fMRI study of expectancy on acupuncture analgesia

描述（由申请人提供）：区分针灸与安慰剂针灸一直是一个方法学上的挑战。我们建议将这个问题转移到一个良好的控制机制的实验室模型，使用定量脑成像方法（fMRI）来研究针刺镇痛，安慰剂镇痛的神经生物学机制及其相互关系。将诱导高期望值和低期望值的经过充分测试的方法与针刺镇痛和假针刺镇痛相结合，以创建真实（真实的）针刺和假针刺的2 × 2神经成像比较，每一个都与阳性和阴性期望值配对。为了描绘不同的大脑网络，我们将比较治疗前和治疗后的功能磁共振成像信号的变化引起的应用校准的伤害性刺激（疼痛感觉编码）和随后的评级任务（疼痛强度评估）后，不同的治疗。 我们假设疼痛强度评估过程的调制是安慰剂镇痛的关键底物。具体来说，我们假设，预期（安慰剂）镇痛，这严重依赖于以前的知识，信仰或经验，将启动中枢神经系统的活动。我们提出，在这个网络的大脑区域的活动将产生镇痛通过激活下行内源性阿片系统，以及通过激活我们所谓的“选择性疼痛强度评估失真过程”。第一种机制也可能与针刺镇痛共享，然而，第二种机制应该是唯一的安慰剂镇痛在我们的研究人群谁没有以前的经验或预期的针刺镇痛。该提案与最近的一项计划公告（PA-03-125）直接相关，该公告呼吁“生物行为疼痛研究”。 该提案也与最近的RFA（AT-02-002）相关，该RFA呼吁“阐明安慰剂效应潜在机制的综合方法”。它也与2003财政年度的研究重点有关，该研究重点要求“对急性或慢性疼痛管理的CAM方法的基础机制进行临床前神经生物学研究”。

DESCRIPTION (provided by applicant): Distinguishing acupuncture from placebo acupuncture has been a methodological challenge. We propose to move this question into a well-controlled mechanistic laboratory model using a quantitative brain imaging method (fMRI) to investigate the neurobiological mechanism of acupuncture analgesia, placebo analgesia and their interrelationship. A well tested method to induce high expectation and low expectation will be combined with acupuncture analgesia and sham acupuncture analgesia to create a 2 X 2 neuroimaging comparison of verum (real) acupuncture and sham acupuncture each paired with positive and negative expectancies. To delineate the different brain networks involved, we will compare pre- and post-treatment fMRI signal changes induced by application of calibrated noxious stimuli (pain sensory encoding) and a subsequent rating task (pain intensity evaluation) after the different treatments. We hypothesize that modulation of the pain intensity evaluation process is a critical substrate of placebo analgesia. Specifically, we hypothesize that expectancy (placebo) analgesia, which critically depends on former knowledge, belief or experience, will be initialized by activity in the central nervous system. We propose that the activity in this network of brain regions will produce analgesia by activating descending endogenous opioid systems as well as by activating what we have called the "selective pain intensity evaluation distortion process". The first mechanism may also be shared with acupuncture analgesia, however, the second mechanism should be unique for placebo analgesia in our study population who have no prior experience or expectancy for acupuncture analgesia. This proposal is directly relevant to a recent Program Announcement (PA-03-125) that calls for "biobehavioral pain research". This proposal is also relevant to a recent RFA (AT-02-002) that calls for "An Integrative Approach to Elucidation of the Underlying Mechanisms of Placebo Effect". It is also relevant to FY 2003 Research Priorities that call for "preclinical neurobiological studies of the mechanisms underlying CAM approaches to the management of acute or chronic pain".