INVESTTGATON OF FACTORS PROMOTING HIPPOCAMPAL SCLEROSIS IN THE MOUSE MODEL OF PROGRESSIVE HYPERTROPHY OF DENTATE GYRUS IN HIPPOCAMPUS.

小鼠海马内单次注射少量kainic acid (KA)，可诱导海马颗粒细胞从注射后第4天开始渐进性弥散和增大，持续到第8周。在本研究中，我们研究了KA注射海马中是否涉及影响神经元分化的因素。1、培养结果：注射KA后第7天，收集分散海马的蛋白提取物和细胞外液（ECF）。将这两种样品分别加入神经元干细胞或海马切片培养基中。将KA注射海马蛋白提取物添加到海马切片培养中，可诱导阿蒙角锥体细胞的神经元细胞变性。注射KA蛋白提取物或ECF均未影响海马神经干细胞向神经元或胶质细胞的分化。由于ECF与人工脑脊液没有任何差异，而脑脊液是收集ECF的载体，因此ECF的浓度被认为很低。从本质上讲，ECF比全细胞蛋白提取物更能检测环境因素。然而，从小鼠海马中收集足够量的ECF可能相当困难。未来的研究将需要另一种动物或方法。2：如上文(1)所述，蛋白提取物对切片培养海马锥体细胞有一定的神经毒性。这种神经毒性被认为与谷氨酸或其相关物质有关，因为已知这些动物会患上癫痫。它们的过度表达可能是颗粒细胞分散的一个原因。为了验证这一假设，我们给药谷氨酸拮抗剂，并观察齿状回的变化。我们发现NMDA受体的激活调节了弥散的发展。3：我们研究了分散海马中特异性表达的mRNA，作为先前科学研究资助(C)的主题，我们采用差异显示方法研究了mRNA。Flamingo/Celsr2被确定为可能与分散有关的候选基因之一，结果发表在《Brain Research》杂志上。少

Single injection of small amount of kainic acid (KA) into mouse hippocampus induces the progressive dispersion and the enlargement of hippocampal granule cells that starts from 4days and lasts till 8weeks after KA injection. In this study, we investigated whether the factors that affect neuronal differentiations are involved or not in the KA injected hippocampus.1, The results of culture studies: At 7 days after KA injection, protein extracts and extracellular fluid (ECF) of the dispersed hippocampus were collected. These two kinds of samples were added to the culture medium of neuronal stem cells or hippocampal slices. Adding the protein extract from the KA injected hippocampus onto slice hippocampal culture induced the neuronal cell degeneration of pyramidal cells of Ammon's horn. The neuronal stem cells did not influenced their differentiation to neuron or glia either by protein extracts or ECF of KA injected hippocampus. Since the ECF did not induce any difference from the artifici … More al cerebrospinal fluid, which is a vehicle to collect the ECF, the concentration of ECF was thought to be very low. Essentially ECF is more important than whole cell protein extracts to examine the environmental factors. However it might be quite difficult to collect enough amount of ECF for this experiment from mouse hippocampus. Another animals or method will be needed for future studies.2: As mentioned above (1), protein extract showed some neurotoxicity to pyramidal cells of slice cultured hippocampus. This neurotoxicity was supposed to relate to glutamate or their related substances since the animals have been known to develop epilepsy. And their over-expression might be a cause of granule cell dispersion. To examine this hypothesis the antagonists of glutamate were administrated and the changes of dentate gyros were examined. And we found that the activation of NMDA receptor regulates the development of the dispersion. This result was submitted to Epilepsia.3: We investigated the mRNA, which were expressed specifically in dispersed hippocampus, by differential display method as an theme of the previous Grant-in-Aid for Scientific Research ( C ). Flamingo/Celsr2 was identified as one of the candidate gene that might be related to the dispersion, and the result was reported in Brain Research. Less