Michigan State University, Grand Rapids, Michigan, USA
| | - Ruth G Perez
- Department of Biomedical Sciences, Center of Emphasis in Neuroscience, Paul L. Foster School of Medicine, Texas Tech University of the Health Sciences El Paso, El Paso, Texas, USA
| | - Fredric P Manfredsson
- Department of Translational Science and Molecular Medicine, College of Human Medicine, Michigan State University, Grand Rapids, Michigan, USA
- Hauenstein Neuroscience Center, Mercy Health Saint Mary's, Grand Rapids, Michigan, USA
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779
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Costantini A, Fancellu R. An open-label pilot study with high-dose thiamine in Parkinson's disease. Neural Regen Res 2016; 11:406-7. [PMID: 27127471 PMCID: PMC4828997 DOI: 10.4103/1673-5374.179047] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
Affiliation(s)
- Antonio Costantini
- Department of Neurological Rehabilitation, "Villa Immacolata" Clinic, Viterbo, Italy
| | - Roberto Fancellu
- Unit of Neurology, IRCCS San Martino University Hospital IST, Genova, Italy
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780
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Burciu RG, Ofori E, Shukla P, Pasternak O, Chung JW, McFarland NR, Okun MS, Vaillancourt DE. Free-water and BOLD imaging changes in Parkinson's disease patients chronically treated with a MAO-B inhibitor. Hum Brain Mapp 2016; 37:2894-903. [PMID: 27089850 DOI: 10.1002/hbm.23213] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2015] [Revised: 03/14/2016] [Accepted: 04/04/2016] [Indexed: 12/25/2022] Open
Abstract
Rasagiline is a monoamine oxidase type B inhibitor that possesses no amphetamine-like properties, and provides symptomatic relief in early and late stages of Parkinson's disease (PD). Data in animal models of PD suggest that chronic administration of rasagiline is associated with structural changes in the substantia nigra, and raise the question whether the structure and function of the basal ganglia could be different in PD patients treated chronically with rasagiline as compared with PD patients not treated with rasagiline. Here, we performed a retrospective cross-sectional magnetic resonance imaging (MRI) study at 3 T that investigated nigrostriatal function and structure in PD patients who had taken rasagiline before testing (∼8 months), PD who had not taken rasagiline before testing, and age-matched controls. The two PD groups were selected a priori to not differ significantly in age, sex, disease duration, severity of symptoms, cognitive status, and total levodopa equivalent daily dose of medication. We evaluated percent signal change in the posterior putamen during force production using functional MRI, free-water in the posterior substantia nigra using diffusion MRI, and performance on a bimanual coordination task using a pegboard test. All patients were tested after overnight withdrawal from antiparkinsonian medication. The rasagiline group had greater percent signal change in the posterior putamen, less free-water in the posterior substantia nigra, and better performance on the coordination task than the group not taking rasagiline. These findings point to a possible chronic effect of rasagiline on the structure and function of the basal ganglia in PD. Hum Brain Mapp 37:2894-2903, 2016. © 2016 Wiley Periodicals, Inc.
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Affiliation(s)
- Roxana G Burciu
- Department of Applied Physiology and Kinesiology, University of Florida, Gainesville, Florida
| | - Edward Ofori
- Department of Applied Physiology and Kinesiology, University of Florida, Gainesville, Florida
| | - Priyank Shukla
- Department of Applied Physiology and Kinesiology, University of Florida, Gainesville, Florida
| | - Ofer Pasternak
- Department of Psychiatry, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts.,Department of and Radiology, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts
| | - Jae Woo Chung
- Department of Applied Physiology and Kinesiology, University of Florida, Gainesville, Florida
| | - Nikolaus R McFarland
- Department of Neurology, University of Florida, Gainesville, Florida.,Center for Movement Disorders and Neurorestoration, College of Medicine, University of Florida, University of Florida, Gainesville, Florida
| | - Michael S Okun
- Department of Neurology, University of Florida, Gainesville, Florida.,Center for Movement Disorders and Neurorestoration, College of Medicine, University of Florida, University of Florida, Gainesville, Florida.,Department of Neurosurgery, University of Florida, Gainesville, Florida
| | - David E Vaillancourt
- Department of Applied Physiology and Kinesiology, University of Florida, Gainesville, Florida.,Department of Neurology, University of Florida, Gainesville, Florida.,Department of Biomedical Engineering, University of Florida, Gainesville, Florida
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781
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Santos-Lobato BLD, Del-Bel E, Pittella JEH, Tumas V. Cytoarchitecture of nitrergic neurons in the human striatum and subthalamic nucleus. Brain Res Bull 2016; 124:129-35. [PMID: 27060610 DOI: 10.1016/j.brainresbull.2016.04.003] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2015] [Revised: 04/04/2016] [Accepted: 04/05/2016] [Indexed: 11/18/2022]
Abstract
BACKGROUND Nitric oxide (NO) is a gaseous molecule that modulates several physiological processes, including signal transmission in the central nervous system. There is evidence supporting NO as a major neurotransmitter involved in motor and emotion/behavior control. We investigated the distribution and morphology of nitrergic neurons in the two main input structures of the basal ganglia of human brain: the striatum and subthalamic nucleus. METHODS We studied samples of striatum (caudate and putamen) and subthalamic nucleus of 20 human brains from subjects without neurological/psychiatric diseases. The tissues were stained by histochemistry for nicotinamide adenine dinucleotide phosphate diaphorase activity and by immunohistochemistry for neuronal NO synthase (nNOS). Subsequently, we analyzed the nitrergic neuronal profile and its morphometric parameters. RESULTS Our data corroborate that approximately 2% of neurons in striatum express nNOS and these exhibited morphology characteristic of interneurons. Posterior regions of the striatum have a higher nitrergic neuronal profile than anterior regions of this nucleus suggesting an anteroposterior gradient of nitrergic neurons. Posterior limbic-associated areas of the striatum have a higher nitrergic neuronal profile compared to other functional subdivisions. Also, approximately 90% of neurons in the subthalamic nucleus express nNOS. CONCLUSIONS A remarkable presence of nitrergic neurons in the human striatum and subthalamic nucleus suggests that NO may play a critical role in the physiology of these nuclei.
