Postnatal changes in the spatial distributions of substance P and neurokinin-1 receptor in the trigeminal subnucleus caudalis of mice
Postnatal changes in the spatial distributions of substance P and neurokinin-1 receptor in the trigeminal subnucleus caudalis of mice
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DOI：
10.1016/j.devbrainres.2004.12.005
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发表时间：
2005-03-22
期刊：
影响因子：
--
通讯作者：
Maeda, T
中科院分区：
文献类型：
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作者：
Aita, M;Seo, K;Maeda, T
口面区的伤害性传入信号通过谷氨酸和/或P物质（SP）的释放传递到三叉神经尾侧亚核（Vc）。虽然已知伤害性感受的传递和/或调节机制在出生后时期发展，但伤害性感受和/或调节的具体发育变化仍不清楚。本研究采用免疫组织化学和定量分析方法，研究了生后小鼠Vc中SP及其受体NK 1受体（NK 1 R）之间空间关系的变化。在灌注和固定后，从C57 BL/6 N小鼠（1、2、4和8周龄）中取出髓质，并以40 μ m的厚度水平切割。统计分析SP和NK 1 R免疫反应区的相对密度及其随年龄的变化。1周龄和2周龄小鼠在边缘层（Mar）和大细胞层（Mag）的深部显示出相对较高的SP阳性结构密度。SP在表层Vc中的分布保持不变，但在深层Mag中的密度随着年龄的增长而逐渐下降，导致出生后4周后完全丧失。NK 1 R免疫反应的分布模式与SP免疫反应的分布模式相似，但在出生后的不同时期，这种分布模式没有变化，SP和NK 1 R的双荧光染色显示，SP阳性结构与NK 1 R仅在浅层有中度的直接接触。SP和NK 1 R在Vc中的分布及生后变化提示Vc中除了突触传递外，还可能存在另一种伤害性传入传递机制，即容积传递。(c)2005 Elsevier B.V保留所有权利。
Nociceptive afferent signals from the orofacial area are transmitted to the trigeminal subnucleus caudalis (Vc) through the release of glutamate and/or substance P (SP). Although nociceptive transmission and/or modulating mechanisms are known to develop during the postnatal period, the specific developmental changes in nociception and/or modulation remain unclear. The present study examined postnatal changes in the spatial relationship between SP and its receptor, the NK1 receptor (NK1R), in the mouse Vc by immunohistochemistry and quantitative analysis. The medulla was removed from C57BL/6N mice (1, 2, 4, and 8 weeks of age) after perfusion and fixation, and cut horizontally at a thickness of 40 mu m. The relative densities of SP- and NK1R-immunoreactive areas and their changes with age were assessed statistically. One- and 2-week-old mice showed relatively high densities of SP-positive structures in the marginal layer (Mar) and the deep part of the magnocellular layer (Mag). The SP distribution in the superficial Vc remained unchanged, but the density in the deep Mag gradually decreased with age, resulting in a complete loss after postnatal week 4. The NK1R-irnmunoreactivity exhibited a similar distribution pattern to that of SP, but the pattern remained unchanged during the postnatal period.Double-iinrnunofluorescence staining for SP and NK1 R demonstrated only moderate direct contact of SP-positive structures with NK1R in the superficial area. These separate distributions and the postnatal changes in SP and NK1R suggest the possibility of another nociceptive afferent transmission mechanists, that is, volume transmission, in the Vc other than synapse-mediated transmission. (c) 2005 Elsevier B.V All rights reserved.