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Changes in responses of neurons in spinal and medullary subnucleus reticularis dorsalis to acupoint stimulation in rats with visceral hyperalgesia.

Yu LL, Li L, Rong PJ, Zhu B, Qin QG, Ben H, Huang GF - Evid Based Complement Alternat Med (2014)

Bottom Line: In medulla oblongata, EA-induced activation of SRD neurons further increased to 63.28 ± 15.96% (1.5 mA) (P < 0.001) and 25.02 ± 7.47% (6 mA) (P < 0.01) compared to that before CRD.Taken together, these data suggest that the viscerosomatic convergence-facilitation effect of WDR and SRD neurons may underlie the mechanism of acupoints sensitization.But the sensitizing effect of visceral nociception on WDR neurons is stronger than that on SRD neurons.

View Article: PubMed Central - PubMed

Affiliation: Department of Acupuncture and Moxibustion, Wuhan Hospital of Integrated Chinese and Western Medicine, 215 Zhongshan Road, Wuhan 430022, China ; Institute of Acupuncture and Moxibustion, China Academy of Chinese Medical Sciences, Beijing 100700, China.

ABSTRACT
The purpose of this study was to explore the mechanism of acupoints sensitization phenomenon at the spinal and medulla levels. Experiments were performed on adult male Sprague-Dawley rats and visceral noxious stimuli was generated by colorectal distension (CRD). The activities of wide dynamic range (WDR) and subnucleus reticularis dorsalis (SRD) neurons were recorded. The changes of the reactions of WDR and SRD neurons to electroacupuncture (EA) on acupoints of "Zusanli-Shangjuxu" before and after CRD stimulation were observed. The results showed that visceral nociception could facilitate the response of neurons to acupoints stimulation. In spinal dorsal horn, EA-induced activation of WDR neurons further increased to 106.84 ± 17.33% (1.5 mA) (P < 0.001) and 42.27 ± 13.10% (6 mA) (P < 0.01) compared to the neuronal responses before CRD. In medulla oblongata, EA-induced activation of SRD neurons further increased to 63.28 ± 15.96% (1.5 mA) (P < 0.001) and 25.02 ± 7.47% (6 mA) (P < 0.01) compared to that before CRD. Taken together, these data suggest that the viscerosomatic convergence-facilitation effect of WDR and SRD neurons may underlie the mechanism of acupoints sensitization. But the sensitizing effect of visceral nociception on WDR neurons is stronger than that on SRD neurons.

No MeSH data available.


Related in: MedlinePlus

The responses of SRD neurons to different stimuli from skin receptive fields and viscera. The whole recording time was 40 s, of which the first 5 s was the duration for recording spontaneous background (BG) discharges; from the 5th to 35th s, the stimuli of (a) touch, (b) the bristles stimuli, (c) 1.5 mA EA, (d) pinch, (e) CRD, and (f) 4 mA EA were consecutively administered; the poststimulus BG discharges were recorded from the 35th to the 40th s.
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fig6: The responses of SRD neurons to different stimuli from skin receptive fields and viscera. The whole recording time was 40 s, of which the first 5 s was the duration for recording spontaneous background (BG) discharges; from the 5th to 35th s, the stimuli of (a) touch, (b) the bristles stimuli, (c) 1.5 mA EA, (d) pinch, (e) CRD, and (f) 4 mA EA were consecutively administered; the poststimulus BG discharges were recorded from the 35th to the 40th s.

Mentions: 28 SRD neurons were recorded in the dorsal medulla and their positions were mapped by electrophoretic deposition of pontamine sky blue at the end of experiments (see Figure 5). The responses of neurons to touch, brush bristles, pinch, CRD, and different intensities of EA stimulation were observed. Results showed that SRD neurons had significant responses to noxious stimulations (such as pinch, CRD, and 4 mA EA) but had no responses to any kind of nonnoxious stimulations (such as touch, brush bristles, and 1.5 mA EA) (see Figure 6).


