Activation of the Opioidergic Descending Pain Control System Underlies Placebo Analgesia
Activation of the Opioidergic Descending Pain Control System Underlies Placebo Analgesia
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DOI：
10.1016/j.neuron.2009.07.014
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发表时间：
2009-08-27
期刊：
影响因子：
16.2
通讯作者：
Buechel, Christian
中科院分区：
文献类型：
--
作者：
Eippert, Falk;Bingel, Ulrike;Buechel, Christian
安慰剂镇痛涉及内源性阿片类药物系统，因为阿片类药物拮抗剂纳洛酮的给药会降低安慰剂镇痛。为了研究安慰剂镇痛的阿片能机制，我们将纳洛酮给药与功能性磁共振成像相结合。纳洛酮降低行为和神经安慰剂效应，以及安慰剂诱导的疼痛调节皮层结构，如喙前扣带皮层（rACC）的反应。在一项脑干特异性分析中，我们观察到在下行疼痛控制系统的关键结构（包括下丘脑、导水管周围灰质（PAG）和延髓头端腹内侧区（RVM））中，安慰剂诱导的反应存在类似的纳洛酮调制。最重要的是，纳洛酮消除了安慰剂诱导的rACC和PAG之间的偶联，这预测了神经和行为安慰剂效应以及RVM的激活。这些研究结果表明，阿片类药物在疼痛调节领域的信号传导和下行疼痛控制系统的下游效应器的预测是至关重要的安慰剂镇痛。
Placebo analgesia involves the endogenous opioid system, as administration of the opioid antagonist naloxone decreases placebo analgesia. To investigate the opioidergic mechanisms that underlie placebo analgesia, we combined naloxone administration with functional magnetic resonance imaging. Naloxone reduced both behavioral and neural placebo effects as well as placebo-induced responses in pain-modulatory cortical structures, such as the rostral anterior cingulate cortex (rACC). In a brain stem-specific analysis, we observed a similar naloxone modulation of placebo-induced responses in key structures of the descending pain control system, including the hypothalamus, the periaqueductal gray (PAG), and the rostral ventromedial medulla (RVM). Most importantly, naloxone abolished placebo-induced coupling between rACC and PAG, which predicted both neural and behavioral placebo effects as well as activation of the RVM. These findings show that opioidergic signaling in pain-modulating areas and the projections to downstream effectors of the descending pain control system are crucially important for placebo analgesia.