Researchers from the University of California, Irvine conclude that acupuncture affects opioid mechanisms. Researchers from the Susan-Samueli Center for Integrative Medicine and Department of Medicine at UC, Irvine measured responses to electroacupuncture (EA) stimulation at acupoints P5 (Jianshi) and P6 (Neiguan). The researchers note that for the very first time, “These data demonstrate for the first time that EA activates preganglionic parasympathetic neurons in the nucleus ambigus (NAmb).” The NAmb is part of the lateral portion of the upper medulla of the brain. This area of the brain is partially responsible for the emanation of the efferent motor fibers of the vagus nerve.
The results suggest that electroacupuncture interacts with nearby nerve fibers that contain encephalin. Enkephalin regulates nociception (partially responsible for pain perception) and binds to the body’s opioid receptors. The researchers conclude, “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.”
Nucleus ambiguus cholinergic neurons activated by acupuncture: Relation to encephalin. Zhi-Ling Guo. Min Li. John C. Longhurst. Susan-Samueli Center for Integrative Medicine and Department of Medicine, School of Medicine, University of California, Irvine, Irvine, CA, USA. Brain Research. 12 January 2012.