• Proceedings of the Korean Society of Applied Pharmacology
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• 1993.11a
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• pp.34-35
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• 1993

Glycine은 GABA와 함께 뇌에 작용하는 중요한 억제성 신경전달 물질이다. GABA가 대뇌등에서 중요한 역할을 하는 반면, GLYCINE은 연수, 척수, 간뇌에 특히 다량 존재한다. GLYCINE은 GLYCINE RECEPTOR에 작용하여 수용체와 연결된 chloride channel의 conductance를 증가시킴으로써 target세포의 활성을 억제한다. 그러므로, glycine의 신경전달체계에 이상이 오면 spastic mouse등에서 볼수 있는 것처럼 neuromuscular disorder가 유발된다. 신경전달 물질은 presynaptic 세포에 자극이 오면 synaptic cleft로 분비가 된후 presynaptic이나 Postsynaptic 세포에 위치한 수용체에 작용하여 생리 활성을 나타내거나, 분해효소에 의해서 생리활성이 없는 물질로 바뀌든지, presynaptic cell에 위치한 transporter(수송체)에 의해서 presynaptic 세포로 reuptake되서 cycle를 끝낸다. Glycine의 경우는 synaptic cleft로 분비된 후 glycine transporter에 의해서 reuptake된다. 그러므로 glycine transporter의 활성 정도는 sysnapse내의 glycine의 농도를 조절하며 더 나아가 glycine이 glycine receptor에 작용하는 시간에 영향을 줌으로써 target 세포의 활성정도를 결정한다.

• Proceedings of the Korean Information Science Society Conference
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• 2011.06c
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• pp.379-382
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• 2011

인터넷 뱅킹, 전자 상거래 등의 도래에 따라 생체 인식이 중요한 이슈가 되고 있다. 이에 따라 뇌전도(Electro Encephalo Graphy: EEG)로 측정되는 생체 신호를 통하여 기존 생체 인식의 단점을 보완하는 새로운 연구가 시도되고 있다. 본 논문에서는 인간 본인의 얼굴 사진에 특별한 반응을 보인다는 신경 생리학적 지식을 기반으로 한, 새로운 개인 인증 기술을 제안한다. 구체적으로는 뇌 신호 반응 유도를 위한 시각 자극 제시 패러다임의 설계 EEG신호의 특징을 추출을 위한 개인-의존적인 시간 영역 및 채널 선택 및 효율적인 분류기 설계 방법을 제안한다. 제안한 방법을 이용한 실험 결과는 EEG 기반의 개인 인증 및 인식의 가능성을 제시한다.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2011.11a
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• pp.258-259
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• 2011

3DTV를 시청하는 경우 조절거리는 TV 화면까지의 거리에 해당하지만, 수렴거리는 좌 우 영상의 화면 시차에 따라 영상의 도출과 후퇴의 깊이가 변하게 되고 수렴거리와 조절거리에 불일치가 발생하게 된다. 3DTV의 입체영상을 시청할 때 발생하는 시각적 불편감은 이러한 수렴과 조절과정의 불일치가 가장 주된 원인으로 알려졌다. 본 연구에서는 입체영상의 시각적 자극으로 눈에서부터 시작된 시각피로감이 인체에 전해지는 단계, 즉 정보의 최종 통합기관인 뇌에 전달결과로서의 생체적 반응을 EEG 방법으로 측정하였다. 3DTV 시청 전 후의 뇌파측정과 뇌기능지수 분석에 의한 방법으로 실험한 결과 시각피로는 ${\delta}$, ${\theta}$, ${\alpha}$, SMR, ${\beta}$Low, ${\beta}$High 파 등 여러 종류의 뇌파 밴드에 영향을 미치고 있었다.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 2000.05a
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• pp.215-219
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• 2000

