Martin Sarah L, Jones Anthony K P, Brown Christopher A, Kobylecki Christopher, Whitaker Grace A, El-Deredy Wael, Silverdale Monty A
Department of Psychology, Manchester Metropolitan University, Manchester M15 6GX, UK.
The Human Pain Research Group, Division of Neuroscience and Experimental Psychology, The University of Manchester, Manchester M13 9PL, UK.
Brain Sci. 2022 Mar 4;12(3):351. doi: 10.3390/brainsci12030351.
Striatal dopamine dysfunction is associated with the altered top-down modulation of pain processing. The dopamine D2-like receptor family is a potential substrate for such effects due to its primary expression in the striatum, but evidence for this is currently lacking. Here, we investigated the effect of pharmacologically manipulating striatal dopamine D2 receptor activity on the anticipation and perception of acute pain stimuli in humans. Participants received visual cues that induced either certain or uncertain anticipation of two pain intensity levels delivered via a CO laser. Rating of the pain intensity and unpleasantness was recorded. Brain activity was recorded with EEG and analysed via source localisation to investigate neural activity during the anticipation and receipt of pain. Participants completed the experiment under three conditions, control (Sodium Chloride), D2 receptor agonist (Cabergoline), and D2 receptor antagonist (Amisulpride), in a repeated-measures, triple-crossover, double-blind study. The antagonist reduced an individuals' ability to distinguish between low and high pain following uncertain anticipation. The EEG source localisation showed that the agonist and antagonist reduced neural activations in specific brain regions associated with the sensory integration of salient stimuli during the anticipation and receipt of pain. During anticipation, the agonist reduced activity in the right mid-temporal region and the right angular gyrus, whilst the antagonist reduced activity within the right postcentral, right mid-temporal, and right inferior parietal regions. In comparison to control, the antagonist reduced activity within the insula during the receipt of pain, a key structure involved in the integration of the sensory and affective aspects of pain. Pain sensitivity and unpleasantness were not changed by D2R modulation. Our results support the notion that D2 receptor neurotransmission has a role in the top-down modulation of pain.
纹状体多巴胺功能障碍与疼痛处理的自上而下调节改变有关。多巴胺D2样受体家族是产生这种效应的潜在底物,因为它主要在纹状体中表达,但目前缺乏相关证据。在此,我们研究了药理学操纵纹状体多巴胺D2受体活性对人类急性疼痛刺激的预期和感知的影响。参与者接受视觉线索,这些线索会引发对通过CO激光传递的两种疼痛强度水平的确定或不确定预期。记录疼痛强度和不愉快程度的评分。用脑电图记录大脑活动,并通过源定位进行分析,以研究疼痛预期和接收过程中的神经活动。在一项重复测量、三交叉、双盲研究中,参与者在三种条件下完成实验,即对照(氯化钠)、D2受体激动剂(卡麦角林)和D2受体拮抗剂(氨磺必利)。拮抗剂降低了个体在不确定预期后区分低疼痛和高疼痛的能力。脑电图源定位显示,激动剂和拮抗剂在疼痛预期和接收过程中,减少了与显著刺激的感觉整合相关的特定脑区的神经激活。在预期过程中,激动剂降低了右侧颞中区和右侧角回的活动,而拮抗剂降低了右侧中央后回、右侧颞中区和右侧顶下区的活动。与对照相比,拮抗剂在疼痛接收过程中降低了脑岛的活动,脑岛是参与疼痛感觉和情感方面整合的关键结构。D2R调节未改变疼痛敏感性和不愉快程度。我们的结果支持D2受体神经传递在疼痛的自上而下调节中起作用这一观点。