I love the first line of this abstract “Acupuncture regulates autonomic function.”  That is precisely what my research looks at.

This is another study looking at the nitty gritty of what happens when PC6 acupuncture point is used.  In the last blog post, they found that the central nervous system affected the sympathetic outflow when PC6 was stimulated.  This study shows that it might stimulate parasympathetic outflow as well, through the endogenous opiate system.  Longhurst has done work on high blood pressure and acupuncture establishing its effectiveness clinically as well as exploring the physiology involved.

Brain Res. 2012 Mar 9;1442:25-35. Epub 2012 Jan 12.
Nucleus ambiguus cholinergic neurons activated by acupuncture: relation to enkephalin.
Guo ZL, Li M, Longhurst JC.
Source

Susan-Samueli Center for Integrative Medicine and Department of Medicine, School of Medicine, University of California, Irvine, Irvine, CA 92697, USA. zguo@uci.edu
Abstract

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…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.