• The Journal of Korean Physical Therapy
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• v.15 no.4
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• pp.190-198
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• 2003

Expression of c-fos, an immediate early gene, has accepted to be a marker of functional activity in neurons. This study was aimed to investigate the effects of cold therapy on the expression of spinal cord c-fos in rats of carrageenan-induced muscle pain. Muscle pain was induced in male Sprague-Dawley rats by intra-muscular injection of gastrocnemius with $2\%$ carrageenan. The paw withdrawal latency (PWL) and tail flick test (TFT) responses to heat stimuli were used to detect secondary hyperalgesia produced by the muscle pain and measured to assess the effects of cold. The expression of c-fos was determined in the lumbar regions of the spinal cord by reverse transcription-polymerase chain reaction (RT-PCR) and immunohistochemistry assays. The secondary hyperalgesia to heat simuli (PWL and TFT) were significantly reduced in cold therapy compared with that in the controls. In RT-PCR assays the expression of c-fos mRNA was down-regulated in the lumbar spinal cord in cold group. In addition, Fos immunoreactivity in the dorsal horn of the lumbar spinal cord was decreased in cold group. These results suggested that application of cold attributed to increase PWL and TFT responses and to decrease expression of the c-fos produced by muscle pain.

• The Journal of Korean Physical Therapy
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• v.13 no.2
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• pp.335-346
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• 2001

This study was performed, using c-fos, to investigate the effect of TENS on pain model induced by capsaicin in spinal level. Twelve rats with 200-250g body weight were randomly divided into three groups: One group which induced by capsaicin, another group which applicated TENS with low frequency(4Hz. 200${\mu}$s, 20min) and the other group which applicated TENS with high frequency(100Hz, 50${\mu}$s, 20 min). The results of this study were as follows: 1. The number of c-fos immunoreactive neurons in superficial dorsal horn was increased markedly 2 hours after capsaicin injection, and decreased gradually from 4 hours to 16 hours after injection. 2. At 2hours after capsaicin injection, both low frequency and high frequency TENS decrease the number of c-fos immunoreactive neurons in superficial dorsal horn .3. In acute pain model, low frequency TENS greatly decrease c-fos expression than high frequency TENS. Therefore. decreasing the number of c-fos immunoreactive neurons which increased after capsaicin injection with application of TENS indicate that both of the TENS have inhibitory effect. In addition. low frequency TENS greatly decreased the number of neurons explains low frequency TENS is more effective than high frequency TENS in acute pain. This study also can become a part of scientific evidence on electrotherapy through measuring quantitively effects of TENS in pain model.

• Journal of Acupuncture Research
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• v.17 no.2
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• pp.153-168
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• 2000

Introduction : In spite of the use of Bee Venom aqua-acupuncture in the clinics, the scientific evaluation on effects is not enough. Bee Venom aqua-acupuncture is used according to the stimulation of acupuncture point and the chemical effects of Bee Venom. The aims of this study is to investigate the analgegic effects of the Bee Venom aqua-acupuncture, through the change of writhing reflex and the change of c-fos in secondary neurons in the spinal cord. Materials and Methods : Pain animal model was used acetic acid method. The changes of writhing reflex of the mice which were derived pain by injecting acetic acid into the abdomen, after stimulating Bee Venom aqua-acupuncture on Chungwan(CV12) were measured. We used Fos immunohistochemical technique to study the neuronal activity in the spinal cord. Results : 1. Expression of c-fos in superficial dorsal horn(SDH), nucleus proprius(NP) and neck of dorsal hom(N) on 6~9th thoracic spine decreased significantly at $2.5{\times}10-4$g/kg Bee Venom aqua-acupuncture, compared with saline-acetic acid group. 2. The numeral change of Fos-LI neurons on the NP, N, and ventral gray(V) on 6-9th thoracic spine, SDH on 9-11th thoracic spine, and SDH and V on 11~13th thoracic spine decreased significantly at Chungwan(CV12) Bee Venom aqua-acupuncture, compared with saline-acetic acid group. 3. The correlation between the numbers of writhing refleax and Fos-LI neurons in T6-13 segment was statistically statistically significant at Chungwan(CV12) Bee Venom aqua-acupuncture. Conclusion : This study shows that the Bee Venom aqua-acupuncture on Chungwan(CV12) decreases the numbers of Fos-LI neurons. As the analgegic effects of Bee Venom aqua-acupuncture is recognized. Bee Venom aqua-acupuncture treatment is expected for pain modulation. In order to use it in many ways, more researches are needed for the dose and stability of Bee Venom aqua-acupuncture.

