Graybiel A M, Liu F C, Dunnett S B
Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge 02139.
J Neurosci. 1989 Sep;9(9):3250-71. doi: 10.1523/JNEUROSCI.09-09-03250.1989.
Fetal striatal grafts display a striking modularity of composition. With acetylcholinesterase (AChE) histochemistry, the tissue of such grafts can be divided into regions with strong AChE staining of the neuropil and regions in which AChE staining of the neuropil is weak. In the experiments reported here, we reexamined the nature of this modularity. Striatal grafts were made by injecting dissociated cells of E15 ganglionic eminence into the striatum of adult rats, which 7 days before had recived intrastriatal deposits of ibotenic acid. Some donors had been exposed to 3H-thymidine at E11-E15. After 9-17 month survivals, the anatomical organization of the grafts was studied by histochemistry, immunohistochemistry, and autoradiography. In every graft, the AChE-rich regions formed patches (P regions) in a larger AChE-poor surround (NP regions). Neurons labeled with 3H-thymidine appeared in both P and NP regions, suggesting that donor cells were distributed in each type of region and that neither type of tissue, P or NP, was composed exclusively of host tissue. In the AChE-rich P regions, markers characteristic of normal perinatal and mature rat striatum were expressed by medium-sized cells: calcium-binding protein (calbindin D28k) immunostaining, metenkephalin (mENK) immunostaining, and, more rarely, somatostatin (SOM) immunostaining. In the NP regions, however, medium-sized cells expressing calbindin and mENK immunostaining were very rare, and there was an abundance of neuronal types not found in normal mature striatal tissue. These included (1) large, multipolar, calbindin-positive neurons with well-ramified, densely stained dendrites, (2) large, SOM-positive neurons with prominent dendritic trees, and (3) mENK-positive cells smaller than typical striatal, medium-sized, mENK-immunoreactive neurons. In Nissl stains, the AChE-rich P regions resembled the normal striatum of mature animals, whereas the AChE-poor NP regions did not. These findings suggest that the P regions of fetal striatal grafts achieve a phenotypy similar to that of normal striatum at maturity and during much of postnatal development. The dominant expression of perikaryal calbindin-like immunoreactivity in the P regions further suggests that these zones have a high proportion of tissue resembling striatal matrix. By contrast, expression of marker antigens in the NP zones of the grafts suggests that these zones are predominantly composed of nonstriatal tissue or that they have the phenotypy of immature striatum intermixed with some nonstriatal cells.(ABSTRACT TRUNCATED AT 400 WORDS)
胎儿纹状体移植显示出显著的组成模块化。通过乙酰胆碱酯酶（AChE）组织化学方法，此类移植组织可分为神经毡AChE染色强的区域和神经毡AChE染色弱的区域。在本文报道的实验中，我们重新审视了这种模块化的本质。通过将E15神经节隆起的解离细胞注射到成年大鼠纹状体中来制作纹状体移植，这些成年大鼠在7天前接受了纹状体内鹅膏蕈氨酸注射。一些供体在E11 - E15时接触过3H - 胸腺嘧啶核苷。在存活9 - 17个月后，通过组织化学、免疫组织化学和放射自显影研究移植组织的解剖结构。在每一个移植组织中，富含AChE的区域在较大的AChE缺乏的周围区域（NP区域）形成斑块（P区域）。用3H - 胸腺嘧啶核苷标记的神经元出现在P区域和NP区域，这表明供体细胞分布在每种区域类型中，并且P或NP这两种组织类型都不是仅由宿主组织组成。在富含AChE的P区域，中等大小的细胞表达正常围产期和成熟大鼠纹状体特有的标志物：钙结合蛋白（钙结合蛋白D28k）免疫染色、甲硫氨酸脑啡肽（mENK）免疫染色，以及更罕见的生长抑素（SOM）免疫染色。然而，在NP区域，表达钙结合蛋白和mENK免疫染色的中等大小细胞非常罕见，并且存在大量正常成熟纹状体组织中未发现的神经元类型。这些包括：（1）大型、多极、钙结合蛋白阳性神经元，其树突分支良好且染色密集；（2）大型、SOM阳性神经元，具有突出的树突；（3）mENK阳性细胞，比典型的纹状体中等大小mENK免疫反应性神经元小。在尼氏染色中，富含AChE的P区域类似于成熟动物的正常纹状体，而AChE缺乏的NP区域则不然。这些发现表明，胎儿纹状体移植的P区域在成熟时以及出生后大部分发育过程中实现了与正常纹状体相似的表型。P区域中核周钙结合蛋白样免疫反应性的主导表达进一步表明，这些区域有很大比例的组织类似于纹状体基质。相比之下，移植组织NP区域中标志物抗原的表达表明，这些区域主要由非纹状体组织组成，或者它们具有与一些非纹状体细胞混合的未成熟纹状体表型。（摘要截取自400字）
