Suhonen J, Hervonen A
Department of Public Health, University of Tampere Medical School, Finland.
J Neural Transplant Plast. 1993 Oct-Dec;4(4):267-78. doi: 10.1155/NP.1993.267.
The purpose of this study was to investigate the viability and ultrastructural characteristics of intraocular superior cervical ganglion (SCG) grafts from young (3 months), aged (24 months) and very old (36 months) rats after short-term (1 month) grafting. The formaldehyde-induced fluorescence (FIF) technique for histochemical demonstration of catecholamines was used to indicate the functionality of transplanted neurons. Ultrastructural changes in grafts were demonstrated by electron microscopy. Four weeks after transplantation, catecholamine histofluorescence in young transplants was almost as strong as in the intact ganglia, while aged and very old grafts showed decreased fluorescence and contained a marked accumulation of autofluorescent lipopigment bodies. Catecholamine histofluorescence showed a decrease in neuronal density of 47%, 59% and 68% in young, aged and very old grafted ganglia, respectively. The shape of most of the transplanted neurons did not differ from that in the intact ganglia, but the average diameter of neurons was decreased after grafting. In electron microscopy, both neurons with normal in vivo fine structure and neurons showing some abnormal cytological alterations were seen in each age group of the transplants. The most prominent feature after grafting was the accumulation of different types of lipopigment bodies in the perikarya of neurons. the organization of the rough endoplasmic reticulum was more irregular in transplanted neurons than in intact neurons. In addition, the amount of neurofilament aggregates increased and some mitochondria were swollen in neurons after transplantation. These results suggest that young sympathetic ganglion tissue survives rather well after transplantation into the anterior eye chamber, while in the aged sympathetic ganglion implants the survival rate is poorer. However, aged and very old SCG grafts were shown to contain and continue to produce noradrenaline, indicating that sympathetic neurons maintain their plasticity and regenerative ability in advanced age. Catecholamine histofluorescence and fine structural changes in the cell structure of grafted sympathetic neurons may indicate an accelerated aging process induced by the transplantation procedure.
本研究的目的是调查幼年（3个月）、老年（24个月）和非常老龄（36个月）大鼠的眼内颈上神经节（SCG）移植物在短期（1个月）移植后的活力和超微结构特征。采用甲醛诱导荧光（FIF）技术进行儿茶酚胺的组织化学显示，以表明移植神经元的功能。通过电子显微镜观察移植物的超微结构变化。移植后四周，幼年移植物中的儿茶酚胺组织荧光几乎与完整神经节中的一样强，而老年和非常老龄的移植物荧光减弱，且含有大量自发荧光脂褐质体的积累。儿茶酚胺组织荧光显示，幼年、老年和非常老龄移植神经节中神经元密度分别降低了47%、59%和68%。大多数移植神经元的形状与完整神经节中的无异，但移植后神经元的平均直径减小。在电子显微镜下，每个移植年龄组中都可见到体内精细结构正常的神经元和显示出一些异常细胞学改变的神经元。移植后最突出的特征是神经元胞体中不同类型脂褐质体的积累。移植神经元中粗面内质网的组织比完整神经元更不规则。此外，移植后神经元中神经丝聚集体的数量增加，一些线粒体肿胀。这些结果表明，幼年交感神经节组织移植到眼前房后存活良好，而老年交感神经节移植物的存活率较低。然而，老年和非常老龄的SCG移植物被证明含有并继续产生去甲肾上腺素，表明交感神经元在高龄时仍保持其可塑性和再生能力。移植交感神经元的儿茶酚胺组织荧光和细胞结构的精细结构变化可能表明移植过程诱导了加速衰老过程。
