| 1. |
- Dunnett, Stephen B, et al.
(författare)
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Introduction (Part I)
- 2012
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Ingår i: Functional Neural Transplantation III : Primary and stem cell therapies for brain repair. Part 1 - Primary and stem cell therapies for brain repair. Part 1. - 0079-6123. - 9780444595751 ; 200, s. 3-5
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Bokkapitel (refereegranskat)
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| 2. |
- Dunnett, Stephen B, et al.
(författare)
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Introduction (Part II)
- 2012
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Ingår i: Functional Neural Transplantation III : Primary and Stem Cell Therapies for Brain Repair, Part II - Primary and Stem Cell Therapies for Brain Repair, Part II. - 0079-6123. - 9780444595447 ; 201, s. 3-5
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Bokkapitel (refereegranskat)
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| 3. |
- Berglöf, Elisabet, 1978-
(författare)
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Dopamine neurons in ventral mesencephalon : interactions with glia and locus coeruleus
- 2008
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Parkinson’s disease is a progressive neurodegenerative disorder, characterized by a depletion of the dopaminergic neurons in the substantia nigra. The cause of the disease is yet unknown but age, oxidative stress, and neuroinflammation are some of the features involved in the degeneration. In addition, substantial cell death of noradrenergic neurons occurs in the locus coeruleus (LC). Noradrenaline has been suggested to protect the dopamine neurons from oxidative stress and neuroinflammation. The main treatment of Parkinson’s disease is Levo-dopa, although severe side effects arise from this therapy. Hence, grafting fetal ventral mesencephalic (VM) tissue into the adult striatum has been evaluated as an alternative treatment for Parkinsons’s disease. However, the survival of the grafted neurons is limited, and the dopamine-denervated striatum does not become fully reinnervated. Therefore, elucidating factors that enhance dopamine nerve fiber formation and/or survival of the grafted neurons is of utmost importance. To investigate dopamine nerve fiber formation and the interactions with glial cells, organotypic VM tissue cultures were utilized. Two morphologically different nerve fiber outgrowths from the tissue slice were observed. Nerve fibers were initially formed in the absence of migrating astrocytes, although thin vimentin-positive astrocytic processes were detected within the same area. A second, persistent nerve fiber outgrowth was observed associated with migrating astrocytes. Hence, both of these nerve fiber outgrowths were to some extent dependent on astrocytes, and appeared as a general feature since this phenomenon was demonstrated in β-tubulin, tyrosine hydroxylase (TH), and aldehyde dehydrogenase A1 (ALDH1)-positive nerve fibers. Neither oligodendrocytes (NG2-positive cells), nor microglia (Iba-1-positive cells) exerted any effect on these two neuronal growths. Since astrocytes appeared to influence the nerve fiber formation, the role of proteoglycans, i.e. extracellular matrix molecules produced by astrocytes, was investigated. β-xyloside was added to the cultures to inhibit proteoglycan synthesis. The results revealed a hampered astrocytic migration and proliferation, as well as a reduction of the glia-associated TH-positive nerve fiber outgrowth. Interestingly, the number of cultures displaying the non-glia-mediated TH-positive nerve fibers increased after β-xyloside treatment, although the amount of TH-protein was not altered. Thus, proteoglycans produced by astrocytes appeared to be important in affecting the dopamine nerve fiber formation. The noradrenaline neurons in LC have been suggested to protect dopamine neurons from damage. Therefore, the interaction between VM and LC was evaluated. Using the intraocular grafting method, fetal VM and LC were grafted either as single grafts or as VM+LC co-grafts. Additionally, the recipient animals received 2% blueberry-enriched diet. The direct contact of LC promoted graft volume and survival of TH-positive neurons in the VM grafts. The number of dopamine neurons, derived preferably from the A9 (ALDH1/TH-positive) was increased, whereas the dopamine neurons from the A10 (calbindin/TH-positive) were not affected. A dense dopamine-β-hydroxylase (DBH)-positive innervation was correlated to the improved survival. Blueberry-enriched diet enhanced the number of TH-positive neurons in VM, although the graft size was not altered. The combination of blueberries and the presence of LC did not yield additive effects on the survival of VM grafts. The attachment of VM or the addition of blueberries did not affect the survival of TH-positive neurons in LC grafts. The number of Iba-1-positive microglia was decreased in co-grafted VM compared to single VM transplants. The addition of blueberries reduced the number of Iba-1-positive microglia in single VM transplants. Hence, the direct contact of LC or the addition of blueberries enhanced the survival of VM grafts. Taken together, these data demonstrate novel findings regarding the importance of astrocytes for the nerve fiber formation of dopamine neurons. Further, both the direct attachment of LC or antioxidant-enriched diet promote the survival of fetal VM grafts, while LC is not affected.
