Among several biological correlates that may explain the principle of acupuncture, the autonomic nervous system (ANS) is frequently considered to be a mediator of acupuncture stimulation because it can interconnect external somatosensory inputs with internal organ responses via the central neural networks. Sympathetic and the parasympathetic nerves broadly regulates the functions of internal organs, which has been a primary target for exploring the possible effect of cutaneous AS on internal organs. Lim et al​(Lim et al. 2016)​ from Daejeon University, Korean investigated the functional involvement of acupuncture stimulation in the regulation of inflammatory responses.

1503 Connections of the Parasympathetic Nervous System.jpg
Illustration from Anatomy & Physiology, Connexions Web site. http://cnx.org/content/col11496/1.6/, Jun 19, 2013. CC BY 3.0
  • TNF-α production in mouse serum, which was induced by lipopolysaccharide (LPS) administration, was decreased by manual acupuncture at the ST36. In the spleen, TNF-α mRNA and protein levels were also downregulated by acupuncture and were recovered by using a splenic neurectomy and a vagotomy.
  • c-Fos, which was induced in the nucleus tractus solitarius (NTS) and dorsal motor nucleus of the vagus nerve (DMV) by LPS and electro-acupuncture, was further increased by focal administration of the AMPA receptor blocker CNQX and the purinergic receptor antagonist PPADS.
  • TNF-α levels in the spleen were decreased by CNQX and PPADS treatments, implying the involvement of inhibitory neuronal activity in the DVC.
  • In unanesthetized animals, both manual acupuncture and electro-acupuncture generated c-Fos induction in the DVC neurons. However, manual acupuncture was effective in decreasing splenic TNF-α production.

They concluded that the therapeutic effects of acupuncture may be mediated through vagal modulation of inflammatory responses in internal organs.

Fig 6. In vivo inductions of c-Fos and TNF-α in animals given LPS and AS without anesthesia.

Sixty minutes after LPS injection, MAC or EAC was given at ST36 for 30 min. Animals were sacrificed 90 min after AS for analyses of the changes in both c-Fos protein signals in the transverse sections through the caudal portion of the brainstem (A) and the TNF-α mRNA and protein in the spleen (B and C, respectively). Quantitations of both the band intensity of splenic TNF-α mRNA relative to the actin control in (B) and the c-Fos and the TNF-α signals in (A) and (C) are shown in bar graphs (mean ± SEM, n = 4 independent experiments). *p<0.05 and **p<0.01 (one-way ANOVA). Arrows in (A) and (B) denote the approximate NTS boundary between two hemispheres. cc: central canal, WP: white pulp, RP: red pulp. CTL: non-treated control. The scale bars in (A) and (C) are 100 μm.

https://doi.org/10.1371/journal.pone.0151882.g006
  1. Lim, Hee-Don, Min-Hee Kim, Chan-Yong Lee, and Uk Namgung. 2016. “Anti-Inflammatory Effects of Acupuncture Stimulation via the Vagus Nerve.” Edited by Michal Hetman. PLOS ONE, March, e0151882. https://doi.org/10.1371/journal.pone.0151882.

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