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Sökning: WFRF:(Cenci M Angela)

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2.
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3.
  • Kuter, Katarzyna Z., et al. (författare)
  • The role of glia in Parkinson's disease : Emerging concepts and therapeutic applications
  • 2020
  • Ingår i: Recent Advances in Parkinson's Disease. - : Elsevier. - 0079-6123 .- 1875-7855. - 9780444642608 ; 252, s. 131-168
  • Bokkapitel (refereegranskat)abstract
    • Originally believed to primarily affect neurons, Parkinson's disease (PD) has recently been recognized to also affect the functions and integrity of microglia and astroglia, two cell categories of fundamental importance to brain tissue homeostasis, defense, and repair. Both a loss of glial supportive-defensive functions and a toxic gain of glial functions are implicated in the neurodegenerative process. Moreover, the chronic treatment with L-DOPA may cause maladaptive glial plasticity favoring a development of therapy complications. This chapter focuses on the pathophysiology of PD from a glial point of view, presenting this rapidly growing field from the first discoveries made to the most recent developments. We report and compare histopathological and molecular findings from experimental models of PD and human studies. We moreover discuss the important role played by astrocytes in compensatory adaptations taking place during presymptomatic disease stages. We finally describe examples of potential therapeutic applications stemming from an increased understanding of the important roles of glia in PD.
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4.
  • Ohlin, Elisabet, et al. (författare)
  • Vascular endothelial growth factor is upregulated by L-dopa in the parkinsonian brain: implications for the development of dyskinesia.
  • 2011
  • Ingår i: Brain. - : Oxford University Press (OUP). - 1460-2156 .- 0006-8950. ; 134, s. 2339-2357
  • Tidskriftsartikel (refereegranskat)abstract
    • Angiogenesis and increased permeability of the blood-brain barrier have been reported to occur in animal models of Parkinson's disease and l-dopa-induced dyskinesia, but the significance of these phenomena has remained unclear. Using a validated rat model of l-dopa-induced dyskinesia, this study demonstrates that chronic treatment with l-dopa dose dependently induces the expression of vascular endothelial growth factor in the basal ganglia nuclei. Vascular endothelial growth factor was abundantly expressed in astrocytes and astrocytic processes in the proximity of blood vessels. When co-administered with l-dopa, a small molecule inhibitor of vascular endothelial growth factor signalling significantly attenuated the development of dyskinesia and completely blocked the angiogenic response and associated increase in blood-brain barrier permeability induced by the treatment. The occurrence of angiogenesis and vascular endothelial growth factor upregulation was verified in post-mortem basal ganglia tissue from patients with Parkinson's disease with a history of dyskinesia, who exhibited increased microvascular density, microvascular nestin expression and an upregulation of vascular endothelial growth factor messenger ribonucleic acid. These congruent findings in the rat model and human patients indicate that vascular endothelial growth factor is implicated in the pathophysiology of l-dopa-induced dyskinesia and emphasize an involvement of the microvascular compartment in the adverse effects of l-dopa pharmacotherapy in Parkinson's disease.
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5.
  • Fieblinger, Tim, et al. (författare)
  • Mechanisms of Dopamine D1 Receptor-Mediated ERK1/2 Activation in the Parkinsonian Striatum and Their Modulation by Metabotropic Glutamate Receptor Type 5
  • 2014
  • Ingår i: Journal of Neuroscience. - : Society for Neuroscience. - 0270-6474 .- 1529-2401. ; 34:13, s. 4728-4740
  • Tidskriftsartikel (refereegranskat)abstract
    • In animal models of Parkinsons disease, striatal overactivation of ERK1/2 via dopamine (DA) D1 receptors is the hallmark of a supersensitive molecular response associated with dyskinetic behaviors. Here we investigate the pathways involved in D1 receptor-dependent ERK1/2 activation using acute striatal slices from rodents with unilateral 6-hydroxydopamine (6-OHDA) lesions. Application of the dopamine D1-like receptor agonist SKF38393 induced ERK1/2 phosphorylation and downstream signaling in the DA-denervated but not the intact striatum. This response was mediated through a canonical D1R/PKA/MEK1/2 pathway and independent of ionotropic glutamate receptors but blocked by antagonists of L-type calcium channels. Coapplication of an antagonist of metabotropic glutamate receptor type 5 (mGluR5) or its downstream signaling molecules (PLC, PKC, IP3 receptors) markedly attenuated SKF38393-induced ERK1/2 activation. The role of striatal mGluR5 in D1-dependent ERK1/2 activation was confirmed in vivo in 6-OHDA-lesioned animals treated systemically with SKF38393. In one experiment, local infusion of the mGluR5 antagonistMTEPin the DA-denervated rat striatum attenuated the activation of ERK1/2 signaling by SKF38393. In another experiment, 6-OHDA lesions were applied to transgenic mice with a cell-specific knockdown of mGluR5 in D1 receptor-expressing neurons. These mice showed a blunted striatal ERK1/2 activation in response to SFK38393 treatment. Our results reveal that D1-dependent ERK1/2 activation in the DA-denervated striatum depends on a complex interaction between PKA-and Ca2+ -dependent signaling pathways that is critically modulated by striatal mGluR5.
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6.
  • Francardo, Veronica, et al. (författare)
  • Impact of the lesion procedure on the profiles of motor impairment and molecular responsiveness to L-DOPA in the 6-hydroxydopamine mouse model of Parkinson's disease.
  • 2011
  • Ingår i: Neurobiology of disease. - : Elsevier BV. - 1095-953X .- 0969-9961. ; 42:3, s. 327-40
  • Tidskriftsartikel (refereegranskat)abstract
    • 6-Hydroxydopamine (6-OHDA) lesions are being used in the mouse for basic research on Parkinson's disease and L-DOPA-induced dyskinesia. We set out to compare unilateral lesion models produced by intrastriatal or intramesencephalic injections of a fixed 6-OHDA concentration (3.2 μg/μl) in C57BL/6 mice. In the first experiment, toxin injections were performed either at two striatal coordinates (1 or 2 μl per site, termed "striatum(2 × 1 μl)" and "striatum(2 × 2 μl)" models), in the medial forebrain bundle (MFB), or in the substantia nigra pars compacta (SN) (1 μl per site). All the four lesion models produced significant forelimb use asymmetry, but spontaneous turning asymmetry only occurred in the MFB and striatum(2 × 2 μl) models. After the behavioral studies, the induction of phosphorylated extracellular signal-regulated kinases 1 and 2 (pERK1/2) by acute L-DOPA (30 mg/kg) was used as a marker of post-synaptic supersensitivity. Striatal pERK1/2 expression was sparse in the SN and striatum(2 × 1 μl) groups, but pronounced in the striatum(2 × 2 μl) and MFB-lesioned mice. In further experiments, mice with MFB and striatal(2 × 2 μl) lesions were used to compare behavioral and molecular responses to chronic L-DOPA treatment (12 days at 3 and 6 mg/kg/day). Maximally severe abnormal involuntary movements (AIMs) occurred in all MFB-lesioned mice, whereas only 35% of the mice with striatal lesions developed dyskinesia. Striatal tissue levels of dopamine were significantly lower in the dyskinetic animals (both MFB and striatum(2 × 2 μl) groups) in comparison with the non-dyskinetic ones. Noradrenaline levels were significantly reduced only in MFB lesioned animals and did not differ among the dyskinetic and non-dyskinetic cases with striatal lesions. In all groups, the L-DOPA-induced AIM scores correlated closely with the number of cells immunoreactive for tyrosine hydroxylase or FosB/∆FosB in the striatum. In conclusion, among the four lesion procedures examined here, only the MFB and striatum(2 × 2 μl) models yielded a degree of dopamine denervation sufficient to produce spontaneous postural asymmetry and molecular supersensitivity to L-DOPA. Both lesion models are suitable to reproduce L-DOPA-induced dyskinesia, although only MFB lesions yield a pronounced and widespread expression of post-synaptic supersensitivity markers in the striatum.
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7.
  • Janelidze, Shorena, et al. (författare)
  • Increased CSF biomarkers of angiogenesis in Parkinson disease
  • 2015
  • Ingår i: Neurology. - 0028-3878 .- 1526-632X. ; 85:21, s. 1834-1842
  • Tidskriftsartikel (refereegranskat)abstract
    • To study biomarkers of angiogenesis in Parkinson disease (PD), and how these are associated with clinical characteristics, blood-brain barrier (BBB) permeability, and cerebrovascular disease.
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8.
  • Lundblad, Martin, et al. (författare)
  • Chronic intermittent L-DOPA treatment induces changes in dopamine release
  • 2009
  • Ingår i: Journal of Neurochemistry. - : Wiley. - 0022-3042 .- 1471-4159. ; 108:4, s. 998-1008
  • Tidskriftsartikel (refereegranskat)abstract
    • 3,4-Dihydroxyphenyl-l-alanine (l-DOPA)-induced dyskinesia often develops as a side effect of chronic l-DOPA therapy. This study was undertaken to investigate dopamine (DA) release upon l-DOPA treatment. Chronoamperometric measurements were performed in unilaterally DA-depleted rats, chronically treated with l-DOPA, resulting in dyskinetic and non-dyskinetic animals. Normal and lesioned l-DOPA naïve animals were used as controls. Potassium-evoked DA releases were significantly reduced in intact sides of animals undertaken chronic l-DOPA treatment, independent on dyskinetic behavior. Acute l-DOPA further attenuated the amplitude of the DA release in the control sides. In DA-depleted striata, no difference was found in potassium-evoked DA releases, and acute l-DOPA did not affect the amplitude. While immunoreactivity to serotonin uptake transporter was higher in lesioned striata of animals displaying dyskinetic behavior, no correlation could be documented between serotonin transporter-positive nerve fiber density and the amplitude of released DA. In conclusions, the amplitude of potassium-evoked DA release is attenuated in intact striatum after chronic intermittent l-DOPA treatment. No change in amplitude was found in DA-denervated sides of either dyskinetic or non-dyskinetic animals, while release kinetics were changed. This indicates the importance of studying DA release dynamics for the understanding of both beneficial and adverse effects of l-DOPA replacement therapy.
