scholarly journals 100 Hz Electroacupuncture Alleviated Chronic Itch and GRPR Expression Through Activation of Kappa Opioid Receptors in Spinal Dorsal Horn

2021 ◽  
Vol 15 ◽  
Author(s):  
Hong-Ping Li ◽  
Xiao-Yu Wang ◽  
Chao Chen ◽  
Jing-Jing Li ◽  
Chi Yu ◽  
...  
Keyword(s):  
Dorsal Horn ◽  
Diethyl Ether ◽  
Opioid Receptors ◽  
Spinal Dorsal Horn ◽  
Underlying Mechanism ◽  
Kappa Opioid Receptors ◽  
Effective Frequency ◽  
Kappa Opioid ◽  
Spinal Dorsal ◽  
Chronic Itch

BackgroundClinical studies have shown that electroacupuncture (EA) alleviates chronic itch. Gastrin-releasing peptide receptor (GRPR) and dynorphin (DYN) in the spinal dorsal horn positively or negatively regulate itch, respectively. However, which frequency of EA is effective on relieving chronic itch and reducing the expression of GRPR, whether DYN-A in the spinal cord is involved in the underlying mechanism of the antipruritus effect of EA remains unknown.MethodsThe mixture of acetone and diethyl ether (1:1) [designated as AEW (acetone/diethyl ether and water) treatment] was used to induce the dry skin model of chronic itch. EA was applied to Quchi (LI11) and Hegu (LI4). Western blot was used to detect the expression of GRPR and DYN-A. Immunofluorescence was used to detect the expression of DYN-A.ResultsThe AEW administration induced remarkable spontaneous scratching, enhanced the expression of GRPR, and reduced the expression of DYN-A. Compared with the sham EA, 2 Hz EA, or 15 Hz EA group, 100 Hz EA was the most effective frequency for relieving chronic itch, reducing the expression of GRPR, and increasing the expression of DYN-A in the cervical dorsal horn. Furthermore, intraperitoneal injection of kappa opioid receptors (KORs) antagonist nor-Binaltorphimine dihydrochloride (nor-BNI) significantly reversed the effect of 100 Hz EA on the inhibition of both itching behavior and GRPR expression.ConclusionEA at 100 Hz is the most effective frequency that inhibits chronic itch and GRPR expression through activation of KORs in the spinal dorsal horn, which can effectively guide the clinical treatment and improve the antipruritic effect of acupuncture.

CONTRIBUTION OF MU AND DELTA OPIOID RECEPTORS TO MORPHINE ANALGESIA IN THE SPINAL DORSAL HORN OF CATS

1989 ◽  
Vol 71 (Supplement) ◽  
pp. A629
Author(s):  
K. Omote ◽  
L. M. Kitahata ◽  
J. G. Collins ◽  
K. Nakatani
Keyword(s):  
Dorsal Horn ◽  
Opioid Receptors ◽  
Spinal Dorsal Horn ◽  
Morphine Analgesia ◽  
Spinal Dorsal ◽  
Delta Opioid Receptors

scholarly journals Kappa opioid receptors in the central amygdala modulate spinal nociceptive processing through an action on amygdala CRF neurons

2020 ◽  
Vol 13 (1) ◽  
Author(s):  
Guangchen Ji ◽  
Volker Neugebauer
Keyword(s):  
Dorsal Horn ◽  
Spinal Dorsal Horn ◽  
Facilitatory Effect ◽  
Functional Coupling ◽  
Kappa Opioid ◽  
Positive Direction ◽  
Dorsal Horn Neurons ◽  
Spinal Dorsal ◽  
Nociceptive Processing ◽  
Spinal Dorsal Horn Neurons

