• 제목/요약/키워드: Brain activation

검색결과 714건 처리시간 0.032초

일차성 불면증에서 전두엽의 역할 : 기능적 자기공명영상 연구 (The Roles of Frontal Cortex in Primary Insomnia : Findings from Functional Magnetic Resonance Imaging Studies)

  • 김보리;박수현;조한별;김정윤
    • 생물정신의학
    • /
    • 제25권1호
    • /
    • pp.1-8
    • /
    • 2018
  • Insomnia is a common sleep-related symptom which occurs in many populations, however, the neural mechanism underlying insomnia is not yet known. The hyperarousal model explains the neural mechanism of insomnia to some extent, and the frontal cortex dysfunction has been known to be related to primary insomnia. In this review, we discuss studies that applied resting state and/or task-related functional magnetic resonance imaging to demonstrate the deficits/dysfunctions of functional activation and network in primary insomnia. Empirical evidence of the hyperarousal model and proposed relation between the frontal cortex and other brain regions in primary insomnia are examined. Reviewing these studies could provide critical insights regarding the pathophysiology, brain network and cerebral activation in insomnia and the development of novel methodologies for the diagnosis and treatment of insomnia.

  • PDF

Resveratrol attenuates lipopolysaccharide-induced dysfunction of blood-brain barrier in endothelial cells via AMPK activation

  • Hu, Min;Liu, Bo
    • The Korean Journal of Physiology and Pharmacology
    • /
    • 제20권4호
    • /
    • pp.325-332
    • /
    • 2016
  • Resveratrol, a phytoalexin, is reported to activate AMP-activated protein kinase (AMPK) in vascular cells. The blood-brain barrier (BBB), formed by specialized brain endothelial cells that are interconnected by tight junctions, strictly regulates paracellular permeability to maintain an optimal extracellular environment for brain homeostasis. The aim of this study was to elucidate the effects of resveratrol and the role of AMPK in BBB dysfunction induced by lipopolysaccharide (LPS). Exposure of human brain microvascular endothelial cells (HBMECs) to LPS ($1{\mu}g/ml$) for 4 to 24 hours week dramatically increased the permeability of the BBB in parallel with lowered expression levels of occluding and claudin-5, which are essential to maintain tight junctions in HBMECs. In addition, LPS significantly increased the reactive oxygen species (ROS) productions. All effects induced by LPS in HBVMCs were reversed by adenoviral overexpression of superoxide dismutase, inhibition of NAD(P) H oxidase by apocynin or gain-function of AMPK by adenoviral overexpression of constitutively active mutant (AMPK-CA) or by resveratrol. Finally, upregulation of AMPK by either AMPK-CA or resveratrol abolished the levels of LPS-enhanced NAD(P)H oxidase subunits protein expressions. We conclude that AMPK activation by resveratrol improves the integrity of the BBB disrupted by LPS through suppressing the induction of NAD(P)H oxidase-derived ROS in HBMECs.

Brain Tumor Detection Based on Amended Convolution Neural Network Using MRI Images

  • Mohanasundari M;Chandrasekaran V;Anitha S
    • KSII Transactions on Internet and Information Systems (TIIS)
    • /
    • 제17권10호
    • /
    • pp.2788-2808
    • /
    • 2023
  • Brain tumors are one of the most threatening malignancies for humans. Misdiagnosis of brain tumors can result in false medical intervention, which ultimately reduces a patient's chance of survival. Manual identification and segmentation of brain tumors from Magnetic Resonance Imaging (MRI) scans can be difficult and error-prone because of the great range of tumor tissues that exist in various individuals and the similarity of normal tissues. To overcome this limitation, the Amended Convolutional Neural Network (ACNN) model has been introduced, a unique combination of three techniques that have not been previously explored for brain tumor detection. The three techniques integrated into the ACNN model are image tissue preprocessing using the Kalman Bucy Smoothing Filter to remove noisy pixels from the input, image tissue segmentation using the Isotonic Regressive Image Tissue Segmentation Process, and feature extraction using the Marr Wavelet Transformation. The extracted features are compared with the testing features using a sigmoid activation function in the output layer. The experimental findings show that the suggested model outperforms existing techniques concerning accuracy, precision, sensitivity, dice score, Jaccard index, specificity, Positive Predictive Value, Hausdorff distance, recall, and F1 score. The proposed ACNN model achieved a maximum accuracy of 98.8%, which is higher than other existing models, according to the experimental results.

