• The Korean Journal of Pain
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• 제13권2호
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• pp.143-148
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• 2000

Background: Trigeminovascular system is implicated in the pathophysiology of the headache in migraine. This study was designed to evaluate the pattern of Fos protein expression in trigeminal nociceptive central pathway after meningeal stimulation of rats by capsaicin. Methods: The expression of Fos protein was examined by immunohistochemistry in thalamus, brainstem and upper cervical cord (at three levels corresponding to obex, 0.8 mm and 2 mm below obex) 2 hours after intracisternal injection of either diluted capsaicin solution (0.1 ml, $61{\mu}g/ml$) or normal saline (0.1 ml) through a catheter placed in the cisterna magna, or following epidural instillation of diluted capsaicin solution in urethane-anesthetized Sprague-Dawley rats. Results: Fos immunoreactivity was strongly expressed within lamina I, II of bilateral trigeminal nucleus caudalis (TNC) after cisternal capsaicin injection and magnitude of expression was greatest at level 2.0 mm below obex. Epidural capsaicin caused much less labelling than cisternal capsaicin. Fos positive cells were also observed in area postrema, nucleus of the solitary tract, medullary reticular nucleus and midline nuclear groups of the thalamus with similar intensity between capsaicin and control group. Conclusions: These results indicate that the injection of capsaicin into the cisterna magna is an effective stimulus for the induction of Fos protein within TNC through activation of trigeminovascular afferents and this animal model can be useful for the evaluation of the pathophysiology and drug development in migraine and related headache.

• The Korean Journal of Physiology and Pharmacology
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• 제13권6호
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• pp.425-429
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• 2009

Intracranial headaches, including migraines, are mediated by nociceptive activation of the trigeminal nucleus caudalis (TNC), but the precise mechanisms are poorly understood. We previously demonstrated that selective blockage of spinal sigma-1 receptors (Sig-1R) produces a prominent antinociceptive effect in several types of pain models. This study evaluates whether the Sig-1R antagonist (BD1047) has an antinociceptive effect on capsaicin (a potent C-fiber activator) induced headache models in rats. Intracisternal infusion of capsaicin evoked pain behavior (face grooming), which was significantly attenuated by BD1047 pretreatment. BD1047 consistently reduced capsaicin-induced Fos-like immunoreactivity (Fos-LI), a neuronal activator, in the TNC in a dose-dependent manner. Moreover, capsaicininduced phosphorylation of N-methyl-D-aspartate receptor subunit 1 was reversed by BD1047 pretreatment in the TNC. These results indicate that the Sig-1R antagonist has an inhibitory effect on nociceptive activation of the TNC in the capsaicin-induced headache animal model.

• The Korean Journal of Physiology and Pharmacology
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• 제17권2호
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• pp.121-125
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• 2013

The purpose of this study is to investigate the antinociceptive effects of ginsenosides on toothache. c-Fos immunoreactive (IR) neurons were examined after noxious intrapulpal stimulation (NS) by intrapulpal injection of 2 M KCl into upper and lower incisor pulps exposed by bone cutter in Sprague Dawley rats. The number of Fos-IR neurons was increased in the trigeminal subnucleus caudalis (Vc) and the transitional region between Vc and subnucleus interpolaris (Vi) by NS to tooth. The intradental NS raised arterial blood pressure (BP) and heart rate (HR). The number of Fos-IR neurons was also enhanced in thalamic ventral posteromedial nucleus (VPMN) and centrolateral nucleus (CLN) by NS to tooth. The intradental NS increased the number of Fos-IR neurons in the nucleus tractus solitarius (NTS) and rostral ventrolateral medulla (RVLM), hypothalamic supraoptic nucleus (SON) and paraventricular nucleus (PVN), central cardiovascular regulation centers. Ginsenosides reduced the number of c-Fos-IR increased by NS to tooth in the trigeminal Vc and thalamic VPMN and CLN. Naloxone, an opioid antagonist, did not block the effect of ginsenoside on the number of Fos-IR neurons enhanced by NS to tooth in the trigeminal Vc and thalamic VPMN and CLN. Ginsenosides ameliorated arterial BP and HR raised by NS to tooth and reduced the number of Fos-IR neurons increased by NS to tooth in the NTS, RVLM, hypothalamic SON, and PVN. These results suggest that ginsenosides have an antinociceptive effect on toothache through non-opioid system and attenuates BP and HR increased by NS to tooth.

