흰쥐 내측 전정신경핵 세포의 자발적인 신경활성에 미치는 apamin 민감성 포타슘전류와 charybdotoxin 민감성 포타슘전류의 역할

천상우,전재우,박병림 원광대학교 치의학연구소 1999 圓光齒醫學 Vol.9 No.2

To investigate the contributions of intrinsic membrane properties to the spontaneous activity of medial vestibular nucleus (MVN) neurons, we assessed the effects of blocking large and small calcium-activated potassium channels by means of patch clamp recordings. Almost all the MVN neurons recorded in neonatal (P13∼P17) rat were shown to have either a single deep after-hyperpolarization (AHP ; type A cells), or an early fast and a delayed slow AHP (type B cells). Among the recorded MVN cells, immature action potential shapes were found. Immature type A cell showed single uniform AHP and immature B cell showed a lack of the early fast AHP, and the delayed AHP was separated from the repolarization phase of the spike by a period of isopotentiality. Application of apamin and charybdotoxin (CTX), which selectively block the small and large calcium-activated potassium channels, respectively, resulted in significant changes in spontaneous firings. In both type A and type B cells, CTX (20 nM) resulted in a significant increase in spike frequency but did not induce bursting activity. By contrast, apamin (300 nM) selectively abolished the delayed slow AHP and induced bursting activity in type B cells. Apamin had no effect on the spike frequency of type A cells. These data suggest that there are differential roles of apamin and CTX sensitive potassium conductances in spontaneous firing patterns of MVN neurons, and these conductances are important in regulating the intrinsic rhythmicity and excitability.

흰쥐 삼차신경 척수감각핵의 미측소핵 세포의 전압의존성 소디움통로와 포타슘통로에 대한 전기생리학적 연구

천상우,최정희,김권수,유용묵,김종구,이동근 대한악안면성형재건외과학회 2002 Maxillofacial Plastic Reconstructive Surgery Vol.24 No.1

The caudal subnucleus of the spinal trigeminal nucleus (medullary dorsal horn ; MDH) receives direct inputs from unmyelinated and thinly myelinated, small diameter primary afferent fibers. Thus, the MDH is implicated in the processing of nociceptive information in the orofacial region. In this study, the types and characteristics of voltage-dependent ion currents were investigated in acutely isolated MDH neurons of postnatal rats by means of the whole cell patch clamp techniques. Coronal slice (400㎛) of the trigeminal caudal subnucleus region was sequentially treated with pronase 0.2㎎/㎖. then single neurons were mechanically dissociated. Voltage-dependent sodium currents showed that the half-maximum activation potential was -41.8±1.8mV and half-maximum inactivation potential was -62.4±3.0mV. And the currents were blocked totally by application of 100nM tetrodotoxin. In a Ca^2+ free solution, low-threshold transient (I_A) and high-threshold sustained (I_K) currents were recorded. The half-maximum activation and inactivation potential of I_K were 2.5±1.9mV and -37.1±2.3mV, respectively. I_A was activated and inactivated more rapidly than I_K. The half-maximum activation and inactivation potential were -21.6±6.3mV and -84.5±5.0mV, respectively. When a 4-aminopyridine of 5mM was applied, I_A was almost totally blocked. These results reveal that MDH neurons express a variety of voltage-dependent ionic currents with distinct physiological and pharmacological properties, and they play an essential role in the transmission and modulation of sensation, especially pain, from trigeminal region.

