• 제목/요약/키워드: Brain activation

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확률 및 통계적 개념에 근거한 한국인 표준 뇌 지도 작성 및 기능 영상 분석을 위한 가시화 방법에 관한 연구 (Developing a Korean Standard Brain Atlas on the basis of Statistical and Probabilistic Approach and Visualization tool for Functional image analysis)

  • 구방본;이종민;김준식;이재성;김인영;김재진;이동수;권준수;김선일
    • 대한핵의학회지
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    • 제37권3호
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    • pp.162-170
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    • 2003
  • 이 논문에서는 한국인의 뇌 기능 영상 연구에서의 정확한 분석을 위한 한국인 뇌 확률 지도를 제작하였고 이를 실제 기능 영상 연구에 적용할 수 있도록 하는 뇌 위치 정보 추출 프로그램에 대하여 소개하였다. 한국인의 표준 뇌 확률 지도를 작성하기 위하여 정신과적 병력이 없는 정상인 76개의 뇌 영상을 서울대학교 신경정신과와 핵의학과로부터 수집하였으며, 이를 바탕으로 표준 뇌 영상을 결정하였다. 결정된 표준 뇌 영상은 숙련된 전문의로부터 89개의 해부학적 영역으로 분할하는 작업이 이루어졌다. 표준 뇌 영상에서 분할된 정보들은 자동 분할 알고리즘에서의 기준으로 사용되어 나머지 75개의 뇌 영상들에 대해서도 해부학적 정보들을 가지도록 하였다. 76개의 뇌 영상들에 생성된 각각의 89개의 해부학적 정보들은 동일 위치에서의 확률정보로서 변환되어 뇌 확률 지도를 생성하였다. 제작된 한국인의 뇌 확률지도는 한국인의 뇌에 대한 편차 정보와 해부학적인 정보를 가지며 이는 한국인의 기능 영상 연구에 있어서 보다 정확한 결과를 제시할 수 있다.

Sustained Intracellular Acidosis Triggers the Na+/H+ Exchager-1 Activation in Glutamate Excitotoxicity

  • Lee, Bo Kyung;Jung, Yi-Sook
    • Biomolecules & Therapeutics
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    • 제25권6호
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    • pp.593-598
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    • 2017
  • The $Na^+/H^+$ exchanger-1 (NHE-1) is a ubiquitously expressed pH-regulatory membrane protein that functions in the brain, heart, and other organs. It is increased by intracellular acidosis through the interaction of intracellular $H^+$ with an allosteric modifier site in the transport domain. In the previous study, we reported that glutamate-induced NHE-1 phosphorylation mediated by activation of protein kinase C-${\beta}$ (PKC-${\beta}$) in cultured neuron cells via extracellular signal-regulated kinases (ERK)/p90 ribosomal s6 kinases (p90RSK) pathway results in NHE-1 activation. However, whether glutamate stimulates NHE-1 activity solely by the allosteric mechanism remains elusive. Cultured primary cortical neuronal cells were subjected to intracellular acidosis by exposure to $100{\mu}M$ glutamate or 20 mM $NH_4Cl$. After the desired duration of intracellular acidosis, the phosphorylation and activation of PKC-${\beta}$, ERK1/2 and p90RSK were determined by Western blotting. We investigated whether the duration of intracellular acidosis is controlled by glutamate exposure time. The NHE-1 activation increased while intracellular acidosis sustained for >3 min. To determine if sustained intracellular acidosis induced NHE-1 phosphorylation, we examined phosphorylation of NHE-1 induced by intracellular acidosis by transient exposure to $NH_4Cl$. Sustained intracellular acidosis led to activation and phosphorylation of NHE-1. In addition, sustained intracellular acidosis also activated the PKC-${\beta}$, ERK1/2, and p90RSK in neuronal cells. We conclude that glutamate stimulates NHE-1 activity through sustained intracellular acidosis, which mediates NHE-1 phosphorylation regulated by PKC-${\beta}$/ERK1/2/p90RSK pathway in neuronal cells.

