Hypothalamospinal oxytocinergic antinociception is mediated by GABAergic and opiate neurons that reduce A-delta and C fiber primary afferent excitation of spinal cord cells
Hypothalamospinal oxytocinergic antinociception is mediated by GABAergic and opiate neurons that reduce A-delta and C fiber primary afferent excitation of spinal cord cells
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DOI：
10.1016/j.brainres.2008.10.030
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发表时间：
2009-01-09
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;Rojas-Piloni, Gerardo;Rodriguez-Jimenez, Javier
最近的研究结果表明，催产素（OT）作为一种通过室旁下丘脑核（PVN）下降纤维的介质，在抗痛觉和镇痛中起着新的原始机制。在大鼠中，电刺激PVN或局部应用OT选择性地抑制浅表背角神经元的a - δ和C纤维反应，这种抑制被选择性OT拮抗剂逆转。然而，关于参与这种现象的机制和脊柱元素知之甚少。本研究表明，局部应用二胡兰可阻断PVN电刺激或OT应用产生的效应。PVN电刺激也激活了II层的神经元亚群。这些PVN-On细胞负责扩大局部gaba能抑制。这一结果强化了椎上下行控制疼痛处理使用脊髓中特定的神经元通路，以产生涉及gaba能中间神经元的抗感觉。此外，局部使用纳洛酮或一种多阿片受体拮抗剂-氟那曲胺只能部分阻断OT应用或PVN电刺激产生的抑制作用。因此，这种OT机制只在很小程度上涉及阿片类药物的参与。ot特异性的内源性下行通路是解决慢性疼痛特别是神经性疼痛的一种有趣的机制。(C) 2008 Elsevier B.V.版权所有
Recent results implicate a new original mechanism involving oxytocin (OT), as a mediator via descending fibers of the paraventricular hypothalamic nucleus (PVN), in antinociception and analgesia. In rats electrical stimulation of the PVN or topical application of OT selectively inhibits A-delta and C fiber responses in superficial dorsal horn neurons, and this inhibition is reversed by a selective OT antagonist. However, little is known about the mechanisms and the spinal elements participating in this phenomenon. Here we show that topical application of bicuculline blocks the effects produced by PVN electrical stimulation or OT application. PVN electrical stimulation also activates a subpopulation of neurons in lamina II. These PVN-On cells are responsible for the amplification of local GABAergic inhibition. This result reinforces the suggestion that a supraspinal descending control of pain processing uses a specific neuronal pathway in the spinal cord in order to produce antinociception involving a GABAergic interneuron. Moreover, the topical administration of naloxone or a mu-opiate receptor antagonist beta-funaltrexamine only partially blocks the inhibitory effects produced by OT application or PVN electrical stimulation. Thus, this OT mechanism only involves opiate participation to a minor extent. The OT-specific, endogenous descending pathway represents an interesting mechanism to resolve chronic pain problems in special the neuropathic pain. (C) 2008 Elsevier B.V. All rights reserved.