흰쥐 내측 전정신경핵 세포의 이온전류에 관한 전기생리학적 연구

천상우,한두석 원광대학교 치의학연구소 1997 圓光齒醫學 Vol.7 No.2

Medial vestibular nucleus (MVN) neurons are the primary central targets of afferent from the ipsilateral horizontal semicircular canal and their projections are involved in the reflex control of the head and eyes. MVN neurons may also be involved in the recovery of vestibular function after peripheral vestibular lesions. In this study, the types and characteristics of voltage-dependent ion currents were investigated in acutely isolated MVN neurons of postnatal rats by means of the whole cell patch clamp techniques. Transverse slice (400μm) of the vestibular nucleus region was sequentially treated with pronase 0.2㎎/㎖ and thermolysin 0.2㎎/㎖, then single neurons were mechanically dissociated. Ionic currents were recorded from the dissociated MVN neurons selected by criteria such as size and shape of cell body. Voltage-dependent sodium currents showed that the half-maximum activation potential was -43㎷ and half-maximum inactivation potential was -60㎷. And the currents were blocked totally by application of 100nM tetrodotoxin. Two types, high and low thresholds, of voltage dependent calcium currents were recorded. High voltage gated currents were present in all investigated neurons but low ones were recorded in only a few neurons. Also, MVN neurons possess at least four types of voltage-dependent potassium currents, including the delayed rectifier current (IK), Ca^2+-dependent transient current (Ic), Ca^2+-dependent sustained current (I_AHP) and A current (I_A) which were identified by the electrical and pharmacological methods. These results reveal that MVN neurons express a variety of voltage-dependent ionic currents with distinct physiological and pharmacological properties. This diversity could be related both with the functional synaptic characteristics and with the intrinsic physiological properties in MVN neurons.

소아에서 소장 내시경으로 제거한 라푼젤 증후군 1예

천상우,이건송,박윤준,신현덕 대한소화기학회 2019 대한소화기학회지 Vol.74 No.1

A trichobezoar is a type of bezoar that is composed of hair. In most cases, it is confined to the stomach, but in rare cases, it may extend to the small intestine. This condition is referred to as Rapunzel syndrome. The therapeutic method for bezoar removal depends on its type, location, and size. Generally, the treatment for Rapunzel syndrome involves surgical laparotomy. Endoscopic removal has also been effective in some cases. On the other hand, complications, such as respiratory difficulty and esophageal impaction may be encountered during endoscopic removal. Until now, the successful endoscopic removal of trichobezoars has been limited to the stomach or duodenum. This paper reports the case of a 4-year-old female patient with Rapunzel syndrome whose trichobezoar reached the proximal jejunum. The trichobezoar was removed without complications using an electrosurgical knife and snare through a single- balloon enteroscopy. The trichobezoar can be removed successfully using enteroscopy under general anesthesia without abdominal laparotomy in young children. Therefore, this method of removal can be considered preferentially for children with Rapunzel syndrome.

흰쥐의 위축된 저작근에 대한 간헐적 전기자극 효과

천상우,박병림,한두석 대한구강생물학회 1992 International Journal of Oral Biology Vol.16 No.2

This study was designed to evaluate the effect of intermittent electrical stimulation on atrophied masseter muscle in the rat(230-250g). Growing Sprague-Dawley rats(80g) were assigned to either a control(CONT), a soft dieted(SOFT), or a soft dieted plus intermittent electrical stimulation(SOFT-ES) group. CONT group was continued to receive an ordinary hard rat diet and SOFT group received an ordinary diet in a ground form, mixed with water in a proportion of 2:5, for 6 weeks. After 6 weeks of soft diet feeding in SOFT group, mechanical properties of contraction in the masseter muscle were measured by means of isometric force transducer and then electrodes were implanted to the masseter muscle for intermittent electrical stimulation(SOFT-ES group). In SOFT-ES group, electrical stimulation was applied directly to the masseter muscle for 2 weeks at supramaximal intensity, 0.3ms, 20Hz for 15 minutes every 6 hours. After electrical stimulation for 2 weeks, mechanical properties and fatigue tendency of the masseter muscle were observed. The results were as follows. 1. Twitch tension was no significant difference according to the mandibular position, however, tetanic tension at 11㎜ interincisal distance was larger than at 7㎜. 2. In SOFT group, tetanic tension and contraction time were decreased, and fatigue tendency was increased compared with the control group. 3. In SOFT-ES group, tetanic tension was increased and fatigue tendency was decresed compared with the soft dieted group, however, all mechanical properties of muscle contraction were similiar to those of the control group. 4. Effects of electrical stimulation in atrophied muscle were more prominant in tension-related properties than speed-related properties. These data suggest that intermittent electrical stimulation may be useful in prevention and treatment of muscle atrophy.