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9.
  • Lundblad, Martin, et al. (författare)
  • Pharmacological validation of behavioural measures of akinesia and dyskinesia in a rat model of Parkinson's disease.
  • 2002
  • Ingår i: European Journal of Neuroscience. - : Wiley. - 1460-9568 .- 0953-816X. ; 15:1, s. 120-132
  • Tidskriftsartikel (refereegranskat)abstract
    • In an attempt to define clinically relevant models of akinesia and dyskinesia in 6-hydroxydopamine (6-OHDA)-lesioned rats, we have examined the effects of drugs with high (L-DOPA) vs. low (bromocriptine) dyskinesiogenic potential in Parkinson's disease on three types of motor performance, namely: (i) abnormal involuntary movements (AIMs) (ii) rotational behaviour, and (iii) spontaneous forelimb use (cylinder test). Rats with unilateral 6-OHDA lesions received single daily i.p. injections of L-DOPA or bromocriptine at therapeutic doses. During 3 weeks of treatment, L-DOPA but not bromocriptine induced increasingly severe AIMs affecting the limb, trunk and orofacial region. Rotational behaviour was induced to a much higher extent by bromocriptine than L-DOPA. In the cylinder test, the two drugs initially improved the performance of the parkinsonian limb to a similar extent. However, L-DOPA-treated animals showed declining levels of performance in this test because the drug-induced AIMs interfered with physiological limb use, and gradually replaced all normal motor activities. L-DOPA-induced axial, limb and orolingual AIM scores were significantly reduced by the acute administration of compounds that have antidyskinetic efficacy in parkinsonian patients and/or nonhuman primates (-91%, yohimbine 10 mg/kg; -19%, naloxone 4-8 mg/kg; -37%, 5-methoxy 5-N,N-dimethyl-tryptamine 2 mg/kg; -30%, clozapine 8 mg/kg; -50%, amantadine 40 mg/kg). L-DOPA-induced rotation was, however, not affected. The present results demonstrate that 6-OHDA-lesioned rats do exhibit motor deficits that share essential functional similarities with parkinsonian akinesia or dyskinesia. Such deficits can be quantified using novel and relatively simple testing procedures, whereas rotometry cannot discriminate between dyskinetic and antiakinetic effects of antiparkinsonian treatments.
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10.
  • Westin, J. E., et al. (författare)
  • Persistent changes in striatal gene expression induced by long-term L-DOPA treatment in a rat model of Parkinson's disease
  • 2001
  • Ingår i: European Journal of Neuroscience. - 0953-816X .- 1460-9568. ; 14:7, s. 1171-1176
  • Tidskriftsartikel (refereegranskat)abstract
    • Current knowledge of the molecular changes induced by dopamine denervation and subsequent treatment with L-DOPA is based on studies performed on relatively acute and young animal models of parkinsonism. It is highly warranted to ask how well these models simulate the state of chronic denervation and sustained L-DOPA pharmacotherapy which are typical of advanced Parkinson's disease. This study investigates the effects of time postdenervation and L-dopa treatment duration on the striatal expression of opioid precursor mRNAs and FosB/DFosB-related proteins. Unilaterally 6-hydroxydopamine-lesioned rats were treated with therapeutical doses of L-DOPA for one year (long-term group) or a few weeks (short-term group). Age-matched lesioned rats received injections of vehicle or bromocriptine, an antiparkinsonian compound which does not produce dyskinesia when administered de novo. The lesion-induced up-regulation of preproenkephalin mRNA expression persisted at more than one year postlesion, and was unaffected by the pharmacological treatments applied. L-DOPA, but not bromocriptine, induced high striatal levels of FosB/DFosB immunoreactivity and prodynorphin mRNA, and these did not differ between short-term and long-term L-DOPA-treated rats. The present data provide the first demonstration that L-DOPA maintains high striatal levels of fosB and prodynorphin gene expression during a prolonged course of treatment, which simulates the clinical practice in Parkinson's disease more closely than the short-treatment paradigms studied thus far.
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11.
  • Andersson, M, et al. (författare)
  • cAMP response element-binding protein is required for dopamine-dependent gene expression in the intact but not the dopamine-denervated striatum
  • 2001
  • Ingår i: The Journal of Neuroscience. - 0270-6474 .- 1529-2401. ; 21:24, s. 9930-9943
  • Tidskriftsartikel (refereegranskat)abstract
    • The cAMP response element-binding protein (CREB) is believed to play a pivotal role in dopamine (DA) receptor-mediated nuclear signaling and neuroplasticity. Here we demonstrate that the significance of CREB for gene expression depends on the experimental paradigm. We compared the role of CREB in two different but related models: L-DOPA administration to unilaterally 6-hydroxydopamine lesioned rats, and cocaine administration to neurologically intact animals. Antisense technology was used to produce a local knockdown of CREB in the lateral caudate-putamen, a region that mediates the dyskinetic or stereotypic manifestations associated with L-DOPA or cocaine treatment, respectively. In intact rats, CREB antisense reduced both basal and cocaine-induced expression of c-Fos, FosB/ΔFosB, and prodynorphin mRNA. In the DA-denervated striatum, CREB was not required for L-DOPA to induce these gene products, nor did CREB contribute considerably to DNA binding activity at cAMP responsive elements (CREs) and CRE-like enhancers. ΔFosB-related proteins and JunD were the main contributors to both CRE and AP-1 DNA-protein complexes in L-DOPA-treated animals. In behavioral studies, intrastriatal CREB knockdown caused enhanced activity scores in intact control animals and exacerbated the dyskinetic effects of acute L-DOPA treatment in 6-OHDA-lesioned animals. These data demonstrate that CREB is not required for the development of L-DOPA-induced dyskinesia in hemiparkinsonian rats. Moreover, our results reveal an unexpected alteration of nuclear signaling mechanisms in the parkinsonian striatum treated with L-DOPA, where AP-1 transcription factors appear to supersede CREB in the activation of CRE-containing genes.
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12.
  • Francardo, Veronica, et al. (författare)
  • Pharmacological stimulation of sigma-1 receptors has neurorestorative effects in experimental parkinsonism
  • 2014
  • Ingår i: Brain. - : Oxford University Press (OUP). - 0006-8950 .- 1460-2156. ; 137, s. 1998-2014
  • Tidskriftsartikel (refereegranskat)abstract
    • Sigma-1 receptor ligands may have neuroprotective and neurorestorative properties. In a mouse model of parkinsonism, Francardo et al. show that chronic treatment with the sigma-1 receptor agonist PRE-084 increases the density of striatal dopaminergic fibres and improves forelimb use. Boosting sigma-1 receptor activity may have disease-modifying effects in ParkinsonA ' s disease.The sigma-1 receptor, an endoplasmic reticulum-associated molecular chaperone, is attracting great interest as a potential target for neuroprotective treatments. We provide the first evidence that pharmacological modulation of this protein produces functional neurorestoration in experimental parkinsonism. Mice with intrastriatal 6-hydroxydopamine lesions were treated daily with the selective sigma-1 receptor agonist, PRE-084, for 5 weeks. At the dose of 0.3 mg/kg/day, PRE-084 produced a gradual and significant improvement of spontaneous forelimb use. The behavioural recovery was paralleled by an increased density of dopaminergic fibres in the most denervated striatal regions, by a modest recovery of dopamine levels, and by an upregulation of neurotrophic factors (BDNF and GDNF) and their downstream effector pathways (extracellular signal regulated kinases 1/2 and Akt). No treatment-induced behavioural-histological restoration occurred in sigma-1 receptor knockout mice subjected to 6-hydroxydopamine lesions and treated with PRE-084. Immunoreactivity for the sigma-1 receptor protein was evident in both astrocytes and neurons in the substantia nigra and the striatum, and its intracellular distribution was modulated by PRE-084 (the treatment resulted in a wider intracellular distribution of the protein). Our results suggest that sigma-1 receptor regulates endogenous defence and plasticity mechanisms in experimental parkinsonism. Boosting the activity of this protein may have disease-modifying effects in Parkinson's disease.
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13.
  • Francardo, Veronica, et al. (författare)
  • Preclinical models of levodopa-induced dyskinesia
  • 2014
  • Ingår i: Levodopa-Induced Dyskinesia in Parkinson's Disease. - London : Springer London. - 1447165020 - 9781447165026 - 9781447165033 ; , s. 335-353
  • Bokkapitel (refereegranskat)abstract
    • L -DOPA-induced dyskinesia (LID) represents one of the major limitations in the current pharmacotherapy of Parkinson's disease (PD) and affects the majority of PD patients. Animal models are the most important preclinical tool for molecular investigations of LID mechanisms and therapeutic targets. Over the last two decades, models of LID have been developed in both nonhuman primate and rodent species, recapitulating several aspects of the human dyskinesia. This chapter will review and compare the main features of the rodent and nonprimate models of LID currently available and summarize some of the main neurobiological fi ndings obtained from these models.
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14.
  • Iderberg, Hanna, et al. (författare)
  • NLX-112, a novel 5-HT1A receptor agonist for the treatment of L-DOPA-induced dyskinesia: Behavioral and neurochemical profile in rat.