태충(太衝)(Liv3)의 전침자극(電鍼刺戟)이 fMRI상 뇌활성(腦活性) 변화(變化)에 미치는 영향(影響) (A fMRI study on the cerebral activity induced by Electro-acupuncture on Taichong(Liv3))

  • 하치홍;이현;임윤경;홍권의;이병렬;김연진
    • Journal of Acupuncture Research
    • /
    • 제20권5호
    • /
    • pp.187-207
    • /
    • 2003
  • Objective: Recently, many studies have showed the evidences of the effect of the acupuncture treatment through scientific methods. One of these methods is functional MRI. We performed electro-acupuncture on Liv3 and observed the change of brain activation using fMRI. Methods: To see the effect of electro-acupuncture stimulation on Liv3. the experiment was carried out on 12 healthy volunteers. using the gradient echo sequence with the 3.0T whole-body MRI system(ISOL). After the needle insertion on right Liv3. 2 Hz of electric stimulation was given for 30 seconds. repeated five times. with 30 seconds' intervals. The Image analysis including motion correction, talairach transformation. and smoothing was done with SPM99. Results : 1. Group averaged brain activation induced by bilateral electro-acupuncture stimulation on Liv3 activates Brodman Area 6, 13, 18, 19, 22, 31, 39, 44, 2. Group averaged brain deactivation induced by bilateral Electro-acupuncture stimulation on Liv3 activates Brodman Area 4, 6, 9, 19, 36, 37, 39. 3. Group averaged brain activation induced by unilateral(right side) electro-acupuncture stimulation on Liv3 activates Brodman Area 2, 3, 6, 9, 10, 22, 40, 42, 43. 4. Group averaged brain deactivation induced by unilateral(right side) electro-acupuncture stimulation on Liv3 activates Brodman Area 6, 18, 19, 28, 30, 31, 35, 37. 5. Brain region activated by motor stimulation activates Brodman Area 4, 6, 13, 19, 42.

  • PDF

삼음교(三陰交)(Sp6) 전침자극(電針刺戟)이 fMRI상 뇌활성변화(腦活性變化)에 미치는 영향(影響) (fMRI study on the cerebral activity induced by Electro-acupuncture on Sanyinjiao(Sp6))

  • 홍권의;이병렬;이현;임윤경;김연진
    • Journal of Acupuncture Research
    • /
    • 제20권3호
    • /
    • pp.86-103
    • /
    • 2003
  • Objective : Recently, many studies have showed the evidences of the effect of the acupunture treatment through scientific methods. One of these methods is functional MRI. We performed electro-acupunture on Sp6 and observed the changes of brain activation using fMRI. Methods : To see the effect of electro-acupunture stimulation on Sp6, the experiment was carried out on 12 healthy volunteers, using the gradient echo sequence with the 3.0T whole-body MRI system(ISOL). After the needle insertion on right Sp6, 2Hz of electric stimulation was given for 30 seconds, repeated five times, with 30 seconds' intervals. The Image analysis including motion correction, talairach transformation, and smoothing was done with SPM99. Results : 1. Group averaged brain activation induced by bilateral eletro-acupunture stimulation on Sp6 activates Brodman Area 3, 7, 13. 2. Group averaged brain deactivation induced by bilateral eletro-acupunture stimulation on Sp6 activates Brodman Area 6, 38, 47. 3. Group averaged brain activation induced by unilateral(right side) eletro-acupunture stimulation on Sp6 activates Brodman Area 5, 6, 13, 17, 18, 19, 31, 38, 40 ptoms, back pain(32.5%) was the 4. Group averaged brain deactivation induced by unilateral(right side) eletro-acupunture stimulation on Sp6 activates Brodman Area 3, 4, 18, 21, 36, 38, 39. 5. Brain region activated by motor stimulation activates Brodman Area 3, 4, 6, 18, 19.

  • PDF

Deficiency or activation of peroxisome proliferator-activated receptor α reduces the tissue concentrations of endogenously synthesized docosahexaenoic acid in C57BL/6J mice

  • Hsiao, Wen-Ting;Su, Hui-Min;Su, Kuan-Pin;Chen, Szu-Han;Wu, Hai-Ping;You, Yi-Ling;Fu, Ru-Huei;Chao, Pei-Min
    • Nutrition Research and Practice
    • /
    • 제13권4호
    • /
    • pp.286-294
    • /
    • 2019
  • BACKGROUND/OBJECTIVES: Docosahexaenoic acid (DHA), an n-3 long chain polyunsaturated fatty acid (LCPUFA), is acquired by dietary intake or the in vivo conversion of ${\alpha}$-linolenic acid. Many enzymes participating in LCPUFA synthesis are regulated by peroxisome proliferator-activated receptor alpha ($PPAR{\alpha}$). Therefore, it was hypothesized that the tissue accretion of endogenously synthesized DHA could be modified by $PPAR{\alpha}$. MATERIALS/METHODS: The tissue DHA concentrations and mRNA levels of genes participating in DHA biosynthesis were compared among $PPAR{\alpha}$ homozygous (KO), heterozygous (HZ), and wild type (WT) mice (Exp I), and between WT mice treated with clofibrate ($PPAR{\alpha}$ agonist) or those not treated (Exp II). In ExpII, the expression levels of the proteins associated with DHA function in the brain cortex and retina were also measured. An n3-PUFA depleted/replenished regimen was applied to mitigate the confounding effects of maternal DHA. RESULTS: $PPAR{\alpha}$ ablation reduced the hepatic Acox, Fads1, and Fads2 mRNA levels, as well as the DHA concentration in the liver, but not in the brain cortex. In contrast, $PPAR{\alpha}$ activation increased hepatic Acox, Fads1, Fads2, and Elovl5 mRNA levels, but reduced the DHA concentrations in the liver, retina, and phospholipid of brain cortex, and decreased mRNA and protein levels of the brain-derived neurotrophic factor in brain cortex. CONCLUSIONS: LCPUFA enzyme expression was altered by $PPAR{\alpha}$. Either $PPAR{\alpha}$ deficiency or activation-decreased tissue DHA concentration is a stimulus for further studies to determine the functional significance.