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Affiliation(s)
- Bruno Lopes Dos Santos-Lobato
- Department of Neurosciences and Behavioral Sciences, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, SP, Brazil; Center for Research Support on Applied Neuroscience (NAPNA-USP), Brazil.
| | - Elaine Del-Bel
- Department of Neurosciences and Behavioral Sciences, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, SP, Brazil; Department of Morphology, Physiology and Basic Pathology, Ribeirão Preto Dentistry School, University of São Paulo, Ribeirão Preto, SP, Brazil; Center for Research Support on Applied Neuroscience (NAPNA-USP), Brazil.
| | - José Eymard Homem Pittella
- Department of Pathology, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, SP, Brazil.
| | - Vitor Tumas
- Department of Neurosciences and Behavioral Sciences, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, SP, Brazil; Center for Research Support on Applied Neuroscience (NAPNA-USP), Brazil.
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782
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Bartus RT, Johnson EM. Clinical tests of neurotrophic factors for human neurodegenerative diseases, part 1: Where have we been and what have we learned? Neurobiol Dis 2016; 97:156-168. [PMID: 27063798 DOI: 10.1016/j.nbd.2016.03.027] [Citation(s) in RCA: 68] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2015] [Revised: 03/24/2016] [Accepted: 03/30/2016] [Indexed: 02/08/2023] Open
Abstract
Over the past 25years, about 3 dozen clinical reports have been published regarding the safety and possible efficacy of neurotrophic factors in patients with various neurodegenerative diseases. This effort involved a half dozen different neurotrophic factors, using at least 5 different general delivery approaches for ALS (amyolateral sclerosis), peripheral neuropathies, PD (Parkinson's disease) and AD (Alzheimer's disease). While none of these efforts have yet produced efficacy data sufficiently robust or reliable to establish neurotrophic factors as treatments for any human disease, the obstacles encountered and novel information reported, when viewed collectively, provide important insight to help future efforts. Three consistent themes emerge from these publications: (1) unexpected and undesirable side effects, at times serious, have plagued many efforts to deliver neurotrophic factors to humans; (2) the magnitude and consistency of clinical benefit has been disappointing; (3) by far that most consistently proposed reason for the side effects and poor efficacy has been inadequate dosing and delivery. This paper reviews and attempts to synthesize the available data derived from clinical tests of neurotrophic factors for neurodegenerative diseases. The obstacles encountered, the solutions attempted, and the lessons learned are discussed. The vast majority of solutions have involved changes in dosing paradigms and dose levels, which has primarily led to improved safety outcomes. However, lack of adequate efficacy remains a significant issue. While current efforts continue to focus exclusively on still-further changes in dosing parameters, a review of available data argues that it may now be the time to ask whether other, non-dose-related variables should be given more serious consideration as being responsible for the great divide that exists between the robust effects seen in animal models and the relatively weak effects seen in human neurodegenerative patients. Foremost among these appears to be the severe degeneration seen in the majority of patients enrolled in past and current trials testing neurotrophic factors in humans. A companion paper (Bartus and Johnson, 2016), reviews the contemporary data and concludes that compelling empirical evidence already exists for enrolling earlier-stage subjects as likely essential to achieving more robust and reliable benefit.
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Affiliation(s)
| | - Eugene M Johnson
- Departments of Neurology and Developmental Biology, Washington University Medical School, St. Louis, MO, USA
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783
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Sumi-Akamaru H, Beck G, Shinzawa K, Kato S, Riku Y, Yoshida M, Fujimura H, Tsujimoto Y, Sakoda S, Mochizuki H. High expression of α-synuclein in damaged mitochondria with PLA2G6 dysfunction. Acta Neuropathol Commun 2016; 4:27. [PMID: 27030050 PMCID: PMC4815115 DOI: 10.1186/s40478-016-0298-3] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2016] [Accepted: 03/10/2016] [Indexed: 01/03/2023] Open
Abstract
To clarify the role of α-synuclein (αSyn) in neuronal membrane remodeling, we analyzed the expression of αSyn in neurons with a dysfunction of PLA2G6, which is indispensable for membrane remodeling. αSyn/phosphorylated-αSyn (PαSyn) distribution and neurodegeneration were quantitatively estimated in PLA2G6-knockout (KO) mice, which demonstrate marked mitochondrial membrane degeneration. We also assessed the relationship between αSyn deposits and mitochondria in brain tissue from patients with PLA2G6-associated neurodegeneration (PLAN) and Parkinson’s disease (PD), and quantitatively examined Lewy bodies (LBs) and neurons. The expression level of αSyn was elevated in PLA2G6-knockdown cells and KO mouse neurons. Strong PαSyn expression was observed in neuronal granules in KO mice before onset of motor symptoms. The granules were mitochondrial outer membrane protein (TOM20)-positive. Ultramicroscopy revealed that PαSyn-positive granules were localized to mitochondria with degenerated inner membranes. After symptom onset, TOM20-positive granules were frequently found in ubiquitinated spheroids, where PαSyn expression was low. Axons were atrophic, but the neuronal loss was not evident in KO mice. In PLAN neurons, small PαSyn-positive inclusions with a TOM20-positive edge were frequently observed and clustered into LBs. The surfaces of most LBs were TOM20-positive in PLAN and TOM20-negative in PD brains. The high proportion of LB-bearing neurons and the preserved neuronal number in PLAN suggested long-term survival of LB-bearing neurons. Elevated expression of αSyn/PαSyn in mitochondria appears to be the early response to PLA2G6-deficiency in neurons. The strong affinity of αSyn for damaged mitochondrial membranes may promote membrane stabilization of mitochondria and neuronal survival in neurons.
