Nigral targeting strategies for neural function restora

项目3.神经功能恢复的黑质靶向策略 虽然胚胎DA神经元的纹状体内移植物存活，将神经突送入宿主脑，提高移植物附近的DA水平，并恢复帕金森病MPTP治疗猴的运动功能，但人类的功能益处是可变的，有些有限，有时与运动障碍有关。这些限制可能是由于移植物在纹状体的异位放置以及由此导致的多巴胺释放失调。最近的研究表明，将胚胎黑质（SN）移植到 宿主SN和胚胎纹状体到纹状体中的移植物，其可用于促进从含DA的神经突朝向适当的靶向定向纤维生长。所提出的实验建立在这一知识的基础上。该假说认为，共同移植胚胎纹状体到纹状体和腹侧中脑组织邻近黑质将改善恢复，因为替代黑质细胞可以在黑质中调节，并在正常目标区域提供适当的多巴胺释放。行为措施将 评估功能恢复，DA神经元的免疫组织化学标记物将用作靶区域中移植物存活的指标，并确定生物化学效应。共聚焦显微镜和电子显微镜将有助于描绘电路重建，可能导致共同移植。在处死前，将逆行示踪剂荧光金注射到尾状核或壳核中，以确定黑质中移植的多巴胺能神经元是否被标记。使用相同的结果测量，将有策略地植入封装的产生GDNF的细胞，以在另一个实验中吸引适当的生长。一些猴子将被研究三年，以允许更完全的恢复，确定恢复的程度，以及可能的副作用，如运动障碍。总之，这些实验将测量通过将DA特异性移植物放置到更生理的部位而获得的功能恢复程度，所述DA特异性移植物受到适当的调节影响。这些实验的结果将与项目1和2产生的行为、形态和生化数据进行比较，以及与之前在类似条件下在圣基茨绿色猴中进行的移植进行比较。

PROJECT 3. NIGRAL TARGETING STRATEGIES FOR RESTORATION OF NEURAL FUNCTION Although intrastriatal grafts of embryonic DA neurons survive, send neurites into the host brain, elevate DA levels in the vicinity of the grafts, and restore motor function in parkinsonian MPTP-treated monkeys, the functional benefits in humans have been variable, somewhat limited and sometimes associated with dyskinesia. These limitations may be due to the ectopic placement of grafts in the striatum and the resulting dysregutated release of dopamine. Recent studies have shown the feasibility of grafting embryonic substantia nigra (SN) into the host SN and grafts of embryonic striatum into the striatum, which can be used to promote directed fiber outgrowth from DA-containing neurites towards appropriate targets. The experiments proposed build upon this knowledge. The hypothesis is that co-grafting embryonic striatum into the striatum and ventral mesencephalic tissue adjacent to the substantia nigra will improve recovery, since replacement nigral cells can be regulated in the nigra and provide appropriate release of dopamine in the normal target areas. Behavioral measures will assess functional recovery, immunohistochemical markers for DA neurons will be used as indices of graft survival in the target regions, and biochemical effects will be determined. Confocal and electron microscopy will aid the depiction of circuit reconstruction that may result from co-grafts. Prior to sacrifice, the retrograde tracer fluorogold wilt be injected in the caudate or putamen to determine if grafted dopaminergic neurons in the nigra are labeled. Using the same outcome measures encapsulated GDNF-producing cells will be implanted strategically to attract appropriate outgrowth in another experiment. Some monkeys will be studied for three years to allow for more complete restoration, determine extent of recovery, and possible side effects, such as dyskinesia. Together, these experiments will measure the degree of functional recovery attained through the placement of DA-specific grafts, subject to proper regulatory influences, into more physiological sites. Results from these experiments will be compared with behavioral, morphological, and biochemical data generated from Projects 1 & 2, as well as with prior transplants done under similar conditions in St. Kitts green monkeys.