Hypothalamic projections to cardiovascular centers of the medulla
Hypothalamic projections to cardiovascular centers of the medulla
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DOI：
10.1016/s0006-8993(01)02053-4
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发表时间：
2001-03-16
期刊：
影响因子：
2.9
通讯作者：
Hardy, SGP
中科院分区：
文献类型：
--
作者：
Hardy, SGP
本项目的目的是确定下丘脑神经元投射到延髓的两个心血管中枢，延髓头端腹外侧区(RVLM；血管升压区)和孤束核(NTS；血管降压区)。为了实现这一点，在对大鼠的每个部位进行生理学鉴定后，将荧光示踪剂(快速蓝和二氨基黄)注射到NTS和RVLM。在每种情况下，一个示踪剂被注射到RVLM中，另一个被注射到NTS中。随后，沿着下丘脑吻-尾侧的整个范围观察到标记的神经元，它们在具有已知心血管功能的核团中被发现。虽然两组下丘脑延髓神经元的分布在很大程度上是重叠的，但只有不到0.1%的神经元被双重标记。除了这种重叠的神经元分布，在下丘脑内的一些区域，两组下丘脑延髓神经元在某种程度上是分开的。这种聚集模式见于下丘脑后外侧核(PLH)，其次是室旁核(PVN)。在PLH内，位于丘脑底核内侧，几乎所有标记的神经元都专门投射到NTS。在PVN内，投射到NTS的神经元更多地位于腹侧，而投射到RVLM的神经元更均匀地分布在PVN内。除下丘脑标记外，在未定带和终纹间质核中也观察到标记神经元的簇状分布。在未定带内，几乎所有标记神经元都投射到RVLM。在终纹间质核内，投射到NTS的神经元在该核的背侧部分更为丰富，而投射到RVLM的神经元在腹侧更为丰富。这项研究的发现进一步支持了下丘脑对心血管功能的影响部分是通过下丘脑延髓投射来调节的观点。(C)2001 Elsevier Science B.V.保留所有权利。
The purpose of this project was to identify hypothalamic neurons having projections to two cardiovascular centers of the medulla, the rostral ventrolateral medulla (RVLM; a vasopressor region) and the nucleus of the solitary tract (NTS; a vasodepressor region). To accomplish this, fluorescent tracers (fast blue and diamidino yellow) were injected into NTS and RVLM, after each site had been physiologically identified in rats. In each case, one of the tracers was injected into the RVLM and another was injected into the NTS. Labelled neurons were subsequently observed along the entire rostral-caudal extent of the hypothalamus, where they were found in nuclei having known cardiovascular functions. Although the two groups of hypothalamomedullary neurons were largely overlapped in their distributions, less than 0.1% of the neurons were double labelled. In addition to this overlapping distribution of neurons, there were some areas within the hypothalamus where the two groups of hypothalamomedullary neurons were somewhat segregated. This clustering pattern was observed in the posterolateral hypothalamus (PLH) and, to a much lesser degree, in the paraventricular nucleus (PVN). Within the PLH, lying medial to the subthalamic nucleus, virtually all the labelled neurons projected exclusively to the NTS. Within the PVN, neurons projecting to the NTS were more numerous ventrally, whereas neurons projecting to the RVLM were more evenly dispersed within the PVN. In addition to hypothalamic labeling, clusters of labelled neurons were also observed in the zona incerta and the interstitial nucleus of the stria terminalis. Within the zona incerta, almost all the labelled neurons projected to the RVLM. Within the interstitial nucleus of the stria terminalis, neurons projecting to NTS were much more abundant in the dorsal portion of this nucleus; whereas, neurons projecting to the RVLM were more abundant ventrally. The findings of this study provide additional support to the notion that hypothalamic influences upon cardiovascular functions are in part mediated through hypothalamomedullary projections. (C) 2001 Elsevier Science B.V. All rights reserved.