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784
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Kneynsberg A, Collier TJ, Manfredsson FP, Kanaan NM. Quantitative and semi-quantitative measurements of axonal degeneration in tissue and primary neuron cultures. J Neurosci Methods 2016; 266:32-41. [PMID: 27031947 DOI: 10.1016/j.jneumeth.2016.03.004] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2015] [Revised: 03/04/2016] [Accepted: 03/04/2016] [Indexed: 12/19/2022]
Abstract
BACKGROUND Axon viability is critical for maintaining neural connectivity, which is central to neural functionality. Many neurodegenerative diseases (e.g., Parkinson's disease (PD) and Alzheimer's disease) appear to involve extensive axonal degeneration that often precedes somatic loss in affected neural populations. Axonal degeneration involves a number of intracellular pathways and characteristic changes in axon morphology (i.e., swelling, fragmentation, and loss). NEW METHOD We describe a relatively simple set of methods to quantify the axonal degeneration using the 6-hydroxydopamine neurotoxin model of PD in rats and a colchicine-induced model in primary rat neurons. Specifically, approaches are described that use the spaceballs stereological probe for tissue sections and petrimetrics stereological probe for cultured neurons, and image analysis techniques in both tissue sections and cultured neurons. RESULTS These methods provide a mechanism for obtaining quantitative and semi-quantitative data to track the extent of axonal degeneration and may prove useful as outcome measures in studies aimed at preventing or slowing axonal degeneration in disease models. COMPARISON WITH EXISTING METHODS Existing methods of quantification of axonal degeneration use densitometry and manual counts of axonal projections, but they do not utilize the random, unbiased systematic sampling approaches that are characteristic of stereological methods. The ImageJ thresholding analyses described here provide a descriptive method for quantifying the state of axonal degeneration. CONCLUSIONS These methods provide an efficient and effective means to quantify the extent and state of axonal degeneration in animal tissue and cultured neurons and can be used in other models for the same purposes.
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Affiliation(s)
- Andrew Kneynsberg
- Neuroscience Program, Michigan State University, East Lansing, MI, USA; Department of Translational Science and Molecular Medicine, College of Human Medicine, Michigan State University, Grand Rapids, MI, USA
| | - Timothy J Collier
- Neuroscience Program, Michigan State University, East Lansing, MI, USA; Department of Translational Science and Molecular Medicine, College of Human Medicine, Michigan State University, Grand Rapids, MI, USA; Morris K. Udall Center of Excellence for Parkinson's Disease Research at Michigan State University, USA; Hauenstein Neuroscience Center, Mercy Health Saint Mary's, Grand Rapids, MI, USA
| | - Fredric P Manfredsson
- Neuroscience Program, Michigan State University, East Lansing, MI, USA; Department of Translational Science and Molecular Medicine, College of Human Medicine, Michigan State University, Grand Rapids, MI, USA; Hauenstein Neuroscience Center, Mercy Health Saint Mary's, Grand Rapids, MI, USA
| | - Nicholas M Kanaan
- Neuroscience Program, Michigan State University, East Lansing, MI, USA; Department of Translational Science and Molecular Medicine, College of Human Medicine, Michigan State University, Grand Rapids, MI, USA; Morris K. Udall Center of Excellence for Parkinson's Disease Research at Michigan State University, USA; Hauenstein Neuroscience Center, Mercy Health Saint Mary's, Grand Rapids, MI, USA.
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785
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Duda J, Pötschke C, Liss B. Converging roles of ion channels, calcium, metabolic stress, and activity pattern of Substantia nigra dopaminergic neurons in health and Parkinson's disease. J Neurochem 2016; 139 Suppl 1:156-178. [PMID: 26865375 PMCID: PMC5095868 DOI: 10.1111/jnc.13572] [Citation(s) in RCA: 112] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2015] [Revised: 02/03/2016] [Accepted: 02/05/2016] [Indexed: 12/18/2022]
Abstract
Dopamine‐releasing neurons within the Substantia nigra (SN DA) are particularly vulnerable to degeneration compared to other dopaminergic neurons. The age‐dependent, progressive loss of these neurons is a pathological hallmark of Parkinson's disease (PD), as the resulting loss of striatal dopamine causes its major movement‐related symptoms. SN DA neurons release dopamine from their axonal terminals within the dorsal striatum, and also from their cell bodies and dendrites within the midbrain in a calcium‐ and activity‐dependent manner. Their intrinsically generated and metabolically challenging activity is created and modulated by the orchestrated function of different ion channels and dopamine D2‐autoreceptors. Here, we review increasing evidence that the mechanisms that control activity patterns and calcium homeostasis of SN DA neurons are not only crucial for their dopamine release within a physiological range but also modulate their mitochondrial and lysosomal activity, their metabolic stress levels, and their vulnerability to degeneration in PD. Indeed, impaired calcium homeostasis, lysosomal and mitochondrial dysfunction, and metabolic stress in SN DA neurons represent central converging trigger factors for idiopathic and familial PD. We summarize double‐edged roles of ion channels, activity patterns, calcium homeostasis, and related feedback/feed‐forward signaling mechanisms in SN DA neurons for maintaining and modulating their physiological function, but also for contributing to their vulnerability in PD‐paradigms. We focus on the emerging roles of maintained neuronal activity and calcium homeostasis within a physiological bandwidth, and its modulation by PD‐triggers, as well as on bidirectional functions of voltage‐gated L‐type calcium channels and metabolically gated ATP‐sensitive potassium (K‐ATP) channels, and their probable interplay in health and PD.
