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| 2. |
- Andreoli, Laura, et al.
(författare)
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Distinct patterns of dyskinetic and dystonic features following D1 or D2 receptor stimulation in a mouse model of parkinsonism
- 2021
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Ingår i: Neurobiology of Disease. - : Elsevier BV. - 0969-9961. ; 157
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Tidskriftsartikel (refereegranskat)abstract
- L-DOPA-induced dyskinesia (LID) is a significant complication of dopamine replacement therapy in Parkinson's disease (PD), and the specific role of different dopamine receptors in this disorder is poorly understood. We set out to compare patterns of dyskinetic behaviours induced by the systemic administration of L-DOPA and D1 or D2 receptor (D1R, D2R) agonists in mice with unilateral 6-hydroxydopamine lesions. Mice were divided in four groups to receive increasing doses of L-DOPA, a D1R agonist (SKF38393), a D2/3 agonist (quinpirole), or a selective D2R agonist (sumanirole). Axial, limb and orofacial abnormal involuntary movements (AIMs) were rated using a well-established method, while dystonic features were quantified in different body segments using a new rating scale. Measures of abnormal limb and trunk posturing were extracted from high-speed videos using a software for markerless pose estimation (DeepLabCut). While L-DOPA induced the full spectrum of dyskinesias already described in this mouse model, SKF38393 induced mostly orofacial and limb AIMs. By contrast, both of the D2-class agonists (quinpirole, sumanirole) induced predominantly axial AIMs. Dystonia ratings revealed that these agonists elicited marked dystonic features in trunk/neck, forelimbs, and hindlimbs, which were overall more severe in sumanirole-treated mice. Accordingly, sumanirole induced pronounced axial bending and hindlimb divergence in the automated video analysis. In animals treated with SKF38393, the only appreciable dystonic-like reaction consisted in sustained tail dorsiflexion and stiffness. We next compared the effects of D1R or D2R selective antagonists in L-DOPA-treated mice, where only the D2R antagonist had a significant effect on dystonic features. Taken together these results indicate that the dystonic components of LID are predominantly mediated by the D2R.
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| 3. |
- Arkan, Sertan, et al.
(författare)
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DNAJB6 suppresses alpha-synuclein induced pathology in an animal model of Parkinson's disease
- 2021
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Ingår i: Neurobiology of Disease. - : Elsevier BV. - 0969-9961. ; 158
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Tidskriftsartikel (refereegranskat)abstract
- Background: α-synuclein (α-syn) aggregation can lead to degeneration of dopaminergic neurons in the substantia nigra pars compacta (SNpc) as invariably observed in patients with Parkinson's Disease (PD). The co-chaperone DNAJB6 has previously been found to be expressed at higher levels in PD patients than in control subjects and was also found in Lewy bodies. Our previous experiments showed that knock out of DNAJB6 induced α-syn aggregation in cellular level. However, effects of overexpression of DNAJB6 against α-syn aggregation remains to be investigated. Methods: We used a α-syn CFP/YFP HEK293 FRET cell line to investigate the effects of overexpression of DNAJB6 in cellular level. α-syn aggregation was induced by transfection α-syn preformed fibrils (PPF), then was measured FRET analysis. We proceeded to investigate if DNAJB6b can impair α-syn aggregation and toxicity in an animal model and used adeno associated vira (AAV6) designed to overexpress of human wt α-syn, GFP-DNAJB6 or GFP in rats. These vectors were injected into the SNpc of the rats, unilaterally. Rats injected with vira to express α-syn along with GFP in the SNpc where compared to rats expressing α-syn and GFP-DNAJB6. We evaluated motor functions, dopaminergic cell death, and axonal degeneration in striatum. Results: We show that DNAJB6 prevent α-syn aggregation induced by α-syn PFF's, in a cell culture model. In addition, we observed α-syn overexpression caused dopaminergic cell death and that this was strongly reduced by co-expression of DNAJB6b. The lesion caused by α-syn overexpression resulted in behavior deficits, which increased over time as seen in stepping test, which was rescued by co-expression of DNAJB6b. Conclusion: We here demonstrate for the first time that DNAJB6 is a strong suppressor of α-syn aggregation in cells and in animals and that this results in a suppression of dopaminergic cell death and PD related motor deficits in an animal model of PD.
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| 4. |
- Crittenden, Jill R., et al.
