ROLE OF PEPTIDES AS A TROPHIC FACTOR ON THE INPLANTED AND CULTURED NEURONS

将5、6只经dht治疗的成年大鼠的中脑和中脑髓组织块移植到小脑中。用免疫组织化学方法观察移植物中5 -羟色胺能神经元和多巴胺能神经元轴突生长的程度。中脑中缝移植物生长出的血清素能纤维在移植物附近的小脑皮层显示出神经支配过度的模式。此外，在颗粒层观察到5 -羟色胺能纤维的肾小球样积累。在中缝髓移植物中，相对丰富的生长的5 -羟色胺能纤维在移植物附近的小脑皮层呈层状组织，与正常分布模式相似。这些结果表明，位于中脑中叶移植物内的5 -羟色胺能神经元和多巴胺能神经元在将其过程延伸到宿主小脑的能力上明显不同，这进一步证明了生长中的5 -羟色胺能纤维与其末端纤维目标之间存在特定的相互作用。突变小鼠的纯合子（Pdn/Pdn）显示出一些脑异常，s -100 β显著降低。为了阐明s -100 β阻滞产生对单胺能神经元系统发育的影响，我们对Pdn/Pdn小鼠的TH、5-HT、s -100 β和GFAP进行了免疫细胞化学研究，并对5-HT和5-HIAA进行了HPLC研究，并与对照组进行了比较。在这两种动物中，s -100 β阳性细胞和血清素能纤维广泛分布于整个大脑。Pdn/Pdn小鼠海马和尾背皮层s -100 β阳性细胞和血清素能纤维明显减少。GFAP阳性纤维在新皮层和海马中也有异常分布。这些结果表明s -100 β是一种血清素能生长因子，这种突变小鼠是研究神经胶质神经营养相互作用的有用模型。

Pieces of mesencephalic and medullary raphe tissues were transplanted into the cerebella of 5,6 DHT-treated adults rats. The extent of axonal outgrowth of serotonergic and dopaminergic neurons in the grafts was immunohistochemically studied. The outgrowing serotonergic fibers from the mesencephalic raphe graft showed a hyperinnervation pattern in the cerebellar cortex adjacent to the graft. Furthermore, a glomerulus-like accumulation of serotonergic fibers was observed in the granular layer. In the cases of medullary raphe grafts, the relatively abundant outgrowing serotonergic fibers showed a laminar organization in the cerebellar cortex near the graft, which was similar to the normal distributional pattern. These results indicate that serotonergic and dopaminergic neurons located within the mesencephalic raphe graft clearly differed from each other in their ability to extend their processes into the host cerebellum, which provides further evidence for the existence of specific interactions between outgrowing serotonergic fibers and their terminal fiber targets. The homozygote (Pdn/Pdn) of the mutant mouse showed several brain abnormalities, and a significant decrease of S-100beta. In order to clarify the effects of the retarded production of S-100beta on the development of monoaminergic neuron system, immunocytochemical studies of TH, 5-HT, S-100beta and GFAP, and HPLC study for 5-HT and 5-HIAA of Pdn/Pdn mouse were examined, the results were compared with the control. In both animals, S-100beta positive cells and serotonergic fibers were widely distributed throughout the brain. however, hippocampus and caudo-dorsal cortex of Pdn/Pdn mouse were markedly reduced in S-100beta positive cells and serotonergic fibers. Abnormal distribution of GFAP positive fibers was also observed in the neocortex and hippocampus. These results suggest that S-100beta is a serotonergic growth factor, and this mutant mouse is a useful model to study neuro-glial neurotrophic interactions.