| 1. |
- Dunnett, Stephen B, et al.
(author)
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Introduction (Part I)
- 2012
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In: 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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Book chapter (peer-reviewed)
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| 2. |
- Dunnett, Stephen B, et al.
(author)
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Introduction (Part II)
- 2012
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In: 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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Book chapter (peer-reviewed)
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| 3. |
- Thompson, Lachlan, et al.
(author)
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Survival, differentiation, and connectivity of ventral mesencephalic dopamine neurons following transplantation
- 2012
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In: Functional Neural Transplantation III : Primary and Stem Cell Therapies for Brain Repair, Part I - Primary and Stem Cell Therapies for Brain Repair, Part I. - 0079-6123. - 9780444595751 ; 200, s. 61-95
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Book chapter (peer-reviewed)abstract
- The reconstruction of midbrain dopamine (DA) circuitry through intracerebral transplantation of new DA neurons contained in embryonic ventral mesencephalon (VM) is a promising therapeutic approach for Parkinson's disease (PD). Although some of the early open-label trials have provided proof-of-principal that VM grafts can provide sustained improvement of motor function in some patients, subsequent trials showed that the functional response can be highly variable. This chapter reviews an extensive body of basic and clinical research on the survival, differentiation, and connectivity of DA neurons in VM grafts, and also looks at how these parameters are affected by certain host- and donor-specific variables. We also review how technical advances in the tools available to study the integration of grafted DA neurons, such as transgenic reporter mice, have made significant contributions to our understanding of the capacity of different DA neuronal subtypes for target-directed growth and innervation of appropriate host brain structures. Our established and on-going understanding of the capacity of grafted DA neurons to structurally and functionally integrate following transplantation forms an important basis for the refinement and optimization of VM grafting procedures, and also the development of new procedures based on the use of stem cells.
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| 4. |
- Björklund, Anders, et al.
(author)
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Intracerebral grafting of neuronal cell suspensions. I. Introduction and general methods of preparation.
- 1983
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In: Acta Physiologica Scandinavica. ; Suppl. 522, s. 1-7
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Journal article (peer-reviewed)abstract
- The steps involved in the grafting of mesencephalic and septal embryonic tissue in the form of dissociated cell suspensions are described in detail. This includes dissection of the donor embryos, incubation in trypsin, mechanical dissociation, and stereotaxic injection into the brains of adult recipient rats. Some of the technical problems and limitations are discussed.
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| 5. |
- Björklund, Anders, et al.
(author)
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Intracerebral grafting of neuronal cell suspensions. II. Survival and growth of nigral cells implanted in different brain sites
- 1983
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In: Acta Physiologica Scandinavica. ; Suppl. 522, s. 9-18
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Journal article (peer-reviewed)abstract
- Dissociated dopamine-rich cell suspensions were prepared from the ventral mesencephalon of rat embryos and injected in one or several sites in striatal and non-striatal regions in the dopaminergically denervated brain of adult rats. While the grafts survived well in all sites, the dopamine fibre outgrowth was markedly different depending on whether the grafts occurred in an area normally innervated by the mesencephalic dopamine neurones (i.e. neostriatum or nc. accumbens) or in areas not normally innervated by these neurones (i.e. parietal cortex, lateral hypothalamus or substantia nigra). Moreover, in grafts placed at different sites along the trajectory of the nigrostriatal pathway the outgrowing fibres remained confined to the graft, and there was little evidence that the implanted neurones could elongate their axons along the pathway of the nigrostriatal tract to reach the striatum from a distance. Thus, the intracerebral suspension grafts provided efficient reinnervation of a denervated target only when placed in the immediate vicinity of the target area. The results of multiple graft placements indicate that a relatively complete restoration of a lost innervation should be possible to achieve in large areas of the brain, such as the striatal complex, with the suspension grafting technique.
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| 6. |
- Björklund, Anders, et al.
(author)
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Intracerebral grafting of neuronal cell suspensions. VI. Survival and growth of intrahippocampal implants of septal cell suspensions
- 1983
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In: Acta Physiologica Scandinavica. ; Suppl. 522, s. 49-58
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Journal article (peer-reviewed)abstract
- The survival and growth of intrahippocampal septal suspension grafts were investigated by acetylcholine esterase (AChE) histochemistry in animals with lesions of the intrinsic septohippocampal cholinergic pathways. AChE was demonstrable in the grafts after the first postoperative week, and AChE-positive fibres were seen to extend into the host hippocampus by 3 weeks. Rapid fibre outgrowth occurred between 3 weeks and 3 months after grafting, and continued at a slower rate thereafter. By 6 months a fairly complete reinnervation of the initially denervated hippocampus was achieved in most specimens, and this persisted at 14 months, the longest postoperative time analysed. A comparison between the development of the AChE-positive neurones in the suspension grafts with that seen during ontogeny in situ suggested that the grafted neurones lagged behind normal development by at least 1 week. Similar to our previous observations on septal grafts implanted as solid tissue pieces, the pattern of the newly-formed AChE-positive innervation in the host hippocampal formation, established from the septal suspension grafts, was remarkably similar to that of the normal AChE-positive septal innervation. This pattern became established as soon as the graft-derived fibres first grew in, suggesting that the ingrowing axons extended and ramified preferentially into those hippocampal subfields which normally receive an AChE-positive innervation from the septal-diagonal band area.
