• The Korean Journal of Physiology
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• v.21 no.1
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• pp.79-90
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• 1987

The present experiment was performed in 35 normal male volunteers to evaluate the effect of electroacupuncture on the human nociception more clearly and to demonstrate the effect of different parameters of electrical stimulation through acupuncture needles. The threshold of the pain(Tp) and the nociceptive flexion reflex(Tr), the threshold for intolerable pain(Tip) and that for obtaining maximal reflex response(Tmr) were studied before and after electroacupuncture performed on the acupoints of tsusanli and hsuanchung. 1) For the pricking pain, electroacupuncture with intermittent stimulation induced a significant decrease in Tp which recovered after removal of the needles. There was no significant change in other thresholds. 2) For the dull pain, electroacupuncture with intermittent stimulation produced a significant increase in Tp which continued after removal of the needles. But there was no signifcant change in Tip. Electroacupuncture with continuous stimulation induced a slight increase in Tp. 3) After resting without electroacupuncture, Tp and Tip of the dull pain were slightly decreased. These results suggest that electroacupuncture had no significant analgesic effect on the pricking pain induced by electrical stimulation of the foot skin. However, electroacupuncture with intermittent stimulation had significant analgesic effect on the weak dull pain and it had slightly greater analgesic effect than electroacupuncture with continuous stimulation.

• Natural Product Sciences
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• v.18 no.4
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• pp.215-220
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• 2012

The stem of Lindera obtusiloba (Lauraceae), has been widely used as a traditional medicine for the treatment of abdominal pain, bruise and hepatocirrhosis. In the present study, antinociceptive and sedative properties of the methanol extract of L. obtusiloba (MLO) were evaluated. MLO demonstrated strong and dose-dependent antinociceptive activities on various experimental pain models including thermal nociception and chemical nociception, compared to tramadol and indomethacin, reference drugs. In combination test using naloxone, the diminished analgesic activity of MLO was observed, indicating the relation with opioid receptor. Moreover, MLO also decreases pentobarbital-induced sleep latency and increases sleeping time suggesting its hypnotic and sedative action. The present results indicate that MLO could be used as valuable antinociceptive and sedative agent for the treatment of various diseases.

• Korean Journal of Pharmacognosy
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• v.51 no.3
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• pp.186-191
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• 2020

In this study, we evaluated the anti-nociceptive activities of Sorbus alnifolia. To investigate the anti-nociceptive properties of the methanolic extract of Sorbus alnifolia (MSA), we conducted several tests using various experimental mouse pain models. Herein, MSA significantly delayed the latency time and writhing motion in the hotplate test and acetic acid test, respectively. These result indicated that MSA has an ability to manage both peripheral and central nociception. We could further confirm the analgesic effects of MSA by performing formalin test. In combination test using naloxone, a non-selective opioid receptor antagonist, analgesic activity of MSA was partly antagonized by naloxone, but not completely, indicating that the MSA acts as a partial opioid receptor agonist. Out results suggest that the S. alnifolia may be possibly used as valuable anti-nociceptive agent.

• Journal of Acupuncture Research
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• v.24 no.2
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• pp.39-49
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• 2007

목적 : 봉독으로 유발된 통각수용의 강도와 봉독으로 나타나는 항통각수용(통각억제성)의 강도를 쥐의 포르말린 테스트를 통해 상호관련됨을 확인하고 capsaicin과 bradykinin으로 통증 유발된 쥐의 자발적인 통증행동(핥기횟수측정; LN), 꼬리경타시험(TFL)과 열판시험(HPL)을 통해 봉독의 항통각수용(통각억제)작용을 재확인 하고자 하였다. 방법 : 쥐의 뒷다리에 통증유도 물질인 Capsaicin 또는 Bradykinin을 20${\mu}l$를 주사하여 동통을 유발하고 자발적 통증행동인 핥기횟수측정(LN), 꼬리경타기간(TFL)과 열판 위에서의 온도자극에 쥐가 반응하는 시간을 측정(HPL)하는 실험을 봉독을 주입하거나, 몰핀을 주입하거나, 아무것도 주입하지 않고 통증유발만 시킨 이후에 각각 시행하였다. 결과: 1. Capsaicin 또는 Bradykinin으로 동통유발 후 LN은 두드러증가를 보임, HPL은 감소를 TFL은 두드러진 감소를 나타내었다. 2. 봉독이나 몰핀 주입 30분 후에 Capsaicin으로 동통유발 이후 LN은 봉독과 몰핀에서 모두 현격한 감소를, HPL은 봉침은 현격한 증가를, 몰핀에서는 감소를, TFL은 봉침과 몰핀에서 모두 현격한 증가를 나타내었다. 3 봉독과 몰핀주입 30분후에 Bradykinin으로 동통유발 이후 LN은 봉독은 증가 몰핀은 현격한 감소를, HPL은 봉침은 증가 몰핀에서는 현격한 증가를, TFL은 봉침과 볼핀에서 모두 증가를 나타내었다. 결론 : 봉독은 Capsaicin 또는 Bradykinin으로 동통유발된 통각수용행동을 감소시키는 결과를 나타내었는데 이것은 기존의 연구결과들에서의 봉독의 항통각수용(통각억제성)의 효과를 입증하였고 봉약침은 염증의 개선이나 암과 관련된 동통에 유효한 방법임을 시사하는 것이다.