파킨슨병 모델 흰쥐에서 침치료에 의한 microglia 활성화 억제에 관한 연구 (Acupuncture inhibits microglial activation in the rat model of Parkinson's disease)

  • 황정연;최일환;박재현;강전모;박히준;임사비나
    • Korean Journal of Acupuncture
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    • 제24권1호
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    • pp.131-144
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    • 2007
  • Objectives : Although the cause of neuronal death of Parkinson's disease remains unclear, increasing evidence points to the role of inflammatory processes. And the hallmark of brain inflammation is the activation of microglia. This study was performed to prove the effect of acupuncture on inhibiting microglial activation. Methods : The rat models which were injected with 6-hydroxydopamine were treated with acupuncture once a day on LR3 (太衝) and GB34 (陽陵泉). To prove the effect of inhibiting microglial activation, we examined the tyrosine hydroxylase (TH) immunopositive neurons and CD11b immunohistochemistry in the substantia nigra. Results : There were 18% (third day), 32% (seventh day) loss of TH-positive cell bodies in the control group and 23% (third day), 26% (seventh day) in the acupuncture group, whereas 3% (third day), 10% (seventh day) in vehicle group. The difference of optical density in substantia nigra was evaluated by subtracting log inverse gray value of contralateral side from that of ipsilateral side. With regards to the result of CD11b immunohistochemistry, acupuncture group showed significantly inhibited microglial activation compared with control group (p<0.01) on the seventh day. Conclusions : Acupuncture showed the effect of inhibition of microglial activation in seventh day. However, the effect of protection of TH positive cell bodies was not shown. So we need longer investigation of the effect of acupuncture on Parkinson's disease.

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양면성 혁신의 선행요인에 대한 연구 (A Study on Ambidextrous Innovation's Proceeding Elements)

  • 성기욱;김봉선
    • 대한안전경영과학회:학술대회논문집
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    • 대한안전경영과학회 2012년 추계학술대회
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    • pp.253-268
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    • 2012
  • Recently, creative innovation has become a major topic in management innovation and due to this, various researches on its need and methodologies are being performed. According to previous studies on ambidexterity, explorative innovation is closer to divergent and right-sided brain, while exploitative innovation is closer to convergent and left-sided brain. Topic was to identify preceding element which affects Ambidextrous Innovation. For this topic, 129 Six Sigma projects from 19 different companies were collected. Ambidextrous index from preceding studies was used. This index represents the degree of ambidextrous activation and can be calculated by multiplying cumulative usage of exploitative tools with that of explorative tools. In the project characteristics, simple linear regression result showed leadership degree, team's vitalization degree and leader capability degree have effect in positive direction.

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Improved Feature Extraction of Hand Movement EEG Signals based on Independent Component Analysis and Spatial Filter

  • 응웬탄하;박승민;고광은;심귀보
    • 한국지능시스템학회논문지
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    • 제22권4호
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    • pp.515-520
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    • 2012
  • In brain computer interface (BCI) system, the most important part is classification of human thoughts in order to translate into commands. The more accuracy result in classification the system gets, the more effective BCI system is. To increase the quality of BCI system, we proposed to reduce noise and artifact from the recording data to analyzing data. We used auditory stimuli instead of visual ones to eliminate the eye movement, unwanted visual activation, gaze control. We applied independent component analysis (ICA) algorithm to purify the sources which constructed the raw signals. One of the most famous spatial filter in BCI context is common spatial patterns (CSP), which maximize one class while minimize the other by using covariance matrix. ICA and CSP also do the filter job, as a raw filter and refinement, which increase the classification result of linear discriminant analysis (LDA).

주요우울증에서 스트레스, 염증반응, 신경조직발생 (Stress, Inflammation and Neurogenesis in Major Depression)

  • 김용구
    • 생물정신의학
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    • 제18권4호
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    • pp.169-175
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    • 2011
  • Stress, a risk factor of major depression induces cytokine mediated inflammation and decreased neurogenesis. In patients with major depression, significant increases of pro-inflammatory cytokines have been consistently reported. The pro-inflammatory cytokines can stimulate the hypothalamic-pituitary-adrenal (HPA) axis to release glucocorticoids. In the brain, microglia and play a role of immune activation in response to stress. Increased pro-inflammatory cytokine play a role in restricting neurogenesis in the brain. Although neurogenesis may not be essential for the development of depression, it may be required for clinically effective antidepressant treatment. Hence, stimulation of neurogenesis is regarded as a promising strategy for new antidepressant targets. This review introduces changes in neurotransmitter, cytokine and neurogenesis in major depression and explores the possible relationship between pro-inflammatory cytokines and neurogenesis related to stress in major depression.