  • 2015
  • Ingår i: Experimental Neurology. - : Elsevier BV. - 0014-4886. ; 271:May 30, s. 335-350
  • Tidskriftsartikel (refereegranskat)abstract
    • L-DOPA is the gold-standard treatment for Parkinson's disease (PD), but induces troublesome dyskinesia after prolonged treatment. This is associated with the 'false neurotransmitter' conversion of L-DOPA to dopamine by serotonin neurons projecting from the raphe to the dorsal striatum. Reducing their activity by targeting pre-synaptic 5-HT1A receptors should thus be an attractive therapeutic strategy, but previous 5-HT1A agonists have yielded disappointing results. Here, we describe the activity of a novel, highly selective and potent 5-HT1A agonist, NLX-112 (also known as befiradol or F13640) in rat models relevant to PD and its associated affective disorders. NLX-112 (0.16mg/kgi.p.) potently and completely reversed haloperidol-induced catalepsy in intact rats and abolished L-DOPA-induced Abnormal Involuntary Movements (AIMs) in hemiparkinsonian rats, an effect that was reversed by the selective 5-HT1A antagonist, WAY100635. In microdialysis experiments, NLX-112 profoundly decreased striatal 5-HT extracellular levels, indicative of inhibition of serotonergic function. NLX-112 also blunted the L-DOPA-induced surge in dopamine levels on the lesioned side of the brain, an action that likely underlies its anti-dyskinetic effects. NLX-112 (0.16mg/kgi.p.) robustly induced rotations in hemiparkinsonian rats, suggesting that it has a motor facilitatory effect. Rotations were abolished by WAY100635 and were ipsilateral to the lesioned side, suggesting a predominant stimulation of the dopamine system on the non-lesioned side of the brain. NLX-112 also efficaciously reduced immobility time in the forced swim test (75% reduction at 0.16mg/kgi.p.) and eliminated stress-induced ultrasonic vocalization at 0.08mg/kgi.p., effects consistent with potential antidepressant- and anxiolytic-like properties. In other tests, NLX-112 (0.01-0.16mg/kgi.p.) did not impair the abilityof L-DOPA to rescue fore-paw akinesia in the cylinder test but decreased rotarod performance, probably due to induction of flat body posture and fore-paw treading which are typical of 5-HT1A agonists upon acute administration. However, upon repeated administration of NLX-112 (0.63mg/kgi.p., twice a day), flat body posture and fore-paw treading subsided within 4days of treatment. Taken together, these observations suggest that NLX-112 could exhibit a novel therapeutic profile, combining robust anti-dyskinetic properties without impairing the therapeutic properties of L-DOPA, and with additional beneficial effects on non-motor (affective) symptoms.
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15.
  • Lindgren, Hanna, et al. (författare)
  • L-DOPA-induced dopamine efflux in the striatum and the substantia nigra in a rat model of Parkinson's disease: temporal and quantitative relationship to the expression of dyskinesia.
  • 2010
  • Ingår i: Journal of neurochemistry. - : Wiley. - 1471-4159 .- 0022-3042. ; 112:6, s. 1465-76
  • Tidskriftsartikel (refereegranskat)abstract
    • Abstract L-DOPA-induced dyskinesia in Parkinson's Disease (PD) is associated with large increases in brain dopamine (DA) levels following drug dosing, but the precise significance of this phenomenon is not understood. Here we compare DA efflux and metabolism in the striatum and the substantia nigra (SN) in dyskinetic and non-dyskinetic animals following a standard dose of L-DOPA. Rats with 6-OHDA lesions were treated chronically with L-DOPA, monitored on the abnormal involuntary movements (AIMs) scale, and then subjected to intracerebral microdialysis under freely-moving conditions. Following s.c. L-DOPA injection, peak extracellular DA levels in both striatum and SN were twice as large in dyskinetic animals compared to non-dyskinetic rats. This effect was not attributable to differences in DOPA levels or DA metabolism. The larger DA efflux in dyskinetic animals was blunted by 5-HT1A/5-HT1B receptor agonists and TTX infusion, reflecting release from serotonin neurons. Striatal levels of serotonin and its main metabolite, 5-hydroxyindolacetic acid were indeed elevated in dyskinetic animals compared to non-dyskinetic rats, indicating a larger serotonergic innervation density in the former group. High DA release was, however, not sufficient to explain dyskinesia. The AIMs output per unit concentration of striatal extracellular DA was indeed much larger in dyskinetic animals compared to non-dyskinetic cases at most time points examined. The present results indicate that both a high DA release post L-DOPA administration and an increased responsiveness to DA must coexist for a full expression of dyskinesia.
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16.
  • Andersson, M, et al. (författare)
  • Time course of striatal DeltaFosB-like immunoreactivity and prodynorphin mRNA levels after discontinuation of chronic dopaminomimetic treatment.
  • 2003
  • Ingår i: European Journal of Neuroscience. - : Wiley. - 1460-9568 .- 0953-816X. ; 17:3, s. 661-666
  • Tidskriftsartikel (refereegranskat)abstract
    • DFosB-like proteins are particularly stable transcription factors that accumulate in the brain in response to chronic perturbations. In this study we have compared the time-course of striatal FosB/DFosB-like immunoreactivity and prodynorphin mRNA expression after discontinuation of chronic cocaine treatment to intact rats and chronic L-DOPA treatment to unilaterally 6-hydroxydopamine (6-OHDA) lesioned rats. The animals were killed between 3 h and 16 days after the last drug injection. In both treatment paradigms, the druginduced FosB/DFosB immunoreactivity remained significantly elevated in the caudate putamen even at the longest withdrawal period examined. The concomitant upregulation of prodynorphin mRNA, a target of DFosB, paralleled the time-course of DFosB-like immunoreactivity in the 6-OHDA-lesion/L-DOPA model, but was more transient in animals treated with cocaine. These results suggest that DFosB-like proteins have exceptional in vivo stability. In the dopamine-denervated striatum, these proteins may exert sustained effects on the expression of their target genes long after discontinuation of L-DOPA pharmacotherapy.
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17.
  • Angela Cenci-Nilsson, M., et al. (författare)
  • Oral and infusion levodopa therapy in the management of Parkinson’s disease
  • 2016
  • Ingår i: Parkinson's Disease : Current and Future Therapeutics and Clinical Trials - Current and Future Therapeutics and Clinical Trials. - 9781107053861 - 9781107284210 ; , s. 63-75
  • Bokkapitel (refereegranskat)abstract
    • Introduction: The clinical diagnosis of Parkinson’s disease (PD) is based on the identification of bradykinesia and at least one additional feature among rigidity, resting tremor and postural instability. These clinical features have been estimated to appear when at least 50% of the nigral dopamine neurons and 70% of putaminal dopamine tissue contents are lost [1]. Dopaminergic imaging suggests that at least 30% of the dopamine storage capacity (measured by 18 F-DOPA uptake) and 50% of putamen dopamine transporters have been lost by the onset of contralateral limb bradykinesia and rigidity [2]. In addition to the above motor symptoms, a number of nonmotor symptoms are associated with PD. These include gastrointestinal, cardiovascular, urological and psychiatric symptoms, as well as problems with vision, pain and sleep [3]. There is general agreement that the typical motor features of PD depend on putaminal dopamine depletion. Indeed, these features respond well to dopaminergic treatments, the most effective being levodopa (l-DOPA), a dopamine precursor that can cross the blood-brain barrier. Treatment with levodopa contributes significantly to improvements in the quality of life of people with PD and increases their expected life length (reviewed in [4]). Moreover, treatment with peroral levodopa is relatively well tolerated and inexpensive [5]. Many of nonmotor symptoms may also respond to levodopa treatment [3]. Because of the above reasons, levodopa is currently considered the “gold standard” for the symptomatic treatment of PD [4, 5]. However, the response to levodopa changes with disease progression, becoming complicated by motor fluctuations and dyskinesias in a majority of patients within a few years. As will be discussed below, these motor complications can become disabling, calling for a reduction in oral levodopa dosage and/or for its replacement with advanced invasive treatments. Moreover, levodopa is poorly effective against clinical features that mainly depend on the degeneration of nondopaminergic systems. These include some nonmotor symptoms as well as motor features that occur in advanced disease stages, such as freezing of gait and falls [6]. In this chapter, we will review the history of levodopa pharmacotherapy in PD, the complications of this therapy, the options currently available to optimize oral treatment with levodopa, and recent advances in developing methods for a more continuous levodopa delivery.
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18.
  • Bimpisidis, Zisis, et al. (författare)
  • Differential effects of gaseous versus injectable anesthetics on changes in regional cerebral blood flow and metabolism induced by l-DOPA in a rat model of Parkinson's disease
  • 2017
  • Ingår i: Experimental Neurology. - : Elsevier BV. - 0014-4886. ; 292, s. 113-124
  • Tidskriftsartikel (refereegranskat)abstract
    • Preclinical imaging of brain activity requires the use of anesthesia. In this study, we have compared the effects of two widely used anesthetics, inhaled isoflurane and ketamine/xylazine cocktail, on cerebral blood flow and metabolism in a rat model of Parkinson's disease and l-DOPA-induced dyskinesia. Specific tracers were used to estimate regional cerebral blood flow (rCBF - [(14)C]-iodoantipyrine) and regional cerebral metabolic rate (rCMR - [(14)C]-2-deoxyglucose) with a highly sensitive autoradiographic method. The two types of anesthetics had quite distinct effects on l-DOPA-induced changes in rCBF and rCMR. Isoflurane did not affect either the absolute rCBF values or the increases in rCBF in the basal ganglia after l-DOPA administration. On the contrary, rats anesthetized with ketamine/xylazine showed lower absolute rCBF values, and the rCBF increases induced by l-DOPA were masked. We developed a novel improved model to calculate rCMR, and found lower metabolic activities in rats anesthetized with isoflurane compared to animals anesthetized with ketamine/xylazine. Both anesthetics prevented changes in rCMR upon l-DOPA administration. Pharmacological challenges in isoflurane-anesthetized rats indicated that drugs mimicking the actions of ketamine/xylazine on adrenergic or glutamate receptors reproduced distinct effects of the injectable anesthetics on rCBF and rCMR. Our results highlight the importance of anesthesia in studies of cerebral flow and metabolism, and provide novel insights into mechanisms mediating abnormal neurovascular responses to l-DOPA in Parkinson's disease.
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19.
