Napadow Vitaly, Dhond Rupali, Park Kyungmo, Kim Jieun, Makris Nikos, Kwong Kenneth K, Harris Richard E, Purdon Patrick L, Kettner Norman, Hui Kathleen K S
Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Charlestown, MA 02129, USA.
Neuroimage. 2009 Aug 1;47(1):289-301. doi: 10.1016/j.neuroimage.2009.03.060. Epub 2009 Apr 1.
Acupuncture modulation of activity in the human brainstem is not well known. This structure is plagued by physiological artifact in neuroimaging experiments. In addition, most studies have used short (<15 min) block designs, which miss delayed responses following longer duration stimulation. We used brainstem-focused cardiac-gated fMRI and evaluated time-variant brain response to longer duration (>30 min) stimulation with verum (VA, electro-stimulation at acupoint ST-36) or sham point (SPA, non-acupoint electro-stimulation) acupuncture. Our results provide evidence that acupuncture modulates brainstem nuclei important to endogenous monoaminergic and opioidergic systems. Specifically, VA modulated activity in the substantia nigra (SN), nucleus raphe magnus, locus ceruleus, nucleus cuneiformis, and periaqueductal gray (PAG). Activation in the ventrolateral PAG was greater for VA compared to SPA. Linearly decreasing time-variant activation, suggesting classical habituation, was found in response to both VA and SPA in sensorimotor (SII, posterior insula, premotor cortex) brain regions. However, VA also produced linearly time-variant activity in limbic regions (amygdala, hippocampus, and SN), which was bimodal and not likely habituation--consisting of activation in early blocks, and deactivation by the end of the run. Thus, acupuncture induces different brain response early, compared to 20-30 min after stimulation. We attribute the fMRI differences between VA and SPA to more varied and stronger psychophysical response induced by VA. Our study demonstrates that acupuncture modulation of brainstem structures can be studied non-invasively in humans, allowing for comparison to animal studies. Our protocol also demonstrates a fMRI approach to study habituation and other time-variant phenomena over longer time durations.
针刺对人脑干活动的调节作用尚不为人所知。在神经影像学实验中,这个结构受到生理伪影的困扰。此外,大多数研究使用的是短(<15分钟)的组块设计,这会错过较长时间刺激后的延迟反应。我们使用聚焦脑干的心脏门控功能磁共振成像(fMRI),并评估了在真穴(VA,针刺足三里穴)或假穴(SPA,非穴位电刺激)针刺较长时间(>30分钟)刺激下随时间变化的脑反应。我们的结果提供了证据,表明针刺调节了对内源性单胺能和阿片样物质系统重要的脑干核团。具体而言,VA调节了黑质(SN)、中缝大核、蓝斑、楔形核和导水管周围灰质(PAG)的活动。与SPA相比,VA引起的腹外侧PAG激活更强。在感觉运动(SII、后岛叶、运动前皮层)脑区,对VA和SPA的反应均发现呈线性下降的随时间变化的激活,提示经典的习惯化。然而,VA在边缘区域(杏仁核、海马体和SN)也产生了线性随时间变化的活动,这种活动是双峰的,不太可能是习惯化——包括早期组块中的激活,以及在实验结束时的失活。因此,与刺激后20 - 30分钟相比,针刺在早期会引起不同的脑反应。我们将VA和SPA之间的fMRI差异归因于VA诱导的更多样化和更强的心理物理反应。我们的研究表明,可以在人体中无创地研究针刺对脑干结构的调节作用,以便与动物研究进行比较。我们的方案还展示了一种fMRI方法,用于研究更长时间内的习惯化和其他随时间变化的现象。