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| 4. |
- Björklund, Anders, et al.
(författare)
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Dopamine neuron systems in the brain: an update
- 2007
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Ingår i: Trends in Neurosciences. - : Elsevier BV. - 1878-108X .- 0166-2236. ; 30:5, s. 194-202
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Forskningsöversikt (refereegranskat)abstract
- The basic organization of the catecholamine-containing neuronal systems and their axonal projections in the brain was initially worked out using classical histofluorescence techniques during the 1960s and 1970s. The introduction of more versatile immunohistochemical methods, along with a range of highly sensitive tract-tracing techniques, has provided a progressively more detailed picture, making the dopamine system one of the best known, and most completely mapped, neurotransmitter systems in the brain. The purpose of the present review is to summarize our current knowledge of the diversity and neurochemical features of the nine dopamine-containing neuronal cell groups in the mammalian brain, their distinctive cellular properties, and their ability to regulate their dopaminergic transmitter machinery in response to altered functional demands and aging.
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| 5. |
- Björklund, Anders, et al.
(författare)
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Fifty years of dopamine research.
- 2007
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Ingår i: Trends in Neurosciences. - : Elsevier BV. - 1878-108X .- 0166-2236. ; 30:5, s. 185-187
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Tidskriftsartikel (refereegranskat)
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| 6. |
- Björklund, Anders, et al.
(författare)
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The amphetamine induced rotation test : A re-assessment of its use as a tool to monitor motor impairment and functional recovery in rodent models of Parkinson's disease
- 2019
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Ingår i: Journal of Parkinson's Disease. - 1877-7171. ; 9:1, s. 17-29
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Forskningsöversikt (refereegranskat)abstract
- Rats and mice with unilateral damage to the nigrostriatal dopamine system-induced by neurotoxins, such as 6-hydroxydopamine, overexpression of α-synuclein, or injections of toxic synuclein protofibrils-are widely used as experimental models to mimic the loss of dopamine neurons seen in Parkinson's disease. The amphetamine rotation test is commonly used to monitor the extent of motor impairment induced by the lesion, and this test has also become the standard tool to demonstrate transplant-induced functional recovery or the efficacy of neuroprotective interventions aimed to preserve or restore DA neuron function. Although the amphetamine-induced rotation test is highly useful for this purpose it has some important pitfalls and the interpretation of the data may not always be straightforward. Unless the test is applied properly and the data are displayed and interpreted appropriately the conclusions may be misleading or simply totally wrong. The purpose of this review is to draw attention to the potential problems and pitfalls involved in the use of drug-induced rotation tests, and to provide recommendations and advice on how to avoid them.
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| 7. |
- Fricker-Gates, Rosemary A., et al.
(författare)
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Neural transplantation: restoring complex circuitry in the striatum
- 2001
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Ingår i: Restorative Neurology and Neuroscience. - 1878-3627. ; 19:1-2, s. 119-138
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Tidskriftsartikel (refereegranskat)abstract
- During the last 30 years, the promise of neural transplantation as a therapeutic strategy for neurodegenerative disease has been slowly recognised. Across the world, clinical transplants of embryonic primary dopamine neurones have been shown to ameliorate some of the motor deficits in Parkinson s disease (PD) patients, and more recently, systematic clinical trials have been initiated for the replacement of striatal projection neurones lost in Huntington's disease (HD). Clinical transplantation as a prospective therapy for HD poses a particular set of difficulties. The hallmarks of this neurodegenerative disease include extensive loss of medium spiny long-distance projection neurones of the caudate and putamen, affecting downstream target nuclei, the globus pallidus and substantia nigra, leading to dysregulation of motor control. In addition, extensive loss of cortical neurones that form the afferent systems to the basal ganglia leads to widespread cognitive decline. If transplantation therapy is to succeed in replacing degenerating neurones in HD and reinstating controlled function of complex basal gan-glia circuitry, the new neurones must be able to develop specific long-distance projections that can form accurate and functional connections with neurones in precise target regions. Our ongoing studies are aimed at addressing how we can improve the function of striatal transplants, in particular to optimise the reformation of precise long-distance connections and to re-establish normal motor and cognitive function. In particular, we have investigated optimal requirements for embryonic primary tissue to achieve these aims, and also the potential of other cell sources to provide long-distance projection neurones and reconnect complex circuitry. This review describes current progress of experiments to optimise the reconstruction of neuronal circuitry using primary embryonic tissue transplants, as well as our current initiatives to use neural stem cells or precursors to replace long distance projection neurones in the degenerating basal ganglia.
