Library

feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    Electronic Resource
    Electronic Resource
    Springer
    Journal of neurology 238 (1991), S. 65-74 
    ISSN: 1432-1459
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 2
    Electronic Resource
    Electronic Resource
    Springer
    Journal of neurology 242 (1994), S. S43 
    ISSN: 1432-1459
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Neural grafts can reverse many functional deficits associated with brain damage, whether of traumatic, toxic, neurodegenerative or genetic origin. In some model systems recovery can be partial or complete, whereas in others the grafts have limited effects or may actually cause further dysfunction. In order to devise rational and effective transplantation strategies it is necessary to understand the mechanisms by which grafts exert their functional effects. Several alternatives have been proposed, and these include non-specific consequences of surgery, acute diffuse neurotrophic and growth mechanisms, chronic diffuse release of deficient neurochemicals, bridging tissues for host regeneration, diffuse reinnervation of the host brain, and reciprocal graft-host reconnection. These alternative mechanisms are not necessarily exclusive in any particular situation, and all have been seen to apply in different model systems.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 3
    Electronic Resource
    Electronic Resource
    Springer
    Experimental brain research 101 (1994), S. 365-374 
    ISSN: 1432-1106
    Keywords: 6-Hydroxydopamine ; Ibotenic acid ; Rotation ; Amphetamine ; Apomorphine ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Lesions of the dopaminergic nigrostriatal tract produce a range of motor and sensorimotor deficits. One of the simplest and most reliable is the rotational response of the animal following activation with drugs that stimulate the dopaminergic network, most notably amphetamine and apomorphine. Consequently, the rotation test has been extensively used in assessing the success of treatments designed to restore dopaminergic function, including neural transplants. The present study investigates whether rotation induced by 6-hydroxydopamine lesions of the nigrostriatal bundle in rats is modified by additional lesions in the neostriatum. It was found that apomorphine-induced rotation can be reduced by ibotenic acid lesions of the dopamine-deafferented striatum, and that the extent of the reduction was proportional to the size of the lesions. In contrast, such lesions produced a non-significant reduction in amphetamine-induced rotation, although the correlation between the extent of the reduction and the size of the lesion was again apparent. Since the pattern of change was similar in direction, albeit smaller in magnitude, than the previously reported effects of intrastriatal transplantation in rats with similar nigrostriatal lesions, rotation tests alone do not provide an unequivocal test of graft survival and function.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 4
    ISSN: 1432-1106
    Keywords: Neural transplantation ; Parkinson's disease ; Tissue cultures ; Mesencephalon ; Human embryo ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Free-floating roller tube cultures of human fetal (embryonic age 6–10 weeks post-conception) and rat fetal (embryonic day 13) ventral mesencephalon were prepared. After 7–15 days in vitro, the mesencephalic tissue cultures were transplanted into the striatum of adult rats that had received unilateral injections of 6-hydroxydopamine into the nigrostriatal bundle 3–5 weeks prior to transplantation. Graft survival was assessed in tyrosine hydroxylase (TH)-immunostained serial sections of the grafted brains up to post-transplantation week 4 for the human fetal xenografts and post-transplantation week 11 for the rat fetal allografts. d-amphetamine-induced rotation was monitored up to 10 weeks after transplantation in the allografted animals and compared with that of lesioned-only control animals. All transplanted animals showed large, viable grafts containing TH-immunoreactive (ir) neurons. The density of TH-ir neurons in the human fetal xenografts and in rat fetal allografts was similar. A significant amelioration of the amphetamine-induced rotation was observed in the animals that received cultured tissue allografts. These results promote the feasibility of in vitro maintenance of fetal human and rat nigral tissue prior to transplantation using the free-floating roller tube technique.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 5
    Electronic Resource
    Electronic Resource
    Springer
    Experimental brain research 105 (1995), S. 76-86 
    ISSN: 1432-1106
    Keywords: Neural transplantation ; Striatal grafts ; Ventral striatum ; Nucleus accumbens ; DRL schedule
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Bilateral damage to the ventral striatum induced by the excitotoxin ibotenic acid was found to have profound disinhibitory effects on rats' behaviour. Lesioned animals were unable to acquire efficient levels of performance on an operant schedule (differential reinforcement of low rates of responding, DRL) that required them to inhibit a previously rewarded response. In addition, lesioned subjects were relatively resistant to the disruptive effects of amphetamine on performance of the DRL schedule and were slower to cease responding under conditions of non-reward. A measure of unconditioned behaviour, overnight locomotor activity, was also disinhibited by the presence of the lesion. Grafts of embryonic striatal tissue transplanted to the lesioned ventral striatum were found to survive well. Moreover, the presence of the grafts reversed the effects of the lesion on measures of conditioned and unconditioned behaviour. The nature of the lesion-induced behavioural deficit and the ability of the embryonic transplants to reverse it are discussed in terms of the possible restoration of limbicsubcortical circuitry.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 6
    ISSN: 1432-1106
    Keywords: Substantia nigra ; Neuronal transplantation ; Trophic Factors ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Embryonic substantia nigra cells when transplanted into the striatum can reverse many of the defects of Parkinson's disease. The efficacy of such grafts is compromised by the poor survival of grafted dopaminergic neurones; typically, 3–10% survive transplantation. We used three tissue culture models to identify stages in the procedure for the preparation and insertion of grafts which might be responsible for this cell death and to identify environments in which survival is optimised. (1) The ventral mesencephalon was dissected from the donor brain, then placed immediately into culture contained in a collagen gel. (2) The dissected tissue fragments were enzymatically dissociated, then the cells placed into monolayer culture. (3) Enzymatically dissociated tissue was packed into 0.5-mm-diameter porous tubes, to simulate the compaction of cells into a graft deposit in the host brain. Dissociation of the tissue by itself caused the death of approximately 30% of dopaminergic neurones, as judged by the difference in cell counts between the intact embryonic day 14 (E14) mesencephalon, and cells dissociated then packed into tubes. Of the dissociated neurones approximately 60% died during the first 24 h and 87% during the first 3 days in monolayer culture, while only 7% of dopaminergic neurones in three-dimensional cultures and 11% of neurones in explant cultures died over the first 3 days. Embryonic dopaminergic neurones are clearly very vulnerable to adverse conditions during the first days after their removal from the donor brain. The excellent survival of neurones in three-dimensional and explant cultures indicates that close association with other cells, which may provide greatly improved access to trophic factors, can enable the cells to survive this period of vulnerability. In contrast to its effects in monolayer cultures, bFGF had no effect on dopaminergic neuronal survival in either explant or three-dimensional cultures.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 7
    Electronic Resource
    Electronic Resource
    [s.l.] : Nature Publishing Group
    Nature 399.1999, Supplementary, A32-, (8 S.) 