• The Korean Journal of Physiology and Pharmacology
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• 제25권4호
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• pp.365-374
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• 2021

The mammalian target of rapamycin (mTOR) plays a role in various cellular phenomena, including autophagy, cell proliferation, and differentiation. Although recent studies have reported its involvement in nociceptive responses in several pain models, whether mTOR is involved in orofacial pain processing is currently unexplored. This study determined whether rapamycin, an mTOR inhibitor, reduces nociceptive responses and the number of Fos-immunoreactive (Fos-ir) cells in the trigeminal nucleus caudalis (TNC) in a mouse orofacial formalin model. We also examined whether the glial cell expression and phosphorylated p38 (p-p38) mitogen-activated protein kinases (MAPKs) in the TNC are affected by rapamycin. Mice were intraperitoneally given rapamycin (0.1, 0.3, or 1.0 mg/kg); then, 30 min after, 5% formalin (10 μl) was subcutaneously injected into the right upper lip. The rubbing responses with the ipsilateral forepaw or hindpaw were counted for 45 min. High-dose rapamycin (1.0 mg/kg) produced significant antinociceptive effects in both the first and second phases of formalin test. The number of Fos-ir cells in the ipsilateral TNC was also reduced by high-dose rapamycin compared with vehicle-treated animals. Furthermore, the number of p-p38-ir cells the in ipsilateral TNC was significantly decreased in animals treated with high-dose rapamycin; p-p38 expression was co-localized in microglia, but not neurons and astrocytes. Therefore, the mTOR inhibitor, rapamycin, reduces orofacial nociception and Fos expression in the TNC, and its antinociceptive action on orofacial pain may be associated with the inhibition of p-p38 MAPK in the microglia.

• 대한치과교정학회지
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• 제28권3호
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• pp.441-452
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• 1998

이 연구의 목적은 말초조직에 유해 자극을 가하였을 때 중추 신경계내 이차 신경 세포체내에 발현되어 neuronal marker로 사용되고 있는 c-fos를 사용한 면역 조직화학법으로 치아이동시 동반되는 동통의 투사경로의 이해에 도움을 주고자하는 것이다. 생후 9주령의 210gm내외의 Sprague-Dawley계 웅성 백서 21마리를 교정력을 가하지않고 마취만을 시행한 정상 대조군과 교정력 적용 시간 경과에 따라 1시간, 3시간, 6시간, 12시간, 1일, 3일군으로 나누어 각 해당 시간동안 상악 우측 제1 대구치와 상악 우측 측절치사이에 Ni-Ti coil spring를 결찰하여 30gm내외의 지속적인 교정력을 가한 후 희생시켰다. 희생시킨 백서의 뇌간을 적출하여 토끼의 항체를 이용하여 면역화학 염색을 시행하였다. 삼차신경 감각핵군내 부위에 따른 c-fos 면역 반응 세포를 측정하여 교정력 적용 시간 경과에 따른 변화를 관찰하였다. $\cdot$c-fos면역 반응 세포의 배측에서의 분포는 자극측 중위핵과 미측핵의 이행부위에서 시작하여 제1경추 척수 후각에 까지 이어졌는데 가장 많은 분포를 보인 곳은 미측핵의 문측 부위였다. 그리고 주로 I층 과 II층에서 관찰되었다. $\cdot$복측에서의 c-fos면역 반응 세포의 분포는 자극측 중위핵의 미측 부위에서 시작하여 미측핵의 중간부위에 까지 이어졌다. $\cdot$교정력 적용3, 6시간군에서 c-fos면역 반응 세포가 가장 많이 관찰 되었으며 12시간군에서 감소되기 시작하여 1일, 3일군에서는 현저히 감소 하였다. 위로 미루어 볼때 지속적인 교정력에 의한 동통은 중위핵과 미측핵의 이행부위, 미측핵, 제 1경추 척수후각에서 매개되는 것으로 생각된다.