• International Journal of Oral Biology
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• v.45 no.4
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• pp.225-231
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• 2020

Glial cells, including astrocytes and microglia, interact closely with neurons and modulate pain transmission, particularly under pathological conditions. In this study, we examined the excitability of substantia gelatinosa (SG) neurons of the spinal dorsal horn using a patch clamp recording to investigate the roles of microglial activation in the nociceptive processes of rats. We used xanthine/xanthine oxidase (X/XO), a generator of superoxide anion (O2·-), to induce a pathological pain condition. X/XO treatment induced an inward current and membrane depolarization. The inward current was significantly inhibited by minocycline, a microglial inhibitor, and fluorocitrate, an astrocyte inhibitor. To examine whether toll-like receptor 4 (TLR4) in microglia was involved in the inward current, we used lipopolysaccharide (LPS), a highly specific TLR4 agonist. The LPS induced inward current, which was decreased by pretreatment with Tak-242, a TLR4-specific inhibitor, and phenyl N-t-butylnitrone, a reactive oxygen species scavenger. The X/XO-induced inward current was also inhibited by pretreatment with Tak-242. These results indicate that the X/XO-induced inward current of SG neurons occurs through activation of TLR4 in microglial cells, suggesting that neuroglial cells modulate the nociceptive process through central sensitization.

• Korean Journal of Acupuncture
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• v.36 no.4
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• pp.264-273
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• 2019

Objectives : Microglia play a crucial role in electroacupuncture (EA) analgesia on neuropathic pain. The role of chemokines in producing analgesic effects of EA, however, is largely unknown. In the present study, we investigated the role of chemokines in producing analgesic effects of EA in the neuropathic pain model. Methods : Sprague-Dawley rats were randomly assigned into three groups (anesthetized group (ANE), non-acupoint EA group (NAP), and ST36 - GB34 EA group (ACU)). Neuropathic pain was induced by tight ligation of L5 spinal nerve. Mechanical and thermal hypersensitivity of hind paw was tested. Western blot tests and immunofluorescence assay for C-C motif chemokine ligand 2 (CCL2) levels and microglia activation were performed on spinal cord L5/6. EA was treated once daily from the 3rd day after surgery for 5 days. Results : EA treatments applied to ST36 and GB34 significantly reduced both mechanical and thermal hypersensitivity after two and three times of treatment, respectively. While CCL2 expression significantly increased in neuropathic rats, it was significantly reduced in the ACU. In addition, co-localization of CCL2 and activated microglia significantly decreased in the ACU compared to those of ANE and NAP in the spinal cord L5/L6 dorsal horn. Conclusions : The present results suggest that EA applied to ST36 and GB34 modulates the reduction of CCL2 release from the injured neurons and consequently decreases microglia activation in the spinal cord. Regulation of chemokine induced spinal activation of microglia plays a key role in analgesic effects of EA in the rat model of neuropathic pain.

• Korean Journal of Acupuncture
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• v.23 no.3
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• pp.55-71
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• 2006

Objectives : The present study was investigated the effect and pathway of heterotopic electroacupuncture (EA) on pain induced by formalin in rats. Methods : Acupoints in the right forepaws, $HT_7$ and $PC_7$, were stimulated with 3 mA, 2 ms, and 10 Hz before subcutaneously formalin injection (5%, $50{\mu}l$) to the left hind paw. Moreover, it was investigated whether the dorsolateral funiculus (DLF), as known to the descending inhibition, mediates analgesia of the heterotopic EA, and an administration of naltrexone blocks the effect of EA. Results : In the immunohistochemistry of cFos-like protein (cFL), there were inhibitory effects of EA on the increased expression of cFL in the lumbar spinal dorsal horn neurons following formalin injection. Especially, EA inhibited the expression of cFL on the superficial laminae than that on the deep laminae at 1 hr after, but that on the deep laminae than that on the superficial laminae at 2 hr after. Also, EA suppressed the increased expression of nitric oxide (NO) and neuronal nitric oxide synthase (nNOS) in the lumbosacral spinal cord after formalin injection, but not Sham-EA. Suppressed expressions of cFL, NO and nNOS in the spinal cord were eliminated after transection of the ipsilateral DLF at $T_{10}{\sim}T_{11}$ levels. However, pretreatment of naltrexone could not prevent the suppressive expressions of cFL, NO and nNOS at the spinal cord. Conclusions : These results suggest that the analgesia of heterotopic EA may be modulated through the DLF constituting the descending inhibition.

