Regulatory Mechanism of Synthesis of Peptides and Receptors in Motoneurons : in Situ Hybridization Study

运动神经元肽和受体合成的调控机制：原位杂交研究

基本信息

批准号：
01570027
负责人：
SENBA Emiko
金额：
$ 1.34万
依托单位：
Osaka University
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (C)
财政年份：
1989
资助国家：
日本
起止时间：
1989 至 1990
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-01570027/
关键词：
Motoneuron Axotomy In Situ Hybridization Galanin CCK CGRP Neuronal Hicotinic Ach Receptor NGF receptor αーCGRP βーCGRP in situ ハイブリダイゼ-ション NGF リセプタ-axotomy(軸索切断)ペプタイド NGFーリセプタ-アセチルコリン・リセプタ-mRNA

项目摘要

Acetylcholine (Ach) has been a sole candidate of neurotransmitter in motoneurons for a long time. Recent advance of molecular biology and applied morphological techniques have revealed the presence of neuropeptides in moto-neurons. These peptides are considered to modulate the activity of moto-neurons and muscles, or exert neurotrophic effects on them. In addition to peptides, neurotransmitter receptors are also synthesized in moto-neurons indicating that various kinds of neurotransmitters regulate the activity of motoneurons. Moreover, motoneurons are under the control of neurotrophic factors, such as nerve growth factor (NGF). It has been demonstrated that both NGF-receptor mRNA and NGF-receptor protein are expressed in developing motoneurons, and also in mature motoneurons under some experimental conditions. In the present study, we employed in situ hybridization histochemistry to demonstrate how the production of these peptides and receptors are regulated in injured motoーneurons.It … More is well documented that calcitonin gene-related peptide (CGRP)-like immunoreactivity in motoneurons of the rat spinal cord is increased after peripheral axotomy. In these neurons, axotomy caused the increase of alpha -CGRP mRNA, but not beta -CGRP mRNA, indicating that alpha -CGRP and beta -CGRP are regulated independently and have different roles in motoneurons. We have also shown that alpha - and beta -subunits constructing neuronal nicotinic Ach receptor are also differentially regulated in motoneurons. alpha 3 and beta 2 subunit mRNAs were expressed in 12% and 40% of facial motoneurons of the rat. alpha 3 subunit mRNA signals disappeared in response to axotomy, whereas the beta 2 subunit mRNA signal was remarkably enhanced.Some 38%, 55% and 7% of the facial motoneurons of the rat expressed alpha -CGRP, beta -CGRP and CCK mRNAs, respectively. No galanin mRNA containing motoneurons were observed. The levels of mRNA for alpha -CGRP, CCK and galanin were increased while beta -CGRP mRNA level was decreased after axotomy. The levels of mRNAs for these peptides returned to the control values by 2-4 weeks after injury, nerve transection had greater effects on beta -CGRP, CCK and galanin mRNAs than did nerve crush. These changing patterns of neuropeptides in motoneurons do not coincide with that of NGF-receptor mRNA after the same procedures ; the increase of NGF-receptor mRNA with crushing was more pronounced than with transection from the 3rd to the 14th day after the injury. These findings suggest that the production of these peptides in motoneurons is not regulated by NGF. Less

长期以来，乙酰胆碱（Ach）一直是运动神经元中神经递质的唯一候选者，分子生物学和应用形态学技术的最新进展揭示了运动神经元中神经肽的存在，这些肽被认为可以调节运动神经元的活性。和肌肉，或对其产生神经营养作用除了肽之外，运动神经元中还合成神经递质受体，这表明各种神经递质具有调节作用。此外，运动神经元受神经营养因子（例如神经生长因子（NGF））的控制。已经证明，NGF-受体mRNA和NGF-受体蛋白在发育中的运动神经元中表达，并且也在成熟的运动神经元中表达。在本研究中，我们采用原位杂交组织化学来证明这些肽和受体的产生如何在受损的运动神经元中受到调节。 … 更多证据表明，外周轴突切除术后，大鼠脊髓运动神经元中的降钙素基因相关肽 (CGRP) 样免疫反应性增加。在这些神经元中，轴突切除导致 α -CGRP mRNA 增加，但不增加 β -CGRP mRNA。，表明 α-CGRP 和 β-CGRP 是独立调节的，并且在运动神经元中具有不同的作用。我们还表明，构建神经元烟碱 Ach 受体的 α 和 β 亚基也是独立调节的。 α 3 和 β 2 亚基 mRNA 在 12% 和 40% 的大鼠面部运动神经元中表达差异，轴切术导致 α 3 亚基 mRNA 信号消失，而 β 2 亚基 mRNA 信号显着增强。大鼠的面部运动神经元分别有38%、55%和7%表达α-CGRP、β-CGRP和CCK mRNA，无甘丙肽mRNA。观察到含有运动神经元的 α-CGRP、CCK 和甘丙肽的 mRNA 水平在轴突切除后增加，而 β-CGRP mRNA 水平降低。这些肽的 mRNA 水平在 2-4 周后恢复到对照值。损伤、神经横断对 β-CGRP、CCK 和甘丙肽 mRNA 的影响比神经挤压时更大，运动神经元中神经肽的这些变化模式与 NGF 受体 mRNA 的变化模式不一致。损伤后第 3 天至第 14 天，NGF 受体 mRNA 的增加比横切更为明显。这些结果表明，运动神经元中这些肽的产生不受 NGF 的调节。