• 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.

• Annals of Clinical Neurophysiology
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• v.25 no.2
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• pp.78-83
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• 2023

Nociplastic pain refers to pain arising from altered nociception without evidence of tissue or somatosensory damage. It encompasses various clinical conditions with shared neurophysiological mechanisms involving different organ systems. Nociplastic pain can occur independently or alongside chronic pain conditions with a nociceptive or neuropathic origin. This review introduces the concept of nociplastic pain, its clinical manifestations and the underlying pathophysiology. Taking a biopsychosocial approach can lead to a better understanding of nociplastic pain and improved treatment outcomes for affected individuals.

• Restorative Dentistry and Endodontics
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• v.27 no.6
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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.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.23 no.2
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• pp.144-154
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• 2001

Dysfunction of the inferior alveolar nerve indicated by various degree of numbness of the lower lip and chin is one of the few drawbacks of mandibular osteotomy, especially Bilateral Sagittal Split Ramus Osteotomy(BSSRO) and genioplasty. Although it has been recorded throughout the history of this techniques, it is true etiology poorly understood. In this study, 22 consecutive patients under class III malocclusiion impression and undergoing orthognathic surgery(BSSRO only 11 case, BSSRO with genioplasty 11 case) were studied using 4 neurosensory test(static light touch, directional discrimination, two-point discrimination, pin pressure nociception) with post OP 1 week, 2 weeks, 4 weeks, 8 weeks, 12 weeks, 24 weeks, On control group, 10 members without trauma and nerve damage history, nerve test was accomplished. We concluded majority of patients return of sensation during post operative 24 weeks. Althought immediate nerve deficit are 92.2%, 97.2% 88.9% these are recovered to 25%, 35.72%, 10.71% at 24 weeks. Nerve recovery rate increased prominently between post 4 weeks and 8 weeks. There is no statistically difference about neurosensory deficit among the chin area. Neurosensory deficit more severe when the BSSRO with genioplasty group than the only BSSRO group. Immediate neurosensory deficit is larger left side than right side but after 6 months, there is no significantly difference between left side and right side. Static light touch and pin pressure nociception are more sensitive method of neurosensory deficit than two point discrimination.

• International Journal of Oral Biology
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• v.42 no.3
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• pp.129-135
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• 2017

The present study investigated the role of spinal glutamate recycling in the development of orofacial inflammatory pain or trigeminal neuropathic pain. Experiments were carried out on male Sprague-Dawley rats weighing between 230 and 280 g. Under anesthesia, a polyethylene tube was implanted in the atlanto-occipital membrane for intracisternal administration. IL-$1{\beta}$-induced inflammation was employed as an orofacial acute inflammatory pain model. IL-$1{\beta}$ (10 ng) was injected subcutaneously into one vibrissal pad. We used the trigeminal neuropathic pain animal model produced by chronic constriction injury of the infraorbital nerve. DL-threo-${\beta}$-benzyloxyaspartate (TBOA) or methionine sulfoximine (MSO) was administered intracisternally to block the spinal glutamate transporter and the glutamine synthetase activity in astroglia. Intracisternal administration of TBOA produced mechanical allodynia in naïve rats, but it significantly attenuated mechanical allodynia in rats with interleukin (IL)-$1{\beta}$-induced inflammatory pain or trigeminal neuropathic pain. In contrast, intracisternal injection of MSO produced anti-allodynic effects in rats treated with IL-$1{\beta}$ or with infraorbital nerve injury. Intracisternal administration of MSO did not produce mechanical allodynia in naive rats. These results suggest that blockade of glutamate recycling induced pro-nociception in na?ve rats, but it paradoxically resulted in anti-nociception in rats experiencing inflammatory or neuropathic pain. Moreover, blockade of glutamate reuptake could represent a new therapeutic target for the treatment of chronic pain conditions.

• The Korean Journal of Pain
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• v.19 no.2
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• pp.137-141
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• 2006

Background: It has been known that melatonin is involved in the modulation of nociceptive transmission. However, the effect of melatonin administered spinally has not been examined. Therefore, we examined the effect of melatonin on the formalin-induced or thermal-induced nociception at the spinal level. Methods: Intrathecal catheter was inserted into the subarachnoid space of male Sprague-Dawley rats. Pain was assessed by formalin test (induced by injection of $50{\mu}l$ of a 5% formalin solution to the hindpaw) or Hot-Box test (induced by radiant heat application to the hindpaw). The effect of intrathecal melatonin was examined on flinching behavior in the formalin test or withdrawal response in Hot-Box test. Results: Intrathecal melatonin produced a limited, but dose-dependent reduction of the flinching response during phase 1 and 2 in the formalin test. In addition, melatonin delivered at evening also decreased the flinching response in both phases of the formalin test. Melatonin restrictively increased the withdrawal latency in Hot-Box test. Conclusions: These results suggest that melatonin is active against the formalin- and thermal-induced nocicpetion at the spinal level, but the effect is limited.