Strömberg I, Almqvist P, Bygdeman M, Finger T E, Gerhardt G, Granholm A C, Mahalik T J, Seiger A, Olson L, Hoffer B
Department of Histology and Neurobiology, Karolinska Institute, Stockholm, Sweden.
J Neurosci. 1989 Feb;9(2):614-24. doi: 10.1523/JNEUROSCI.09-02-00614.1989.
Human fetal mesencephalic tissue obtained from elective first-trimester abortions was grafted to 6-hydroxydopamine-denervated striatum of athymic (nude) rats. After 3-6 months, the transplants were evaluated by light and electron microscopy using antibodies against tryosine hydroxylase (TH), human specific Thy-1 (Thy-1), 5-hydroxytryptamine (5-HT), and laminin. In vivo chronoamperometric studies of K+-induced release of electroactive species were done prior to the histochemical evaluations. At the light microscopical level, Thy-1-immunoreactivity was evenly distributed throughout the entire transplants. Thy-1-immunoreactive nerve fibers were observed radiating from the graft into the host striatum. In sections that were double-stained with antibodies against Thy-1 and TH, such nerve fibers contained both markers. Also 5-HT-immunoreactive cells were found in the grafts with processes both in the grafts and radiating into host neuropil. Laminin immunohistochemistry showed an even distribution of capillaries in the graft with less density than in host brain, suggesting immaturity of graft tissue. At the ultrastructural level, TH-immunoreactive axons made symmetric contacts with unlabeled dendritic shafts and dendritic spines within the host brain. A few asymmetric contacts with TH-immunoreactive axons were seen. 5-HT-immunoreactive terminals made both symmetric and asymmetric contacts with unlabeled dendritic shafts and spines. In vivo chronoamperometry using local application of K+ revealed average signals that were lower on the transplanted side than in control striatum. However, close to the grafts significant amounts of the K+-evoked signal amplitudes were as large as 1.3 microM, and the ratio of the reduction to oxidation currents suggested release of a mixture of dopamine and 5-HT. Taken together, this study shows that human fetal mesencephalic tissue pieces survive grafting into nude rats, develop normal vascularization, and express coexistence of TH- and Thy-1-immunoreactivity. Human TH- and 5-HT-immunoreactive nerve fibers form synapses in host striatum and release monoamine neurotransmitters.
从选择性早期人工流产中获取的人胎儿中脑组织被移植到无胸腺（裸）大鼠经6-羟基多巴胺去神经支配的纹状体中。3至6个月后，通过光学显微镜和电子显微镜，使用抗酪氨酸羟化酶（TH）、人特异性Thy-1（Thy-1）、5-羟色胺（5-HT）和层粘连蛋白的抗体对移植组织进行评估。在进行组织化学评估之前，对钾离子诱导的电活性物质释放进行了体内计时电流法研究。在光学显微镜水平上，Thy-1免疫反应性均匀分布于整个移植组织中。观察到Thy-1免疫反应性神经纤维从移植物向宿主纹状体呈放射状分布。在使用抗Thy-1和TH抗体进行双重染色的切片中，此类神经纤维同时含有这两种标记物。在移植物中还发现了5-HT免疫反应性细胞，其突起存在于移植物中并向宿主神经毡呈放射状分布。层粘连蛋白免疫组织化学显示移植物中毛细血管分布均匀，但其密度低于宿主脑，提示移植组织不成熟。在超微结构水平上，TH免疫反应性轴突与宿主脑内未标记的树突干和树突棘形成对称突触。可见少数与TH免疫反应性轴突形成的不对称突触。5-HT免疫反应性终末与未标记的树突干和树突棘形成对称和不对称突触。使用局部施加钾离子的体内计时电流法显示，移植侧的平均信号低于对照纹状体。然而，在移植物附近，大量钾离子诱发的信号幅度高达1.3微摩尔，还原电流与氧化电流的比值表明释放了多巴胺和5-HT的混合物。综上所述，本研究表明人胎儿中脑组织块在移植到裸大鼠后能够存活，形成正常的血管化，并表达TH和Thy-1免疫反应性的共存。人TH和5-HT免疫反应性神经纤维在宿主纹状体中形成突触并释放单胺类神经递质。