  • Cenci, M. Angela, et al. (författare)
  • Animal models of l-dopa-induced dyskinesia in Parkinson's disease
  • 2018
  • Ingår i: Movement Disorders. - : Wiley. - 0885-3185. ; 33:6, s. 889-899
  • Forskningsöversikt (refereegranskat)abstract
    • Understanding the biological mechanisms of l-dopa-induced motor complications is dependent on our ability to investigate these phenomena in animal models of Parkinson's disease. The most common motor complications consist in wearing-off fluctuations and abnormal involuntary movements appearing when plasma levels of l-dopa are high, commonly referred to as peak-dose l-dopa-induced dyskinesia. Parkinsonian models exhibiting these features have been well-characterized in both rodent and nonhuman primate species. The first animal models of peak-dose l-dopa-induced dyskinesia were produced in monkeys lesioned with N-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) and treated chronically with l-dopa to elicit choreic movements and dystonic postures. Seminal studies were performed in these models using both metabolic mapping and electrophysiological techniques, providing fundamental pathophysiological insights that have stood the test of time. A decade later, it was shown possible to reproduce peak-dose l-dopa-induced dyskinesia in rats and mice rendered parkinsonian with nigrostriatal 6-hydroxydopamine lesions. When treated with l-dopa, these animals exhibit abnormal involuntary movements having both hyperkinetic and dystonic components. These models have enabled molecular- and cellular-level investigations into the mechanisms of l-dopa-induced dyskinesia. A flourishing literature using genetically engineered mice is now unraveling the role of specific genes and neural circuits in the development of l-dopa-induced motor complications. Both non-human primate and rodent models of peak-dose l-dopa-induced dyskinesia have excellent construct validity and provide valuable tools for discovering therapeutic targets and evaluating potential treatments.
  •  
20.
  • Cenci, M. Angela, et al. (författare)
  • Cells, pathways, and models in dyskinesia research
  • 2024
  • Ingår i: Current Opinion in Neurobiology. - : Elsevier BV. - 0959-4388 .- 1873-6882. ; 84
  • Forskningsöversikt (refereegranskat)abstract
    • L-DOPA-induced dyskinesia (LID) is the most common form of hyperkinetic movement disorder resulting from altered information processing in the cortico-basal ganglia network. We here review recent advances clarifying the altered interplay between striatal output pathways in this movement disorder. We also review studies revealing structural and synaptic changes to the striatal microcircuitry and altered cortico-striatal activity dynamics in LID. We furthermore highlight the recent progress made in understanding the involvement of cerebellar and brain stem nuclei. These recent developments illustrate that dyskinesia research continues to provide key insights into cellular and circuit-level plasticity within the cortico-basal ganglia network and its interconnected brain regions.
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21.
  • Cenci, M. Angela, et al. (författare)
  • Dyskinesia matters
  • 2020
  • Ingår i: Movement Disorders. - : Wiley. - 0885-3185 .- 1531-8257. ; 35:3, s. 392-396
  • Tidskriftsartikel (refereegranskat)abstract
    • Levodopa-induced dyskinesia (LID) represents a significant source of discomfort for people with Parkinson's disease (PD). It negatively affects quality of life, it is associated with both motor and nonmotor fluctuations, and it brings an increased risk of disability, balance problems, and falls. Although the prevalence of severe LID appears to be lower than in previous eras (likely owing to a more conservative use of oral levodopa), we have not yet found a way to prevent the development of this complication. Advanced surgical therapies, such as deep brain stimulation, ameliorate LID, but only a minority of PD patients qualify for these interventions. Although some have argued that PD patients would rather be ON with dyskinesia than OFF, the deeper truth is that patients would very much prefer to be ON without dyskinesia. As researchers and clinicians, we should aspire to make that goal a reality. To this end, translational research on LID is to be encouraged and persistently pursued.
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22.
  • Cenci, M. Angela, et al. (författare)
  • Non-dopaminergic approaches to the treatment of motor complications in Parkinson's disease
  • 2022
  • Ingår i: Neuropharmacology. - : Elsevier BV. - 0028-3908. ; 210
  • Forskningsöversikt (refereegranskat)abstract
    • Dopamine replacement therapy with L-DOPA is the most efficacious symptomatic treatment for Parkinson's disease, but its utility is limited by a development of motor fluctuations and abnormal involuntary movements (dyskinesia) in the majority of patients. These complications are attributed to the combined effects of dopaminergic degeneration and non-physiological reinstatement of dopamine transmission by the standard oral medications. There is substantial evidence that this altered state of dopamine transmission causes pathophysiological changes to a variety of non-dopaminergic neurotransmitter systems in the brain. This evidence has prompted an interest in developing drugs that target non-dopaminergic receptors for the purpose of improving L-DOPA-induced dyskinesia and/or motor fluctuations. We here review all the most important categories of non-dopaminergic targets that have been investigated so far, but with a particular focus on modulators of glutamatergic and serotonergic transmission, which continue to inspire significant efforts towards clinical translation. In particular, we discuss both the experimental rationale and the clinical experience thus far gained from studying 5-HT1A and 5-HT1B receptor agonists, NMDA and AMPA receptor antagonists, mGluR5 negative allosteric modulators, mGluR4 positive allosteric modulators, and adenosine A2a receptor antagonists. We also review compounds with complex pharmacological properties that are already used clinically or about to enter an advanced phase of clinical development (amantadine, safinamide, zonisamide, pridopidine, mesdopetam). We conclude with an outlook on possible directions to address unmet needs and improve the chance of successful translation in this therapeutic area.
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23.
  • Cenci, M. Angela, et al. (författare)
  • On the neuronal circuitry mediating l-DOPA-induced dyskinesia
  • 2018
  • Ingår i: Journal of neural transmission. - : Springer. - 0300-9564 .- 1435-1463. ; 125:8, s. 1157-1169
  • Forskningsöversikt (refereegranskat)abstract
    • With the advent of rodent models of l-DOPA-induced dyskinesia (LID), a growing literature has linked molecular changes in the striatum to the development and expression of abnormal involuntary movements. Changes in information processing at the striatal level are assumed to impact on the activity of downstream basal ganglia nuclei, which in turn influence brain-wide networks, but very little is actually known about systems-level mechanisms of dyskinesia. As an aid to approach this topic, we here review the anatomical and physiological organisation of cortico-basal ganglia-thalamocortical circuits, and the changes affecting these circuits in animal models of parkinsonism and LID. We then review recent findings indicating that an abnormal cerebellar compensation plays a causal role in LID, and that structures outside of the classical motor circuits are implicated too. In summarizing the available data, we also propose hypotheses and identify important knowledge gaps worthy of further investigation. In addition to informing novel therapeutic approaches, the study of LID can provide new clues about the interplay between different brain circuits in the control of movement.
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24.
  • Cenci, M. Angela, et al. (författare)
  • Toxin-Based Rodent Models of Parkinson’s Disease
  • 2021
  • Ingår i: Neuromethods. - New York, NY : Springer US. - 1940-6045 .- 0893-2336. - 9781071609118 - 9781071609125 ; 160, s. 3-19
  • Bokkapitel (refereegranskat)abstract
    • A major pathological hallmark of Parkinson’s disease (PD) is a severe degeneration of dopamine (DA)-producing neurons in the substantia nigra pars compacta (SNc) projecting to the motor part of the striatum. Therefore, there is a long-standing interest in using animal models with severe nigrostriatal degeneration for experimental research. Pathophysiological and behavioral features of PD are best studied in mammalian species endowed with well-developed corticobasal ganglia thalamocortical loops, such as rodents. Different toxins can be used to generate nigrostriatal damage, including 6-hydroxydopamine (6-OHDA), 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP), paraquat, and rotenone. Models based on 6-OHDA lesions provide the main advantage of a severe and reproducible DA lesions. Models based on MPTP provide easy and versatile tools to rapidly evaluate potential neuroprotective treatments. Models based on paraquat and rotenone are appealing for their relevance to some well-known environmental risk factors of the human PD, although they yield only partial dopaminergic degeneration and entail a considerable risk of nonspecific toxicity. The main general limitation of neurotoxin-based models is that they do not replicate some characterizing features of PD pathology, such as the formation of Lewy body–like proteinaceous aggregates or the anatomical pattern of neurodegeneration, which also affects nondopaminergic brain regions.
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25.
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26.
  • Clemensson, Erik K.H., et al. (författare)
  • Tracking Rats in Operant Conditioning Chambers Using a Versatile Homemade Video Camera and DeepLabCut
  • 2020
  • Ingår i: Journal of visualized experiments : JoVE. - : MyJove Corporation. - 1940-087X. ; :160
  • Tidskriftsartikel (refereegranskat)abstract
    • Operant conditioning chambers are used to perform a wide range of behavioral tests in the field of neuroscience. The recorded data is typically based on the triggering of lever and nose-poke sensors present inside the chambers. While this provides a detailed view of when and how animals perform certain responses, it cannot be used to evaluate behaviors that do not trigger any sensors. As such, assessing how animals position themselves and move inside the chamber is rarely possible. To obtain this information, researchers generally have to record and analyze videos. Manufacturers of operant conditioning chambers can typically supply their customers with high-quality camera setups. However, these can be very costly and do not necessarily fit chambers from other manufacturers or other behavioral test setups. The current protocol describes how to build an inexpensive and versatile video camera using hobby electronics components. It further describes how to use the image analysis software package DeepLabCut to track the status of a strong light signal, as well as the position of a rat, in videos gathered from an operant conditioning chamber. The former is a great aid when selecting short segments of interest in videos that cover entire test sessions, and the latter enables analysis of parameters that cannot be obtained from the data logs produced by the operant chambers.
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27.
  • Cortés, Marisol, et al. (författare)
  • CK2 oppositely modulates L-DOPA-induced dyskinesia via striatal projection neurons expressing D1 or D2 receptors
  • 2017
  • Ingår i: The Journal of Neuroscience. - 0270-6474. ; 37:49, s. 11930-11946
  • Tidskriftsartikel (refereegranskat)abstract
    • We have previously shown that casein kinase 2 (CK2) negatively regulates dopamine D1 and adenosine A2A receptor signaling in the striatum. Ablation of CK2 in D1 receptor-positive striatal neurons caused enhanced locomotion and exploration at baseline, whereas CK2 ablation in D2 receptor-positive neurons caused increased locomotion after treatment with A2A antagonist, caffeine. Because both, D1 and A2A receptors, play major roles in the cellular responses toL-DOPA in the striatum, these findings prompted us to examine the impact of CK2 ablation on the effects ofL-DOPA treatment in the unilateral 6-OHDA lesioned mouse model of Parkinson’s disease. We report here that knock-out of CK2 in striatonigral neurons reduces the severity ofL-DOPA-induced dyskinesia (LID), a finding that correlates with lowered pERK but unchanged pPKA substrate levels in D1 medium spiny neurons as well as in cholinergic interneurons. In contrast, lack of CK2 in striatopallidal neurons enhances LID and ERK phosphorylation. Coadministration of caffeine with a low dose ofL-DOPA reduces dyskinesia in animals with striatopallidal knock-out to wild-type levels, suggesting a dependence on adenosine receptor activity. We also detect reduced Golf levels in the striatonigral but not in the striatopallidal knock-out in response toL-DOPA treatment. Our work shows, in a rodent model of PD, that treatment-induced dyskinesia and striatal ERK activation are bidirectionally modulated by ablating CK2 in D1- or D2-positive projection neurons, in male and female mice. The results reveal that CK2 regulates signaling events critical to LID in each of the two main populations of striatal neurons.
