• Title/Summary/Keyword: Brain activation

검색결과 715건 처리시간 0.028초

뇌파 기반 실시간 뇌활동 모니터링 시스템의 타당성 조사 (Feasibility Study of EEG-based Real-time Brain Activation Monitoring System)

  • 채희제;임창환;이승환
    • 대한의용생체공학회:의공학회지
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    • 제28권2호
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    • pp.258-264
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    • 2007
  • Spatiotemporal changes of brain rhythmic activity at a certain frequency have been usually monitored in real time using scalp potential maps of multi-channel electroencephalography(EEG) or magnetic field maps of magnetoencephalography(MEG). In the present study, we investigate if it is possible to implement a real-time brain activity monitoring system which can monitor spatiotemporal changes of cortical rhythmic activity on a subject's cortical surface, neither on a sensor plane nor on a standard brain model, with a high temporal resolution. In the suggested system, a frequency domain inverse operator is preliminarily constructed, considering the individual subject's anatomical information, noise level, and sensor configurations. Spectral current power at each cortical vertex is then calculated for the Fourier transforms of successive sections of continuous data, when a single frequency or particular frequency band is given. An offline study which perfectly simulated the suggested system demonstrates that cortical rhythmic source changes can be monitored at the cortical level with a maximal delay time of about 200 ms, when 18 channel EEG data are analyzed under Pentium4 3.4GHz environment. Two sets of artifact-free, eye closed, resting EEG data acquired from a dementia patient and a normal male subject were used to show the feasibility of the suggested system. Factors influencing the computational delay are investigated and possible applications of the system are discussed as well.

Transcriptional activation of human GM3 synthase (hST3Gal V) gene by valproic acid in ARPE-19 human retinal pigment epithelial cells

  • Song, Na-Ree;Kim, Seok-Jo;Kwon, Haw-Young;Son, Sung-Wook;Kim, Kyoung-Sook;Ahn, Hee-Bae;Lee, Young-Choon
    • BMB Reports
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    • 제44권6호
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    • pp.405-409
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    • 2011
  • The present study demonstrated that valproic acid (VPA) transcriptionally regulates human GM3 synthase (hST3Gal V), which catalyzes ganglioside GM3 biosynthesis in ARPE-19 human retinal pigment epithelial cells. For this, we characterized the promoter region of the hST3Gal V gene. Functional analysis of the 5'-flanking region of the hST3Gal V gene revealed that the -177 to -83 region functions as the VPA-inducible promoter and that the CREB/ATF binding site at -143 is crucial for VPA-induced expression of hST3Gal V in ARPE-19 cells. In addition, the transcriptional activity of hST3Gal V induced by VPA in ARPE-19 cells was inhibited by SP600125, a c-Jun N-terminal kinase (JNK) inhibitor. In summary, our results identified the core promoter region in the hST3Gal V promoter and for the first time demonstrated that ATF2 binding to the CREB/ATF binding site at -143 is essential for transcriptional activation of hST3Gal V in VPA-induced ARPE-19 cells.

Telmisartan Inhibits TNFα-Induced Leukocyte Adhesion by Blocking ICAM-1 Expression in Astroglial Cells but Not in Endothelial Cells

  • Jang, Changhwan;Kim, Jungjin;Kwon, Youngsun;Jo, Sangmee A.
    • Biomolecules & Therapeutics
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    • 제28권5호
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    • pp.423-430
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    • 2020
  • Telmisartan is an angiotensin-II receptor blocker and acts as a selective modulator of peroxisome proliferator-activated receptor gamma (PPARγ). Several studies have demonstrated that telmisartan ameliorates depression and memory dysfunction and reduces brain inflammation. We hypothesized that the beneficial effects of telmisartan on brain could be due to modulation of the blood-brain barrier (BBB) function. Here, we examined the effect of telmisartan on tumor necrosis factor alpha (TNF-α)-induced expression of intercellular adhesion molecule 1 (ICAM-1) which plays an important role in leukocyte transcytosis through the BBB. Telmisartan blocked TNF-α-induced ICAM-1 expression and leukocyte adhesion in U87MG human glioma cells but showed no effect on human brain microvascular endothelial cells. In U87MG cells, a PPAR antagonist, GW9662 did not block the effect of telmisartan on ICAM1 expression but rather potentiated. Moreover, GW9662 caused no change in TNF-α-induced ICAM-1 expression, suggesting no implication of PPARγ in the telmisartan effect. Further studies showed that telmisartan blocked TNF-α-induced activation of c-Jun N-terminal kinase (JNK), extracellular signal-regulated kinase 1/2 (ERK1/2), p38, and nuclear factorkappa B (NF-κB). In contrast, inhibitors of JNK, ERK1/2 and NF-κB but not p38, blocked ICAM-1 expression induced by TNF-α. Thus, our findings suggest that the beneficial effect of telmisartan is likely due to the reduction of astrocytic ICAM1 expression and leukocytes adhesion to astrocytes, and that this response was mediated by the inhibition of JNK/ERK1/2/NF-κB activation and in the PPAR-independent manner. In conclusion, this study enhances our understanding of the mechanism by which telmisartan exerts the beneficial brain function.