We propose that SN DA neurons possess several feedback and feed‐forward mechanisms to protect and adapt their activity‐pattern and calcium‐homeostasis within a physiological bandwidth, and that PD‐trigger factors can narrow this bandwidth. We summarize roles of ion channels in this view, and findings documenting that both, reduced as well as elevated activity and associated calcium‐levels can trigger SN DA degeneration.
This article is part of a special issue on Parkinson disease.
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Affiliation(s)
- Johanna Duda
- Department of Applied Physiology, Ulm University, Ulm, Germany
| | | | - Birgit Liss
- Department of Applied Physiology, Ulm University, Ulm, Germany.
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786
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787
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Principal Component Analysis of Multimodal Neuromelanin MRI and Dopamine Transporter PET Data Provides a Specific Metric for the Nigral Dopaminergic Neuronal Density. PLoS One 2016; 11:e0151191. [PMID: 26954690 PMCID: PMC4783074 DOI: 10.1371/journal.pone.0151191] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2015] [Accepted: 02/24/2016] [Indexed: 01/29/2023] Open
Abstract
The loss of dopaminergic (DA) neurons in the substantia nigra (SN) is a major pathophysiological feature of patients with Parkinson's disease (PD). As nigral DA neurons contain both neuromelanin (NM) and dopamine transporter (DAT), decreased intensities in both NM-sensitive MRI and DAT PET reflect decreased DA neuronal density. This study demonstrates that a more specific metric for the nigral DA neuronal density can be derived with multimodal MRI and PET. Participants were 11 clinically diagnosed PD patients and 10 age and gender matched healthy controls (HCs). Two quantities, the NM-related index (RNM) and the binding potential of the radiotracer [18F]FE-PE2I to DAT (BPND) in SN, were measured for each subject using MRI and PET, respectively. Principal component analysis (PCA) was applied to the multimodal data set to estimate principal components. One of the components, PCP, corresponds to a basis vector oriented in a direction where both BPND and RNM increase. The ability of BPND, RNM and PCP to discriminate between HC and PD groups was compared. Correlation analyses between the motor score of the unified Parkinson's disease rating scale and each metric were also performed. PCP, BPND and RNM for PD patients were significantly lower than those for HCs (F = 16.26, P<0.001; F = 6.05, P = 0.008; F = 7.31, P = 0.034, respectively). The differential diagnostic performance between the HC and PD groups as assessed by the area under the receiver-operating characteristic curve was best for PCP (0.94, 95% CI: 0.66–1.00). A significant negative correlation was found between the motor severity score and PCp (R = -0.70, P<0.001) and RNM (R = -0.52, P = 0.015), but not for BPND (R = -0.36, P = 0.110). PCA of multimodal NM-sensitive MRI and DAT PET data provides a metric for nigral DA neuronal density that will help illuminate the pathophysiology of PD in SN. Further studies are required to explore whether PCA is useful for other parkinsonian syndromes.
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788
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Navntoft CA, Dreyer JK. How compensation breaks down in Parkinson's disease: Insights from modeling of denervated striatum. Mov Disord 2016; 31:280-9. [PMID: 26890687 PMCID: PMC4787207 DOI: 10.1002/mds.26579] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2015] [Revised: 01/13/2016] [Accepted: 01/22/2016] [Indexed: 12/23/2022] Open
Abstract
The bradykinesia and other motor signs of Parkinson's disease (PD) are linked to progressive loss of substantia nigra dopamine (DA) neurons innervating the striatum. However, the emergence of idiopathic PD is likely preceded by a prolonged subclinical phase, which may be masked by a variety of pre‐ and postsynaptic compensatory mechanisms. It is often considered self‐evident that the signs of PD manifest only when nigrostriatal degeneration has proceeded to such an extent that putative compensatory mechanisms fail to accommodate the depletion of striatal DA levels. However, the precise nature of the compensatory mechanisms, and the reason for their ultimate failure, has been elusive. In a recent computational study we modeled the effects of progressive denervation, including changes in the dynamics of interstitial DA and also adaptive or compensatory changes in postsynaptic responsiveness to DA signaling in the course of progressive nigrostriatal degeneration. In particular, we found that failure of DA signaling can occur by different mechanisms at different disease stages. We review these results and discuss their relevance for clinical and translational research, and we draw a number of predictions from our model that might be tested in preclinical experiments. © 2016 The Authors. Movement Disorders published by Wiley Periodicals, Inc. on behalf of International Parkinson and Movement Disorder Society.
