• The Korean Journal of Physiology and Pharmacology
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• 제7권6호
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• pp.295-301
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• 2003

Striatum plays a crucial role in the movement control and habitual learning. It receives an information from wide area of cerebral cortex as well as an extensive serotonergic (5-hydroxytryptamine, 5-HT) input from raphe nuclei. In the present study, the effects of 5-HT to modulate synaptic transmission were studied in the rat corticostriatal brain slice using in vitro extracellular recording technique. Synaptic responses were evoked by stimulation of cortical glutamatergic inputs on the corpus callosum and recorded in the dorsal striatum. 5-HT reversibly inhibited coticostriatal glutamatergic synaptic transmission in a dose-dependent fashion (5, 10, 50, and $10{\mu}M$), maximally reducing in the corticostriatal population spike (PS) amplitude to $40.1{\pm}5.0$% at a concentration of $50{\mu}M$ 5-HT. PSs mediated by non-NMDA glutamate receptors, which were isolated by bath application of the NMDA receptor antagonist, d,l-2-amino-5-phospohonovaleric acid (AP-V), were decreased by application of $50{\mu}M$ 5-HT. However, PSs mediated by NMDA receptors, that were activated by application of zero $Mg^{2+}$ aCSF, were not significantly affected by $50{\mu}M$ 5-HT. To test whether the corticostriatal synaptic inhibitions by 5-HT might involve a change in the probability of neurotransmitter release from presynaptic nerve terminals, we measured the paired-pulse ratio (PPR) evoked by 2 identical pulses (50 ms interpulse interval), and found that PPR was increased ($33.4{\pm}5.2$%) by 5-HT, reflecting decreased neurotransmitter releasing probability. These results suggest that 5-HT may decrease neurotransmitter release probability of glutamatergic corticostriatal synapse and may be able to selectively decrease non-NMDA glutamate receptor-mediated synaptic transmission.

• Journal of Korean Neurosurgical Society
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• 제37권2호
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• pp.112-115
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• 2005

Objective: Thalamic lesioning and deep brain stimulation(DBS) have proved to be beneficial to the treatment of essential tremor(ET). The authors compared the effects and complications of two modalities. Methods: A total of 34 patients with ET were treated with ventral intermediate(Vim) nucleus thalamotomy or Vim DBS from May 1999 to May 2003. The procedure of lesioning or stimulation were performed as usual manner with or without microelectrode recording. Postoperatively, utilizing the various combinations of frequency, voltage and pulse width optimized the stimulation. The degree of improvements of tremor and the occurrence of the complications were evaluated postoperatively and at follow-up. Results: There were 38 procedures, including 27 with Vim thalamotomy and 11 with DBS, in 34 patients. Of the thalamotomy group, left Vim lesioning is 25 and right one is 2. Follow-up duration ranged from 12 to 57 months. In the thalamotomy group, the rate of overall good outcome was 88.9% but 12 patients (44.4%) showed permanent adverse effects. In the cases of stimulation, the rate of overall good outcome was 90.9% and two patients had acceptable dysarthria. Conclusion: Both Vim thalamotomy and Vim DBS were effective for the treatment of ET, although perioperative adverse effects tended to be higher in patients who had thalamotomy. In cases of DBS, adjustments of stimulation parameters enabled an acceptable position to be achieved with tremor control and unwanted effects.

• 대한의용생체공학회:의공학회지
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• 제36권4호
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• pp.95-102
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• 2015

Epilepsy is a chronic neurological disease which produces repeated seizures. Over 30% of epileptic patients cannot be treated with anti-epileptic drugs, and surgical resection may cause loss of brain functions. Seizure suppression by electrical stimulation is currently being investigated as a new treatment method as clinical evidence has shown that electrical stimulation to brain could suppress seizure activity. In this paper, design of a real-time closed-loop neurostimulation system for epileptic seizure suppression is presented. The system records neural signals, detects seizures and delivers electrical stimulation. The system consists of a 6-channel electrode, front-end amplifiers, a data acquisition board by National Instruments, and a neurostimulator and Generic Osorio-Frei algorithm was applied for seizure detection. The algorithm was verified through simulation using electroencephalogram data, and the operation of whole system was verified through simulation and in- vivo test.

