• Restorative Dentistry and Endodontics
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• 제24권4호
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• pp.614-622
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• 1999

Recent studies have implicated that more rostral components of the trigeminal spinal nucleus including subnucleus oralis (Vo) in orofacial nociceptive mechanisms. Since there is only limited electrophysiological evidence, the present study was initiated to characterize the receptive field and response properties of malls nociceptive neurons in chloralose/urethan-anesthetized rats. Single neuronal activity was recorded in right subnucleus oralis, and types of nociceptive neurons classified wide dynamic range (WDR), NS (nociceptive specific) and deep nociceptive (D) and the mechanoreceptive field (RF) and response properties were determined. A total of 34 nociceptive neurons could be subdivided into 17WDR neurons, 12NS neurons and 5D neurons. Vo nociceptive neurons had RF involving maxillary and/or mandibular divisions mainly located in the intraoral and/or perioral regions. Majority of Vo nociceptive neurons showed spontaneous activity less than 1Hz. The NS and D neurons activated only by heavy pressure and/or pinch stimuli had high mechanical thresholds compared to WDR neurons activated also by tactile stimuli. Vo nociceptive neurons showed a progressive increase of response to the graded mechanical stimuli. 39% of Vo nociceptive neurons received C-fiber electrical input as well as A-fiber electrical input from their RF, and 45% of them responded to electrical stimulation of the right maxillary first molar. 41% of Vo nociceptive neurons responded to noxious heat applied to their RF, and 18% of them showed an immediate burst of discharges following MO application to the right maxillary first molar pulp. These results indicate that Vo is involved in the transmission of nociceptive information mainly coming from intraoral or perioral region including tooth pulp.

• Restorative Dentistry and Endodontics
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• 제27권6호
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• pp.587-599
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• 2002

Extracellular single unit recordings were made from the ventral posteromedial thalamic (VPM) nociceptive neurons to determine mechanoreceptive field (RF) and response properties. A total of 44 VPM thalamic nociceptive neurons were isolated from rats anesthetized with urethane-chloralose. Based on responses to various mechanical stimuli including touch, pressure and pinch applied to the RF, 32 of 44 neurons were classified as nociceptive specific (NS) neuron. The other 12 neurons, classified as wide dynamic range (WDR), showed a graded response to increasingly intense stimuli, with a maximum discharge to noxious pinch. The VPM nociceptive neurons showed various spontaneous activity ranged from 0-6 Hz. They were located throughout the VPM, and had an contralateral RF including mainly intraoral (and perioral) regions. The RF size was relatively small, and very few neurons had a receptive field involving 3 trigeminal divisions. The NS neurons activated only by pressure and pinch stimuli had high mechanical thresholds compared to WDR neurons activated also by touch stimuli. The VPM nociceptive neurons were tested with suprathershold graded mechanical stimuli. Most of 21 NS and 8 WDR neurons showed a progressive increase in number of spikes as mechanical stimulus intensity was increased. In some neurons, the responses reached a peak before the highest intensity was given. Application of 5 mM $CoCl_2{\;}(10{\;}{\mu}\ell)$ solution to the trigeminal subnucleus caudalis did not produce any significant changes in the spontaneous activity, RF size, mechanical threshold, and response to suprathreshold mechanical stimuli of 9 VPM nociceptive neurons tested. 17 of 33 VPM nociceptive neurons responded to noxious heat as well as noxious mechanical stimuli applied to their RF. Application of the mustard oil, a small-fiber excitant and inflammatory irritant, to the right maxillary first molar tooth pulp induced an immediate but short-lasting neuronal discharges upto approximately 4 min in 16 of 42 VPM nociceptive neurons. These results suggest that VPM thalamic nucleus may contribute to the sensory discriminative aspect of orofacial nociception.

• The Korean Journal of Physiology and Pharmacology
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• 제3권4호
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• pp.365-373
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• 1999

Somatostatin (SOM) is one of the major neuropeptides in dorsal root ganglion cells, but its role in spinal nociceptive process has not been well known. In present study we aimed to investigate the effect of SOM on the response of dorsal horn neurons to the various types of peripheral nociceptive stimuli in anesthetized cats. Using carbon-filament microelectrode, the single cell activities of wide dynamic range neurons were recorded from the lumbosacral enlargement after noxious mechanical (squeeze), thermal (radiant heat lamp) and cold (dry ice) stimulation to the receptive field. Sciatic nerve was stimulated electrically to evoke $A\;{\delta}-$ and C-nociceptive responses. SOM analogue, octreotide $(10\;{\mu}g/kg),$ was applied intravenously and the results were compared with those of morphine (2 mg/kg, MOR). Systemic SOM decreased the cellular responses to the noxious heat and the mechanical stimulation, but increased those to the cold stimulation. In the responses to the electric stimuli of sciatic nerve, $A\;{\delta}-nociceptive$ response was increased by SOM, while C-nociceptive response was decreased. On the other hand, MOR inhibited the dorsal horn cell responses to all the noxious stimuli. From the above results, it is concluded that SOM suppresses the transmission of nociceptive heat and mechanical stimuli, especially via C-fiber, while it facilitates those of nociceptive cold stimuli via $A\;{\delta}-fiber$.