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| 8. |
- Kirkeby, Agnete, et al.
(författare)
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Predictive Markers Guide Differentiation to Improve Graft Outcome in Clinical Translation of hESC-Based Therapy for Parkinson's Disease
- 2017
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Ingår i: Cell Stem Cell. - : Elsevier BV. - 1934-5909 .- 1875-9777. ; 20:1, s. 135-148
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Tidskriftsartikel (refereegranskat)abstract
- Stem cell treatments for neurodegenerative diseases are expected to reach clinical trials soon. Most of the approaches currently under development involve transplantation of immature progenitors that subsequently undergo phenotypic and functional maturation in vivo, and predicting the long-term graft outcome already at the progenitor stage remains a challenge. Here, we took an unbiased approach to identify predictive markers expressed in dopamine neuron progenitors that correlate with graft outcome in an animal model of Parkinson's disease through gene expression analysis of >30 batches of grafted human embryonic stem cell (hESC)-derived progenitors. We found that many of the commonly used markers did not accurately predict in vivo subtype-specific maturation. Instead, we identified a specific set of markers associated with the caudal midbrain that correlate with high dopaminergic yield after transplantation in vivo. Using these markers, we developed a good manufacturing practice (GMP) differentiation protocol for highly efficient and reproducible production of transplantable dopamine progenitors from hESCs.
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| 9. |
- Lane, Emma L., et al.
(författare)
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Neural grafting in Parkinson's disease: unraveling the mechanisms underlying graft-induced dyskinesia
- 2010
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Ingår i: Progress in Brain Research. - 1875-7855. ; 184, s. 295-309
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Forskningsöversikt (refereegranskat)abstract
- The development of neural transplantation as a treatment for Parkinson's disease has been compromised by a lack of functional efficacy and the appearance of transplant-induced motor side-effects in some patients. Since the first reports of these graft-induced dyskinesias (GID), and the realization of their impact on the progress of the field, a great deal of experimental work has been performed to determine the underlying cause(s) of this problematic side-effect. In this review we describe the clinical phenomenon of GID, explore the different representations of GID in rodent models, and examine the various hypotheses that have been postulated to be the cause. Based on the available clinical and preclinical data we outline strategies to avoid GID in future clinical trials using fetal cell transplants or cell preparations derived from stem cells.
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| 10. |
- Lindgren, Hanna, et al.
(författare)
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Nigral 6-hydroxydopamine lesion impairs performance in a lateralised choice reaction time task-Impact of training and task parameters
- 2014
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Ingår i: Behavioural Brain Research. - : Elsevier BV. - 0166-4328. ; 266, s. 207-215
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Tidskriftsartikel (refereegranskat)abstract
- Unilateral intrastriatal and intra-medial forebrain bundle injections of 6-OHDA impair the performance in a lateralised choice reaction time task. However, the extent and pattern of deficits after nigral 6-OHDA injections is less well studied, as well as the impact of training regime or the modification of various task parameters. The nigral 6-OHDA lesion resulted in impaired response accuracy and an increased time to react to and execute the response on the side contralateral to the lesion as compared to sham-lesioned controls. Pre-training of the rats on the task prior to the lesion resulted in slightly faster reaction times as well as a reduced number of preservative panel presses compared to when rats were trained after the 6-OHDA injection. When the rat had to perform a longer sustained nose poke before responding to the lateralised stimuli, the number of useable trials was reduced in both controls and 6-OHDA rats as a result of an increased number of premature withdrawals from the centre hole. This study demonstrates that rats with a nigral 6-OHDA lesion display several distinct deficits in this operant task, which are similar to those seen after striatal and bundle 6-OHDA injections. In addition, by combining pre-training with the use of a short set of holds, improved sensitivity of this task can be achieved. This improvement in sensitivity may be of advantage when exploring new therapeutic interventions for PD, where subtle but relevant changes in performance may arise. (C) 2014 Elsevier B.V. All rights reserved.
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