demonstrating-hairy-glabrous-skin-innervation-3d-pattern-using

Demonstrating Hairy and Glabrous Skin Innervation in a 3D Pattern Using Multiple Fluorescent Staining and Tissue Clearing Approaches

Skin innervation is an important part of the peripheral nervous system. Although the study of the cutaneous nerve fibers has progressed rapidly, most of ...

China Academy of Chinese Medical Sciences

China Academy Of Chinese Medical Sciences

Previous studies showed primo vessels (PVs), which were referred to as Bonhan ducts (BHDs) and a part of circulatory system by Kim, located in different places of the body. The BHDs system was once considered as the anatomical basis of classical acupuncture meridian but not clearly identified by other investigators. In the present study, we tried to address the relationship between PVs and meridians through detecting the modulation of gastric motility by stimulating the PVs on the surface of stomach or intestine, as well as acupoints Zusanli (ST36) and Zhongwan (CV12). The results showed electric stimulation of the PVs had no effect on the gastric motility. While stimulating CV12 inhibited gastric motility significantly in PVs-intact and PVs-cut rats, there is no significant difference between the inhibition rate of the PVS-intact and the PVS-cut rats. Stimulating at ST36 increased gastric motility significantly in both the PVs-intact and the PVs-cut rats, yet there was no significant difference between the facilitation rate of the both groups. Taken together, the PVs on the surface of stomach or intestine did not mediate the regulation of gastric motility induced by stimulating at the acupoints ST36 or CV12.

Are Primo Vessels (PVs) on the Surface of Gastrointestine Involved in Regulation of Gastric Motility Induced by Stimulating Acupoints ST36 or CV12?

Previous studies demonstrated that primo vessels (PVs) were distributed in different parts of the body in mammals, and PVs were also involved in some processes of pathology such as cancer. Whether PVs are intrinsic structures in mammals or not is still ignored. In this study, a peritonitis model rat was induced by i.p. administration of E. coli in rats. PVs were observed in all infected rats, but it appeared less in untreated rats, taking 10.53% (4/38). In addition, we examined cell types in celiac PVs by fluorescent staining with 4',6-diamidino-2-phenylindole (DAPI) and Alexa Fluor 488 phalloidin, as well as immunofluorescent staining with CD11b and intercellular adhesion molecule-1(ICAM-1), and found the following. (1) The rod-shaped nuclei aligned longitudinally along PVs. (2) DAPI-, phalloidin-, CD11b-, and ICAM-1-positive labeling coexisted in PVs, suggesting that fibroblasts and leucocytes might be two kinds of cell types in PVs for both infected and control rats. (3) The difference was that numerous cells in PVs of the infected rats contained DAPI-labeled multilobal nucleus and were expressed with CD11b- and ICAM-1-positive labeling on the cytoplasm and membrane, showing the typical characteristics of neutrophil. (4) The cells in PVs from the untreated rats are those of loose connective tissue. Therefore, it is reasonably considered that PVs from infected rats might be the pathological products which might be involved in inflammation.

Preliminary Research of Relationship between Acute Peritonitis and Celiac Primo Vessels.

Previous studies have shown that the effects of manual acupuncture (MA) are contributed by collagen fibers and mast cells in local acupoints, at which acupuncture stimulation causes various afferent fiber groups to be excited. However what happens in local nerve fibers and mast cells after MA remains unclear. The aim of this study was to examine the response of cutaneous nerve fibers and mast cells to MA stimulation in acupoint Hegu (LI4). The contralateral LI4 of the same rat was used as a non-stimulated control. Immnohistochemistry analysis were carried out to observe the expression of histamine (HA), serotonin (5-HT) and nociceptive neuropeptides, calcitonin gene-related peptide (CGRP) and substance P (SP), in the LI4 area. Mast cells were labeled with anti-mast cell tryptase antibody and simultaneously with HA or 5-HT primary antibodies to observe their co-expression. Our results showed that SP and CGRP were expressed more highly on the cutaneous nerve fibers of LI4 after MA stimulation than that of the control. Mast cells aggregated in close proximity to the blood vessels in intra-epidermis and dermis and some of them with degranulation in the lower dermis and subcutaneous tissue of LI4. Both mast cells and their granules appeared with HA (+) and 5-HT (+) expression at stimulated L14 sites, while a few intact mast cells with a little expression of 5-HT and HA were distributed in areas of non-stimulated L14. The results indicated that local cutaneous nerve terminals and mast cells responded to MA with higher expression of SP and CGRP in nerve fibers, as well as with aggregation and degranulation of mast cells with HA and 5-HT granules at acupoint LI4. These neuroactive substances may convey signals to certain pathways that contribute to the effects of acupuncture.

Local cutaneous nerve terminal and mast cell responses to manual acupuncture in acupoint LI4 area of the rats.