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| 7. |
- Björklund, Anders, et al.
(author)
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Intracerebral grafting of neuronal cell suspensions. VII. Recovery of choline acetyltransferase activity and acetylcholine synthesis in the denervated hippccampus reinnervated by septal suspension implants
- 1983
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In: Acta Physiologica Scandinavica. ; Suppl. 522, s. 59-66
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Journal article (peer-reviewed)abstract
- The time-course and magnitude of fibre outgrowth from septal suspension grafts injected into the previously denervated hippocampal formation was monitored by measurements of choline acetyltransferase (ChAT), and the activity of the grafted neurons was assessed by measurements of [14C]acetylcholine (ACh) synthesis from [14C]glucose in vitro. Graft-derived ChAT activity was barely detectable 10 days after grafting, but increased sharply between 10 days and 1 month in the areas of the hippocampus located close to the septal implants. By 6 months ChAT activity was restored to near normal levels in all segments of the previously denervated hippocampus. The overall hippocampal [14C]ACh synthesis was also restored to normal levels in the grafted animals, and estimates of the ACh turnover rate suggested that the transmitter machinery of the newly established "septo-hippocampal" connections operated at a rate similar to that of the intrinsic septohippocampal pathway. The intrahippocampal septal suspension grafts, similar to the intrastriatal nigral grafts, thus seem to be capable of maintaining function at a relatively "physiological" level despite their abnormal positions.
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| 8. |
- Dunnett, S B, et al.
(author)
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Intracerebral grafting of neuronal cell suspensions. IV. Behavioural recovery in rats with unilateral implants of nigral cell suspensions in different forebrain sites
- 1983
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In: Acta Physiologica Scandinavica. ; Suppl. 522, s. 29-38
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Journal article (peer-reviewed)abstract
- Single and multiple implants of nigral cell suspensions were grafted to the forebrains of rats with unilateral 6-hydroxydopamine-induced dopamine denervations. Control lesions alone induced a marked behavioural asymmetry, as assessed by amphetamine- and apomorphine-induced rotation, sensorimotor tests and side bias in an unbaited T-maze, and the animals were hyperactive to a low dose of apomorphine. Single suspension placements into different denervated striatal regions were capable of reversing the behavioural asymmetries dependent upon the specific placement for each test. Multiple suspension grafts were capable of reversing all behavioural asymmetries, and additionally abolished the supersensitive hyperactivity to apomorphine. By contrast, single suspension grafts placed into the substantia nigra or lateral hypothalamus had no detectable effect on any functional measure. The results indicate that nigral suspension grafts can be at least as effective as solid grafts in reversing the functional deficits induced by dopamine denervation, provided that placements are selected within appropriate dopamine terminal regions of the forebrain (e.g. caudate-putamen or nucleus accumbens).
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| 9. |
- Dunnett, S B, et al.
(author)
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Intracerebral grafting of neuronal cell suspensions. V. Behavioural recovery in rats with bilateral 6-OHDA lesions following implantation of nigral cell suspensions.
- 1983
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In: Acta Physiologica Scandinavica. ; Suppl. 522, s. 39-48
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Journal article (peer-reviewed)abstract
- Bilateral 6-hydroxydopamine-induced lesions of the ascending forebrain dopamine neurones induce a behavioural syndrome in rats which includes profound aphagia, adipsia, akinesia and bilateral sensorimotor neglect. Such animals will die unless maintained by intragastric feeding. Three experiments are reported in which we have attempted to ameliorate this syndrome with single or multiple placements of nigral cell suspensions into the forebrains of rats with bilateral dopamine depletions. Although the grafts were efficient in reversing the sensorimotor and akinetic impairments, and produced a significant increase in eating, the grafted rats remained hypophagic and adipsic. The results indicate that although many components of the bilateral dopamine denervation syndrome can be reversed by intrastriatal nigral suspension grafts, the severe eating and drinking deficits remain unameliorated.
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| 10. |
- Gage, F H, et al.
(author)
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Intracerebral grafting of neuronal cell suspensions. VIII. Cell survival and axonal outgrcwth of dcpaminergic and cholinergic cells in the aged brain.
- 1983
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In: Acta Physiologica Scandinavica. ; Suppl. 522, s. 67-75
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Journal article (peer-reviewed)abstract
- Neuronal cell suspensions prepared from the ventral mesencephalon and the septal-diagonal band area of rat embryos were implanted into the depth of the intact neostriatum or hippocampus of 21-23 month old female rats. Graft survival, assessed 3-4 months after grafting, was comparable to that seen in our previous studies of young adult recipients. Fibre outgrowth into the host brain was evaluated in animals which were subjected to lesions of the intrinsic nigrostriatal or septohippocampal system 6-10 days before killing. Dense dopamine fibre outgrowth was seen within a zone of up to about 1 mm radius around the nigral implants, and dense growth of acetylcholine esterase (AChE) positive fibres occurred up to about 2 mm away from the septal implants. The overall magnitude of fibre outgrowth was less than that generally seen in previously denervated targets in young adult recipients, but it appeared to be as extensive as in young recipients when the grafts are placed in non-denervated targets. The distribution of the AChE-positive fibres from the septal implants in the host hippocampus suggested that the pattern found in the non-denervated target of the aged recipients was more diffuse, and partly different, from normal, and that age-dependent synapse loss in intrinsic connections may influence the patterning of the graft-derived innervation.
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