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Affiliation(s)
| | - Jakob Kisbye Dreyer
- Department of Neuroscience and Pharmacology, University of Copenhagen, Copenhagen, Denmark
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789
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Ding C, Ganesvaran G, Alty JE, Clissold BG, McColl CD, Reardon KA, Schiff M, Srikanth V, Kempster PA. Study of levodopa response in Parkinson's disease: Observations on rates of motor progression. Mov Disord 2016; 31:589-92. [DOI: 10.1002/mds.26497] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2015] [Revised: 10/27/2015] [Accepted: 11/03/2015] [Indexed: 11/08/2022] Open
Affiliation(s)
- Catherine Ding
- Neurosciences Department; Monash Medical Center; Clayton Victoria Australia
| | - Ganga Ganesvaran
- Neurosciences Department; Monash Medical Center; Clayton Victoria Australia
| | - Jane E. Alty
- Neurosciences Department; Monash Medical Center; Clayton Victoria Australia
| | | | - Craig D. McColl
- Neurosciences Department; Monash Medical Center; Clayton Victoria Australia
| | - Katrina A. Reardon
- Neurosciences Department; Monash Medical Center; Clayton Victoria Australia
| | - Mark Schiff
- Neurosciences Department; Monash Medical Center; Clayton Victoria Australia
| | - Velandai Srikanth
- Neurosciences Department; Monash Medical Center; Clayton Victoria Australia
- Stroke and Ageing Research Group, Vascular Brain Aging Division, Department of Medicine, School of Clinical Sciences; Monash University; Melbourne Victoria Australia
- Menzies Research Institute Tasmania; University of Tasmania; Hobart Tasmania Australia
| | - Peter A. Kempster
- Neurosciences Department; Monash Medical Center; Clayton Victoria Australia
- Department of Medicine; Monash University; Clayton Victoria Australia
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790
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van Wouwe NC, Kanoff KE, Claassen DO, Spears CA, Neimat J, van den Wildenberg WPM, Wylie SA. Dissociable Effects of Dopamine on the Initial Capture and the Reactive Inhibition of Impulsive Actions in Parkinson's Disease. J Cogn Neurosci 2016; 28:710-23. [PMID: 26836515 DOI: 10.1162/jocn_a_00930] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Dopamine plays a key role in a range of action control processes. Here, we investigate how dopamine depletion caused by Parkinson disease (PD) and how dopamine restoring medication modulate the expression and suppression of unintended action impulses. Fifty-five PD patients and 56 healthy controls (HCs) performed an action control task (Simon task). PD patients completed the task twice, once withdrawn from dopamine medications and once while taking their medications. PD patients experienced similar susceptibility to making fast errors in conflict trials as HCs, but PD patients were less proficient compared with HCs at suppressing incorrect responses. Administration of dopaminergic medications had no effect on impulsive error rates but significantly improved the proficiency of inhibitory control in PD patients. We found no evidence that dopamine precursors and agonists affected action control in PD differently. Additionally, there was no clear evidence that individual differences in baseline action control (off dopamine medications) differentially responded to dopamine medications (i.e., no evidence for an inverted U-shaped performance curve). Together, these results indicate that dopamine depletion and restoration therapies directly modulate the reactive inhibitory control processes engaged to suppress interference from the spontaneously activated response impulses but exert no effect on an individual's susceptibility to act on impulses.
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791
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Algarni MA, Stoessl AJ. The role of biomarkers and imaging in Parkinson’s disease. Expert Rev Neurother 2016; 16:187-203. [DOI: 10.1586/14737175.2016.1135056] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
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792
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Arcuri L, Viaro R, Bido S, Longo F, Calcagno M, Fernagut PO, Zaveri NT, Calò G, Bezard E, Morari M. Genetic and pharmacological evidence that endogenous nociceptin/orphanin FQ contributes to dopamine cell loss in Parkinson's disease. Neurobiol Dis 2016; 89:55-64. [PMID: 26804029 DOI: 10.1016/j.nbd.2016.01.016] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2015] [Revised: 01/09/2016] [Accepted: 01/19/2016] [Indexed: 12/30/2022] Open
Abstract
To investigate whether the endogenous neuropeptide nociceptin/orphanin FQ (N/OFQ) contributes to the death of dopamine neurons in Parkinson's disease, we undertook a genetic and a pharmacological approach using NOP receptor knockout (NOP(-/-)) mice, and the selective and potent small molecule NOP receptor antagonist (-)-cis-1-methyl-7-[[4-(2,6-dichlorophenyl)piperidin-1-yl]methyl]-6,7,8,9-tetrahydro-5H-benzocyclohepten-5-ol (SB-612111). Stereological unbiased methods were used to estimate the total number of dopamine neurons in the substantia nigra of i) NOP(-/-) mice acutely treated with the parkinsonian neurotoxin 1-methyl-4-phenyl-1,2,5,6-tetrahydropyridine (MPTP), ii) naïve mice subacutely treated with MPTP, alone or in combination with SB-612111, iii) rats injected with a recombinant adeno-associated viral (AAV) vector overexpressing human mutant p.A53T α-synuclein, treated with vehicle or SB-612111. NOP(-/-) mice showed a 50% greater amount of nigral dopamine neurons spared in response to acute MPTP compared to controls, which was associated with a milder motor impairment. SB-612111, given 4 days after MPTP treatment to mimic the clinical condition, prevented the loss of nigral dopamine neurons and striatal dopaminergic terminals caused by subacute MPTP. SB-612111, administered a week after the AAV injections in a clinically-driven protocol, also increased by 50% both the number of spared nigral dopamine neurons and striatal dopamine terminals, and prevented accompanying motor deficits induced by α-synuclein. We conclude that endogenous N/OFQ contributes to dopamine neuron loss in pathogenic and etiologic models of Parkinson's disease through NOP receptor-mediated mechanisms. NOP receptor antagonists might prove effective as disease-modifying agents in Parkinson's disease, through the rescue of degenerating nigral dopamine neurons and/or the protection of the healthy ones.