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28.
  • Dekundy, A, et al. (författare)
  • Effects of group I metabotropic glutamate receptors blockade in experimental models of Parkinson's disease
  • 2006
  • Ingår i: Brain Research Bulletin. - : Elsevier BV. - 0361-9230. ; 69:3, s. 318-326
  • Tidskriftsartikel (refereegranskat)abstract
    • The present study was devoted to investigate the effects of the metabotropic glutamate receptor(mGluR)5 antagonist [(2-methyl-1,3-thiazol-4-yl)ethynyl]pyridine (MTEP) and the mGluR1 antagonist, (3-ethyl-2-methyl-quinolin-6-yl)-(4-methoxy-cyclohexyl)-methanone methanesulfonate (EMQMCM), in animal studies indicative of antiparkinsonian-like activity such as haloperidol-induced catalepsy, hypoactivity in open field following haloperidol, and rotation in rats with unilateral 6-hydroxydopamine(OHDA)-induced lesions of the midbrain dopaminergic system (alone and in combination with L-DOPA). Moreover, antidyskinetic activity of different mGluR ligands was evaluated in the rat model of L-DOPA-induced dyskinesia. Both MTEP (5 mg/kg) and EMQMCM (4 mg/kg) slightly inhibited haloperidol (0.5 mg/kg)-induced catalepsy. However, neither substance reversed the hypoactivity produced by haloperidol (0.2 mg/kg). Although MTEP and not produce significant turning, it inhibited contralateral rotations after L-DOPA (at 5 mg/kg) and alleviated L-DOPA-induced dyskinesia (at 2.5 and 5 mg/kg) in 6-OHDA-lesioned rats. In contrast, mGluR1 antagonists EMQMCM and RS-1-aminoindan-1,5-dicarboxylic acid (AIDA) failed to modify L-DOPA-induced dyskinesia. The results of the present study suggest that either subtype of group I of mGluRs may be involved in the pathologically altered circuitry in the basal ganglia. However, the equivocal results do not strongly support the hypothesis that mGluR1 and mGluR5 antagonists may be beneficial in the symptomatic treatment of Parkinson's disease. However, mGluR5 antagonists may prove useful for the symptomatic treatment Of L-DOPA-induced dyskinesia. (c) 2006 Elsevier Inc. All rights reserved.
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29.
  • Espa, Elena, et al. (författare)
  • Dopamine Agonist Cotreatment Alters Neuroplasticity and Pharmacology of Levodopa-Induced Dyskinesia
  • 2023
  • Ingår i: Movement Disorders. - : Wiley. - 0885-3185 .- 1531-8257. ; 38:3, s. 410-422
  • Tidskriftsartikel (refereegranskat)abstract
    • BACKGROUND: Current models of levodopa (L-dopa)-induced dyskinesia (LID) are obtained by treating dopamine-depleted animals with L-dopa. However, patients with LID receive combination therapies that often include dopamine agonists.OBJECTIVE: Using 6-hydroxydopamine-lesioned rats as a model, we aimed to establish whether an adjunct treatment with the D2/3 agonist ropinirole impacts on patterns of LID-related neuroplasticity and drug responses.METHODS: Different regimens of L-dopa monotreatment and L-dopa-ropinirole cotreatment were compared using measures of hypokinesia and dyskinesia. Striatal expression of ∆FosB and angiogenesis markers were studied immunohistochemically. Antidyskinetic effects of different drug categories were investigated in parallel groups of rats receiving either L-dopa monotreatment or L-dopa combined with ropinirole.RESULTS: We defined chronic regimens of L-dopa monotreatment and L-dopa-ropinirole cotreatment inducing overall similar abnormal involuntary movement scores. Compared with the monotreatment group, animals receiving the L-dopa-ropinirole combination exhibited an overall lower striatal expression of ∆FosB with a distinctive compartmental distribution. The expression of angiogenesis markers and blood-brain barrier hyperpermeability was markedly reduced after L-dopa-ropinirole cotreatment compared with L-dopa monotreatment. Moreover, significant group differences were detected upon examining the response to candidate antidyskinetic drugs. In particular, compounds modulating D1 receptor signaling had a stronger effect in the L-dopa-only group, whereas both amantadine and the selective NMDA antagonist MK801 produced a markedly larger antidyskinetic effect in L-dopa-ropinirole cotreated animals.CONCLUSIONS: Cotreatment with ropinirole altered LID-related neuroplasticity and pharmacological response profiles. The impact of adjuvant dopamine agonist treatment should be taken into consideration when investigating LID mechanisms and candidate interventions in both clinical and experimental settings. © 2023 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.
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30.
  • Espa, Elena, et al. (författare)
  • Seeding of protein aggregation causes cognitive impairment in rat model of cortical synucleinopathy
  • 2019
  • Ingår i: Movement Disorders. - : Wiley. - 0885-3185 .- 1531-8257. ; 34:11, s. 1699-1710
  • Tidskriftsartikel (refereegranskat)abstract
    • Background: Cortical α-synuclein pathology plays a role in the development of cognitive dysfunction in both Parkinson's disease and dementia with Lewy bodies, although the causative cellular lesions have remained unclear. We aimed to address causal links between α-synuclein-driven pathology in the cerebral cortex and the development of cognitive impairments using new experimental models. Methods: Neuronal overexpression of human α-synuclein was induced in the rat medial prefrontal cortex using viral vectors. This was combined with inoculations of preformed fibrils of human α-synuclein in some animals. Rats were evaluated with tests probing prefrontal cognitive functions (delayed matching/nonmatching to position and 5-choice serial reaction time task). Patterns of neuropathology were characterized immunohistochemically. Results: Neither α-synuclein overexpression nor the fibril seeds alone yielded any behavioral phenotype. In contrast, combining the 2 approaches produced significant impairments in working memory, attention, and inhibitory control. All animals injected with α-synuclein vectors exhibited high immunoreactivity for human α-synuclein in the medial prefrontal cortex and its primary projection targets. However, only when this overexpression was combined with fibril inoculations did animals exhibit large, proteinase K-resistant and Ser129-phosphorylated α-synuclein intraneuronal inclusions in the medial prefrontal cortex and its closely interconnected brain regions. The inclusions were associated with distorted dendritic morphologies and partial neuronal loss in the targeted cortical areas. Conclusions: Cortical overexpression of human α-synuclein is not sufficient to produce cognitive dysfunction, whereas combining this overexpression with fibril seeds yields both cognitive and histopathological phenotypes that are relevant to human Lewy body disease.
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31.
  • Fieblinger, Tim, et al. (författare)
  • Cell type-specific plasticity of striatal projection neurons in parkinsonism and L-DOPA-induced dyskinesia.
  • 2014
  • Ingår i: Nature Communications. - : Springer Science and Business Media LLC. - 2041-1723. ; 5
  • Tidskriftsartikel (refereegranskat)abstract
    • The striatum is widely viewed as the fulcrum of pathophysiology in Parkinson's disease (PD) and L-DOPA-induced dyskinesia (LID). In these disease states, the balance in activity of striatal direct pathway spiny projection neurons (dSPNs) and indirect pathway spiny projection neurons (iSPNs) is disrupted, leading to aberrant action selection. However, it is unclear whether countervailing mechanisms are engaged in these states. Here we report that iSPN intrinsic excitability and excitatory corticostriatal synaptic connectivity were lower in PD models than normal; L-DOPA treatment restored these properties. Conversely, dSPN intrinsic excitability was elevated in tissue from PD models and suppressed in LID models. Although the synaptic connectivity of dSPNs did not change in PD models, it fell with L-DOPA treatment. In neither case, however, was the strength of corticostriatal connections globally scaled. Thus, SPNs manifested homeostatic adaptations in intrinsic excitability and in the number but not strength of excitatory corticostriatal synapses.
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32.
  • Fieblinger, Tim, et al. (författare)
  • Non‐Apoptotic Caspase‐3 Activation Mediates Early Synaptic Dysfunction of Indirect Pathway Neurons in the Parkinsonian Striatum
  • 2022
  • Ingår i: International Journal of Molecular Sciences. - : MDPI AG. - 1661-6596 .- 1422-0067. ; 23:10
  • Tidskriftsartikel (refereegranskat)abstract
    • Non‐apoptotic caspase‐3 activation is critically involved in dendritic spine loss and synaptic dysfunction in Alzheimer’s disease. It is, however, not known whether caspase‐3 plays similar roles in other pathologies. Using a mouse model of clinically manifest Parkinson’s disease, we provide the first evidence that caspase‐3 is transiently activated in the striatum shortly after the degeneration of nigrostriatal dopaminergic projections. This caspase‐3 activation concurs with a rapid loss of dendritic spines and deficits in synaptic long‐term depression (LTD) in striatal projection neurons forming the indirect pathway. Interestingly, systemic treatment with a caspase inhibitor prevents both the spine pruning and the deficit of indirect pathway LTD without interfering with the ongoing dopaminergic degeneration. Taken together, our data identify transient and non‐apoptotic caspase activation as a critical event in the early plastic changes of indirect pathway neurons following dopamine denervation.
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33.