    ISSN: 1476-4687
    Source: Nature Archives 1869 - 2009
    Topics: Biology , Chemistry and Pharmacology , Medicine , Natural Sciences in General , Physics
    Notes: [Auszug] Parkinson's disease (PD) is one of the major neurodegenerative disorders of middle and old age, and was originally described by James Parkinson in 1817. It is characterized by a trio of cardinal symptoms—muscle rigidity, tremor and bradykinesia—but can also involve postural deficits and ...
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 8
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Publishing Ltd
    European journal of neuroscience 1 (1989), S. 0 
    ISSN: 1460-9568
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: The effects of quisqualic acid lesions of the nucleus basalis magnocellularis on short-term memory capacities of the rat have been investigated using the delayed matching and non-matching to position tasks. The lesions do not disrupt performance of either task by pretrained animals, but do disrupt the ability to acquire the non-matching contingency, and to reverse to the non-matching task when trained on the matching task. The unidirectional nature of the reversal deficit has been replicated. The generalized disruption of performance of either task by the muscarinic antagonist scopolamine was comparable in lesioned and control rats. The lesions were associated with extensive loss of acetylcholinesterase staining in the basal forebrain and in the neocortex, and 55% depletions of choline acetyltransferase activity in the neocortex but not in the hippocampus. These observations demonstrate that the cholinergic projection from nucleus basalis to the neocortex is not critical for normal short-term memory, but that lesions involving this system do disrupt specific types of conditional discrimination learning.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 9
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Science Ltd
    European journal of neuroscience 19 (2004), S. 0 
    ISSN: 1460-9568
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: Environmental conditions and behavioural experience can affect neuronal function and morphology. It is less well known whether such factors also influence the growth, integration and functional recovery provided by neural grafts placed within the damaged brain. Here we report on the effects of differential housing conditions on striatal graft morphology and functional recovery after striatal lesions. Rats were pretrained on a skilled bilateral forelimb task, the staircase test, and lesioned unilaterally in the lateral dorsal striatum with quinolinic acid. One group of lesioned animals was given suspension grafts of E15 whole ganglionic eminence implanted into the lesioned striatum. Following transplantation, the animals were housed either in standard cages (four per cage) or in enriched environment housing conditions (10 per cage) with tunnels, ladders and increased living space available for exploration, social interaction and play. The differentially housed animals were retested on the skilled staircase test at two separate time points. Repeated testing, environmental enrichment and transplantation positively influenced behavioural recovery. Partial recovery was observed bilaterally amongst the grafted animals in both housing conditions. Nevertheless, the grafted animals housed in the enriched environment performed significantly better in the final test compared with all of the other experimental groups. The grafts survived equally well under both housing conditions but the grafts of animals housed in the enriched environment contained larger projection neurons and were somewhat better reinnervated by dopaminergic afferents. An increased level of striatal brain-derived neurotrophic factor was observed in the control animals housed under the enriched compared with the standard conditions. The results indicate that an enriched environment can affect both graft function and graft morphology through as yet unknown mechanisms.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 10
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Science Ltd
    European journal of neuroscience 19 (2004), S. 0 
    ISSN: 1460-9568
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: Transplants of embryonic striatal tissue are characteristically heterogeneous, containing patches (P-zones) of striatal medium spiny projection neurons. It is not yet known how this morphology develops, and whether the striatal neurons in the grafts are derived from post-mitotic neuroblasts in the embryonic brain or from striatal progenitors that continue to divide after transplantation. To address this question we labelled dividing cells in the transplants with bromodeoxyuridine (BrdU), either prior to or after transplantation into the adult lesioned rat striatum. Cells for transplantation were either pre-labelled in utero by intraperitoneal (i.p.) injections of BrdU, or post-labelled after transplantation by i.p. injections to the hosts. Either two or six months after transplantation the brains were processed using double immunohistochemical techniques to detect BrdU and calbindin-positive neurons in the transplants. In the transplants pre-labelled with BrdU, approximately 30% of calbindin-positive cells were heavily labelled with BrdU, suggesting these had undergone a final division prior to transplantation. In transplants where cells had been labelled post-transplantation, approximately 17% of calbindin cells were heavily BrdU labelled. These results suggest that whereas a proportion of striatal medium spiny neurons in the striatal grafts were post-mitotic at the time of transplantation, other striatal progenitor cells can continue to divide after transplantation, and then complete an appropriate neuronal maturation programme in the adult host brain environment.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...