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Affiliation(s)
- Ludovico Arcuri
- Department of Medical Sciences, Section of Pharmacology, University of Ferrara, via Fossato di Mortara 17-19, 44121 Ferrara, Italy; Neuroscience Center and National Institute of Neuroscience, University of Ferrara, via Fossato di Mortara 17-19, 44121 Ferrara, Italy
| | - Riccardo Viaro
- Department of Biomedical and Specialty Surgical Sciences, Section of Human Physiology, University of Ferrara, via Fossato di Mortara 19, 44121 Ferrara, Italy
| | - Simone Bido
- Department of Medical Sciences, Section of Pharmacology, University of Ferrara, via Fossato di Mortara 17-19, 44121 Ferrara, Italy; Neuroscience Center and National Institute of Neuroscience, University of Ferrara, via Fossato di Mortara 17-19, 44121 Ferrara, Italy
| | - Francesco Longo
- Department of Medical Sciences, Section of Pharmacology, University of Ferrara, via Fossato di Mortara 17-19, 44121 Ferrara, Italy; Neuroscience Center and National Institute of Neuroscience, University of Ferrara, via Fossato di Mortara 17-19, 44121 Ferrara, Italy
| | - Mariangela Calcagno
- Department of Medical Sciences, Section of Pharmacology, University of Ferrara, via Fossato di Mortara 17-19, 44121 Ferrara, Italy; Neuroscience Center and National Institute of Neuroscience, University of Ferrara, via Fossato di Mortara 17-19, 44121 Ferrara, Italy
| | - Pierre-Olivier Fernagut
- Université de Bordeaux, Institut des Maladies Neurodégénératives, UMR 5293, F-33000 Bordeaux, France; CNRS, Institut des Maladies Neurodégénératives, UMR 5293, F-33000 Bordeaux, France
| | - Nurulain T Zaveri
- Astraea Therapeutics, 320 Logue Avenue, Mountain View, CA 94040, USA
| | - Girolamo Calò
- Department of Medical Sciences, Section of Pharmacology, University of Ferrara, via Fossato di Mortara 17-19, 44121 Ferrara, Italy; Neuroscience Center and National Institute of Neuroscience, University of Ferrara, via Fossato di Mortara 17-19, 44121 Ferrara, Italy
| | - Erwan Bezard
- Université de Bordeaux, Institut des Maladies Neurodégénératives, UMR 5293, F-33000 Bordeaux, France; CNRS, Institut des Maladies Neurodégénératives, UMR 5293, F-33000 Bordeaux, France
| | - Michele Morari
- Department of Medical Sciences, Section of Pharmacology, University of Ferrara, via Fossato di Mortara 17-19, 44121 Ferrara, Italy; Neuroscience Center and National Institute of Neuroscience, University of Ferrara, via Fossato di Mortara 17-19, 44121 Ferrara, Italy.
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793
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Finkelstein DI, Hare DJ, Billings JL, Sedjahtera A, Nurjono M, Arthofer E, George S, Culvenor JG, Bush AI, Adlard PA. Clioquinol Improves Cognitive, Motor Function, and Microanatomy of the Alpha-Synuclein hA53T Transgenic Mice. ACS Chem Neurosci 2016; 7:119-29. [PMID: 26481462 DOI: 10.1021/acschemneuro.5b00253] [Citation(s) in RCA: 59] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
The abnormal accumulation of alpha-synuclein (α-syn) has been linked to a number of neurodegenerative disorders, the most noteworthy of which is Parkinson's disease. Alpha-synuclein itself is not toxic and fulfills various physiological roles in the central nervous system. However, specific types of aggregates have been shown to be toxic, and metals have been linked to the assembly of these toxic aggregates. In this paper, we have characterized a transgenic mouse that overexpresses the A53T mutation of human α-syn, specifically assessing cognition, motor performance, and subtle anatomical markers that have all been observed in synucleinopathies in humans. We hypothesized that treatment with the moderate-affinity metal chelator, clioquinol (CQ), would reduce the interaction between metals and α-syn to subsequently improve the phenotype of the A53T animal model. We showed that CQ prevents an iron-synuclein interaction, the formation of urea-soluble α-syn aggregates, α-syn-related substantia nigra pars compacta cell loss, reduction in dendritic spine density of hippocampal and caudate putamen medium spiny neurons, and the decline in motor and cognitive function. In conclusion, our data suggests that CQ is capable of mitigating the pathological metal/α-syn interactions, suggesting that the modulation of metal ions warrants further study as a therapeutic approach for the synucleinopathies.
