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Introduction: Studies of neural transplants in experimental models of Parkinson's disease have concentrated their attention on ectopic transplants of foetal mesencephalic cells to denervated striatum. However, the external globus pallidus has recently been shown to play an important part in the physiopathology of this disease., Objective: Bearing in mind the importance of loss of extra-striatal dopamine in the genesis of the clinical signs found in parkinsonism, the objective of this study was to evaluate the effect of foetal mesencephalic transplantation to the globus pallidus of hemiparkinsonian rats., Material and Methods: Following conventional transplantation methodolgy, suspensions of cells from the ventral mesencephalum of rat embryos (E-14) were implanted. The tissue was grafted into the striatum, pallidum-striatum and pallidum areas of rats with unilateral lesions of the striatonigral bundle. One, two, three and six months after transplantation, the rotatory activity induced by D-amphetamine was evaluated. The rotatory behaviour induced by apomorphine was evaluated at three months. Motor ability of the front legs was evaluated in all experimental groups three months after transplantation using the 'ladder test'., Results: In the experimental groups in which a transplant was made to the globus pallidus there was a significant reduction (p < 0.01) in rotatory activity induced by D-amphetamine and by apomorphine as compared with the non-transplanted groups., Conclusions: Transplants of foetal dopaminergic cells survive in the globus pallidus of hemiparkinsonian rats and can improve the rotational activity induced by dopaminergic agonists.

Introduction: Transplantation of foetal dopaminergic cells has been extensively used as restorative treatment for Parkinson's disease., Objective: This study was carried out to determine the survival, modifications in rotatory activity induced by D-amphetamine and total content of dopamine in the striatal and nigra regions of hemiparkinsonian rats which had had foetal mesencephalic cells simultaneously transplanted to the striatum and pars reticularis of the substancia nigra., Material and Methods: The study was done using adult male Wistar rats weighing 200-250 gms. The following experimental groups were formed, depending on the site of transplant: St: transplant to striatum (n = 2); SNr: transplant to SNr (n = 20), ST + Snr; transplant to striatum and SNr simultaneously n = 20; and control (lesion with no transplant) n = 20. We studied the rotatory activity induced by D-amphetamine 1, 2, 3 and 6 months after transplantation. After this time the rats were deeply anaesthetized and randomly allocated for morphological study or biochemical determination of the total dopamine content in the St and SNr using the HPLC technique., Results: Study of conduct showed no significant differences in rotatory activity induced by D-amphetamine between the groups with intrastriatal transplants, but there was a difference between these and the SNr and control groups. Biochemical analysis showed that striatal DA content was significantly greater in the ST for the groups with intrastriatal transplants. The content of substancia nigra DA was significantly greater in the SNr of the ST + SNr group, followed by the ST group. Morphometric study showed differences, which were not significant, between ST transplanted animals and significant differences between the SNr transplanted group with a significant increase in survival of the SNr of the ST + SNr group., Conclusions: These results suggest a positive effect due to intrastriatal transplants compared to survival following intranigral transplants.

Two groups of Sprague-Dawley male rats received bilateral aspirative lesions of the fimbria fornix under chloral hydrate anesthesia. One group (n = 9) received no further treatment (lesioned). In the second group (n = 8), a piece of septal fetal tissue, obtained at day E15-16, was implanted into each lesion cavity (transplanted). A third group consisted of shamlesioned rats (controls, n = 14). Two months after the operations, a recording electrode was implanted in the hilar region of the dentate gyrus of each animal, and a bipolar stimulating electrode was implanted in the perforant path. Long-term potentiation at 400 Hz was induced and followed for two hours. FF-lesioned rats showed an impaired potentiation of the field excitatory post-synaptic potential, which rapidly declined to basal levels within 15 minutes. The transplanted rats showed a normal potentiation of this parameter, similar to that seen in the control animals. A decrease in choline acetyltransferase activity in the hippocampi of the lesioned animals showed a tendency toward recovery after septal fetal tissue transplantation. In all the dorsal hippocampal areas of the lesioned animals, acetylcholinesterase histochemistry showed an almost complete loss of enzymatic activity, which was partially restored by the transplants. The improved synaptic plasticity in the transplanted animals might be related to septal transplant-induced recovery of mnemonic functions.