  • Francardo, Veronica, et al. (författare)
  • Investigating the molecular mechanisms of L-DOPA-induced dyskinesia in the mouse
  • 2014
  • Ingår i: Parkinsonism and Related Disorders. - 1353-8020. ; 20:SUPPL.1, s. 20-22
  • Tidskriftsartikel (refereegranskat)abstract
    • L-DOPA-induced dyskinesia (LID) is a major complication of the pharmacotherapy of Parkinson's disease (PD). Animal models of LID are essential for investigating pathogenic pathways and therapeutic targets. While non-human primates have been the preferred species for pathophysiological studies, mouse models of LID have been recently produced and characterized to facilitate molecular investigations. Most of these studies have used mice with unilateral 6-hydroxydopamine (6-OHDA) lesions of the nigrostriatal projection sustaining treatment with L-DOPA for 1-4 weeks. Mice with complete medial forebrain bundle lesions have been found to develop dyskinetic movements of maximal severity associated with a pronounced post-synaptic supersensitivity of D1-receptor dependent signaling pathways throughout the striatum. In contrast, mice with striatal 6-OHDA lesions have been found to exhibit a variable susceptibility to LID and a regionally restricted post-synaptic supersensitivity. Genetic mouse models of PD have just started to be used for studies of LID, providing an opportunity to dissect the impact of genetic factors on the maladaptive neuroplasticity that drives the development of treatment-induced involuntary movements in PD.
  •  
34.
  • Francardo, Veronica, et al. (författare)
  • Neuroprotection and neurorestoration as experimental therapeutics for Parkinson's disease
  • 2017
  • Ingår i: Experimental Neurology. - : Elsevier BV. - 0014-4886. ; 298:Pt. B, s. 137-147
  • Tidskriftsartikel (refereegranskat)abstract
    • Disease-modifying treatments remain an unmet medical need in Parkinson's disease (PD). Such treatments can be operationally defined as interventions that slow down the clinical evolution to advanced disease milestones. A treatment may achieve this outcome by either inhibiting primary neurodegenerative events ("neuroprotection") or boosting compensatory and regenerative mechanisms in the brain ("neurorestoration"). Here we review experimental paradigms that are currently used to assess the neuroprotective and neurorestorative potential of candidate treatments in animal models of PD. We review some key molecular mediators of neuroprotection and neurorestoration in the nigrostriatal dopamine pathway that are likely to exert beneficial effects on multiple neural systems affected in PD. We further review past and current strategies to therapeutically stimulate these mediators, and discuss the preclinical evidence that exercise training can have neuroprotective and neurorestorative effects. A future translational task will be to combine behavioral and pharmacological interventions to exploit endogenous mechanisms of neuroprotection and neurorestoration for therapeutic purposes. This type of approach is likely to provide benefit to many PD patients, despite the clinical, etiological, and genetic heterogeneity of the disease.
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35.
  • Francardo, Veronica, et al. (författare)
  • Pridopidine Induces Functional Neurorestoration Via the Sigma-1 Receptor in a Mouse Model of Parkinson’s Disease
  • 2019
  • Ingår i: Neurotherapeutics. - : Springer Science and Business Media LLC. - 1933-7213 .- 1878-7479. ; 16:2, s. 465-479
  • Tidskriftsartikel (refereegranskat)abstract
    • Pridopidine is a small molecule in clinical development for the treatment of Huntington’s disease. It was recently found to have high binding affinity to the sigma-1 receptor, a chaperone protein involved in cellular defense mechanisms and neuroplasticity. Here, we have evaluated the neuroprotective and neurorestorative effects of pridopidine in a unilateral 6-hydroxydopamine (6-OHDA) lesion model of parkinsonism in mice. By 5 weeks of daily administration, a low dose of pridopidine (0.3 mg/kg) had significantly improved deficits in forelimb use (cylinder test, stepping test) and abolished the ipsilateral rotational bias typical of hemiparkinsonian animals. A higher dose of pridopidine (1 mg/kg) significantly improved only the rotational bias, with a trend towards improvement in forelimb use. The behavioral recovery induced by pridopidine 0.3 mg/kg was accompanied by a significant protection of nigral dopamine cell bodies, an increased dopaminergic fiber density in the striatum, and striatal upregulation of GDNF, BDNF, and phosphorylated ERK1/2. The beneficial effects of pridopidine 0.3 mg/kg were absent in 6-OHDA-lesioned mice lacking the sigma-1 receptor. Pharmacokinetic data confirmed that the effective dose of pridopidine reached brain concentrations sufficient to bind S1R. Our results are the first to show that pridopidine promotes functional neurorestoration in the damaged nigrostriatal system acting via the sigma-1 receptor.
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36.
  • Grigoriou, Sotirios, et al. (författare)
  • Comparison of dyskinesia profiles after L-DOPA dose challenges with or without dopamine agonist coadministration
  • 2023
  • Ingår i: Neuropharmacology. - 0028-3908. ; 237
  • Tidskriftsartikel (refereegranskat)abstract
    • Many patients with Parkinson's disease (PD) experiencing L-DOPA-induced dyskinesia (LID) receive adjunct treatment with dopamine agonists, whose functional impact on LID is unknown. We set out to compare temporal and topographic profiles of abnormal involuntary movements (AIMs) after L-DOPA dose challenges including or not the dopamine agonist ropinirole. Twenty-five patients with PD and a history of dyskinesias were sequentially administered either L-DOPA alone (150% of usual morning dose) or an equipotent combination of L-DOPA and ropinirole in random order. Involuntary movements were assessed by two blinded raters prior and every 30 min after drug dosing using the Clinical Dyskinesia Rating Scale (CDRS). A sensor-recording smartphone was secured to the patients' abdomen during the test sessions. The two raters’ CDRS scores were highly reliable and concordant with models of hyperkinesia presence and severity trained on accelerometer data. The dyskinesia time curves differed between treatments as the L-DOPA-ropinirole combination resulted in lower peak severity but longer duration of the AIMs compared with L-DOPA alone. At the peak of the AIMs curve (60–120 min), L-DOPA induced a significantly higher total hyperkinesia score, whereas in the end phase (240–270 min), both hyperkinesia and dystonia tended to be more severe after the L-DOPA-ropinirole combination (though reaching statistical significance only for the item, arm dystonia). Our results pave the way for the introduction of a combined L-DOPA-ropinirole challenge test in the early clinical evaluation of antidyskinetic treatments. Furthermore, we propose a machine-learning method to predict CDRS hyperkinesia severity using accelerometer data.
  •  
37.
  • Hauser, RA, et al. (författare)
  • Reply to: Letter to Editor by Chaudhuri, Jenner, Antonini
  • 2020
  • Ingår i: Movement disorders : official journal of the Movement Disorder Society. - : Wiley. - 1531-8257 .- 0885-3185. ; 35:5, s. 901-
  • Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)
  •  
38.
  • Iderberg, Hanna, et al. (författare)
  • Activity of serotonin 5-HT1A receptor 'biased agonists' in rat models of Parkinson's disease and l-DOPA-induced dyskinesia.
  • 2015
  • Ingår i: Neuropharmacology. - : Elsevier BV. - 1873-7064 .- 0028-3908. ; 93, s. 52-67
  • Tidskriftsartikel (refereegranskat)abstract
    • Serotonin 5-HT1A receptor agonists reduce l-DOPA-induced dyskinesia (LID) in animal models of Parkinson's disease (PD). Here, we compared the effects of novel 5-HT1A receptor 'biased agonists' on LID in hemiparkinsonian rats. F13714 preferentially activates pre-synaptic 5-HT1A autoreceptors. F15599 preferentially activates cortical postsynaptic 5-HT1A heteroreceptors. The partial agonist, tandospirone, does not differentiate these receptor subpopulations. The drugs were also tested on rotational behavior, rotarod and cylinder test for evaluation of locomotor activity, motor coordination and forelimb akinesia. Finally, the effects of F13714 and F15599 on 5-HT, DA, glutamate, and GABA release were investigated by microdialysis. F13714 abolished l-DOPA-induced AIMs even at very low doses (0.02-0.04 mg/kg). This effect was reversed by the selective 5-HT1A receptor antagonist, WAY100635. F13714 also elicited ipsilateral rotations (which were blocked by WAY100635) and potentiated the rotational activity of a sub-threshold dose of l-DOPA (2 mg/kg). F13714 profoundly inhibited striatal 5-HT release on both sides of the brain, and slightly increased DA release on the intact side. F15599 inhibited the l-DOPA-induced AIMs only at a dose (0.16 mg/kg) that reduced 5-HT release. Tandospirone produced a modest attenuation of peak AIMs severity and did not elicit rotations. F13714, F15599 and tandospirone did not modify the action of l-DOPA in the cylinder test but impaired rotarod performance at the highest doses tested. Targeting 5-HT1A receptors with selective biased agonists exerts distinct effects in the rat model of PD and LID. Preferential activation of 5-HT1A autoreceptors could potentially translate to superior antidyskinetic and l-DOPA dose-sparing effects in PD patients.
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39.
  • Iderberg, Hanna, et al. (författare)
  • Pharmacological stimulation of metabotropic glutamate receptor type 4 in a rat model of Parkinson's disease and l-DOPA-induced dyskinesia: Comparison between a positive allosteric modulator and an orthosteric agonist.
  • 2015
  • Ingår i: Neuropharmacology. - : Elsevier BV. - 1873-7064 .- 0028-3908. ; 95, s. 121-129
  • Tidskriftsartikel (refereegranskat)abstract
    • Metabotropic glutamate receptor 4 (mGlu4) negatively modulates GABA and glutamate release in the 'indirect pathway' of the basal ganglia, and has thus been proposed as a potential target to treat motor symptoms in Parkinson's disease. Here, we present an extensive comparison of the behavioural effects produced by the mGlu4 positive allosteric modulator (PAM), VU0364770, and the mGlu4 orthosteric agonist, LSP1-2111, in rats with unilateral 6-OHDA lesions. The compounds' activity was initially assessed in a test of haloperidol-induced catalepsy in intact rats, and effective doses were then evaluated in the hemiparkinsonian animal model. Neither of the two compounds modified the development of dyskinetic behaviours elicited by chronic treatment with full doses of l-DOPA. When given together with l-DOPA to rats with already established dyskinesias, neither VU0364770 nor LSP1-2111 modified the abnormal involuntary movement scores. VU0364770 potentiated, however, the motor stimulant effect of a subthreshold l-DOPA dose in certain behavioural tests, whereas LSP1-2111 lacked this ability. Taken together, these results indicate that a pharmacological stimulation of mGlu4 lacks intrinsic antidyskinetic activity, but may have DOPA-sparing activity in Parkinson's disease. For the latter indication, mGlu4 PAMs appear to provide a better option than orthosteric agonists.
