visualizing-calcitonin-gene-related-peptide-immunoreactive

Visualizing the Calcitonin Gene-Related Peptide Immunoreactive Innervation of the Rat Cranial Dura Mater with Immunofluorescence and Neural Tracing

The aim of this study was to examine the distribution and origin of the calcitonin gene-related peptide (CGRP)-immunoreactive sensory nerve fibers of the ...

China Academy of Chinese Medical Sciences

China Academy Of Chinese Medical Sciences

Neurostimulation procedures like vagus nerve stimulation (VNS) and deep brain stimulation have been used to treat refractory epilepsy and other neurological disorders. While holding promise, they are invasive interventions with serious complications and adverse effects. Moreover, their efficacies are modest with less seizure free. Acupuncture is a simple, safe, and effective traditional healing modality for a wide range of diseases including pain and epilepsy. Thalamus takes critical role in sensory transmission and is highly involved in epilepsy genesis particularly the absence epilepsy. Considering thalamus serves as a convergent structure for both acupuncture and VNS and the thalamic neuronal activities can be modulated by acupuncture, we propose that acupuncture could be a promising therapy or at least a screening tool to select suitable candidates for those invasive modalities in the management of refractory epilepsy. 

Acupuncture for refractory epilepsy: role of thalamus.

Visceral pain is the most common form of pain caused by varied diseases and a major reason for patients to seek medical consultation. Despite much advances, the pathophysiological mechanism is still poorly understood comparing with its somatic counterpart and, as a result, the therapeutic efficacy is usually unsatisfactory. Acupuncture has long been used for the management of numerous disorders in particular pain and visceral pain, characterized by the high therapeutic benefits and low adverse effects. Previous findings suggest that acupuncture depresses pain via activation of a number of neurotransmitters or modulators including opioid peptides, serotonin, norepinephrine, and adenosine centrally and peripherally. It endows us, by advancing the understanding of the role of ion channels and gut microbiota in pain process, with novel perspectives to probe the mechanisms underlying acupuncture analgesia. In this review, after describing the visceral innervation and the relevant afferent pathways, in particular the ion channels in visceral nociception, we propose three principal mechanisms responsible for acupuncture induced benefits on visceral pain. Finally, potential topics are highlighted regarding the future studies in this field. 

Acupuncture for visceral pain: neural substrates and potential mechanisms.

Chronic pain is a common disability influencing quality of life. Results of previous studies showed that acupuncture has a cumulative analgesic effect, but the relationship with spinal cytokines neurotrophic factors released by astrocytes remains unknown. The present study was designed to observe the effect of electroacupuncture (EA) treatment on spinal cytokines neurotrophic factors in chronic neuropathic pain rats. The chronic neuropathic pain was established by chronic constrictive injury (CCI). EA treatment was applied at Zusanli (ST36) and Yanglingquan (GB34) (both bilateral) once a day, for 30 min. IL-1 mRNA, TNF- mRNA, and IL-1 mRNA were detected by quantitative real-time PCR, and the proteins of BDNF, NGF, and NT3/4 were detected by Western blot. The expression levels of cytokines such as IL-1 mRNA, TNF- mRNA, IL-6 mRNA, and neurotrophic factors such as BDNF, NGF, and NT3/4 in the spinal cord were increased significantly after CCI. The astrocytes released more IL-1 and BDNF after CCI. Repeated EA treatment could suppress the elevated expression of IL-1 mRNA, TNF mRNA, and BDNF, NGF, and NT3/4 but had no effect on IL-6 mRNA. It is suggested that cytokines and neurotrophic factors which may be closely associated with astrocytes participated in the process of EA relieving chronic pain.

The Effect of Repeated Electroacupuncture Analgesia on Neurotrophic and Cytokine Factors in Neuropathic Pain Rats.

The neurovascular structures in the cranial dura mater have been studied with various histological techniques in the past years. In order to obtain a proper approach to reveal the detailed structures, different labeling methods for the cranial vessels and nerve fibers were tested in this study. Firstly, the labeling characteristics of phalloidin, alpha smooth muscle actin (α-SMA), and CD31 were compared in rat whole-mount cranial dura mater by using fluorescent immunohistochemistry or histochemistry. Secondly, according to their properties, phalloidin and α-SMA were selected to combine with calcitonin gene-related peptide (CGRP) to further demonstrate the cranial neurovascular structure. By these approaches, a three-dimensional map of blood vessels and nerve fibers within the whole-mount rat cranial dura mater was obtained. The results showed that phalloidin, α-SMA, and CD31 were preferably expressed in the wall of cranial vessels, corresponding to the arteriors, venules, and capillaries, respectively. Additionally, CGRP + nerve fibers were clearly demonstrated together with phalloidin + or α-SMA + vessels, forming a delicate neurovascular network in the cranial dura mater. The thick nerve bundles ran closely to the phalloidin + or α-SMA + vessels in parallel pattern, while the thin nerve fibers branched off from the bundles tending to surround the phalloidin + arterioles rather than α-SMA + venules. These findings suggest that phalloidin could be an appropriate biochemical maker to be effectively used together with CGRP for experiments examining the detailed spatial correlation of cranial blood vessels and nerve fibers in a three-dimensional view, which may provide clues for understanding the underlying mechanisms of cranial neurovascular disorders.

Jianliang Zhang

Institute of Acupuncture and Moxibustion

China Academy of Chinese Medical Sciences

Visualizing the Calcitonin Gene-Related Peptide Immunoreactive Innervation of the Rat Cranial Dura Mater with Immunofluorescence and Neural Tracing