인간의 뇌 정보처리를 이해하기 위한 일환으로서, 많은 연구자들이 사람의 두피에서 자발적으로 발생하는 전기 활동인 뇌파(EEG)를 분석하였다. 측정된 뇌파는 잡음처럼 보이는 비선형적인 거동으로 인하여 단순한 관찰만으로는 그 특징을 분석하기가 매우 어렵다. 따라서 이러한 뇌파를 분석하고 이해하기 위한 방법으로 파워스펙트럼, 바이스펙트럼 등과 같은 스펙트럼 분석과 상관차원, 프랙탈 차원과 같은 비선형 카오스 분석 등과 같은 해석법들이 활발히 연구되어왔다. 본 논문에서는 이러한 기존의 방법 외에 두 신호사이의 통계적 의존성을 측정하는 양인 상호정보를 이용하여 뇌파의 특징을 분석하였다. 뇌파간의 상호정보 분석을 통해 두뇌에서의 정보의 흐름에 관한 특징을 알아보았고, 감성자극에 반응하는 두뇌의 활동영역을 알 수 있었다.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2011.06a
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• pp.963-964
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• 2011

• Parasites, Hosts and Diseases
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• v.21 no.2
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• pp.234-240
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• 1983

The pathogenicity of free-living amoeba, Waegleria fcwleri, is influenced according to the strain, cultural condition and host (Culbertson et at., 1968; Carter, 1970; Wong et at., 1975), Phillips (1973) demonstrated that Entamoeba histolytica became avirulent after more than 2 year maintenance in axonic culture in vitro. This study was carried out to compare the difference in pathogenicity between two strains of N. fowleri, one of a prolonged maintenance in arsenic medium and the other one obtained by serial brain passage in mice. The 0 strain was that N. fowleri had cultivated axenically more than 7 years in CGVS medium. The 2-1 strain was obtained from the brain of mouse inoculated intranasally with a strain, which was from the mouse brain infected with 0 strain, and cultured for 15 weeks until the beginning of this experiment. White male mice weighing 18-22 g were used. Mice were anesthetized by an intraperitoneal injection of about 1 mg secobarbital, and inoculated intranasally with $10{\times}$10^4 live N. fowleri trophoBoites in a $5{\;}{\mu}l$ cell suspension. Sluggish behaviour, nervousness, rotation and leg paralysis were developed earlier and more frequently in the 2-1 experimental group than the control 0 group. Pathological changes such as inflammatory and necrotic lesion were observed in the olfactory and anterior portion of brain, and these changes were more extensive in the 2-1 group. The edematous and inflammatory changes in lung were demonstrated in mice died after 13th day post-inoculation. The experimental mice of 2-1 group began to die suddenly from 7th day post-inoculation, and the survival time in 2-1 group mice was shorter than 0 group mice. The typical primary amoebic meningoencephalitis was developed in the mice inoculated intranasally with N. fowleri. The prolonged maintenance of N. fowleri amoebae in axonic CGVS medium was observed to have lost their original pathogenicity for mice, but their pathogenicity was restored by serial brain passage in mice.

• Progress in Medical Physics
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• v.16 no.1
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• pp.32-38
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• 2005

Impaired processing of facial information is one of the broad ranges of cognitive deficits seen in patients with schizophrenia. The purpose of this study was to elucidate the differences in brain activities involved in the process of facial working memory between schizophrenic patients and healthy comparison subjects. Ten patients with schizophrenia were recruited along with matched healthy volunteers as a comparison group. Functional magnetic resonance imaging (fMRI) was used to assess cortical activities during the performance of a 1-back working memory paradigm using images of neutral faces as mnemonic content. The patient group performed the tasks with reduced accuracy. Group analysis revealed that left fusiform gyrus, right superior frontal gyrus, bilateral middle frontal gyri/insula, left middle temporal gyrus, precuneus and vermis of cerebellum and showed decreased cortical activities in the patient group. On the other hand, an increased level of activation in lateral prefrontal cortex and parietal lobule was observed from the patient group, all in the right hemisphere. A decreased level of activity in the left fusiform gyrus among the patient group implicates inefficient processing of facial information. An increased level of activation in prefrontal and parietal neural networks from the patient group confirms earlier findings on the impaired working memory of patients with schizophrenia.