• The Korean Journal of Pain
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• 제35권1호
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• pp.33-42
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• 2022

Background: Cupressus arizonica Greene is a coniferous tree with great importance in fragrance and pharmaceutical industries. Essential oils from C. arizonica (EC) have shown potential antioxidant, and anti-microbial activities. This study aimed at investigating the anti-nociceptive and anti-inflammatory effects/mechanisms of EC. Methods: The EC was evaluated for anti-nociceptive and anti-inflammatory activities on male Wistar rats using a formalin test and carrageenan-induced paw edema, respectively. Also, we pre-treated some of the animals with naloxone and flumazenil in the formalin test to find out the possible contributions of opioid and benzodiazepine receptors to EC anti-nociceptive effects. Finally, gas chromatography/mass spectrometry (GC/MS) analysis was used to identify the EC's constituents. Results: EC in intraperitoneal doses of 0.5 and 1 g/kg significantly decrease the nociceptive responses in both early and late phases of the formalin test. From a mechanistic point of view, flumazenil administration 20 minutes before the most effective dose of EC (1 g/kg) showed a meaningful reduction in the associated anti-nociceptive responses during the early and late phases of the formalin test. Naloxone also reduced the anti-nociceptive role of EC in the late phase. Furthermore, EC at the doses of 1, 0.5, and 0.25 g/kg significantly reduced paw edema from 0.5 hours after carrageenan injection to 4 hours. GC/MS analysis showed that isolated EC is a monoterpene-rich oil with the major presence of α-pinene (71.92%), myrcene (6.37%), δ-3-carene (4.68%), β-pinene (3.71%), and limonene (3.34%). Conclusions: EC showed potent anti-nociceptive and anti-inflammatory activities with the relative involvement of opioid and benzodiazepine receptors.

• The Korean Journal of Physiology and Pharmacology
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• 제10권6호
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• pp.323-327
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• 2006

Despite the wealth of data concerning the roles of ${\alpha}-CGRP$ in nociceptive behaviors, ${\alpha}-CGRP-null$ mice showed no obvious phenotypic differences in nociceptive behaviors from wild type. The present studies specifically demonstrate that ${\alpha}-CGRP$ null mice showed no CGRP immunoreactivity from the spinal cord, implying that CGRPs in the mice spinal cord are mainly a-isoforms. However, the nociceptive behaviors of the null mice are not significantly different from the wild type mice in thermal nociceptive behaviors on hotplate, chemical nociception tests to intraplantar capsaicin or formalin injection, and visceral pain behaviors to intraperitoneal acetic acid or magnesium sulfate injections. These data suggest that ${\alpha}-CGRP$ is dispensable for nociceptive behaviors or that compensatory mechanisms may exist to overcome the absence of this peptide.

• 대한추나의학회지
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• 제3권1호
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• pp.111-123
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• 2002

Objectives : There have been many studies of the effect of Bee Venom therapy about arthritis, but no one study was reported about its whole functional mechanism to musculo-skeletal system. This study was designed to investigate the effect, Indication, and side effect of Bee Venom therapy on musculo-skeletal disease by literature review of articles. Results : The effects of Bee Venom therapy to musculo-skeletal system are divided to Anti_inflammatory effect and Anti-nociceptive effect. Anti_inflammatory effect is achieved through competitive chemotaxis, immuno-regulation, increasing of cortisol secretion by stimulating hypothalamus-pituitary gland-adrenal cortex axis. Anti-nociceptive effect is achieved by Anti-inflammatory mechanism and it works similar to anti-nociceptive effect of the acupuncture acting on central and peripheral nociceptive transduction system. The Bee Venom therapy could cause severe side effect, for example, hypersensitivity and anaphylaxis, injury to central nerve system and cardiovascular system, peripheral blood system, and renal dysfunction. Conclusions : With its Anti-inflammatory and Anti-nociceptive mechanism, Bee Venom therapy is considered that has good effects to autoimmune disease, chronic inflammation of various musculo-skeletal disease and various pain syndrome. But the clinician must be careful for its side effects.