• Journal of Physiology & Pathology in Korean Medicine
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• v.20 no.6
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• pp.1672-1677
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• 2006

Sarcodon aspratus is the mushroom of Telephoracea which was been classified into Alphllophorales. The aqueous extract of Sarcodon aspratus in known to have anti-tumor activity, immune modulatory effect, and anti-oxidative action. The descending pain control system consists of three major components: the periaqueductal gray (PAG) of the midbrain, the rostroventral medulla including the nucleus raphe magnus, and the spinal dorsal horn. Glutamate is the primary excitatory neurotransmitter in the brain. Glutamate ionotropic receptors are classified as N-methyl-D-aspartate (NMDA) receptor, ${\alpha}$-amino-3-hydroxy-5-methyl-4-isoxazolepropionate (AMPA) receptor, and kainate receptor. In the present study, the modulation of Sarcodon aspratus on the ion currents activated by glutamate, NMDA, AMPA, and kainate in the acutely dissociated PAG neurons was investigated by nystatin-perforated patch-clamp technique under boltage-clamp condition. Sarcodon aspratus increased glutamate- and NMDA-induced ion currents were not increased by Sarcodon aspratus. The present results show that Sarcodon aspratus may activate the descending pain control system in rat PAG neurons through NMDA receptor.

• The Journal of Korean Physical Therapy
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• v.14 no.2
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• pp.16-25
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• 2002

Low energy laser irradiation(LELI) therapy in physical therapy is widespread but the mechanisms are not fully understood. The purpose of the present study was to examine the epidermal growth factor(EGF)'s expression within lumbar spinal cord which corresponding with crushed extensor digitorum longus(EDL) of rats after low-power laser irradiation applied. After a crushed injury on the right EDL, low-power laser irradiation was applied by using 2000mW, 2000Hz, 830nm GaAlAs(Gallium-aluminum-arsenide) semiconductor diode laser. The laser treatment was performed with 10 minutes daily for 3days. After EDL crush injury, EGF immunoreactive positive neurons in experimental group were progressively decreased from the first to third days. Especially 1 day subgroup is highly expressed in dorsal horn(Lamina I, II, III) and around of central cannal of spinal cord(Lamina VII). Control group was only expressed slightly at 3 days. This study suggests that LELI stimulate that release and migration of EGF in spinal cord, which distict to wound site, therfore promote wound healing of EDL crush injury.

• The Korean Journal of Physiology and Pharmacology
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• v.10 no.6
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• pp.297-302
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• 2006

Melittin, a major component of bee venom, produces a sustained decrease in mechanical threshold, and an increase in spontaneous flinchings and paw thickness, which are characteristics similar to those induced by whole bee venom. Melittin-induced nociception has been known to be modulated by the changes in the activity of excitatory amino acid receptors, voltage-dependent calcium channels, cyclooxygenase and serotonin receptors. The present study was undertaken to investigate the role of calcium chelators (TMB-8 & Quin 2) in melittin-induced nociceptive responses. Changes of mechanical threshold and spontaneous flinching behaviors were measured at a given time point following intraplantar injection of melittin ($30{\mu}g/paw$). Intrathecal or intraplantar pre-administration and intrathecal posttreatment of TMB-8 and Quin 2 significantly prevented the melittin-induced reduction of mechanical threshold, and intraplantar or intrathecal pre-treatment of TMB-8 and Quin 2 suppressed melittininduced flinching behaviors. These results indicate that calcium ion in the spinal dorsal horn neurons and peripheral nerves plays an important role in the production and maintenance of mechanical allodynia and spontaneous pain by melittin.

• The Korean Journal of Physiology and Pharmacology
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• v.13 no.5
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• pp.379-383
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• 2009

Nitric oxide (NO), a diffusible gas, is produced in the central nervous system, including the spinal cord dorsal horn and the trigeminal nucleus, the first central areas processing nociceptive information from periphery. In the spinal cord, it has been demonstrated that NO acts as pronociceptive or antinociceptive mediators, apparently in a concentration-dependent manner. However, the central role of NO in the trigeminal nucleus remains uncertain in support of processing the orofacial nociception. Thus, we here investigated the central role of NO in formalin (3%)-induced orofacial pain in rats by administering membrane-permeable or -impermeable inhibitors, relating to the NO signaling pathways, into intracisternal space. The intracisternal pretreatments with the NO synthase inhibitor L-NAME, the NO-sensitive guanylate cyclase inhibitor ODQ, and the protein kinase C inhibitor GF109203X, all of which are permeable to the cell membrane, significantly reduced the formalin-induced pain, whereas the membrane-impermeable NO scavenger PTIO significantly enhanced it, compared to vehicle controls. These data suggest that an overall effect of NO production in the trigeminal nucleus is pronociceptive, but NO extracellularly diffused out of its producing neurons would have an antinociceptive action.