Baicalein이 Lipopolysaccharide에 의한 생쥐의 Neuroinflammation에 미치는 영향 (Effects of Baicalein on Neuroinflammation in Lipopolysaccharide-treated Mice)

  • 하경운;김연섭
    • 대한본초학회지
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    • 제28권2호
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    • pp.93-101
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    • 2013
  • Objects : Baicalein is a major bioactive flavonoid component of Scutellaria baicalensis Georgi that shows a wide range of biological activities, including neuroprotections and anti-inflammatory actions. Hence it is a potential therapeutic material for the treatment of neuroinflammation. In this study, we investigated the modulatory effect of baicalein on neuroinflammation. Method : Pro-inflammatory cytokines (TNF-${\alpha}$, IL-$1{\beta}$ and IL-6 mRNA), COX-2 mRNA expression and microglial activation in the brain tissue is induced by systemic lipopolysaccharide (LPS) treatment in C57BL/6 mice. Baicalein was treated orally with 10, 20, and 30 mg/kg 1 hour prior to the LPS (3 mg/kg, i.p.) injection. TNF-${\alpha}$, IL-$1{\beta}$, IL-6 and COX-2 mRNA expression in the brain tissue was measured by the quantitative real-time polymerase chain reaction(PCR) method. Iba1 expression in the brain was measured by western blotting method. Microglia was observed with immunohistochemistry. Results : Baicalein 30 mg/kg significantly attenuated the expression of TNF-${\alpha}$, IL-$1{\beta}$, IL-6 and COX-2 mRNA in the brain tissue. Baicalein 20 mg/kg significantly attenuated the expression of IL-6 mRNA in the brain tissue. Baicalein 30 mg/kg significantly attenuated the expression of Iba1 protein expression in the brain tissue. Baicalein 30 mg/kg significantly decreased the number and cell size of microglia in the cerebral cortex and hypothalamic region and the area percentage of Iba1-expressed microglia in the hippocampus. Conclusion : These results demonstrated that baicalein attenuates LPS induced neuroinflammation in the mice via reduction of pro-inflammatory cytokines (TNF-${\alpha}$, IL-$1{\beta}$, IL-6), COX-2 mRNA expression and microglial activation.

Effect of Lactobacillus dominance modified by Korean Red Ginseng on the improvement of Alzheimer's disease in mice

  • Lee, Mijung;Lee, So-Hee;Kim, Min-Soo;Ahn, Kwang-Sung;Kim, Manho
    • Journal of Ginseng Research
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    • 제46권3호
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    • pp.464-472
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    • 2022
  • Background: Gut microbiota influence the central nervous system through gut-brain-axis. They also affect the neurological disorders. Gut microbiota differs in patients with Alzheimer's disease (AD), as a potential factor that leads to progression of AD. Oral intake of Korean Red Ginseng (KRG) improves the cognitive functions. Therefore, it can be proposed that KRG affect the microbiota on the gut-brain-axis to the brain. Methods: Tg2576 were used for the experimental model of AD. They were divided into four groups: wild type (n = 6), AD mice (n = 6), AD mice with 30 mg/kg/day (n = 6) or 100 mg/kg/day (n = 6) of KRG. Following two weeks, changes in gut microbiota were analyzed by Illumina HiSeq4000 platform 16S gene sequencing. Microglial activation were evaluated by quantitative Western blot analyses of Iba-1 protein. Claudin-5, occludin, laminin and CD13 assay were conducted for Blood-brain barrier (BBB) integrity. Amyloid beta (Aβ) accumulation demonstrated through Aβ 42/40 ratio was accessed by ELISA, and cognition were monitored by Novel object location test. Results: KRG improved the cognitive behavior of mice (30 mg/kg/day p < 0.05; 100 mg/kg/day p < 0.01), and decreased Aβ 42/40 ratio (p < 0.01) indicating reduced Aβ accumulation. Increased Iba-1 (p < 0.001) for reduced microglial activation, and upregulation of Claudin-5 (p < 0.05) for decreased BBB permeability were shown. In particular, diversity of gut microbiota was altered (30 mg/kg/day q-value<0.05), showing increased population of Lactobacillus species. (30 mg/kg/day 411%; 100 mg/kg/day 1040%). Conclusions: KRG administration showed the Lactobacillus dominance in the gut microbiota. Improvement of AD pathology by KRG can be medicated through gut-brain axis in mice model of AD.