분류 지식의 생성과 이해 형태 학습을 통한 학생들의 두뇌활성 변화 (Learning-Related Changes on the Brain Activation Patterns in Classification of Knowledge-Generation and -Understanding)

  • 권용주;이준기
    • 한국과학교육학회지
    • /
    • 제30권4호
    • /
    • pp.487-497
    • /
    • 2010
  • 이 연구의 목적은 교사의 교수-학습 방식(범주생성형 vs. 범주이해형)이 학생의 분류능력에 어떤 영향을 미치는지를 두뇌 수준에서 규명하는 것이다. 이를 위해 대학교에 재학 중인 24명의 건강한 오른손잡이 학생들이 이 연구에 참여하였다. 이들은 생성 집단과 이해 집단의 두 집단으로 나뉘어 12주간의 서로 다른 학습프로그램을 체험하였다. 연구 참여자들의 과제수행 과정에서의 두뇌활성을 측정하기 위하여 학습프로그램 경험 전후에 fMRI 측정과 지필 검사를 실시했다. 연구결과에 따르면, 분류범주생성 과제의 수행에서 생성집단은 교수-학습 경험 후 대뇌피질 영역과 기저핵 영역이 함께 증가되었으며, 선택-갈등과 관련된 전두피질 영역과 해마옆이랑의 활성감소가 나타났다. 반면 이해집단은 의미 있는 활성변화가 나타나지 않았다. 분류범주이해 과제의 수행에서는 이해집단이 교수-학습 경험 후 대뇌피질 영역과 해마옆이랑의 활성증가가 있었으며, 우측 전두피질부와 소뇌의 활성감소가 있었다. 이와 같은 사실은 특정 교수-학습 양식에 의해 학생이 경험하는 학습양식은 이와 관련된 학생의 특정 두뇌 시스템의 발달을 강화 혹은 약화 시킬 수 있게 된다는 것을 보여준다. 아울러 이러한 연구결과는 두뇌 맞춤형 과학적 분류 학습프로그램 개발을 위한 근거자료로 활용될 수 있을 것이다.

Role of Protein Kinases on NE-$_{\kappa}B$ Activation and Cell Death in Bovine Cerebral Endothelial Cells

  • Ahn, Young-Soo;Kim, Chul-Hoon;Kim, Joo-Hee
    • The Korean Journal of Physiology and Pharmacology
    • /
    • 제3권1호
    • /
    • pp.11-18
    • /
    • 1999
  • Nuclear factor $_{\kappa}B\;(NF-_{\kappa}B)$ activation is modulated by various protein kinases. Activation of $NF-_{\kappa}B$ is known to be important in the regulation of cell viability. The present study investigated the effect of inhibitors of protein tyrosine kinase (PTK), protein kinase C (PKC) and protein kinase A (PKA) on $NF-_{\kappa}B$ activity and the viability of bovine cerebral endothelial cells (BCECs). In serum-deprivation-induced BCEC death, low doses of $TNF{\alpha}$ showed a protective effect. $TNF{\alpha}$ induced $NF-_{\kappa}B$ activation within 4 h in serum-deprivation. PTK inhibitors (herbimycin A and genistein) and PKC inhibitor (calphostin C) prevented $NF-_{\kappa}B$ activation stimulated by $TNF{\alpha}.$ Likewise, these inhibitors prevented the protective effect of $TNF{\alpha}.$ In contrast to $TNF{\alpha}-stimulated\;NF-_{\kappa}B$ activity, basal $NF-_{\kappa}B$ activity of BCECs in media containing serum was suppressed only by calphostin C, but not by herbimycin A. As well BCEC death was also induced only by calphostin C in serum-condition. H 89, a PKA inhibitor, did not affect the basal and $TNF{\alpha}-stimulated\;NF-_{\kappa}B$ activities and the protective effect of $TNF{\alpha}$ on cell death. These data suggest that modulation of $NF-_{\kappa}B$ activation could be a possible mechanism for regulating cell viability by protein kinases in BCECs.

  • PDF