Chen Y Iris, Wang Fu-Nien, Nelson Aimee J, Xu Haibo, Kim Young, Rosen Bruce R, Kwong Kenneth K
Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA 02129, USA.
Neurosci Lett. 2008 Oct 24;444(2):117-21. doi: 10.1016/j.neulet.2008.08.033. Epub 2008 Aug 15.
Our previous fMRI and microdialysis measurements showed that electroacupuncture (EA) at LI4 was effective in alleviating excessive cerebral dopamine release induced by d-amphetamine (AMPH) in rats. We now compare the effect of EA in adjusting excess dopamine release at two stimulating frequencies (2 Hz versus 100 Hz at LI4) and at two acupoints (forepaw (LI4) versus hindpaw (ST36), at 2 Hz). fMRI measurements of relative cerebral blood volume (rCBV) were used to monitor the brain activity of "rest", followed by AMPH challenge, 10 min "rest", and then 20 min of EA.
EA at LI4 and ST36 significantly attenuated the AMPH-induced rCBV increases in the striatum, S1 cortex, and thalamus. Frequency: EA at 100 Hz induced greater attenuation of rCBV than EA at 2 Hz in the S1, insula, anterior cingulate cortices, dorsolateral striatum, and thalamus. Acupoints: EA at LI4 modulated a broader area in the medial anterior striatum while EA at ST36 modulated a more site-specific area in the dorsolateral striatum. In the thalamus, EA at LI4 showed greater attenuating effect than EA at ST36 did. However, in the insular cortex, EA at ST36 showed stronger attenuation.
EA at both LI4 and ST36 was effective in restoring dopamine homeostasis from an excess state, with the most effective response at LI4 with 100 Hz, while the responses to 2Hz EA at LI4 and ST36 showed slightly different spatial distribution of MR signal. This therefore provided insight into the neurophysiological basis of electroacupuncture effects in cortical and subcortical circuits.
我们之前的功能磁共振成像（fMRI）和微透析测量结果表明，针刺大鼠合谷穴（LI4）可有效减轻由右旋苯丙胺（AMPH）诱导的大脑多巴胺过度释放。我们现在比较针刺在两个刺激频率（LI4穴处2Hz与100Hz）以及两个穴位（前爪（LI4）与后爪（ST36），频率为2Hz）调节过量多巴胺释放的效果。采用fMRI测量相对脑血容量（rCBV）来监测“静息”状态下的大脑活动，随后进行AMPH激发试验，再“静息”10分钟，接着进行20分钟的针刺。
针刺LI4和ST36穴可显著减轻AMPH诱导的纹状体、初级体感皮层（S1）和丘脑的rCBV增加。频率：在初级体感皮层、脑岛、前扣带回皮层、背外侧纹状体和丘脑中，100Hz针刺引起的rCBV衰减大于2Hz针刺。穴位：针刺LI4穴调节的是内侧前纹状体中更广泛的区域，而针刺ST36穴调节的是背外侧纹状体中更具位点特异性的区域。在丘脑中，针刺LI4穴的衰减作用比针刺ST36穴更强。然而，在脑岛皮层中，针刺ST36穴的衰减作用更强。
针刺LI4和ST36穴均可有效将多巴胺稳态从过度状态恢复正常，其中以LI4穴100Hz针刺的效果最佳，而LI4和ST36穴2Hz针刺引起的磁共振信号空间分布略有不同。因此，这为针刺在皮层和皮层下回路中作用的神经生理基础提供了见解。