• Natural Product Sciences
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• 제19권4호
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• pp.311-315
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• 2013

Ribes fasciculatum (Saxifragaceae) has been widely used as a traditional medicine for the treatment of cough, antidote, cold, lacquer poison, and sore throat. In the present study, we evaluated the anti-nociceptive effects of ethyl acetate fraction of Ribes fasciculatum (ERF) in mice. Test results of tail-immersion test and hot plate test revealed that the ERF had strong anti-nociceptive activities on thermal nociception in a dose dependent manner, indicating ERF's anti-nociception on the central pain. Moreover, the acetic acid-induced chemical nociception was also significantly reduced by ERF treatment. This result shows that ERF may also work on the peripheral pain. We further performed formalin test to confirm ERF's anti-nociceptive properties and found that pain responses were significantly decreased by ERF treatment. Interestingly, in the combination test with naloxone, the analgesic activity of ERF was not changed, indicating that the opioid receptor was not involved in the ERF-mediated anti-nociception. These results indicate that ERF might be possibly used as a painkiller for the treatment of nociceptive pains.

• The Korean Journal of Pain
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• 제13권2호
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• pp.175-181
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• 2000

Background: Pain is often measured using psychophysical scaling techniques. However, all of these methods found their limits, since they were based on the subjective sensations reported by the subjects. It is, therefore, desirable to validate psychophysical pain measures by simultaneously measuring some physiological correlate of nociception. We studied an objective method for measuring pain in human volunteer using R(III) nociceptive flexion reflex. Methods: Four different intensity of electrical stimuli between perception and 1.4 times the R(III) nociceptive flexion threshold were delivered to the sole of the feet in 8 normal volunteers. We measured the flexion reflex activity in the skin over the ipsilateral tibialis anterior muscle and subjects rated each stimulus on a visual analog scale (VAS) Results: Both R(III) nociceptive flexion reflex activity and VAS ratings showed a linear relationship with stimulus intensity and with each other in all volunteers. Conclusions: R(III) nociceptive flexion reflex elicited through electrical stimulation may used as an objective pain measurement, previsionary based on our study paradigm.

• 약학회지
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• 제43권2호
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• pp.263-273
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• 1999

When glutamate was infected intrathecally, the result is similar to those produced by TPA injected. The involvement of protein kinase C (PKC) in the nociceptive responses in rat dorsal horn neurons of lumbar spinal cord was studied. In test with formalin, a PKC inhibitor (chelerythrine) inhibited dose-dependently the formalin-induced behavior response. Neomycin also inhibited it significantly. But, a PKC activator (12-O-tetradecanoylphorbol-13-ester, TPA) showed reverse effect. When gluatamate was injected intrathecally, we observed the result is smilar to those produced by TPA injection. On the other hand, intrathecal injection of glutamate induced thermal and mechanical hyperalgesia. In Tail-flick test, we examined the involvement of PKC on the glutamate-indeced thermal hyperalgesia. Chelerythrine showed an inhibitory effect and TPA enhanced thermal response. Glutamate decreased the mechanical threshold significantly. A pretreatment of chelerythrine and neomycin inhibited glutamate-induced mechanical hyperalgesia, but the effect of neomycin was not significant. TPA had little effect on the mechanical nociceptive response. These results suggest that the PKC activation through metabotropic receptor at postsynaptic region of spinal cord dorsal horn neurons may influence on the persistent nociception produced by chemical stimulation with formalin, thermal and mechanical hyperalgesia induced by glutamate.

• The Korean Journal of Pain
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• 제14권1호
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• pp.19-25
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• 2001

Background: Transcutaneous electrical nerve stimulation (TENS) has been used widely, but its effects are controversial. This is probably due to the varying intensity and type of pain. We designed a study to assess the effects of the TENS on the RIII nociceptive flexion reflex as the resting pain level and the temporal summation as a repeated, movement related pain in 7 normal volunteer subjects. Methods: High frequency (80 Hz), non-noxious TENS was applied over the left popliteal fossa for 20 minutes. Ipsilateral RIII reflexes induced by single electrical stimulus and temporal summation of pain responses to repeated stimuli (five stimuli at 2 Hz) were recorded before, during (just before stopping), and subsequently at 20 minutes after TENS. Results: R (III) nociceptive flexion reflex activity during and after TENS was more significantly decreased than before treatment. However, the temporal summation threshold was not changed. Conclusions: We conclude that high frequency, non-noxious TENS could be effective on resting pain relief in the same segment but not on the movement related pain.