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）：本项目旨在研究安慰剂镇痛的神经机制。一个创新的安慰剂方案，评估安慰剂对内脏和皮肤疼痛刺激的反应将被采用。功能磁共振成像（fMRI）将使临床人群中内脏疼痛作为其临床综合征的一部分，参与安慰剂镇痛的脑机制的表征成为可能。该项目将利用先前对肠易激综合征（IBS）患者的研究，在这些研究中，内脏和皮肤疼痛刺激证明了不同的大脑激活。在同一人群中，安慰剂对特定预期反应集的反应已被证明是强大而可靠的。拟议的项目将结合这些方案来获得IBS受试者在自然史、安慰剂和活性药物（直肠利多卡因）条件下的脑图像。预计结果将显示安慰剂反应会选择性地激活特定的大脑区域。与安慰剂相比，在自然历史条件下，以下大脑区域的神经活动（通过rCBF测量）会更大：丘脑外侧和/或内侧、体感区1和2、岛叶皮质、前扣带皮质（ACC）、后扣带皮质（PCC）和前额皮质。此外，安慰剂机制主要通过在较低神经系统水平（脊髓）减弱伤害性信号来起作用，这将通过丘脑、体感、ACC和PCC激活的减少来证明。先前的研究表明，对疼痛缓解的期望和渴望将显著预测安慰剂的疼痛减轻。预计这些措施也将与上述大脑激活模式相关联。通过比较安慰剂组与直肠利多卡因组，将区分脑和中枢神经系统相关机制与外周（受体部位）相关机制。