Molecular and Functional PET-fMRI Measures of Placebo Analgesia in Migraine

描述（由申请人提供）：本申请的目的是通过同时测量脑功能（fMRI）和阿片受体可用性（11C-carnetanil PET）来研究无头痛偏头痛患者的安慰剂镇痛。通过在相关临床人群中研究安慰剂效应，我们将获得关于脑功能、化学以及它们之间相互作用的独特数据。众所周知，持续疼痛会改变大脑的结构、功能、连通性和化学成分。此外，持续的慢性疼痛会影响实验疼痛，这使得对来自患者群体的结果的解释变得困难。差异是由于大脑的改变，还是由于慢性疼痛的持续经历？通过研究偏头痛患者的间期（无头痛）状态，我们可以排除后者和

DESCRIPTION (provided by applicant): The goal of this application is to study placebo analgesia in headache-free migraine patients using simultaneous measures of brain function (fMRI) and ¿-opioid receptor availability (11C-carnetanil PET). By studying the placebo effect in a relevant clinical population, we will obtain unique data on brain function, chemistry, and, critically, their interaction. It is well established that persistent pain changes bothstructure, function, connectivity and chemistry of the brain. Moreover, ongoing chronic pain influences experimental pain, making interpretations of results derived from patient populations difficult. Are differences due to the altered brain, or due to the ongoing experience of chronic pain? By studying migraine patients in the inter-ictal (headache free) state, we can rule out the latter and describe placebo analgesia in pain-altered (but pain free) brains, as compared to healthy brains. By employing simultaneous fMRI and PET imaging, we will be provide novel data on how brain blood flow changes (fMRI) and endogenous opioid release (PET) interact to create the subjective experience of placebo pain reduction. This will provide a new level of understanding of placebo responses, and lay a foundation for studying and developing predictive biomarkers for clinical placebo responses. PUBLIC HEALTH RELEVANCE: Current neurobiological models of the placebo response rely on studies of either brain function or chemistry in healthy subjects. Chronic pain changes the brain and placebo responses in patients may have different mechanisms. We will study placebo responses in migraine patients and measure brain function and chemistry simultaneously.