Susan-Samueli Center for Integrative Medicine and Department of Medicine, School of Medicine, University of California, Irvine, Irvine, CA 92697, USA.
Brain Res. 2012 Mar 9;1442:25-35. doi: 10.1016/j.brainres.2012.01.006. Epub 2012 Jan 12.
Acupuncture regulates autonomic function. Our previous studies have shown that electroacupuncture (EA) at the Jianshi-Neiguan acupoints (P5-P6, underlying the median nerve) inhibits central sympathetic outflow and attenuates excitatory cardiovascular reflexes, in part, through an opioid mechanism. It is unknown if EA at these acupoints influences the parasympathetic system. Thus, using c-Fos expression, we examined activation of nucleus ambiguus (NAmb) neurons by EA, their relation to cholinergic (preganglionic parasympathetic) neurons and those containing enkephalin. To enhance detection of cell bodies containing enkephalin, colchicine (90-100 μg/kg) was administered into the subarachnoid space of cats 30 h prior to EA or sham-operated controls for EA. Following bilateral barodenervation and cervical vagotomy, either EA for 30 min at P5-P6 acupoints or control stimulation (needle placement at P5-P6 without stimulation) was applied. While perikarya containing enkephalin were observed in some medullary nuclei (e.g., raphé), only enkephalin-containing neuronal processes were found in the NAmb. Compared to controls (n=4), more c-Fos immunoreactivity, located principally in close proximity to fibers containing enkephalin was noted in the NAmb of EA-treated cats (n=5; P<0.01). Moreover, neurons double-labeled with c-Fos and choline acetyltransferase in the NAmb were identified in EA-treated, but not control animals. These data demonstrate for the first time that EA activates preganglionic parasympathetic neurons in the NAmb. Because of their close proximity, these EA-activated neurons likely interact with nerve fibers containing enkephalin. These results suggest that EA at the P5-P6 acupoints has the potential to influence parasympathetic outflow and cardiovascular function, likely through an enkephalinergic mechanism.
针刺调节自主功能。我们之前的研究表明，电针（EA）在间使-内关穴（P5-P6，正中神经下方）抑制中枢交感传出，并减弱兴奋性心血管反射，部分是通过阿片机制。目前尚不清楚这些穴位的 EA 是否会影响副交感神经系统。因此，我们使用 c-Fos 表达来检测 EA 对疑核（NAmb）神经元的激活，以及它们与胆碱能（节前副交感）神经元和含有内啡肽的神经元的关系。为了增强对含有内啡肽的细胞体的检测，在 EA 或 EA 假手术对照之前 30 小时，将 colchicine（90-100μg/kg）注入猫蛛网膜下腔。在双侧膈神经切断和颈迷走神经切断后，在 P5-P6 穴位进行 30 分钟的 EA 或对照刺激（在 P5-P6 放置针而不刺激）。虽然在一些髓核（如蓝斑）中观察到含有内啡肽的神经元，但仅在 NAmb 中发现含有内啡肽的神经元过程。与对照组（n=4）相比，在接受 EA 治疗的猫（n=5；P<0.01）的 NAmb 中，更多的 c-Fos 免疫反应位于靠近含有内啡肽的纤维附近。此外，在 NAmb 中，与 c-Fos 和胆碱乙酰转移酶双重标记的神经元仅在 EA 处理的动物中被识别，而在对照动物中未被识别。这些数据首次表明，EA 激活 NAmb 中的节前副交感神经元。由于它们的位置接近，这些 EA 激活的神经元可能与含有内啡肽的神经纤维相互作用。这些结果表明，P5-P6 穴位的 EA 有可能通过内啡肽能机制影响副交感神经传出和心血管功能。