  •  
40.
  • Lee, Chong S., et al. (författare)
  • Embryonic ventral mesencephalic grafts improve levodopa-induced dyskinesia in a rat model of Parkinson's disease
  • 2000
  • Ingår i: Brain. - 0006-8950. ; 123:7, s. 1365-1379
  • Tidskriftsartikel (refereegranskat)abstract
    • We investigated the role of dopamine neurons in the manifestation of levodopa-induced dyskinesia in a rat model of Parkinson's disease. Daily treatment with a subthreshold dose of levodopa gradually induced abnormal involuntary movements (AIM) in 6-hydroxydopamine-lesioned rats, which included stereotypy and contraversive rotation. After 4 weeks of levodopa treatment, rats with mild and severe AIM were assigned to two treatment subgroups. The graft subgroup received embryonic ventral mesencephalic tissue into the striatum, whilst the sham-graft subgroup received vehicle only. Rats continued to receive levodopa treatment for 3 months post-graft. Brain sections at the level of the basal ganglia were processed for autoradiography using a ligand for dopamine transporter, and in situ hybridization histochemistry for mRNAs encoding postsynaptic markers. Levodopa-induced AIM significantly improved in grafted rats. The severity of AIM correlated inversely with the density of dopamine nerve terminals in the striatum (P < 0.001), with almost no AIM when the density of dopamine nerve terminals was > 10-20% of normal. Embryonic dopamine neuronal grafts normalized not only mRNA expression for preproenkephalin (PPE) in the indirect pathway, but also mRNA expression for prodynorphin (PDyn) in the direct pathway, which was upregulated by levodopa treatment. AIM scores correlated linearly with expression of PPE mRNA in the indirect pathway (P < 0.001) and also with PDyn mRNA in the direct pathway (P < 0.001). We conclude that embryonic dopamine neuronal grafts may improve levodopa-induced dyskinesia by restoring altered activities of postsynaptic neurons, resulting not only from dopamine denervation, but also from levodopa therapy, provided that the density of striatal dopaminergic nerve terminals is restored above a 'threshold' level.
  •  
41.
  • Lerner, Renata P., et al. (författare)
  • Levodopa-induced abnormal involuntary movements correlate with altered permeability of the blood-brain-barrier in the basal ganglia
  • 2017
  • Ingår i: Scientific Reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 7:1
  • Tidskriftsartikel (refereegranskat)abstract
    • Chronic levodopa treatment leads to the appearance of dyskinesia in the majority of Parkinson's disease patients. Neurovascular dysregulation in putaminal and pallidal regions is thought to be an underlying feature of this complication of treatment. We used microPET to study unilaterally lesioned 6-hydroxydopamine rats that developed levodopa-induced abnormal involuntary movements (AIMs) after three weeks of drug treatment. Animals were scanned with [15O]-labeled water and [18F]-fluorodeoxyglucose, to map regional cerebral blood flow and glucose metabolism, and with [11C]-isoaminobutyric acid (AIB), to assess blood-brain-barrier (BBB) permeability, following separate injections of levodopa or saline. Multitracer scan data were acquired in each animal before initiating levodopa treatment, and again following the period of daily drug administration. Significant dissociation of vasomotor and metabolic levodopa responses was seen in the striatum/globus pallidus (GP) of the lesioned hemisphere. These changes were accompanied by nearby increases in [11C]-AIB uptake in the ipsilateral GP, which correlated with AIMs scores. Histopathological analysis revealed high levels of microvascular nestin immunoreactivity in the same region. The findings demonstrate that regional flow-metabolism dissociation and increased BBB permeability are simultaneously induced by levodopa within areas of active microvascular remodeling, and that such changes correlate with the severity of dyskinesia.
  •  
42.
  • Li, Chang, et al. (författare)
  • Structural-functional properties of direct-pathway striatal neurons at early and chronic stages of dopamine denervation
  • 2024
  • Ingår i: European Journal of Neuroscience. - 0953-816X. ; 59:6, s. 1227-1241
  • Tidskriftsartikel (refereegranskat)abstract
    • The dendritic arbour of striatal projection neurons (SPNs) is the primary anatomical site where dopamine and glutamate inputs to the basal ganglia functionally interact to control movement. These dendritic arbourisations undergo atrophic changes in Parkinson's disease. A reduction in the dendritic complexity of SPNs is found also in animal models with severe striatal dopamine denervation. Using 6-hydroxydopamine (6-OHDA) lesions of the medial forebrain bundle as a model, we set out to compare morphological and electrophysiological properties of SPNs at an early versus a chronic stage of dopaminergic degeneration. Ex vivo recordings were performed in transgenic mice where SPNs forming the direct pathway (dSPNs) express a fluorescent reporter protein. At both the time points studied (5 and 28 days following 6-OHDA lesion), there was a complete loss of dopaminergic fibres through the dorsolateral striatum. A reduction in dSPN dendritic complexity and spine density was manifest at 28, but not 5 days post-lesion. At the late time point, dSPN also exhibited a marked increase in intrinsic excitability (reduced rheobase current, increased input resistance, more evoked action potentials in response to depolarising currents), which was not present at 5 days. The increase in neuronal excitability was accompanied by a marked reduction in inward-rectifying potassium (Kir) currents (which dampen the SPN response to depolarising stimuli). Our results show that dSPNs undergo delayed coordinate changes in dendritic morphology, intrinsic excitability and Kir conductance following dopamine denervation. These changes are predicted to interfere with the dSPN capacity to produce a normal movement-related output.
  •  
43.
  • Lindgren, Hanna, et al. (författare)
  • Putaminal Upregulation of FosB/Delta FosB-Like Immunoreactivity in Parkinson's Disease Patients with Dyskinesia
  • 2011
  • Ingår i: Journal of Parkinson's Disease. - 1877-718X. ; 1:4, s. 347-357
  • Tidskriftsartikel (refereegranskat)abstract
    • The transcription factor Delta FosB is a mediator of maladaptive neuroplasticity in animal models of Parkinson's disease (PD) and L-DOPA-induced dyskinesia. Using an antibody that recognizes all known isoforms of FosB and Delta FosB, we have examined the expression of these proteins in post-mortem basal ganglia sections from PD patients. The patient cases were classified as being dyskinetic or non-dyskinetic based on their clinical records. Sections from neurologically healthy controls were also included in the study. Compared to both controls and non-dyskinetic cases, the dyskinetic group showed a higher density of FosB/Delta FosB-immunopositive cells in the posterior putamen, which represents the motor region of the striatum in primates. In contrast, the number of FosB/Delta FosB-positive cells did not differ significantly among the groups in the caudate, a region primarily involved with the processing of cognitive and limbic-related information. Only sparse FosB/Delta FosB immunoreactivity was found in the in the pallidum externum and internum, and no significant group differences were detected in these nuclei. The putaminal elevation of FosB/Delta FosB-like immunoreactivity in patients who had been affected by L-DOPA-induced dyskinesia is consistent with results from both rat and non-human primate models of this movement disorder. The present findings support the hypothesis of an involvement of Delta FosB-related transcription factors in the molecular mechanisms of L-DOPA-induced dyskinesia.
  •  
44.
  • Lindgren, Hanna S., et al. (författare)
  • Dyskinesia - Advances in the understanding of pathophysiology and possible treatment options
  • 2010
  • Ingår i: European Neurological Review. - 1758-3837. ; 5:2, s. 34-40
  • Tidskriftsartikel (refereegranskat)abstract
    • The degeneration of nigrostriatal dopaminergic neurons in Parkinson's disease gives rise to tremor and slowness of movement, cardinal motor symptoms of the disease that can be alleviated by the dopamine precursor L-DOPA. Despite this, long-term L-DOPA treatment is hampered by the development of abnormal involuntary movements, i.e. dyskinesia, in the majority of patients. The pathophysiology of dyskinesia is complex and multifactorial, but excessive swings in extracellular dopamine causing aberrant plasticity in dopaminoceptive neurons are attributed a primary role. To date there are few effective treatment alternatives for patients with Parkinson's disease experiencing dyskinesia, representing an unmet therapeutic need in the treatment strategy of the disease. This article reviews recent findings from both clinical and pre-clinical studies and their impact on the search for novel therapeutic approaches to levodopa-induced dyskinesia.
  •  
45.
  • Moenne-Loccoz, Cristobal, et al. (författare)
  • Cortico-Striatal Oscillations Are Correlated to Motor Activity Levels in Both Physiological and Parkinsonian Conditions
  • 2020
  • Ingår i: Frontiers in Systems Neuroscience. - : Frontiers Media S.A.. - 1662-5137. ; 14
  • Tidskriftsartikel (refereegranskat)abstract
    • Oscillatory neural activity in the cortico-basal ganglia-thalamocortical (CBGTC) loop is associated with the motor state of a subject, but also with the availability of modulatory neurotransmitters. For example, increased low-frequency oscillations in Parkinson's disease (PD) are related to decreased levels of dopamine and have been proposed as biomarkers to adapt and optimize therapeutic interventions, such as deep brain stimulation. Using neural oscillations as biomarkers require differentiating between changes in oscillatory patterns associated with parkinsonism vs. those related to a subject's motor state. To address this point, we studied the correlation between neural oscillatory activity in the motor cortex and striatum and varying degrees of motor activity under normal and parkinsonian conditions. Using rats with bilateral or unilateral 6-hydroxydopamine lesions as PD models, we correlated the motion index (MI)-a measure based on the physical acceleration of the head of rats-to the local field potential (LFP) oscillatory power in the 1-80 Hz range. In motor cortices and striata, we observed a robust correlation between the motion index and the oscillatory power in two main broad frequency ranges: a low-frequency range [5.0-26.5 Hz] was negatively correlated to motor activity, whereas a high-frequency range [35.0-79.9 Hz] was positively correlated. We observed these correlations in both normal and parkinsonian conditions. In addition to these general changes in broad-band power, we observed a more restricted narrow-band oscillation [25-40 Hz] in dopamine-denervated hemispheres. This oscillation, which seems to be selective to the parkinsonian state, showed a linear frequency dependence on the concurrent motor activity level. We conclude that, independently of the parkinsonian condition, changes in broad-band oscillatory activities of cortico-basal ganglia networks (including changes in the relative power of low- and high-frequency bands) are closely correlated to ongoing motions, most likely reflecting he operations of these neural circuits to control motor activity. Hence, biomarkers based on neural oscillations should focus on specific features, such as narrow frequency bands, to allow differentiation between parkinsonian states and physiological movement-dependent circuit modulation.