Recently, clinical observations reported the potential benefit of vagus nerve stimulation (VNS) for pediatric epilepsy. Transcutaneous auricular vagus nerve stimulation (ta-VNS) is a newer non-invasive VNS, making it more accessible for treating pediatric epilepsy, yet there is limited clinical evidence for its effectiveness.

Transcutaneous auricular vagus nerve stimulation for pediatric epilepsy: study protocol for a randomized controlled trial.

Previous studies have demonstrated the effects of different afferent fibers on electroacupuncture (EA)-induced analgesia. However, contributions of functional receptors expressed on afferent fibers to the EA analgesia remain unclear. This study investigates the roles of acid-sensing ion channel 3 (ASIC3) and transient receptor potential vanilloid 1 (TRPV1) receptors in EA-induced segmental and systemic analgesia. Effects of EA at acupoint ST36 with different intensities on the C-fiber reflex and mechanical and thermal pain thresholds were measured among the ASIC3, TRPV1, and C57BL/6 mice. Compared with C57BL/6 mice, the ipsilateral inhibition of EA with 0.8 C-fiber threshold (0.8Tc) intensity on C-fiber reflex was markedly reduced in ASIC3 mice, whereas the bilateral inhibition of 1.0 and 2.0Tc EA was significantly decreased in TRPV1 mice. The segmental increase in pain thresholds induced by 0.3 mA EA was significantly reduced in ASIC3 mice, whereas the systemic enhancement of 1.0 mA EA was markedly decreased in TRPV1 mice. Thus, segmental analgesia of EA with lower intensity is partially mediated by ASIC3 receptor on Aβ-fiber, whereas systemic analgesia induced by EA with higher intensity is more likely induced by TRPV1 receptor on Aδ- and C-fibers.

Distinct roles of ASIC3 and TRPV1 receptors in electroacupuncture-induced segmental and systemic analgesia.

Acupuncture at homotopic acupoints or heterotopic acupoints is known to either inhibit or facilitate gastrointestinal motility, depending on the acupoint location. However, little effort has been made to investigate the roles of specific receptors (such as adrenergic and muscarinic acetylcholine receptors) in mediating the effects of acupuncture at heterotopic and homotopic acupoints. Different adrenergic receptor subtypes or cholinergic receptor subtypes are predominantly expressed in various sections of the gut, resulting in variations between the effects of acupuncture at heterotopic or homotopic acupoints on gastrointestinal motility. Here, we investigated the role of β1/β2 receptors and M2/M3 receptors in gastrointestinal motility regulated by acupuncture at ST37, a heterotopic acupoint, and ST25, a homotopic acupoint, by simultaneously recording intraluminal pressures in the distal colon and stomach or jejunum and examining fecal phenol red excretion in β1/2 receptor-knockout mice and M2/3 receptor-knockout mice. We found that knockout of the M2/3 receptor significantly inhibited ST37 acupuncture-induced enhancement of gastric motility, jejunal motility, and colonic motility. Additionally, knocking out of the β1/2 receptor significantly diminished the ST25 acupuncture-induced inhibition of gastric motility and jejunal motility without significantly altering the enhancement of colonic motility induced by acupuncture at ST25. Acupuncture at ST37 significantly accelerated gastrointestinal transition in β1/2 receptor-knockout mice and their wild-type littermates. However, this acceleration of gastrointestinal transition was markedly diminished in M2/3 receptor-knockout mice relative to their wild-type littermates. Acupuncture at ST25 significantly increased gastrointestinal transition in β1/2 receptor-knockout mice and significantly decreased gastrointestinal transition in M2/3 receptor-knockout mice without altering gastrointestinal transition in wild-type littermates of either. Our study revealed that M2/3 receptors are required for the gastrointestinal motility associated with whole gastrointestinal transition enhanced by acupuncture at heterotopic acupoints, whereas β1/2 receptors are required for the same gastrointestinal motility processes inhibited by acupuncture at homotopic acupoints. Therefore, our findings reveal important biological mechanisms underlying acupuncture treatment of disorders involving gastrointestinal motility dysfunction.

β1/2 or M2/3 Receptors Are Required for Different Gastrointestinal Motility Responses Induced by Acupuncture at Heterotopic or Homotopic Acupoints.

To judge whether algesia sensitization of some acupoints is existed and whether the acupoint algesia sensitization area is expanded in the patients of intestinal cancer.

[Distribution of algesia sensitized acupoints in the patients of intestinal cancer].

