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方案来评估安慰剂对内脏和皮肤疼痛刺激的反应。功能性磁共振成像（fMRI）将能够表征临床人群中安慰剂镇痛所涉及的大脑机制，这些临床人群会经历内脏疼痛作为其临床综合征的一部分。该项目将利用之前对肠易激综合症（IBS）患者的研究成果，其中证明了内脏和皮肤疼痛刺激下大脑的差异激活。在同一人群中，已经证明了对特定预期反应组的强大而可靠的安慰剂反应。拟议的项目将结合这些协议，以获得 IBS 受试者在自然史、安慰剂和活性剂（直肠利多卡因）条件下的大脑图像。预计结果将表明安慰剂反应将选择性地激活特定的大脑区域。与安慰剂条件相比，自然历史条件下以下大脑区域的神经活动（通过 rCBF 测量）会更大： - 外侧和/或内侧丘脑、体感区 1 和 2、岛叶皮层、前扣带皮层 (ACC)、后扣带皮层 (PCC) 和前额叶皮层。此外，主要通过减弱较低神经系统水平（脊髓）伤害性信号发挥作用的安慰剂机制将通过丘脑、体感、ACC 和 PCC 激活的减少得到证明。先前的研究表明，对缓解疼痛的期望和愿望将显着预测安慰剂的疼痛减轻情况。预计这些措施也将与上述大脑激活模式相关。通过将安慰剂条件与直肠利多卡因条件进行比较，将区分大脑和中枢神经系统相关机制与外周（受体位点）相关机制。