흰쥐의 위축된 저작근에 대한 간헐적 전기 자극 효과

천상우,박병림,한두석 원광대학교 치의학연구소 1992 圓光齒醫學 Vol.2 No.1

This study was designed to evaluate the effect of intermittent electrical stimulation on atrophied masseter muscle in the rat (230-250g). Growing Sprague-Dawley rats (80g) were assigned to either a control (CONT), a soft dieted (SOFT), or a soft dieted plus intermittent electrical stimulation (SOFT-ES) group. CONT group was continued to receive an ordinary hard rat diet and SOFT group received an ordinary diet in a ground form, mixed with water in a proportion of 2 : 5, for 6 weeks. After 6 weeks of soft diet feeding in SOFT group, mechanical properties of contraction in the masseter muscle were measured by means of isometric force transducer and then electrodes were implanted to the masseter muscle for intermittent electrical stimulation (SOFT-ES group). In SOFT-ES group, electrical stimulation was applied directly to the masseter muscle for 2 weeks at supramaximal intensity, 0.3ms, 20 Hz for 15 minutes every 6 hours. After electrical stimulation for 2 weeks, mechanical properties and fatigue tendency of the masseter muscle were observed. The results were as follows. 1. Twitch tension was no significant difference according to the mandibular position, however, tetanic tension at 11㎜ interincisal distance was larger than at 7㎜. 2. In SOFT group, tetanic tension and contraction time were decreased, and fatigue tendency was increased with the control group. 3. In SOFT-ES group, tetanic tension was increased and fatigue tendency was decresed compared with difference according to the mandibular position, however, tetanic the soft dieted group, and mechanical properties of muscle contraction were similiar to those of the control group. 4. Effects of electrical stimulation in atrophied muscle were more prominant in tension-related properties than speed-related properties. These data suggest that intermittent electrical stimulation may be useful in prevention and treatment of muscle atrophy.

급속분리한 흰쥐 내측 전정 핵 뉴론의 전압의존성 포타슘전류

천상우,이재성,박병림,이재성,박병림 대한이비인후과학회 1999 대한이비인후과학회지 두경부외과학 Vol.42 No.9

Roles of Metabotropic Glutamate Receptors 1 and 5 in Rat Medial Vestibular Nucleus Neurons

천상우 KOREAN ACADAMY OF ORAL BIOLOGY 2011 International Journal of Oral Biology Vol.36 No.2

Using whole cell current- and voltage-clamp recording we investigated the characteristics and pharmacology of group I metabotropic glutamate receptor (mGluR)-mediated responses in rat medial vestibular nucleus (MVN) neurons. In current clamp conditions, activation of mGluR I by application of the group I mGluR agonist (R,S)-3,5-dihydroxyphenylglycine (DHPG) induced a direct excitation of MVN neurons that is characterized by depolarization and increased spontaneous firing frequency. To identify which of mGluR subtypes are responsible for the various actions of DHPG in MVN, we used two subtype-selective antagonists. (S)-(+)- alpha-amino-a-methylbenzeneacetic acid (LY367385) is a potent competitive antagonist that is selective for mGluR1, whereas 2-methyl-6-(phenylethynyl)-pyridine (MPEP) is a potent noncompetitive antagonist that is selective for mGluR5. In voltage clamp conditions, DHPG application increased the frequency of spontaneous and miniature inhibitory postsynaptic currents (IPSCs) but had no effect on amplitude distributions. Antagonism of the DHPG-induced increase of miniature IPSCs required the blockade of both mGluR1 and mGluR5. DHPG application induced an inward current, which can be enhanced under depolarized conditions. DHPG-induced current was blocked by LY367385, but not by MPEP. Both LY367385 and MPEP antagonized the DHPG-induced suppression of the calcium activated potassium current (IAHP). These data suggest that mGluR1 and mGluR5 have similar roles in the regulation of the excitability of MVN neurons, and show a little distinct. Furthermore, mGluR I, via pre- and postsynaptic actions, have the potential to modulate the functions of the MVN.