Changes in responses of neurons in spinal and medullary subnucleus reticularis dorsalis to acupoint stimulation in rats with visceral hyperalgesia.

Yu LL, Li L, Rong PJ, Zhu B, Qin QG, Ben H, Huang GF - Evid Based Complement Alternat Med (2014)

The responses of SRD neurons to different stimuli from skin receptive fields and viscera. The whole recording time was 40 s, of which the first 5 s was the duration for recording spontaneous background (BG) discharges; from the 5th to 35th s, the stimuli of (a) touch, (b) the bristles stimuli, (c) 1.5 mA EA, (d) pinch, (e) CRD, and (f) 4 mA EA were consecutively administered; the poststimulus BG discharges were recorded from the 35th to the 40th s.
© Copyright Policy - open-access
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC4262754&req=5

fig6: The responses of SRD neurons to different stimuli from skin receptive fields and viscera. The whole recording time was 40 s, of which the first 5 s was the duration for recording spontaneous background (BG) discharges; from the 5th to 35th s, the stimuli of (a) touch, (b) the bristles stimuli, (c) 1.5 mA EA, (d) pinch, (e) CRD, and (f) 4 mA EA were consecutively administered; the poststimulus BG discharges were recorded from the 35th to the 40th s.
Mentions: 28 SRD neurons were recorded in the dorsal medulla and their positions were mapped by electrophoretic deposition of pontamine sky blue at the end of experiments (see Figure 5). The responses of neurons to touch, brush bristles, pinch, CRD, and different intensities of EA stimulation were observed. Results showed that SRD neurons had significant responses to noxious stimulations (such as pinch, CRD, and 4 mA EA) but had no responses to any kind of nonnoxious stimulations (such as touch, brush bristles, and 1.5 mA EA) (see Figure 6).

Bottom Line: In medulla oblongata, EA-induced activation of SRD neurons further increased to 63.28 ± 15.96% (1.5 mA) (P < 0.001) and 25.02 ± 7.47% (6 mA) (P < 0.01) compared to that before CRD.Taken together, these data suggest that the viscerosomatic convergence-facilitation effect of WDR and SRD neurons may underlie the mechanism of acupoints sensitization.But the sensitizing effect of visceral nociception on WDR neurons is stronger than that on SRD neurons.

View Article: PubMed Central - PubMed

Affiliation: Department of Acupuncture and Moxibustion, Wuhan Hospital of Integrated Chinese and Western Medicine, 215 Zhongshan Road, Wuhan 430022, China ; Institute of Acupuncture and Moxibustion, China Academy of Chinese Medical Sciences, Beijing 100700, China.

ABSTRACT
The purpose of this study was to explore the mechanism of acupoints sensitization phenomenon at the spinal and medulla levels. Experiments were performed on adult male Sprague-Dawley rats and visceral noxious stimuli was generated by colorectal distension (CRD). The activities of wide dynamic range (WDR) and subnucleus reticularis dorsalis (SRD) neurons were recorded. The changes of the reactions of WDR and SRD neurons to electroacupuncture (EA) on acupoints of "Zusanli-Shangjuxu" before and after CRD stimulation were observed. The results showed that visceral nociception could facilitate the response of neurons to acupoints stimulation. In spinal dorsal horn, EA-induced activation of WDR neurons further increased to 106.84 ± 17.33% (1.5 mA) (P < 0.001) and 42.27 ± 13.10% (6 mA) (P < 0.01) compared to the neuronal responses before CRD. In medulla oblongata, EA-induced activation of SRD neurons further increased to 63.28 ± 15.96% (1.5 mA) (P < 0.001) and 25.02 ± 7.47% (6 mA) (P < 0.01) compared to that before CRD. Taken together, these data suggest that the viscerosomatic convergence-facilitation effect of WDR and SRD neurons may underlie the mechanism of acupoints sensitization. But the sensitizing effect of visceral nociception on WDR neurons is stronger than that on SRD neurons.

No MeSH data available.


Related in: MedlinePlus