마음챙김기반 자비명상프로그램이 배우자 상실을 경험한 여성노인의 뇌 활성과 스트레스에 미치는 영향 분석 (Analysis on the Influence of Mindfulness Based Compassion Meditation Program for Elderly Women's Brain Activation and Stress, Who Experienced Loss of Spouse)

  • 김연금
    • 한국산학기술학회논문지
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    • 제17권4호
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    • pp.312-318
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    • 2016
  • 본 연구는 마음챙김기반 자비명상프로그램이 배우자를 상실한 여성노인의 뇌 활성과 스트레스에 미치는 영향을 분석하기 위하여 2 channel EEG(Electroencephalogram)를 통해 검증하였다. 실험대상은 Y군 소재 65세~75세의 여성노인 60명으로, 30명은 실험집단으로, 30명은 통제집단으로 선정하였다. 연구기간은 2015년 8월에서 2015년 11월까지 매주 1회기씩, 회기 당 60분씩, 총 16회기로 프로그램을 실시하였다. 프로그램은 몸과 마음을 연결해서 통합적으로 치유할 수 있도록 하는 마음챙김과 자기 자신을 향한 사랑, 연민과 자비심 계발을 위한 자비명상을 접목하여 마음챙김기반 자비명상프로그램을 개발한 것이다. 실험결과, 실험집단에서 활성지수 우뇌 사전/사후(82.51/85.83, p<.013)의 변화를 보였으며(유의수준 p=.05). 항스트레스지수는 좌뇌(74.71/71.17, p<.050)로 나타났다. 활성지수는 뇌의 정신적 활동과 행동성향을 판단할 수 있는 지표이고, 항 스트레스지수는 육체적, 정신적 스트레스를 나타내는 지수이다. 본 연구는 마음챙김기반 자비명상프로그램이 배우자 상실을 경험한 여성 노인의 뇌 활성과 스트레스를 향상시킬 수 있는 방법으로서 효용과 가치가 있다는 것을 뇌과학적으로 분석한 것에 의의가 있다.

Facilitation of AMPA receptor-mediated steady-state current by extrasynaptic NMDA receptors in supraoptic magnocellular neurosecretory cells

  • Pai, Yoon Hyoung;Lim, Chae Seong;Park, Kyung-Ah;Cho, Hyun Sil;Lee, Gyu-Seung;Shin, Yong Sup;Kim, Hyun-Woo;Jeon, Byeong Hwa;Yoon, Seok Hwa;Park, Jin Bong
    • The Korean Journal of Physiology and Pharmacology
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    • 제20권4호
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    • pp.425-432
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    • 2016
  • In addition to classical synaptic transmission, information is transmitted between cells via the activation of extrasynaptic receptors that generate persistent tonic current in the brain. While growing evidence supports the presence of tonic NMDA current ($I_{NMDA}$) generated by extrasynaptic NMDA receptors (eNMDARs), the functional significance of tonic $I_{NMDA}$ in various brain regions remains poorly understood. Here, we demonstrate that activation of eNMDARs that generate INMDA facilitates the ${\alpha}$-amino-3-hydroxy-5-methylisoxazole-4-proprionate receptor (AMPAR)-mediated steady-state current in supraoptic nucleus (SON) magnocellular neurosecretory cells (MNCs). In $low-Mg^{2+}$ artificial cerebrospinal fluid (aCSF), glutamate induced an inward shift in $I_{holding}$ ($I_{GLU}$) at a holding potential ($V_{holding}$) of -70 mV which was partly blocked by an AMPAR antagonist, NBQX. NBQX-sensitive $I_{GLU}$ was observed even in normal aCSF at $V_{holding}$ of -40 mV or -20 mV. $I_{GLU}$ was completely abolished by pretreatment with an NMDAR blocker, AP5, under all tested conditions. AMPA induced a reproducible inward shift in $I_{holding}$ ($I_{AMPA}$) in SON MNCs. Pretreatment with AP5 attenuated $I_{AMPA}$ amplitudes to ~60% of the control levels in $low-Mg^{2+}$ aCSF, but not in normal aCSF at $V_{holding}$ of -70 mV. $I_{AMPA}$ attenuation by AP5 was also prominent in normal aCSF at depolarized holding potentials. Memantine, an eNMDAR blocker, mimicked the AP5-induced $I_{AMPA}$ attenuation in SON MNCs. Finally, chronic dehydration did not affect $I_{AMPA}$ attenuation by AP5 in the neurons. These results suggest that tonic $I_{NMDA}$, mediated by eNMDAR, facilitates AMPAR function, changing the postsynaptic response to its agonists in normal and osmotically challenged SON MNCs.

