7T Functional MRS Assessment of Pain Processing in Cannabis Users

项目摘要/摘要 落后于州法律、社会观点和医疗实践的快速变化的是科学调查 大麻对人脑的影响。就在2017年3月，28个州和哥伦比亚特区 颁布了促进使用大麻治疗各种疾病的立法，包括慢性疾病 疼痛、神经性疼痛以及与癌症治疗相关的疼痛(例如，化疗)。然而，止痛药 大麻的特性还没有被很好地理解。一致的证据指向神经递质系统 大麻使用者大脑中的干扰，包括伽马氨基丁酸(GABA)和谷氨酸 与疼痛处理相关的区域。功能磁共振成像(FMRI)是最强大的成像技术之一 以非侵入性方式研究支持心理过程的神经生物系统，如 感受到痛苦。事实上，一篇关于疼痛的适度文献已经将躯体感觉疼痛知觉与前部联系起来。 扣带回皮质(ACC)。此外，最近的一项功能神经成像研究的荟萃分析--手稿 申请人担任第一作者的报告--发现大麻的使用与减少有关 在用户之间的整个ACC中激活。鉴于大麻中神经递质系统的中断 包括GABA和谷氨酸在内的使用者，该领域面临的一个重要挑战是确定大麻如何- 疼痛处理过程中行为和神经激活的相关变化与从属关系的变化有关 神经化学。功能磁共振波谱(FMRS)可以用来解决这一挑战 通过测量与大麻相关的行为和神经差异相关的神经递质波动 使用大麻和不使用大麻的受试者之间的激活。用FMR检查体感 痛觉得到了很好的支持，然而，将这种方法推广到大麻使用者的研究还很少。 此外，大多数FMR研究都是使用较低的磁场强度(即，3T或 较少)，可能限制了有效检测神经递质波动的能力。鉴于研究的匮乏 涉及FMR，并有可能检查疼痛处理过程中神经递质的波动 通过FMR吸食大麻，我们的总体目标是检查可能支持 吸毒者和非吸毒者之间与大麻相关的痛觉差异。为了实现这些目标，我们 建议在体感压力期间在更大的磁场强度(即7T)下实施FMR- 使用MR兼容的压力计，在吸食大麻和不吸食大麻的受试者之间进行疼痛评估 止痛器。

PROJECT SUMMARY/ABSTRACT Lagging behind rapid changes to state laws, societal views, and medical practice is the scientific investigation of cannabis's impact on the human brain. As recently as March of 2017, 28 states and the District of Columbia had enacted legislation that facilitates using cannabis to treat various medical conditions, including chronic pain, neuropathic pain, and pain related to cancer treatment options (e.g., chemotherapy). Yet, the analgesic properties of cannabis are not well understood. Convergent evidence points to neurotransmitter system disruptions among cannabis users, including gamma-Aminobutyric acid (GABA) and glutamate, in brain regions related to pain processing. Functional magnetic resonance imaging (fMRI) is one of the most powerful non-invasive ways to investigate the neurobiological systems that support psychological processes such as perceiving pain. Indeed, a modest literature on pain has linked somatosensory pain perception to the anterior cingulate cortex (ACC). Moreover, a recent meta-analysis of functional neuroimaging studies – a manuscript on which the applicant served as primary author – found that cannabis use was associated with reduced activation throughout the ACC among users. Given the disruption of neurotransmitter systems among cannabis users, including GABA and glutamate, an important challenge facing the field is to determine how cannabis- related changes in behavior and neural activation during pain processing are linked to changes in subservient neurochemistry. Functional magnetic resonance spectroscopy (fMRS) can be used to address this challenge by measuring neurotransmitter fluctuations associated with cannabis-related differences in behavior and neural activation between cannabis-using and non-cannabis-using subjects. Using fMRS to examine somatosensory pain perception is well supported, however, studies extending this approach to cannabis users are lacking. Moreover, most fMRS investigations have been performed using lower magnetic field strengths (i.e., 3T, or less), likely limiting abilities to effectively detect neurotransmitter fluctuations. Given the paucity of studies involving fMRS, and given the potential to examine neurotransmitter fluctuations during pain processing among cannabis users via fMRS, our overall goals are to examine the neurochemical correlates that may support cannabis-related differences in pain perception between users and non-users. To accomplish these goals, we propose to implement fMRS at a greater magnetic field strength (i.e., 7T) during somatosensory pressure- based pain among cannabis-using and non-cannabis-using subjects, using an MR-compatible pressure-based pain apparatus.