• Journal of Life Science
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• v.28 no.11
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• pp.1386-1395
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• 2018

Over recent years, it has become evident that the central nervous system bidirectionally interacts with the gastrointestinal tract along the gut-brain axis. A series of preclinical studies indicate that the gut microbiota can modulate central nervous system function through a multitude of physiological functions. Polyphenols are ubiquitous plant chemicals included in foods such as fruits, vegetables, tea, coffee and wine, and their consumption is directly responsible for beneficial health effects due to antioxidant, anti-inflammatory, antimicrobial, immunomodulatory, anticancer, vasodilating, and prebiotic-like effects. There is increasing evidence that dietary polyphenol can contribute to beneficial effects in neuronal protection acting against oxidative stress and inflammatory injury as well as in cognitive functions. In this paper, we overview the neuroprotective role of dietary polyphenols especially focusing on the neuroinflammation and neurovascular function by interaction with the gut microbiome. Polyphenol metabolites could directly act as neurotransmitters crossing the blood-brain barrier and modulating the cerebrovascular system or indirectly modulating gut microbiota. In addition, evidence suggests that dietary polyphenols are effective in preventing and managing neurological disorders, such as age-related cognitive decline and neurodegeneration, through a multitude of physiological functions. Dietary polyphenols are increasingly envisaged as a potential nutraceuticals in the prevention and treatment of neurological disorders, because they possess the ability to reduce neuroinflammation, to improve memory and cognitive function and to modulate the gut microbiota.

• Sleep Medicine and Psychophysiology
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• v.20 no.2
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• pp.75-81
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• 2013

Objectives: There are a lot of studies that analyze the interaction between the emotion of disgust and the functional brain images using fMRI and PET. But studies using sLORETA (standardized low resolution brain electromagnetic tomography) almost do not exist. The aim of this research is to explore the relationship of the emotion of disgust and the cortical activation using sLORETA analysis. Methods: Forty five healthy young adults ($27.1{\pm}2.6$ years) participated in the study. While they were watching 4 neutral images and 4 disgusting images associated with mutilation selected from the international affective picture system (IAPS), participants' EEGs were taken for 30 seconds per one picture. Through these obtained EEG data, sLORETA analysis was performed to compare EEGs associated with neutral and negative images. Results: During looking for visual disgusting stimulus, all participants reported unpleasantness, arousal and stress. In sLORETA analysis, the decrease of current density in theta wave was shown at left frontal superior gyrus (BA10) and middle gyrus (BA10, 11). This voxel cluster consists of a total of 11 voxels and the threshold of t value indicating statistically significant decreases in the current density (p<0.05) was -1.984. There were no differences between male and female in the degree of being disgusted by the stimuli. Conclusion: This finding may suggest that the activation of dorsolateral prefrontal cortex might be associated with regulating disgust emotion.

• Korean Journal of Cognitive Science
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• v.34 no.2
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• pp.111-151
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• 2023

It is reported that binge drinkers show cognitive impairment similar to alcohol use disorder patients. A previous studies using neuropsychological tests and brain imaging techniques to investigate the visual perception of alcohol use disorder patients reported that they had global-local visual perception defects. Although the neurological basis for the global-local visual perception deficit in the heavy drinking group has been presented, there are no studies to date that have investigated the global-local visual perception in the heavy drinking group. This study investigated local-biased visual perception in female college students with binge drinking (BD) using event-related potentials (ERPs). Based on the scores of the Korean version of Alcohol Use Disorder Identification Test and the Alcohol Use Questionnaire, participants were assigned into BD (n=25) and non-BD (n=25) groups. Local-global visual processing was assessed using a local-global paradigm, in which large stimuli (global level) composed of small stimuli (local level) were presented. The stimuli presented at global and local levels were either congruent or incongruent. The behavioral results exhibited that the BD and non-BD groups did not differ in terms of accuracy and response time. In terms of ERPs, the BD and non-BD groups did not show difference in N100, P150 and N200 amplitude. However, the BD group showed significantly smaller P300 amplitude than non-BD group especially in the local condition. In addition, a negative correlation between P300 amplitude and binge drinking score was observed, i.e., severer binge drinking smaller P300 amplitude. The P300 is known to reflect cognitive inhibition and attentional allocation. In the global-local paradigm, the local condition required to attend to local target while ignoring global non-target. Therefore, the present results indicate that female college students with BD do not have local-biased visual processing, instead they seem to have difficulties in inhibition of irrelevant stimuli.