BRAIN IMAGING AND PAIN: ANALYSIS OF PLACEBO ANALGESIA

脑成像和疼痛：安慰剂镇痛分析

• 批准号: 6586968
• 负责人: Michael E ROBINSON
• 金额: $ 31.12万
• 依托单位: UNIVERSITY OF FLORIDA
• 依托单位国家: 美国
• 财政年份: 2003
• 资助国家: 美国
• 起止时间: 2003-03-15 至 2006-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6586968
• 关键词: analgesia; brain imaging /visualization /scanning; cingulate gyrus; clinical research; functional magnetic resonance imaging; human subject; irritable bowel syndrome; lidocaine; neural information processing; nociceptors; pain; placebos; prefrontal lobe /cortex; psychology; questionnaires; somesthetic sensory cortex; thalamus

DESCRIPTION (provided by applicant): This project is designed to investigate the neural mechanisms of placebo analgesia. An innovative placebo protocol that assesses the placebo response to both visceral and cutaneous pain stimulation will be employed. Functional Magnetic Resonance Imaging (fMRI) will enable the characterization of brain mechanisms involved in placebo analgesia in a clinical population which experiences visceral pain as part of their clinical syndrome. This project will capitalize on previous work with Irritable Bowel Syndrome (IBS) patients where differential brain activation was demonstrated to visceral and cutaneous pain stimuli. In this same population a powerful and reliable placebo response to specific expectancy response sets has been demonstrated. The proposed project will combine these protocols to obtain brain images of IBS subject during natural history, placebo, and active agent (rectal lidocaine) conditions. It is anticipated that results will show that the placebo response will selectively activate specific brain regions. Neural activity (as measured by rCBF) will be greater in natural history conditions as compared to placebo conditions in the following brain regions: - lateral and/or medial thalamus, somatosensory areas 1 and 2, insular cortex, anterior cingulate cortex (ACC), posterior cingulate cortex (PCC), and prefrontal cortex. Furthermore, placebo mechanisms that operate primarily through attenuation of nociceptive signals at lower nervous system levels (spinal cord) will be evidenced by decreased thalamic, somatosensory, ACC, and PCC activation. Previous research indicates that expectancy and desire for pain relief will significantly predict the pain reduction from placebo. It is anticipated that these measures will also be associated with the above described brain activation patterns. By comparing the placebo conditions to the rectal lidocaine condition, brain and central nervous system related mechanisms versus peripheral (receptor site) related mechanisms will be differentiated.

描述（由申请人提供）：该项目旨在研究安慰剂镇痛的神经机制。将采用一种创新的安慰剂协议，以评估安慰剂对内脏和皮肤疼痛刺激的反应。功能磁共振成像（fMRI）将使在临床人群中涉及安慰剂镇痛中涉及的大脑机制，这是其临床综合征的一部分。该项目将利用肠易激综合征（IBS）患者的先前工作，其中证明脑部激活差异为内脏和皮肤疼痛刺激。在同一人群中，已经证明了对特定预期响应集的强大而可靠的安慰剂反应。拟议的项目将结合这些方案，以在自然史，安慰剂和活性剂（直肠利多卡因）条件下获得IBS受试者的大脑图像。预计结果将表明安慰剂反应将有选择地激活特定的大脑区域。与以下大脑区域相比，与安慰剂条件相比，在自然病史条件下，神经活动（如RCBF所测量）将更大： - 侧向和/或中间丘脑，体感应区域1和2，近膜皮层，前扣带回皮质（ACC），后扣皮皮层（PCC），前扣皮皮质（PCC）和前叶状胸腔。此外，主要通过降低丘脑，体感，ACC和PCC激活来证明，主要是通过衰减伤害性信号（脊髓）处于低神经系统水平（脊髓）处的安慰剂机制。先前的研究表明，预期和对缓解疼痛的渴望将显着预测安慰剂的疼痛。预计这些措施也将与上述大脑激活模式有关。通过将安慰剂条件与直肠利多卡因条件进行比较，将分化大脑和中枢神经系统相关机制与外围（受体位点）相关机制。