Department of General Psychiatry, Center for Psychosocial Medicine, University Hospital Heidelberg, Germany.
Department of General Psychiatry, Center for Psychosocial Medicine, University Hospital Heidelberg, Germany; Department of Psychology and Psychotherapy, Ludwigs-Maximilian-University München, Germany.
Neuropharmacology. 2020 Jul;171:108105. doi: 10.1016/j.neuropharm.2020.108105. Epub 2020 Apr 13.
The neuropeptide oxytocin (OT) has been shown to play a modulatory role in nociception. However, analgesic effects of OT in chronic pain conditions remain elusive and the neural underpinnings have not yet been investigated in humans. Here, we conducted an exploratory, randomized, placebo-controlled, cross-over study to examine effects of intranasal OT in male patients suffering from chronic low back pain (CBP) versus healthy controls (HC). N = 22 participants with CBP and 22 HCs were scanned using functional magnetic resonance imaging (fMRI) while they continuously rated either spontaneously occurring back pain or acute thermal pain stimuli applied to the lower back. During heat pain processing we found that OT versus PL attenuated pain intensity ratings and increased BOLD responses in the caudate nucleus of the striatum in CBP versus HCs. Spontaneously experienced pain in contrast to heat pain was associated with activation changes in the medial frontal cortex (MFC) and the anterior cingulate cortex (ACC) as reported in previous studies. However, we did not observe OT effects on spontaneously experienced pain in CBP patients. Overall, our preliminary data may suggest that the striatum is a key structure underlying the pain-modulating effects of OT in patients with chronic pain and adds to the growing evidence linking the neuropeptide to pain modulation in humans. Further studies on neuronal OT effects in larger samples of chronic back pain patients are needed to understand probable mechanisms of OT effects in chronic pain. This article is part of the special issue on Neuropeptides.
神经肽催产素（OT）已被证明在痛觉中起调节作用。然而，OT 在慢性疼痛情况下的镇痛作用仍不清楚，其在人类中的神经基础尚未被研究过。在这里，我们进行了一项探索性、随机、安慰剂对照、交叉研究，以检查鼻内 OT 对慢性下背痛（CBP）男性患者与健康对照（HC）的影响。N = 22 名 CBP 患者和 22 名 HCs 参与者使用功能磁共振成像（fMRI）进行扫描，同时他们连续评估自发出现的背痛或应用于下背部的急性热痛刺激。在热痛处理过程中，我们发现 OT 与 PL 相比，在 CBP 患者的尾状核中减弱了疼痛强度评分并增加了大脑纹状体的 BOLD 反应，而在 HCs 中则增强了大脑纹状体的 BOLD 反应。与热痛相反，我们发现自发经历的疼痛与之前研究中报道的内侧前额叶皮层（MFC）和前扣带皮层（ACC）的激活变化有关。然而，我们没有观察到 OT 对 CBP 患者自发经历的疼痛有影响。总的来说，我们的初步数据可能表明，纹状体是 OT 在慢性疼痛患者中调节疼痛的关键结构，并为越来越多的证据表明该神经肽在人类中与疼痛调节有关提供了补充。需要对更大样本的慢性腰痛患者进行关于神经元 OT 效应的进一步研究，以了解 OT 在慢性疼痛中的可能作用机制。本文是神经肽特刊的一部分。