  •  
46.
  • Outeiro, Tiago F., et al. (författare)
  • From iPS Cells to Rodents and Nonhuman Primates : Filling Gaps in Modeling Parkinson's Disease
  • 2021
  • Ingår i: Movement Disorders. - : Wiley. - 0885-3185 .- 1531-8257. ; 36:4, s. 832-841
  • Tidskriftsartikel (refereegranskat)abstract
    • Parkinson's disease (PD) is primarily known as a movement disorder because of typical clinical manifestations associated with the loss of dopaminergic neurons in the substantia nigra. However, it is now widely recognized that PD is a much more complex condition, with multiple and severe nonmotor features implicating additional brain areas and organs in the disease process. Pathologically, typical forms of PD are characterized by the accumulation of α-synuclein-rich protein inclusions known as Lewy bodies and Lewy neurites, although other types of protein inclusions are also often present in the brain. Familial forms of PD have provided a wealth of information about molecular pathways leading to neurodegeneration, but only to add to the complexity of the problem and uncover new knowledge gaps. Therefore, modeling PD in the laboratory has become increasingly challenging. Here, we discuss knowledge gaps and challenges in the use of laboratory models for the study of a disease that is clinically heterogeneous and multifactorial. We propose that the combined use of patient-derived cells and animal models, along with current technological tools, will not only expand our molecular and pathophysiological understanding of PD, but also assist in the identification of therapeutic strategies targeting relevant pathogenic pathways.
  •  
47.
  • Petersson, Per, et al. (författare)
  • Significance and Translational Value of High-Frequency Cortico-Basal Ganglia Oscillations in Parkinson's Disease
  • 2019
  • Ingår i: Journal of Parkinson's Disease. - : IOS Press. - 1877-7171 .- 1877-718X. ; 9:1, s. 183-196
  • Tidskriftsartikel (refereegranskat)abstract
    • The mechanisms and significance of basal ganglia oscillations is a fundamental research question engaging both clinical and basic investigators. In Parkinson's disease (PD), neural activity in basal ganglia nuclei is characterized by oscillatory patterns that are believed to disrupt the dynamic processing of movement-related information and thus generate motor symptoms. Beta-band oscillations associated with hypokinetic states have been reviewed in several excellent previous articles. Here we focus on faster oscillatory phenomena that have been reported in association with a diverse range of motor states. We review the occurrence of different types of fast oscillations and the evidence supporting their pathophysiological role. We also provide a general discussion on the definition, possible mechanisms, and translational value of synchronized oscillations of different frequencies in cortico-basal ganglia structures. Revealing how oscillatory phenomena are caused and spread in cortico-basal ganglia-thalamocortical networks will offer a key to unlock the neural codes of both motor and non-motor symptoms in PD. In preclinical therapeutic research, recording of oscillatory neural activities holds the promise to unravel mechanisms of action of current and future treatments.
  •  
48.
  • Picconi, B, et al. (författare)
  • Abnormal Ca2+-calmodulin-dependent protein kinase II function mediates synaptic and motor deficits in experimental parkinsonism
  • 2004
  • Ingår i: The Journal of Neuroscience. - 1529-2401. ; 24:23, s. 5283-5291
  • Tidskriftsartikel (refereegranskat)abstract
    • The NMDA receptor complex represents a key molecular element in the pathogenesis of long-term synaptic changes and motor abnormalities in Parkinson's disease (PD). Here we show that NMDA receptor 1 (NR1) subunit and postsynaptic density (PSD)-95 protein levels are selectively reduced in the PSD of dopamine (DA)-denervated striata. These effects are accompanied by an increase in striatal levels of alphaCa(2+)-calmodulin-dependent protein kinase II (alphaCaMKII) autophosphorylation, along with a higher recruitment of activated alphaCaMKII to the regulatory NMDA receptor NR2A-NR2B subunits. Acute treatment of striatal slices with R(+)-7-chloro-8-hydroxy-3-methyl-1-phenyl-2,3,4,5-tetrahydro-1H-3-benzaz epine hydrochloride, but not with L-sulpiride, mimicked the effect of DA denervation on both alphaCaMKII autophosphorylation and corticostriatal synaptic plasticity. In addition to normalizing alphaCaMKII autophosphorylation levels as well as assembly and anchoring of the kinase to the NMDA receptor complex, intrastriatal administration of the CaMKII inhibitors KN-93 (N-[2-[[[3-(4-chlorophenyl)-2-propenyl] methylamino] methyl] phenyl]-N-(2-hydroxyethyl)-4-methoxybenzenesulfonamide) and antennapedia autocamtide-related inhibitory peptide II is able to reverse both the alterations in corticostriatal synaptic plasticity and the deficits in spontaneous motor behavior that are found in an animal model of PD. The same beneficial effects are produced by a regimen of L-3,4-dihydroxyphenylalanine(L-DOPA) treatment, which is able to normalize alphaCaMKII autophosphorylation. These data indicate that abnormal alphaCaMKII autophosphorylation plays a causal role in the alterations of striatal plasticity and motor behavior that follow DA denervation. Normalization of CaMKII activity may be an important underlying mechanism of the therapeutic action of L-DOPA in PD.
  •  
49.
  • Refolo, Violetta, et al. (författare)
  • Progressive striatonigral degeneration in a transgenic mouse model of multiple system atrophy : translational implications for interventional therapies
  • 2018
  • Ingår i: Acta Neuropathologica Communications. - : Springer Science and Business Media LLC. - 2051-5960. ; 6:1, s. 1-24
  • Tidskriftsartikel (refereegranskat)abstract
    • Multiple system atrophy (MSA) is a rapidly progressive neurodegenerative disorder characterized by widespread oligodendroglial cytoplasmic inclusions of filamentous α-synuclein, and neuronal loss in autonomic centres, basal ganglia and cerebellar circuits. It has been suggested that primary oligodendroglial α-synucleinopathy may represent a trigger in the pathogenesis of MSA, but the mechanisms underlying selective vulnerability and disease progression are unclear. The post-mortem analysis of MSA brains provides a static final picture of the disease neuropathology, but gives no clear indication on the sequence of pathogenic events in MSA. Therefore, alternative methods are needed to address these issues. We investigated selective vulnerability and disease progression in the transgenic PLP-α-syn mouse model of MSA characterized by targeted oligodendroglial α-synuclein overexpression aiming to provide a neuropathological correlate of motor deterioration. We show progressive motor deficits that emerge at 6 months of age and deteriorate up to 18 months of follow-up. The motor phenotype was associated with dopaminergic cell loss in the substantia nigra pars compacta at 6 months, followed by loss of striatal dopaminergic terminals and DARPP32-positive medium sized projection neurons at 12 months. Olivopontocerebellar motor loops remained spared in the PLP-α-syn model of MSA. These findings replicate progressive striatonigral degeneration underlying Parkinson-variant MSA. The initiation of the degenerative process was linked to an increase of soluble oligomeric α-synuclein species between 2 and 6 months. Early region-specific α-synuclein-associated activation profile of microglia was found in MSA substantia nigra. The role of abnormal neuroinflammatory signalling in disease progression was further supported by increased levels of CD68, CCL3, CCL5 and M-CSF with a peak in aged PLP-α-syn mice. In summary, transgenic PLP-α-syn mice show a distinctive oligodendroglial α-synucleinopathy that is associated with progressive striatonigral degeneration linked to abnormal neuroinflammatory response. The model provides a relevant tool for preclinical therapeutic target discovery for human Parkinson-variant MSA.
  •  
50.
  • Schuster, Stefan, et al. (författare)
  • Antagonizing L-type Ca2+ Channel Reduces Development of Abnormal Involuntary Movement in the Rat Model of L-3,4-Dihydroxyphenylalanine-Induced Dyskinesia
  • 2009
  • Ingår i: Biological Psychiatry. - : Elsevier BV. - 0006-3223. ; 65:6, s. 518-526
  • Tidskriftsartikel (refereegranskat)abstract
    • Background: Chronic L-3,4-dihydroxyphenylalanine (L-DOPA) treatment of Parkinson's disease (PD) leads to debilitating involuntary movements, termed L-DOPA-induced dyskinesia. Striatofugal medium spiny neurons (MSN) lose their dendritic spines and cortico-striatal glutamatergic synapses in PD and in experimental models of DA depletion. This loss of connectivity is triggered by a dysregulation of intraspine Cav1.3 L-type Ca2+ channels. Here we address the possible implication of DA denervation-induced spine pruning in the development of L-DOPA-induced dyskinesia. Methods: The L-type Ca2+ antagonist, isradipine was subcutaneously delivered to rats at the doses of .05, .1, or .2 mg/kg/day, for 4 weeks, starting the day after a unilateral nigrostriatal 6-hydroxydopamine (6-OHDA) lesion. Fourteen days later, L-DOPA treatment was initiated. Results: Isradipine-treated animals displayed a dose-dependent reduction in L-DOPA-induced rotational behavior and abnormal involuntary movements. Dendritic spine counting at electron microscopy level showed that isradipine (.2 mg/kg/day) prevented the 6-OHDA-induced spine loss and normalized preproenkephalin-A messenger RNA expression. Involuntary movements were not reduced when isradipine treatment was started concomitantly with L-DOPA. Conclusions: These results indicate that isradipine, at a therapeutically relevant dose, might represent a treatment option for preventing L-DOPA-induced dyskinesia in PD.
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