Danish Pain Research Center, Aarhus University Hospital, Aarhus, Denmark.
Pain. 2013 Aug;154(8):1469-76. doi: 10.1016/j.pain.2013.05.011. Epub 2013 May 14.
The perception of pain is determined by a combination of genetic, neurobiological, cultural, and emotional factors. Recent studies have demonstrated an association between specific genotypes and pain perception. Particular focus has been given to the triallelic polymorphism in the promoter region of the serotonin transporter gene in relation to pain perception. The aim of this study was to investigate whether the modulatory effect of emotions mediated by visual stimuli on muscular pain perception is genotype dependent. A total of 150 healthy subjects were selected on the basis of their polymorphism in the serotonin transporter gene. First, visual conditioning was performed with positive, negative, and neutral pictures from the International Affective Picture System, and the unpleasantness/pleasantness of the pictures was rated. Second, visual conditioning stimuli were presented while experimental jaw muscle pain was evoked by injection of hypertonic saline into the masseter muscle, and participants continuously rated pain intensity on an electronic visual analogue scale. The pictures induced similar changes in emotions across the 3 genotype groups, and hypertonic saline evoked moderate pain levels in all participants. However, in participants with a high expression of the serotonin transporter protein, conditioning with negative pictures increased pain intensity and positive pictures decreased pain intensity when compared with neutral pictures. In contrast, there were no significant effects of the pictures on pain perception in participants with either intermediate or low expression of the protein. These results suggest that polymorphisms in the serotonin transporter gene play an important role in emotions modulation of muscle pain.
疼痛的感知是由遗传、神经生物学、文化和情感因素共同决定的。最近的研究表明，特定基因型与疼痛感知之间存在关联。特别关注的是 5-羟色胺转运体基因启动子区域的三核苷酸多态性与疼痛感知的关系。本研究旨在探讨情绪通过视觉刺激对肌肉疼痛感知的调节作用是否依赖于基因型。总共选择了 150 名健康受试者，根据他们 5-羟色胺转运体基因的多态性进行分组。首先，通过国际情感图片系统呈现正性、负性和中性图片进行视觉条件反射，同时对图片的不愉快/愉快程度进行评分。其次，在向咬肌注射高渗盐水诱发实验性颌肌疼痛的同时呈现视觉条件反射刺激，并通过电子视觉模拟量表让参与者持续对疼痛强度进行评分。这三组基因型的图片引起的情绪变化相似，高渗盐水在所有参与者中引起了中等程度的疼痛。然而，在高表达 5-羟色胺转运体蛋白的参与者中，与中性图片相比，负性图片会增加疼痛强度，而正性图片会降低疼痛强度。相比之下，在中间或低表达蛋白的参与者中，图片对疼痛感知没有显著影响。这些结果表明，5-羟色胺转运体基因的多态性在肌肉疼痛的情绪调节中起着重要作用。