흰쥐 삼차신경 척수감각핵 미측소핵 세포의 흥분성 시냅스 전도에 대한 nociceptin의 효과

천상우,민승기 大韓顎顔面成形再建外科學會 2003 Maxillofacial Plastic Reconstructive Surgery Vol.25 No.3

The caudal subnuleus of the spinal trigeminal nucleus(medullary dorsal horn;MDH)is implicated in the processing of nociceptive information in the orofacial region. In the present study, whole cell patch clamp recordings were carried out on MDH neurons in brainstem slic of neonatal rats to investigate the characteristics of spontaneous excitatory postsynaptic currents(sEPSCs) and the roles of nocieptin/orphanin FQ on excitatory synaptic transmission. In the presence of atrychnine(1uM) and bicuculline(20uM), spontaneous inward currents at -70㎷ were observed. the baseline frequency, amplitude and decay time constant of sEPSCs were 2.0±0.5㎐,23.0±1.8㎀, 3.8±0.2㎳, repectively. sEPSCs were mediated by non-NMDA and NMDA receptors. The specific AMPA receptor antagonist GYKI-52466(50uM)completely blocked the non-NMDA mediated sEPSCs, indicating that they are mediated by an AMPA-preferring receptor. Perfusion of the opioid orphan receptor(ORL₁)agonist nociceptin(3uM)reduced the frequency of sEPSCs and miniature EPSCs(mEPSCs). The effects of nociceptin were blocked by the selective ORL₁receptor antagonist〔Nphe'〕nociceptin(1-13)NH_2(3uM)and were not affected by the non-specific opioid receptor antagonist naloxone(10uM). To investigate the specificity of this synaptic inhibition, we selectively astivated the nociceptive C fibers with capsaicin, which induced a strong increase in the frequency of sEPSCs. In the presence of nociceptin, the response to capsaicin was diminished. In concilsion, these results suggest that nociceptin inhibits excitatory synaptic transmission in the MDH by acting on presynaptic ORL₁receptors.

백서 하치조 신경 손상에 따른 감각 유발전위와 체성감각 유발전위의 변화에 관한 연구

김수남,이동근,우승철,천상우 大韓顎顔面成形再建外科學會 1996 Maxillofacial Plastic Reconstructive Surgery Vol.18 No.4

Dysfunction of the inferior alveolar nerve may result from trauma, diseases or iatrogenic injury. The development and refinement of an objective method to evaluate this clinical problem is highly desirable and needed, especially concerning for an increasing medico-legal issue. Evoked potential techniques have attracted considerable attention as a means of assessing the function and integrity of nerve pathways. The purpose of this study was to characterize the Sensory Evoked Potentials(SEPs) and Somatosensory Evoked Potentials(SSEPs) elicited by electrical stimulation of mental nerve. SEPs and SSEPs were measured and analyzed statistically before and after needle injury on the inferior alveolar nerve of Sprague-Dawalye rats. Measuring SEPs was more sensitive in evaluation of the recovery of sensory function from inferior alveolar nerve injury then measuring SSEPs but we measured SSEPs in the hope of providing a safe, simple and objective test to check oral and facial sensibility, which is acceptable to the patient. We stimulated mental nerve after needle injury on the inferior alveolar nerve and SEPS on the level of mandibular foramen and SSEPs on the level of cerebral cortex were recorded. Threshold, amplitude, and latency of both of SEPs and SSEPs were analyzed. The results were as follows; 1. Threshold of SEPs and SSEPs were 184±14㎂ and 164±14㎂ respectively. 2 SEPs were composed of 2 waves, i.e., N1 N2 in which N1 was conducted by Ⅱ fibers and N2 was conducted by Ⅲ fibers. 3. SSEPs were composed of 5 waves, of which N1 and N2 shower statistically singnificant changes(p<0.01, unpaired t-test). 4. SEPs and SSEPs were observed to be abolished immediately after local anesthesia and recovered 30 minutes later. 5. SEPs were abolished immediately after injury. N1 of SSEPs was abolished immediately and amplitued of N2 was decreased(20.7±12.2%) immediately after 23G needle injury, but N3, N4 and N5 did not change significantly. Recovery of waveform delayed 30 minutes in SEPs and 45 minutes in SSEPs. 6. The degree of decrease in amplitude of SEPs and SSEPs, after 30G needle injury was smaller than those with 23G. SEPs recorded on the level of mandibular foramen were though to be reliable and useful in the assessment of the function of the inferior alveolar nerve after injury. Amplitude of SSEPs reflected the function and integrity of nerve and measuring them provided a safe, simple and abjective test to check oral and facial sensibility. These results suggest that measuring SEPs and SSEPs are meaningful methods for objective assessment in the diagnosis of nerve injury. N1 and N2 of SSEPs can be useful parameters for the evaluation of the nerve function following a needle injury.