Abstract The amygdala plays an important role in the emotional-affective aspects of behaviors and pain, but can also modulate sensory aspect of pain (“nociception”), likely through coupling to descending modulatory systems. Here we explored the functional coupling of the amygdala to spinal nociception. We found that pharmacological activation of neurons in the central nucleus of the amygdala (CeA) increased the activity of spinal dorsal horn neurons; and this effect was blocked by optogenetic silencing of corticotropin releasing factor (CRF) positive CeA neurons. A kappa opioid receptor (KOR) agonist (U-69,593) was administered into the CeA by microdialysis. KOR was targeted because of their role in averse-affective behaviors through actions in limbic brain regions. Extracellular single-unit recordings were made of CeA neurons or spinal dorsal horn neurons in anesthetized transgenic Crh-Cre rats. Neurons responded more strongly to noxious than innocuous stimuli. U-69,593 increased the responses of CeA and spinal neurons to innocuous and noxious mechanical stimulation of peripheral tissues. The facilitatory effect of the agonist was blocked by optical silencing of CRF-CeA neurons though light activation of halorhodopsin expressed in these neurons by viral-vector. The CRF system in the amygdala has been implicated in aversiveness and pain modulation. The results suggest that the amygdala can modulate spinal nociceptive processing in a positive direction through CRF-CeA neurons and that KOR activation in the amygdala (CeA) has pro-nociceptive effects.

scholarly journals A central role for spinal dorsal horn neurons that express neurokinin-1 receptors in chronic itch

Pain ◽  
2015 ◽  
Vol 156 (7) ◽  
pp. 1240-1246 ◽  
Author(s):  
Tasuku Akiyama ◽  
Tony Nguyen ◽  
Eric Curtis ◽  
Katsuko Nishida ◽  
Jahnavi Devireddy ◽  
...  
Keyword(s):  
Dorsal Horn ◽  
Spinal Dorsal Horn ◽  
Dorsal Horn Neurons ◽  
Spinal Dorsal ◽  
Chronic Itch ◽  
Spinal Dorsal Horn Neurons ◽  
Neurokinin 1

Functional μ Opioid Receptors Are Reduced in the Spinal Cord Dorsal Horn of Diabetic Rats

2002 ◽  
Vol 97 (6) ◽  
pp. 1602-1608 ◽  
Author(s):  
Shao-Rui Chen ◽  
Kristi L. Sweigart ◽  
Joan M. Lakoski ◽  
Hui-Lin Pan
Keyword(s):  
Spinal Cord ◽  
Dorsal Horn ◽  
Opioid Receptors ◽  
Spinal Dorsal Horn ◽  
Diabetic Rats ◽  
Spinal Cord Dorsal Horn ◽  
Mu Opioid Receptors ◽  
Mu Opioid ◽  
Spinal Dorsal ◽  
Spinal Cord Dorsal

Background The mechanisms of decreased spinal analgesic potency of morphine in neuropathic pain are not fully known. Agonist-stimulated [35S]GTPgammaS receptor autoradiography has been used to measure receptor activation of G proteins in vitro. Using this technique, we determined changes in the functional mu opioid receptors in the spinal dorsal horn in diabetic rats. Methods Rats were rendered diabetic with an intraperitoneal injection of streptozotocin. The lumbar spinal cord was obtained from age-matched normal and diabetic rats 4 weeks after streptozotocin treatment. [D-Ala2,N-MePhe4,Gly5-ol]-enkephalin (DAMGO, 10 microm)-stimulated [35S]GTPgammaS binding was performed in both tissue sections and isolated membranes. Results The DAMGO-stimulated [35S]GTPgammaS binding in the spinal dorsal horn was significantly reduced (approximately 37%) in diabetic rats compared with normal rats. However, [35S]GTPgammaS bindings in the spinal dorsal horn stimulated by other G protein-coupled receptor agonists, including [D-Pen2,D-Pen5]-enkephalin, R(-)N6-(2-phenylisopropyl)-adenosine, and WIN-55212, were not significantly altered in diabetic rats. The basal [35S]GTPgammaS binding in the spinal dorsal horn was slightly (approximately 13%) but significantly increased in diabetic rats. Western blot analysis revealed no significant difference in the expression of the alpha subunits of G(i) and G(o) proteins in the dorsal spinal cord between normal and diabetic rats. Conclusions These data suggest that the functional mu opioid receptors in the spinal cord dorsal horn of diabetic rats are reduced. The impaired functional mu opioid receptors in the spinal cord may constitute one of the mechanisms underlying the reduced spinal analgesic effect of mu opioids in diabetic neuropathic pain.