• The Korean Journal of Physiology and Pharmacology
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• 제12권6호
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• pp.293-297
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• 2008

The effect of forskolin on corticostriatal synaptic transmission was examined by recording excitatory postsynaptic currents (EPSCs) in rat brain slices using the whole-cell voltage-clamp technique. Forskolin produced a dose-dependent increase of corticostriatal EPSCs (1, 3, 10, and $30{\mu}M$) immediately after its treatment, and the increase at 10 and $30{\mu}M$ was maintained even after its washout. When the brain slices were pre-treated with (DL)-2-amino-phosphonovaleric acid (AP-V, $100{\mu}M$), an NMDA receptor antagonist, the acute effect of forskolin ($10{\mu}M$) was blocked. However, after washout of forskolin, an increase of corticostriatal EPSCs was still observed even in the presence of AP-V. When KT 5720 ($5{\mu}M$), a protein kinase A (PKA) inhibitor, was applied through the patch pipette, forskolin ($10{\mu}M$) increased corticostriatal EPSCs, but this increase was not maintained. When forskolin was applied together with AP-V and KT 5720, both the increase and maintenance of the corticostriatal EPSCs were blocked. These results suggest that forskolin activates both NMDA receptors and PKA, however, in a different manner.

• 한국컴퓨터정보학회논문지
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• 제25권8호
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• pp.47-54
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• 2020

발달장애는 영유아 기부터 시작하는 뇌 신경계 발달장애들의 집합으로 언어 및 의사소통, 인지력, 사회성 등의 측면에서 이루어져야 할 발달이 심하게 지체되거나 성취되지 않은 장애를 의미한다. 이러한 발달장애 진단에는 아동의 얼굴 표정과 같은 감정표현의 의미와 맥락 등 비언어적 반응에 대한 관찰로 이루어진다. 이를 사람이 측정기에는 상당히 주관적인 판단이 개입하게 되어 객관적인 기술이 필요하다. 따라서 본 연구에서는 영유아/아동의 언어, 비언어적 행동 반응을 관찰하는 ADOS(Autism Diagnostic Observation Schedule)와 BeDevel(Behavior Development Screening for Toddler) 검사에서 검사자와 피검사자간의 상호작용이 녹화된 영상을 리빙랩 환경에서 획득하여 인공지능 기반의 비정상적/상동적 행동 인지 기술 개발에 필요한 영상 및 음성 데이터 확보를 목표로 한다.

• Journal of Ginseng Research
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• 제34권3호
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• pp.212-218
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• 2010

Korean red ginseng (KRG) has been shown to enhance endothelium-dependent vasorelaxation in experimental animals; however, little is known about its pharmacological effects on vascular stiffness in patients with coronary artery disease (CAD). This randomized, double-blind, placebo-controlled crossover trial was carried out to determine whether KRG has beneficial effects on arterial stiffness, cardiovascular risk factors such as plasma lipid profiles and blood pressure (BP), and Rho-associated kinase (ROCK) activity. Twenty patients (mean age, 62.5 years) with stable angina pectoris were given KRG (2.7 g/day) and a placebo alternatively for 10 weeks. Blood biochemical analysis and pulse wave velocity (PWV) recording were performed on day 0 and after the completion of each treatment. ROCK activity was assessed based on the level of phospho-$Thr^{853}$ in the myosin-binding subunit of myosin light chain phosphatase, determined by Western blot analysis of peripheral blood mononuclear cells. KRG significantly decreased the systolic BP, brachial ankle PWV, and heart femoral PWV in the patients (all p<0.05), but did not significantly alter the serum lipid profiles, including triglycerides and total, high-density lipoprotein, and low-density lipoprotein cholesterol levels. The ROCK activity tended to decrease (p=0.068) following KRG treatment. The placebo did not significantly alter any of the variables. In conclusion, KRG decreased systolic BP and arterial stiffness, probably via the inhibition of ROCK activity, in patients with CAD, but had a neutral effect on serum lipid profiles. Our data suggest that KRG has a therapeutic effect on CAD.