전산화단층영상 기반 뇌출혈 검출을 위한 YOLOv5s 성능 평가 (Performance Evaluation of YOLOv5s for Brain Hemorrhage Detection Using Computed Tomography Images)

  • 김성민;이승완
    • 한국방사선학회논문지
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    • 제16권1호
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    • pp.25-34
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    • 2022
  • 뇌 전산화단층촬영은 비침습성, 3차원 영상 제공, 저방사선량 등의 장점 때문에 뇌출혈과 같은 질병 진단을 위해 시행된다. 하지만 뇌 전산화단층영상 판독을 위한 전문의의 인력 공급 부족 및 막대한 업무량으로 인해 수많은 판독 오류 및 오진이 발생하고 있다. 이와 같은 문제를 해결하기 위해 객체 검출을 위한 다양한 인공지능 기술이 개발되고 있다. 본 연구에서는 뇌 전산화단층영상으로부터 뇌출혈 검출을 위한 딥러닝 기반 YOLOv5s 모델의 적용 가능성을 확인하였다. 또한 YOLOv5s 모델 학습 시 초매개변수를 변화시켜 학습된 모델의 성능을 평가하였다. YOLOv5s 모델은 backbone, neck 및 output 모듈로 구성하였고, 입력 CT 영상 내 뇌출혈로 의심되는 부위를 검출하여 출력할 수 있도록 하였다. YOLOv5s 모델 학습 시 활성화함수, 최적화함수, 손실함수 및 학습 횟수를 변화시켰고, 학습된 모델의 뇌출혈 검출 정확도 및 학습 시간을 측정하였다. 연구결과 학습된 YOLOv5s 모델은 뇌출혈로 의심되는 부위에 대한 경계 박스 및 해당 경계박스에 대한 정확도를 출력할 수 있음을 확인하였다. Mish 활성화함수, stochastic gradient descent 최적화함수 및 completed intersection over union 손실함수 적용 시 YOLOv5s 모델의 뇌출혈 검출 정확도 향상 및 학습 시간이 단축되는 결과를 확인하였다. 또한 YOLOv5s 모델의 뇌출혈 검출 정확도 및 학습 시간은 학습 횟수에 비례하여 증가하는 결과를 확인하였다. 따라서 YOLOv5s 모델은 뇌 전산화단층영상을 이용한 뇌출혈 검출을 위해 활용할 수 있으며, 최적의 초매개변수 적용을 통해 성능을 향상 시킬 수 있다.

Age-related epigenetic regulation in the brain and its role in neuronal diseases

  • Kim-Ha, Jeongsil;Kim, Young-Joon
    • BMB Reports
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    • 제49권12호
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    • pp.671-680
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    • 2016
  • Accumulating evidence indicates many brain functions are mediated by epigenetic regulation of neural genes, and their dysregulations result in neuronal disorders. Experiences such as learning and recall, as well as physical exercise, induce neuronal activation through epigenetic modifications and by changing the noncoding RNA profiles. Animal models, brain samples from patients, and the development of diverse analytical methods have broadened our understanding of epigenetic regulation in the brain. Diverse and specific epigenetic changes are suggested to correlate with neuronal development, learning and memory, aging and age-related neuronal diseases. Although the results show some discrepancies, a careful comparison of the data (including methods, regions and conditions examined) would clarify the problems confronted in understanding epigenetic regulation in the brain.

fMRI STUDTY ON HUMAN BRAIN'S ACTIVATION BY THE BRAIN STIMULATOR

  • Jeong, Hee-Chang;Choe, Bo-Young;Chung, Sung-Taek;Lee, Hyoung-Koo;Suh, Tae-Suk
    • 한국의학물리학회:학술대회논문집
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    • 한국의학물리학회 2002년도 Proceedings
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    • pp.359-359
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    • 2002
  • Brain Stimulator processes both visual and audible stimulus and send them human sensory organ. The stimulus was accepted by our sensory organ effect upon human mental function. In this study, we examine the actual effect of commercial brain stimulator using tMRI system.

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