Studies on neural regeneration and reorganization of neural circuits in neuropathic pain

神经病理性疼痛的神经再生和神经回路重组的研究

基本信息

批准号：
13470039
负责人：
ITO Seiji
金额：
$ 6.21万
依托单位：
Kansai Medical University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
财政年份：
2001
资助国家：
日本
起止时间：
2001 至 2002
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-13470039/
关键词：
spinal cord neuropathic pain transgenic mice neural stem cell nestin GFP nitric oxide 神経再生ネスチン後根神経節

项目摘要

The present study focused on the role of neural regeneration and reorganization of neural circuit in induction of tactile pain (allodynia) by use of pNestin-GFP transgenic mice, which are introduced by a transgene of green fluorescent protein (GFP) driven by a promotor of nestin, an intermediate filament expressed in neural stem cells. To induce allodynia, we established a neuropathic pain model in mice by selective 5^<th> lumbar spinal nerve transection, in addition to intrathecal injection model previously established.We extensively examined the expression of GFP in dorsal root ganglia (DRG) and spinal cord in embryos to adult mice. In whole embryos, the intense expression of GFP was observed around central canals over the spinal cord, which was gradually decreased after birth. This expression around the central canal was confirmed by the lumbar slice. In DRG neurons, GFP was strongly expressed in pericytes, rather than neurons themselves. In neuropathic mice, GFP-positive cells bilaterally increased in the dorsal horn on days 2 and 3 after operation. Following subsidence of inflammation, neuropathic pain was established in the ipsilateral side to the operation and the number of GFP-positive cells was significantly larger in the ipsilateral side than in the contralateral side. These cells were not stained by antibodies specific for neurons and astrocytes. In parallel, we showed that nitric oxide synthase activity was increased around the central canal in neuropathic mice. This finding may imply that the relationship between noxious inputs from the periphery to the central canal and chronic pain or neural plasticity. At present, in order to clarify where neural stem cells proliferate, to where they migrate, and how they differentiate into neurons and glias, the mechanism of activation and the pathway of migration of neural stem cells are under investigation.

本研究的重点是使用 pNestin-GFP 转基因小鼠来研究神经再生和神经回路重组在诱发触觉痛（异常性疼痛）中的作用，该转基因小鼠是由绿色荧光蛋白（GFP）的转基因引入的，该转基因由巢蛋白，一种在神经干细胞中表达的中间丝。为了诱导异常性疼痛，除了先前建立的鞘内注射模型外，我们还通过选择性第5腰椎神经横断建立了小鼠神经病理性疼痛模型。我们广泛检查了背根神经节（DRG）和脊髓中的GFP表达从胚胎到成年小鼠。在整个胚胎中，脊髓中央管周围观察到GFP的强烈表达，但在出生后逐渐减少。腰椎切片证实了中央管周围的这种表达。在 DRG 神经元中，GFP 在周细胞中强烈表达，而不是神经元本身。在神经病小鼠中，术后第 2 天和第 3 天，背角双侧 GFP 阳性细胞增加。炎症消退后，手术同侧出现神经性疼痛，同侧 GFP 阳性细胞数量明显多于对侧。这些细胞没有被神经元和星形胶质细胞特异性抗体染色。与此同时，我们发现神经病小鼠中央管周围的一氧化氮合酶活性增加。这一发现可能意味着从外周到中央管的有害输入与慢性疼痛或神经可塑性之间的关系。目前，为了阐明神经干细胞在哪里增殖、迁移到哪里以及如何分化为神经元和胶质细胞，神经干细胞的激活机制和迁移途径正在研究中。