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Affiliation(s)
- David I. Finkelstein
- The
Florey Institute of Neuroscience and Mental Health, The University of Melbourne, Parkville, Victoria 3052, Australia
| | - Dominic J. Hare
- The
Florey Institute of Neuroscience and Mental Health, The University of Melbourne, Parkville, Victoria 3052, Australia
- Elemental
Bio-imaging Facility, University of Technology Sydney, Broadway, New South Wales 2007, Australia
- Senator
Frank R. Lautenberg Environmental Science Laboratory, Icahn School of Medicine at Mount Sinai, New York, New York 10029, United States
| | - Jessica L. Billings
- The
Florey Institute of Neuroscience and Mental Health, The University of Melbourne, Parkville, Victoria 3052, Australia
| | - Amelia Sedjahtera
- The
Florey Institute of Neuroscience and Mental Health, The University of Melbourne, Parkville, Victoria 3052, Australia
| | - Milawaty Nurjono
- The
Florey Institute of Neuroscience and Mental Health, The University of Melbourne, Parkville, Victoria 3052, Australia
| | - Elisa Arthofer
- The
Florey Institute of Neuroscience and Mental Health, The University of Melbourne, Parkville, Victoria 3052, Australia
- Department
of Physiology and Pharmacology, Karolinska Institut, Stockholm SE-171 77, Sweden
| | - Sonia George
- School
of Medicine, Dentistry and Health Sciences, The University of Melbourne, Parkville, Victoria 3052, Australia
| | - Janetta G. Culvenor
- School
of Medicine, Dentistry and Health Sciences, The University of Melbourne, Parkville, Victoria 3052, Australia
| | - Ashley I. Bush
- The
Florey Institute of Neuroscience and Mental Health, The University of Melbourne, Parkville, Victoria 3052, Australia
| | - Paul A. Adlard
- The
Florey Institute of Neuroscience and Mental Health, The University of Melbourne, Parkville, Victoria 3052, Australia
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794
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Vidyadhara DJ, Yarreiphang H, Abhilash PL, Raju TR, Alladi PA. Differential expression of calbindin in nigral dopaminergic neurons in two mice strains with differential susceptibility to 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine. J Chem Neuroanat 2016; 76:82-89. [PMID: 26775762 DOI: 10.1016/j.jchemneu.2016.01.001] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2015] [Accepted: 01/04/2016] [Indexed: 01/13/2023]
Abstract
Parkinson's disease (PD) affects the A9 dopaminergic (DA) neurons of substantia nigra pars compacta (SNpc) whereas other DA neuronal subtypes are spared. The role of calbindin in this differential vulnerability has been long elicited, and is seen in the MPTP induced mice models of PD. A peculiar feature of mice models is the strain specific differences in the susceptibility to MPTP. Here, calbindin-D28K expression in DA neurons of SNpc of MPTP susceptible C57BL/6 mice and MPTP resistant CD-1 mice was studied as a susceptibility marker of degeneration. Unbiased stereological estimation of immunoperoxidase stained midbrain sections revealed significantly higher number of calbindin immunoreactive cells in SNpc of CD-1 mice compared to that of C57BL/6 strain. Western blotting showed minimal differences in the levels. Calbindin-tyrosine hydroxylase immunofluorescence co-labeling was performed to map the calbindin immunoreactive DA neurons in SNpc and ventral tegmental area (VTA) and to quantify the calbindin expression at cellular level. While the levels were comparable in VTA of both mice strains, the SNpc of CD-1 mice showed significantly higher calbindin expression. Within the SNpc, the medial and dorsal subdivisions showed higher calbindin expression in CD-1. The expression in the ventrolateral SNpc of both strains remained comparable. Our observations clearly point at overall higher levels and sizeable percentage of cells expressing more calbindin in SNpc of CD-1 mice, which might confer neuroprotection against MPTP, while its lower expression makes C57BL/6 mice more susceptible. Similar mechanism may be attributed to the phenomenon of differential prevalence of PD in different ethnic populations.
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Affiliation(s)
- D J Vidyadhara
- Department of Neurophysiology, National Institute of Mental Health and Neuro Sciences, Hosur Road, Bengaluru 560029, India
| | - H Yarreiphang
- Department of Neurophysiology, National Institute of Mental Health and Neuro Sciences, Hosur Road, Bengaluru 560029, India
| | - P L Abhilash
- Department of Neurophysiology, National Institute of Mental Health and Neuro Sciences, Hosur Road, Bengaluru 560029, India
| | - T R Raju
- Department of Neurophysiology, National Institute of Mental Health and Neuro Sciences, Hosur Road, Bengaluru 560029, India
| | - Phalguni Anand Alladi
- Department of Neurophysiology, National Institute of Mental Health and Neuro Sciences, Hosur Road, Bengaluru 560029, India.
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795
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GDNF and AADC Gene Therapy for Parkinson’s Disease. Transl Neurosci 2016. [DOI: 10.1007/978-1-4899-7654-3_4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
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796
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Gurevich EV, Gainetdinov RR, Gurevich VV. Regulation of Dopamine-Dependent Behaviors by G Protein-Coupled Receptor Kinases. METHODS IN PHARMACOLOGY AND TOXICOLOGY 2016. [DOI: 10.1007/978-1-4939-3798-1_11] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
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797
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Salvatore MF, Terrebonne J, Fields V, Nodurft D, Runfalo C, Latimer B, Ingram DK. Initiation of calorie restriction in middle-aged male rats attenuates aging-related motoric decline and bradykinesia without increased striatal dopamine. Neurobiol Aging 2016; 37:192-207. [PMID: 26610387 PMCID: PMC4688216 DOI: 10.1016/j.neurobiolaging.2015.10.006] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2015] [Revised: 10/07/2015] [Accepted: 10/08/2015] [Indexed: 01/07/2023]
Abstract
Aging-related bradykinesia affects ∼ 15% of those reaching age 65 and 50% of those reaching their 80s. Given this high risk and lack of pharmacologic therapeutics, noninvasive lifestyle strategies should be identified to diminish its risk and identify the neurobiological targets to reduce aging-related bradykinesia. Early-life, long-term calorie restriction (CR) attenuates aging-related bradykinesia in rodents. Here, we addressed whether CR initiation at middle age could attenuate aging-related bradykinesia and motoric decline measured as rotarod performance. A 30% CR regimen was implemented for 6 months duration in 12-month-old male Brown-Norway Fischer 344 F1 hybrid rats after establishing individual baseline locomotor activities. Locomotor capacity was assessed every 6 weeks thereafter. The ad libitum group exhibited predictably decreased locomotor activity, except movement speed, out to 18 months of age. In contrast, in the CR group, movement number and horizontal activity did not decrease during the 6-month trial, and aging-related decline in rotarod performance was attenuated. The response to CR was influenced by baseline locomotor activity. The lower the locomotor activity level at baseline, the greater the response to CR. Rats in the lower 50th percentile surpassed their baseline level of activity, whereas rats in the top 50th percentile decreased at 6 weeks and then returned to baseline by 12 weeks of CR. We hypothesized that nigrostriatal dopamine tissue content would be greater in the CR group and observed a modest increase only in substantia nigra with no group differences in striatum, nucleus accumbens, or ventral tegmental area. These results indicate that initiation of CR at middle age may reduce aging-related bradykinesia, and, furthermore, subjects with below average locomotor activity may increase baseline activity. Sustaining nigral dopamine neurotransmission may be one component of preserving locomotor capabilities during aging.