The neuroanatomical basis behind acupuncture practice is still poorly understood. Here, we used intersectional genetic strategy to ablate NPY noradrenergic neurons and/or adrenal chromaffin cells. Using endotoxin-induced systemic inflammation as a model, we found that electroacupuncture stimulation (ES) drives sympathetic pathways in somatotopy- and intensity-dependent manners. Low-intensity ES at hindlimb regions drives the vagal-adrenal axis, producing anti-inflammatory effects that depend on NPY adrenal chromaffin cells. High-intensity ES at the abdomen activates NPY splenic noradrenergic neurons via the spinal-sympathetic axis; these neurons engage incoherent feedforward regulatory loops via activation of distinct adrenergic receptors (ARs), and their ES-evoked activation produces either anti- or pro-inflammatory effects due to disease-state-dependent changes in AR profiles. The revelation of somatotopic organization and intensity dependency in driving distinct autonomic pathways could form a road map for optimizing stimulation parameters to improve both efficacy and safety in using acupuncture as a therapeutic modality.

Somatotopic Organization and Intensity Dependence in Driving Distinct NPY-Expressing Sympathetic Pathways by Electroacupuncture.

The aim of this study was to explore the potential effect of electroacupuncture (EA) at ST36 on mice bearing breast tumors by regulating inflammatory cytokines to enhance antitumor immunity via vagus nerve.

Electroacupuncture regulates inflammatory cytokines by activating the vagus nerve to enhance antitumor immunity in mice with breast tumors.

Recent studies have shown that both superficial and deep acupuncture produced clinically relevant and persistent effect on chronic pain, and several subtypes of somatic primary afferents played critical roles in acupuncture and moxibustion analgesia. However, which kind of primary afferents in the superficial and deep tissue of the acupoint is activated by acupuncture or moxibustion to relieve pain persistently remains unclear. The aim of this study is to investigate the roles of distinct peripheral afferents in different layers of the tissue (muscle or skin) in the acupoint for pain relief. Muscular A-fibers activated by deep electroacupuncture (dEA) with lower intensity (approximately 1 mA) persistently alleviated inflammatory muscle pain. Meanwhile, cutaneous C-nociceptors excited by noxious moxibustion-like stimulation (MS) and topical application of capsaicin (CAP) on local acupoint area produced durable analgesic effect. Additionally, spontaneous activity of C-fibers caused by muscular inflammation was also inhibited by dEA and CAP. Furthermore, decreases in pain behavior induced by dEA disappeared after deep A-fibers were demyelinated by cobra venom, whereas CAP failed to relieve pain following cutaneous denervation. Collectively, these results indicate that dEA and MS ameliorate inflammatory muscle pain through distinct primary afferents in different layers of somatic tissue; the former is achieved by activating muscular A-fibers, while the latter is mediated by activating cutaneous C-fibers.

Electroacupuncture and Moxibustion-Like Stimulation Relieves Inflammatory Muscle Pain by Activating Local Distinct Layer Somatosensory Afferent Fibers.

Somatosensory autonomic reflexes allow electroacupuncture stimulation (ES) to modulate body physiology at distant sites (for example, suppressing severe systemic inflammation). Since the 1970s, an emerging organizational rule about these reflexes has been the presence of body-region specificity. For example, ES at the hindlimb ST36 acupoint but not the abdominal ST25 acupoint can drive the vagal-adrenal anti-inflammatory axis in mice. The neuroanatomical basis of this somatotopic organization is, however, unknown. Here we show that PROKR2-marked sensory neurons, which innervate the deep hindlimb fascia (for example, the periosteum) but not abdominal fascia (for example, the peritoneum), are crucial for driving the vagal-adrenal axis. Low-intensity ES at the ST36 site in mice with ablated PROKR2-marked sensory neurons failed to activate hindbrain vagal efferent neurons or to drive catecholamine release from adrenal glands. As a result, ES no longer suppressed systemic inflammation induced by bacterial endotoxins. By contrast, spinal sympathetic reflexes evoked by high-intensity ES at both ST25 and ST36 sites were unaffected. We also show that optogenetic stimulation of PROKR2-marked nerve terminals through the ST36 site is sufficient to drive the vagal-adrenal axis but not sympathetic reflexes. Furthermore, the distribution patterns of PROKR2 nerve fibres can retrospectively predict body regions at which low-intensity ES will or will not effectively produce anti-inflammatory effects. Our studies provide a neuroanatomical basis for the selectivity and specificity of acupoints in driving specific autonomic pathways.

A neuroanatomical basis for electroacupuncture to drive the vagal-adrenal axis.

Author Correction: A neuroanatomical basis for electroacupuncture to drive the vagal-adrenal axis.

Corrigendum to "Electroacupuncture regulates inflammatory cytokines by activating the vagus nerve to enhance antitumor immunity in mice with breast tumors" [Life Sciences, 2021, 272: 119259].

Yangshuai Su

Institute of Acupuncture and Moxibustion

China Academy of Chinese Medical Sciences

Demonstrating Hairy and Glabrous Skin Innervation in a 3D Pattern Using Multiple Fluorescent Staining and Tissue Clearing Approaches