Neuronal Regeneration Therapy for Cerebral Ischemia

在这项研究项目中，研究人员最初试图在大鼠局灶性缺血中再生纹状体神经元。由于没有显着数量的神经元可以再生，我们改变了模型，以全球缺血一致的纹状体神经元死亡可以量化。在这个模型中，位于纹状体背外侧部分的神经元超过95%丢失。缺血6周后，未处理动物中未观察到显著的神经元再生。由于在血管下区的增殖祖细胞的数量在第7天达到峰值，我们从第2天到第9天开始用生长因子处理大鼠以覆盖这一时期。因此，神经元的数量在6周时增加了15%，这在p<0.05时是显著的。这些神经元掺入了增殖细胞的标记物BrdU，并表现出成熟的神经元表型。特别地，这些神经元表达GABA能中间神经元的标记物，但不表达投射神经元的标记物DARPP-32。我们还开始建立非人灵长类动物（Macaca fascicularis）的脑缺血模型。虽然我们首次尝试通过血管内技术闭塞大脑中动脉来造成局灶性缺血，但我们无法在相应半球获得一致的病变。因此，我们将模型改为全脑缺血。在该模型中，通过血管内球囊闭塞通向大脑的大血管，这导致脑电图在1分钟内消失。根据文献，我们首先最初闭塞20分钟，然而这太严重而无法获得长期存活。我们逐渐缩短了时间，最多8分钟。这个时间段，在现在看来，似乎很合适。建立灵长类动物全脑缺血模型以评价神经元再生是走向临床应用的重要一步

In this research project, the investigators initially tried to regenerate striatal neurons in focal ischemia in rats. Since no significant number of neurons could be regenerated, we changed the model to global ischemia in which consistent striatal neuronal death can be quantified. In this model, more than 95% of neurons located in the dorsolateral part of the striatum are lost. Six weeks after ischemia, no significant neuronal regeneration was observed in untreated animals. Since the number of proliferating progenitor at the subventircular zone peaked at 7 day, we treated the rats with growth factors starting form Day 2 to 9 to cover this period. Consequently, the number of neurons increased by 15 % at 6 week, which is significant at p<0.05. These neurons incorporated BrdU, a marker of proliferating cells, and exhibit mature neuronal phenotype. In particular, these neurons expressed the marker for GABAergic interneurons, but not DARPP-32, a marker for projection neurons.We also started to establish a model of cerebral ischemia in non-human primates (Macaca fascicularis). Although we first tried to make focal ischemia by occluding the middle cerebral artery by endvascular technique, we could not obtain consistent lesion in the corresponding hemisphere. We, therefore, changed the model to global ischemia. In this model, great vessels to the brain are occluded by endvascular balloon, which led to disappearance of electroencephalogram within 1 minute. We first initially occlude for 20 minutes, according to the literature, which however was too severe to obtain long-term survival. We gradually shortened the time, up to 8 minute. This time period appeared to be suitable at the moment. The establishment of primate model of global ischemia for assessment of neuronal regeneration seems to be an important step toward clinical application