(författare)
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CalDAG-GEFI mediates striatal cholinergic modulation of dendritic excitability, synaptic plasticity and psychomotor behaviors
- 2021
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Ingår i: Neurobiology of Disease. - Maryland Heights, MO, United States : Academic Press. - 0969-9961 .- 1095-953X. ; 158
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Tidskriftsartikel (refereegranskat)abstract
- CalDAG-GEFI (CDGI) is a protein highly enriched in the striatum, particularly in the principal spiny projection neurons (SPNs). CDGI is strongly down-regulated in two hyperkinetic conditions related to striatal dysfunction: Huntingtons disease and levodopa-induced dyskinesia in Parkinsons disease. We demonstrate that genetic deletion of CDGI in mice disrupts dendritic, but not somatic, M1 muscarinic receptors (M1Rs) signaling in indirect pathway SPNs. Loss of CDGI reduced temporal integration of excitatory postsynaptic potentials at dendritic glutamatergic synapses and impaired the induction of activity-dependent long-term potentiation. CDGI deletion selectively increased psychostimulant-induced repetitive behaviors, disrupted sequence learning, and eliminated M1R blockade of cocaine self-administration. These findings place CDGI as a major, but previously unrecognized, mediator of cholinergic signaling in the striatum. The effects of CDGI deletion on the selfadministration of drugs of abuse and its marked alterations in hyperkinetic extrapyramidal disorders highlight CDGIs therapeutic potential.
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| 5. |
- Damenti, Martina, et al.
(författare)
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STED and parallelized RESOLFT optical nanoscopy of the tubular endoplasmic reticulum and its mitochondrial contacts in neuronal cells
- 2021
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Ingår i: Neurobiology of Disease. - : Elsevier BV. - 0969-9961 .- 1095-953X. ; 155
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Tidskriftsartikel (refereegranskat)abstract
- The classic view of organelle cell biology is undergoing a constant revision fueled by the new insights unraveled by fluorescence nanoscopy, which enable sensitive, faster and gentler observation of specific proteins in situ. The endoplasmic reticulum (ER) is one of the most challenging structure to capture due the rapid and constant restructuring of fine sheets and tubules across the full 3D cell volume. Here we apply STED and parallelized 2D and 3D RESOLFT live imaging to uncover the tubular ER organization in the fine processes of neuronal cells with focus on mitochondria-ER contacts, which recently gained medical attention due to their role in neurodegeneration. Multi-color STED nanoscopy enables the simultaneous visualization of small transversal ER tubules crossing and constricting mitochondria all along axons and dendrites. Parallelized RESOLFT allows for dynamic studies of multiple contact sites within seconds and minutes with prolonged time-lapse imaging at similar to 50 nm spatial resolution. When operated in 3D super resolution mode it enables a new isotropic visualization of such contacts extending our understanding of the three-dimensional architecture of these packed structures in axons and dendrites.
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| 7. |
- Götze, Karl, et al.
(författare)
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Plasma neurofilament light chain in memory clinic practice: Evidence from a real-life study.
- 2023
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Ingår i: Neurobiology of disease. - : Elsevier BV. - 1095-953X .- 0969-9961. ; 176
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Tidskriftsartikel (refereegranskat)abstract
- To explore the accuracy of plasma neurofilament light chain (NfL) as a biomarker for diagnosis and staging of cognitive impairment, in a large cohort with of previously diagnosed patients in clinical practice.Retrospective, cross-sectional, monocentric study, from a tertiary memory clinic. Patients underwent cerebrospinal fluid core Alzheimer's disease (AD) biomarker evaluation using ELISA or Elecsys methods, and plasma NfL analysis using the single molecule array technology. The patients' biomarker data were examined for associations with: i/cognitive status ii/presence of neurodegenerative disease and iii/diagnostic groups. Associations between core CSF biomarkers and plasma NfL were determined.Participants (N=558, mean age=69.2±8.8, 56.5% women) were diagnosed with AD (n=274, considering dementia and MCI stages), frontotemporal dementia (FTD, n=55), Lewy body disease (LBD, n=40, considering MCI and dementia stages), other neurodegenerative diseases, n=57 (e.g Supranuclear Palsy, Corticobasal syndrome), non-neurodegenerative cognitive impairment (NND, n=79, e.g. vascular lesions, epilepsy or psychiatric disorders) or subjective cognitive impairment (SCI, n=53). Mean plasma NfL (log, pg/mL) levels were higher in neurodegenerative than non-neurodegenerative disorders (1.35±0.2 vs 1.16±0.23, p<0.001), higher in all diagnostic groups than in SCI (1.06±0.23) p<0.001), and associated with the stage of cognitive impairment (p<0.001). The addition of plasma NfL to a clinical model (age, MMSE and APOE ε4 carriership) marginally improved the discrimination of degenerative from non-degenerative disorders in ROC analysis (AUC clinical model: 0.81, 95% CI=[0.77;0.85] AUC clinical model + plasma NfL: AUC=0.83 95% CI=[0.78;0.87], delta Akaike information criterion=-11.7).Plasma NfL could help discrimination between degenerative and non-degenerative cognitive disorders, albeit not better than comprehensive clinical evaluation.
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| 8. |
- Hulme, Heather, et al.