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Affiliation(s)
- Michael F Salvatore
- Department of Pharmacology, Toxicology, & Neuroscience, Louisiana State University Health Sciences Center, Shreveport, LA, USA; Department of Pharmacology & Neuroscience, University of North Texas Health Science Center, Fort Worth, TX, USA.
| | - Jennifer Terrebonne
- Pennington Biomedical Research Center, Louisiana State University, Baton Rouge, LA, USA
| | - Victoria Fields
- Department of Pharmacology, Toxicology, & Neuroscience, Louisiana State University Health Sciences Center, Shreveport, LA, USA
| | - Danielle Nodurft
- Department of Pharmacology, Toxicology, & Neuroscience, Louisiana State University Health Sciences Center, Shreveport, LA, USA
| | - Cori Runfalo
- Pennington Biomedical Research Center, Louisiana State University, Baton Rouge, LA, USA
| | - Brian Latimer
- Department of Pharmacology, Toxicology, & Neuroscience, Louisiana State University Health Sciences Center, Shreveport, LA, USA
| | - Donald K Ingram
- Pennington Biomedical Research Center, Louisiana State University, Baton Rouge, LA, USA
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798
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Neuroprotective Transcription Factors in Animal Models of Parkinson Disease. Neural Plast 2015; 2016:6097107. [PMID: 26881122 PMCID: PMC4736191 DOI: 10.1155/2016/6097107] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2015] [Revised: 07/10/2015] [Accepted: 07/14/2015] [Indexed: 11/28/2022] Open
Abstract
A number of transcription factors, including En1/2, Foxa1/2, Lmx1a/b, Nurr1, Otx2, and Pitx3, with key roles in midbrain dopaminergic (mDA) neuron development, also regulate adult mDA neuron survival and physiology. Mouse models with targeted disruption of some of these genes display several features reminiscent of Parkinson disease (PD), in particular the selective and progressive loss of mDA neurons in the substantia nigra pars compacta (SNpc). The characterization of these animal models has provided valuable insights into various mechanisms of PD pathogenesis. Therefore, the dissection of the mechanisms and survival signalling pathways engaged by these transcription factors to protect mDA neuron from degeneration can suggest novel therapeutic strategies. The work on En1/2-mediated neuroprotection also highlights the potential of protein transduction technology for neuroprotective approaches in PD.
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799
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Bartus RT. Gene therapy for Parkinson's disease: a decade of progress supported by posthumous contributions from volunteer subjects. Neural Regen Res 2015; 10:1586-8. [PMID: 26692850 PMCID: PMC4660746 DOI: 10.4103/1673-5374.167783] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Affiliation(s)
- Raymond T Bartus
- RTBioconsultants, Inc., San Diego, CA, USA; formerly, EVP and CSO, Ceregene, Inc., San Diego, CA, USA
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800
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Sharp ME, Foerde K, Daw ND, Shohamy D. Dopamine selectively remediates 'model-based' reward learning: a computational approach. Brain 2015; 139:355-64. [PMID: 26685155 DOI: 10.1093/brain/awv347] [Citation(s) in RCA: 82] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2015] [Accepted: 10/04/2015] [Indexed: 11/13/2022] Open
Abstract
Patients with loss of dopamine due to Parkinson's disease are impaired at learning from reward. However, it remains unknown precisely which aspect of learning is impaired. In particular, learning from reward, or reinforcement learning, can be driven by two distinct computational processes. One involves habitual stamping-in of stimulus-response associations, hypothesized to arise computationally from 'model-free' learning. The other, 'model-based' learning, involves learning a model of the world that is believed to support goal-directed behaviour. Much work has pointed to a role for dopamine in model-free learning. But recent work suggests model-based learning may also involve dopamine modulation, raising the possibility that model-based learning may contribute to the learning impairment in Parkinson's disease. To directly test this, we used a two-step reward-learning task which dissociates model-free versus model-based learning. We evaluated learning in patients with Parkinson's disease tested ON versus OFF their dopamine replacement medication and in healthy controls. Surprisingly, we found no effect of disease or medication on model-free learning. Instead, we found that patients tested OFF medication showed a marked impairment in model-based learning, and that this impairment was remediated by dopaminergic medication. Moreover, model-based learning was positively correlated with a separate measure of working memory performance, raising the possibility of common neural substrates. Our results suggest that some learning deficits in Parkinson's disease may be related to an inability to pursue reward based on complete representations of the environment.
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Affiliation(s)
- Madeleine E Sharp
- 1 Department of Neurology, Columbia University Medical Centre, New York NY, USA
| | - Karin Foerde
- 2 Department of Psychology, New York University, New York NY, USA
| | - Nathaniel D Daw
- 3 Center for Neural Science, New York University, New York NY, USA
| | - Daphna Shohamy
- 4 Department of Psychology and Kavli Center for Brain Sciences, Columbia University, New York NY, USA
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