Neuroanatomical analysis for onomatopoeia : fMRI study

  • 한종혜;최원일;장용민;정옥란;남기춘
    • 한국정보과학회 언어공학연구회:학술대회논문집(한글 및 한국어 정보처리)
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    • 한국정보과학회언어공학연구회 2004년도 제16회 한글.언어.인지 한술대회
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    • pp.315-318
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    • 2004
  • The purpose of this study is to examine the neuroanatomical areas related with onomatopoeia (sound-imitated word). Using the block-designed fMRI, whole-brain images (N=11) were acquired during lexical decisions. We examined how the lexical information initiates brain activation during visual word recognition. The onomatopoeic word recognition activated the bilateral occipital lobes and superior mid-temporal gyrus.

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Update on dentin hypersensitivity: with the focus on hydrodynamic theory and mechanosensitive ion channels

  • Won, Jonghwa;Oh, Seog Bae
    • International Journal of Oral Biology
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    • 제44권3호
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    • pp.71-76
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    • 2019
  • Dentin hypersensitivity is an abrupt intense pain caused by innocuous stimuli to exposed dentinal tubules. Mechanosensitive ion channels have been assessed in dental primary afferent neurons and odontoblasts to explain dentin hypersensitivity. Dentinal fluid dynamics evoked by various stimuli to exposed dentin cause mechanical stress to the structures underlying dentin. This review briefly discusses three hypotheses regarding dentin hypersensitivity and introduces recent findings on mechanosensitive ion channels expressed in the dental sensory system and discusses how the activation of these ion channels is involved in dentin hypersensitivity.

Erythropoietin increases neuronal cell differentiation : association of transcriptional factors AP-l and NF-$\kappa$B activation

  • Lee, Sang-Min;Park, Hye-Ji;Lee, Yoot-Mo;Moon, Dong-Cheul;Kim, Kyong-Soon;Cho, Kyong-Ju;Yoon, Do-Young;Song, Suk-Gil;Hong, Jin-Tae
    • 대한약학회:학술대회논문집
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    • 대한약학회 2003년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.2-2
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    • pp.169.2-170
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    • 2003
  • Erythropietin (EPO), a hematopoietic factor is also required for normal brain development, and its receptor is localized in brain. Therefore, it is possible that EPO could act as a neurotropic factor inducing differentiation of neurons. The present study, we therefore investigated whether EPO can increase differentiation of undifferentiated cortical neuron isolated from postneonatal (Day 1) rat brains and PC12 cell, undifferentiated dopaminagic cell line. EPO dose (1-100 U/ml) dependently increased cell differentiation and expression of differentiation marker gene (neurofilament and tyrosine hydroxylase) in both cells. (omitted)

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Enhanced Calreticulin Expression Promotes Calcium-dependent Apoptosis in Postnatal Cardiomyocytes

  • Lim, Soyeon;Chang, Woochul;Lee, Byoung Kwon;Song, Heesang;Hong, Ja Hyun;Lee, Sunju;Song, Byeong-Wook;Kim, Hye-Jung;Cha, Min-Ji;Jang, Yangsoo;Chung, Namsik;Choi, Soon-Yong;Hwang, Ki-Chul
    • Molecules and Cells
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    • 제25권3호
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    • pp.390-396
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    • 2008
  • Calreticulin (CRT) is one of the major $Ca^{2+}$ binding chaperone proteins of the endoplasmic reticulum (ER) and an unusual luminal ER protein. Postnatally elevated expression of CRT leads to impaired development of the cardiac conductive system and may be responsible for the pathology of complete heart block. In this study, the molecular mechanisms that affect $Ca^{2+}$-dependent signal cascades were investigated using CRT-overexpressing cardiomyocytes. In particular, we asked whether calreticulin plays a critical role in the activation of $Ca^{2+}$-dependent apoptosis. In the cells overexpressing CRT, the intracellular calcium concentration was significantly increased and the activity of PKC and level of SECAR2a mRNA were reduced. Phosphorylation of Akt and ERKs decreased compared to control. In addition the activity of the anti-apoptotic factor, Bcl-2, was decreased and the activities of pro-apoptotic factor, Bax, p53 and caspase 8 were increased, leading to a dramatic augmentation of caspase 3 activity. Our results suggest that enhanced CRT expression in mature cardiomyocytes disrupts intracellular calcium regulation, leading to calcium-dependent apoptosis.