(författare)
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Simultaneous mass spectrometry imaging of multiple neuropeptides in the brain and alterations induced by experimental parkinsonism and L-DOPA therapy
- 2020
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Ingår i: Neurobiology of Disease. - : ACADEMIC PRESS INC ELSEVIER SCIENCE. - 0969-9961 .- 1095-953X. ; 137
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Tidskriftsartikel (refereegranskat)abstract
- Neuropeptides are important signalling molecules in the brain and alterations in their expression levels have been linked to neurological disorders such as Parkinson's disease. It is challenging to map neuropeptide changes across and within brain regions because of their low in vivo concentrations and complex post-translational processing. Consequently, the role of neuropeptides in Parkinson's disease is not well understood. Thus, we have developed and evaluated a method to image multiple neuropeptides simultaneously in both rat and primate brain tissue sections by matrix-assisted laser desorption/ionisation mass spectrometry imaging at high lateral resolution. Using a unilateral 6-hydroxydopamine rat model of Parkinson's disease, we imaged changes in enkephalins, dynorphins, tachykinins and neurotensin associated with the dopaminergic denervation and L-DOPA treatment in multiple brain regions. L-DOPA administration significantly affected neuropeptides in the globus pallidus, while neuropeptides in the caudate-putamen were mostly affected by dopamine depletion. Using high lateral resolution imaging, we observed an increase of neurotensin in the dorsal sub-region of the globus pallidus after dopamine depletion. This study highlights the capacity of mass spectrometry imaging to elucidate the dynamics of neuropeptide signalling during Parkinson's disease and its treatment.
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| 9. |
- Höglund, Kina, 1976, et al.
(författare)
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Cerebrospinal fluid neurogranin in an inducible mouse model of neurodegeneration : A translatable marker of synaptic degeneration
- 2020
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Ingår i: Neurobiology of Disease. - : Elsevier BV. - 0969-9961 .- 1095-953X. ; 134
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Tidskriftsartikel (refereegranskat)abstract
- Synapse impairment is thought to be an early event in Alzheimer's disease (AD); dysfunction and loss of synapses are linked to cognitive symptoms that precede neuronal loss and neurodegeneration. Neurogranin (Ng) is a somatodendritic protein that has been shown to be reduced in brain tissue but increased in the cerebrospinal fluid (CSF) of AD patients compared to age-matched controls. High levels of CSF Ng have been shown to reflect a more rapid AD progression. To gauge the translational value of Ng as a biomarker, we developed a new, highly sensitive, digital enzyme-linked immunosorbent assay (ELISA) on the Simoa platform to measure Ng in both mouse and human CSF. We investigated and confirmed that Ng levels are increased in the CSF of patients with AD compared to controls. In addition, we explored how Ng is altered in the brain and CSF of transgenic mice that display progressive neuronal loss and synaptic degeneration following the induction of p25 overexpression. In this model, we found that Ng levels increased in CSF when neurodegeneration was induced, peaking after 2 weeks, while they decreased in brain. Our data suggest that CSF Ng is a biomarker of synaptic degeneration with translational value.
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| 10. |
- Ledri, Marco, et al.
(författare)
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Optogenetics for controlling seizure circuits for translational approaches
- 2023
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Ingår i: Neurobiology of Disease. - 0969-9961. ; 184, s. 1-13
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Tidskriftsartikel (refereegranskat)abstract
- The advent of optogenetic tools has had a profound impact on modern neuroscience research, revolutionizing our understanding of the brain. These tools offer a remarkable ability to precisely manipulate specific groups of neurons with an unprecedented level of temporal precision, on the order of milliseconds. This breakthrough has significantly advanced our knowledge of various physiological and pathophysiological processes in the brain. Within the realm of epilepsy research, optogenetic tools have played a crucial role in investigating the contributions of different neuronal populations to the generation of seizures and hyperexcitability. By selectively activating or inhibiting specific neurons using optogenetics, researchers have been able to elucidate the underlying mechanisms and identify key players involved in epileptic activity. Moreover, optogenetic techniques have also been explored as innovative therapeutic strategies for treating epilepsy. These strategies aim to halt seizure progression and alleviate symptoms by utilizing the precise control offered by optogenetics. The application of optogenetic tools has provided valuable insights into the intricate workings of the brain during epileptic episodes. For instance, researchers have discovered how distinct interneuron populations contribute to the initiation of seizures (ictogenesis). They have also revealed how remote circuits in regions such as the cerebellum, septum, or raphe nuclei can interact with hyperexcitable networks in the hippocampus. Additionally, studies have demonstrated the potential of closed-loop systems, where optogenetics is combined with real-time monitoring, to enable precise, on-demand control of seizure activity. Despite the immense promise demonstrated by optogenetic approaches, it is important to acknowledge that many of these techniques are still in the early stages of development and have yet to reach potential clinical applications. The transition from experimental research to practical clinical use poses numerous challenges. In this review, we aim to introduce optogenetic tools, provide a comprehensive survey of their application in epilepsy research, and critically discuss their current potential and limitations in achieving successful clinical implementation for the treatment of human epilepsy. By addressing these crucial aspects, we hope to foster a deeper understanding of the current state and future prospects of optogenetics in epilepsy treatment.
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