• 대한기관식도과학회:학술대회논문집
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• 대한기관식도과학회 1991년도 제25차 학술대회 연제순서 및 초록
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• pp.14-14
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• 1991

후두의 생리적 기능은 하기도를 보호하는 방어기능과 호흡기능 그리고 발성기능으로 대별할 수 있는데 이 가운데 계통발생적으로 가장 원시적이지만 중요한 기능은 하기도 방어기능으로 이는 다른 기능과 달리 전적으로 불수의적이고 반사적으로 이루어진다. 이 기능은 후두내 점막에 존재하는 촉각 수용체(tactile receptor)가 자극되면서 후두근육이 수축 반사를 일으켜 성문이 닫히는 성문폐쇄반사(glottic closure reflex)로서 다접합뇌간반사(polysynaptic brain stem response)이다. 현재까지 후두의 신경장애에서 그 부위나 정도 또는 신경재생 상태 등을 검사하는 방법으로 근전도검사가 주로 쓰여져 왔으나 그것이 주는 정보가 극히 제한되어 있다. 그러나 최근 청각뇌간유발반응과 같이 후두뇌간유발반응 이라 명명된 wave가 존재한다는 사실이 밝혀져 이에 대한 연구가 이루어지고 있어 이것이 임상에 쓰여질 수 있다면 현재 성문폐쇄반사의 소실이나 이상이 원인으로 사료되는 idiopathic laryngospasm, gastroesophageal reflux, spastic dysphonia, stuttering, sudden infant death syndrome과 같은 질환의 진단과 치료에 커다란 진전이 있을 것이다. 이에 저자들은 고양이 6마리를 이용하여 상후두신경을 전기적으로 자극하여 유발되는 반응을 far field recording을 이용 평균 가산법으로 그 wave를 측정하여 다음과 같은 결과를 얻었다. 1. 상후두신경자극(2㎃, stimuli frequency 3/s, Band filter 320-1000, 0.2 ㎳ duration)에 의한 반회신경에의 유발 반응을 기록하였고 그 잠복시간은 평균 8.2 ㎳ 였다. 2. 상후두신경을 자극하여 후두뇌간유발반응을 기록하였고 후두뇌간유발반응은 4개의 양 wave와 4개의 음 wave로 구성되었다. 3. 각 wave의 평균 잠복시간은 P1은 0.8㎳, P2는 2.3㎳, P3는 3.6㎳, P4는 4.3㎳였고 N1은 1.5㎳, N2 은 2.7㎳, N3는 3.9㎳, N4는 5.5㎳ 였다.

• The Korean Journal of Physiology
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• 제24권2호
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• pp.403-411
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• 1990