STAT3-dependent reactive astrogliosis in the spinal dorsal horn underlies chronic itch

2015 ◽  
Vol 21 (8) ◽  
pp. 927-931 ◽  
Author(s):  
Miho Shiratori-Hayashi ◽  
Keisuke Koga ◽  
Hidetoshi Tozaki-Saitoh ◽  
Yuta Kohro ◽  
Honami Toyonaga ◽  
...  
Keyword(s):  
Dorsal Horn ◽  
Spinal Dorsal Horn ◽  
Reactive Astrogliosis ◽  
Spinal Dorsal ◽  
Chronic Itch

Specific activation of inhibitory interneurons in the spinal dorsal horn suppresses repetitive scratching in mouse models of chronic itch

2017 ◽  
Vol 88 (2) ◽  
pp. 251-254 ◽  
Author(s):  
Kensho Kanehisa ◽  
Miho Shiratori-Hayashi ◽  
Keisuke Koga ◽  
Hidetoshi Tozaki-Saitoh ◽  
Yuta Kohro ◽  
...  
Keyword(s):  
Dorsal Horn ◽  
Mouse Models ◽  
Spinal Dorsal Horn ◽  
Inhibitory Interneurons ◽  
Spinal Dorsal ◽  
Chronic Itch

Endogenous Opioid Peptides Acting at μ-Opioid Receptors in the Dorsal Horn Contribute to Midbrain Modulation of Spinal Nociceptive Neurons

1998 ◽  
Vol 79 (2) ◽  
pp. 677-687 ◽  
Author(s):  
Dénes Budai ◽  
Howard L. Fields
Keyword(s):  
Dorsal Horn ◽  
Opioid Receptors ◽  
Spinal Dorsal Horn ◽  
Endogenous Opioid Peptides ◽  
Endogenous Opioid ◽  
Nociceptive Neurons ◽  
Dorsal Horn Neurons ◽  
Spinal Dorsal ◽  
Spinal Dorsal Horn Neurons ◽  
Μ Opioid Receptors

Budai, Dénes and Howard L. Fields. Endogenous opioid peptides acting at μ-opioid receptors in the dorsal horn contribute to midbrain modulation of spinal nociceptive neurons. J. Neurophysiol. 79: 677–687, 1998. Activation of neurons in the midbrain periaqueductal gray (PAG) inhibits spinal dorsal horn neurons and produces behavioral antinociception in animals and analgesia in humans. Although dorsal horn regions modulated by PAG activation contain all three opioid receptor classes (μ, δ, and κ), as well as enkephalinergic interneurons and terminal fields, descending opioid-mediated inhibition of dorsal horn neurons has not been demonstrated. We examined the contribution of dorsal hornμ-opioid receptors to the PAG-elicited descending modulation of nociceptive transmission. Single-unit extracellular recordings were made from rat sacral dorsal horn neurons activated by noxious heating of the tail. Microinjections of bicuculline (BIC) in the ventrolateral PAG led to a 60–80% decrease in the neuronal responses to heat. At the same time, the responses of the same neurons to iontophoretically applied NMDA or kainic acid were not consistently inhibited. The inhibition of heat-evoked responses by PAG BIC was reversed by iontophoretic application of the selective μ-opioid receptor antagonists, d-Phe-Cys-Tyr-d-Trp-Orn-Thr-Pen-Thr-NH2 (CTOP) and d-Phe-Cys-Tyr-d-Trp-Arg-Thr-Pen-Thr-NH2 (CTAP). A similar effect was produced by naloxone; however, naloxone had an excitatory influence on dorsal horn neurons in the absence of PAG-evoked descending inhibition. This is the first demonstration that endogenous opioids acting via spinal μ-opioid receptors contribute to brain stem control of nociceptive spinal dorsal horn neurons. The inhibition appears to result in part from presynaptic inhibition of afferents to dorsal horn neurons.

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