Branched oxytocinergic innervations from the paraventricular hypothalamic nuclei to superficial layers in the spinal cord
Branched oxytocinergic innervations from the paraventricular hypothalamic nuclei to superficial layers in the spinal cord
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DOI：
10.1016/j.brainres.2007.05.031
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发表时间：
2007-07-30
期刊：
影响因子：
2.9
通讯作者：
Rodriguez-Jimenez, Javier
中科院分区：
文献类型：
--
作者：
Condes-Lara, Miguel;Martinez-Lorenzana, Guadalupe;Rodriguez-Jimenez, Javier
下丘脑的室旁核（PVN）是一个有趣的结构，由于其不同的神经元群、神经递质和对其他中枢神经系统结构的投射而具有多种功能。 PVN 是中枢神经系统中催产素 (OT) 的主要来源。事实上，逆行和顺行示踪剂已证实 PVN 直接投射到脊髓，并且超过 50% 的投射是催产素能的。这种 OT 下降投射被认为是一个内源性系统，控制到达脊髓的伤害性信息。然而，我们没有关于不同脊髓节段的 OT 下行神经支配的具体组织的信息。本研究的目的是确定突出的 PVN 神经元是否到达颈部区域，然后继续到达腰部区域。也就是说，我们试图确定 OT 投射细胞是否具有主题或弥漫性投射，以获得组织学数据来支持其他地方描述的内源性 OT 弥漫性镇痛机制。考虑到这一目的，我们将 OT 免疫组织化学技术与脊髓中的逆行神经元示踪剂相结合。我们将二脒黄 (DY) 用于浅表背角颈段，将真蓝 (TB) 用于腰段。数据是从八只经过适当注射的大鼠身上收集的。我们仅使用示踪剂沉积仅限于背角浅层 I 和 II 的动物。主要观察到同侧投影，但在对侧 PVN 中也观察到染色的神经元。大部分染色的 PVN 细胞是双标记的，但有些是单标记的。结合逆行示踪技术和 OT 检测程序，我们观察到了三重标记的神经元。目前的结果表明，PVN 神经元至少将侧支循环发送到脊髓背角的浅表颈段和腰段。此外，其中一些染色细胞使用 OT 作为神经递质。这些结果具有很大的相关性，因为它们证明了 PVN 在体感系统中发挥着重要作用，并且它们支持了参与镇痛的内源性机制的解剖学证据。最后，我们还描述了中缝核双标记细胞（DY + TB）信号传导弥漫性下降投射，该细胞核参与内源性镇痛。 (C) 2007 Elsevier B.V. 保留所有权利。
The paraventricular nucleus (PVN) of the hypothalamus is an interesting structure with diverse functions due to its different neuronal populations, neurotransmitters, and projections to other central nervous system structures. The PVN is a primary source of oxytocin (OT) in the central nervous system. In fact, a direct PVN projection to the spinal cord has been demonstrated by retrograde and anterograde tracers, and more than the 50% of this projection is oxytocinergic. This OT descending projection is proposed to be an endogenous system that controls the nociceptive information arriving at the spinal cord. However, we have no information about the specific organization of the OT descending innervations to the different spinal cord segments. The aim of the present study was to determine whether the projecting PVN neurons arrive at cervical regions and then continue to lumbar regions. That is, we sought to establish if the OT projecting cells have a topic or a diffuse projection in order to obtain histological data to support the endogenous OT diffuse mechanism of analgesia described elsewhere. With this purpose in mind we combined the OT immunohistochemistry technique with retrograde neuronal tracers in the spinal cord. We applied Diamidino Yellow (DY) for the superficial dorsal horn cervical segments and True Blue (TB) for the lumbar segments. Data were collected from eight rats with well-placed injections. We only used the animals in which the tracer deposits were confined to superficial layers I and II of the dorsal horn. A mainly ipsilateral projection was observed, but stained neurons were also observed in the contralateral PVN. A large fraction of the stained PVN cells was doubled labeled but some were single labeled. Combining the retrograde tracer techniques and the OT detection procedure, we observed triple-labeled neurons. The present results demonstrate that PVN neurons send collaterals at least to the superficial cervical and lumbar segments of the dorsal horn of the spinal cord. Moreover, some of these stained cells use OT as a neurotransmitter. These results are of great relevance since they demonstrate that the PVN plays an important role in the somatosensorial system, and they support anatomic evidence of an endogenous mechanism involved in analgesia. Finally, we also describe median raphe nucleus double-labeled cells (DY+TB) signaling diffuse descending projections for this largely studied nucleus that are involved in endogenous analgesia. (C) 2007 Elsevier B.V. All rights reserved.