The present investigation was performed to see a possible influence of the dorsal raphe nucleus (DRN) on pancreatic exocrine secretion in anesthetized rats since the DRN had been known to exert a regulatory mechanism on sympathetic activity which was known to be very important for pancreatic exocrine secretion, particularly in rats. Twenty-nine Sprague-Dawley rats fasted for 24 hours were anesthetized by i.p. injection of 1 g/kg of urethane. The pancreatic duct was cannulated to collect pancreatic juice while bile juice was diverted into the jejunum. The duodenopyloric junction was tightly ligated. After surgery for collection of pancreatic exocrine secretion and recording of carotid blood pressure, a coaxial electrode was stereotaxically inserted in the DRN with a guide of a brain atlas. And then, electrical stimulus of biphasic square wave with 2 v, 2 msec, 40 Hz was applied on the electrode for 10 minutes. Pancreatic volume flow and protein output secreted in 10 min were measured. Either bilateral cervical vagotomy or spinal cord transection at the level of $C4{\sim}C5$ was performed 20 min prior to stimulation of the DRN. 1) Electrical stimulation of the DRN resulted in significant (p<0.05) increase in pancreatic volume flow and protein output. These stimulatory effects were not affected by cervical vagotomy but completely abolished by cervical cord transection. 2) Electrical stimulation of the DRN also resulted in significant (p<0.05) rise of blood pressure of the carotid artery. The hypertensive effect was not affected by cervical vagotomy but completely abolished by cervical cord transection. The results strongly suggest that the DRN, a part of the central serotonergic system, could exert a stimulatory influence on pancreatic exocrine secretion by increasing the sympathetic activity in anesthetized rats.

• Research in Vestibular Science
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• 제17권4호
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• pp.142-151
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• 2018

Objectives: Excitability o medial vestibular nucleus (MVN) in the brainstem can be affected by changes in the arterial blood pressure. Several animal studies have demonstrated that acute hypotension results in the alteration of multiunit activities and expression of cFos protein in the MVN. In the field of extracellular electrophysiological recording, tetrode technology and spike sorting algorithms can easily identify single unit activity from multiunit activities in the brain. However, detailed properties of electrophysiological changes in single unit of the MVN during acute hypotension have been unknown. Methods: Therefore, we applied tetrode techniques and electrophysiological characterization methods to know the effect of acute hypotension on single unit activities of the MVN of rats. Results: Two or 3 types of unit could be classified according to the morphology of spikes and firing properties of neurons. Acute hypotension elicited 4 types of changes in spontaneous firing of single unit in the MVN. Most of these neurons showed excitatory responses for about within 1 minute after the induction of acute hypotension and then returned to the baseline activity 10 minutes after the injection of sodium nitroprusside. There was also gradual increase in spontaneous firing in some units. In contrast small proportion of units showed rapid reduction of firing rate just after acute hypotension. Conclusions: Therefore, application of tetrode technology and spike sorting algorithms is another method for the monitoring of electrical activity of vestibular nuclear during acute hypotension.

• Korean Journal of Acupuncture
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• 제35권4호
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• pp.187-202
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• 2018

Objectives : Non-invasive transcranial electrical stimulation is one of therapeutic interventions to change in neural excitability of the cortex. Transcranial electro-acupuncture (TEA) can modulate brain functions through changes in cortical excitability as a model of non-invasive transcranial electrical stimulation. Some composites of fermented Scutellaria baicalenis (FSB) can activate intercellular signaling pathways for activation of brain-derived neurotrophic factor that is critical for formation of neural plasticity in stroke patients. This study was aimed at evaluation of combinatory treatment of TEA and FSB on behavior recovery and cortical neural excitability in rodent focal stroke model. Methods : Focal ischemic stroke was induced by photothrombotic injury to the motor cortex of adult rats. Application of TEA with 20 Hz and $200{\mu}A$ in combination with daily oral treatment of FBS was given to stroke animals for 3 weeks. Motor recovery was evaluated by rotating bean test and ladder working test. Electrical activity of cortical pyramidal neurons of stroke model was evaluated by using multi-channel extracellular recording technique and thallium autometallography. Results : Compared with control stroke group who did not receive any treatment, Combination of TEA and FSB treatment resulted in more rapid recovery of forelimb movement following focal stroke. This combination treatment also elicited increase in spontaneous firing rate of putative pyramidal neurons. Furthermore expression of metabolic marker for neural excitability was upregulated in peri-infract area under thallium autometallography. Conclusions : These results suggest that combination treatment of TEA and FSB can be a possible remedy for motor recovery in focal stroke.