• 제목/요약/키워드: Brain Research

검색결과 3,371건 처리시간 0.037초

Nano-Resolution Connectomics Using Large-Volume Electron Microscopy

  • Kim, Gyu Hyun;Gim, Ja Won;Lee, Kea Joo
    • Applied Microscopy
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    • 제46권4호
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    • pp.171-175
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    • 2016
  • A distinctive neuronal network in the brain is believed to make us unique individuals. Electron microscopy is a valuable tool for examining ultrastructural characteristics of neurons, synapses, and subcellular organelles. A recent technological breakthrough in volume electron microscopy allows large-scale circuit reconstruction of the nervous system with unprecedented detail. Serial-section electron microscopy-previously the domain of specialists-became automated with the advent of innovative systems such as the focused ion beam and serial block-face scanning electron microscopes and the automated tape-collecting ultramicrotome. Further advances in microscopic design and instrumentation are also available, which allow the reconstruction of unprecedentedly large volumes of brain tissue at high speed. The recent introduction of correlative light and electron microscopy will help to identify specific neural circuits associated with behavioral characteristics and revolutionize our understanding of how the brain works.

Effects of National Gymnastics and Brain Gymnastics on Frontal Lobe Activity

  • Jeon, Kyung Hee
    • 국제물리치료학회지
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    • 제6권2호
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    • pp.896-901
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    • 2015
  • The effects of national gymnastics and brain gymnastics on brain activity were analyzed in 20 healthy university students. The students were assigned to either a national gymnastics group or a brain gymnastics group. Their frontal lobe activity was recorded before and after the exercise, and the resting, attention, and concentration indexes of brain waves were measured. The resting index significantly decreased and concentration index significantly increased(p<.05) after the exercise in both the national and brain gymnastics groups. However, the attention index significantly increased only after brain gymnastics, and, on the contrary, decreased after national gymnastics. These findings suggest that brain gymnastics is effective for improving attention.

Cerebellar maturation ratio of forebrain and brainstem at magnetic resonance imaging in the micropig

  • Yi, Kang-Jae;Kim, Jun-Young;Lee, Namsoon;Choi, Mihyun;Yoon, Jung-Hee;Choi, Min-Cheol
    • 대한수의학회지
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    • 제52권2호
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    • pp.83-87
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    • 2012
  • The study of pigs as a human disease model has been conducted in neuroscience. But the morphological development of pig brain by using MRI is rare. The purpose of this study is to determine whether cerebellum maintains consistent proportion to other brain regions in aging. Clinically healthy sixteen micropigs, 1, 2, 4, and 8 months were studied. The micropigs were anesthetized with isoflorane. MRI was acquired using a 0.3T system. To figure out development of ratio that allowed identification of normal cerebellum size, we measured the area of the cerebellum, brainstem, and forebrain from the mid-sagittal brain images on T1W. Mid-sagittal cross-sectional area (CSA) of total brain, forebrain, brainstem, and cerebellum were expressed as absolute values and also as percentages which were compared between the four age groups of micropigs for the purpose to define the effect of age on brain morphometry. It was found that there was not a significant difference in the percentage of the brain occupied by an individual region between groups although the absolute CSA differed significantly among age groups. There was no effect of age on the ratio between the cerebellum and total brain in 4 age groups. The normal size of cerebellum changes during brain development maintained a consistent ratio to other brain regions in normal micropigs. The ratio of CSA quantified on the mid-sagittal MR images offers a suitable method to detect presence of cerebellar anomalies in micropigs.

Functional Analysis of the Stress-Inducible Soybean Calmodulin Isoform-4 (GmCaM-4) Promoter in Transgenic Tobacco Plants

  • Park, Hyeong Cheol;Kim, Man Lyang;Kang, Yun Hwan;Jeong, Jae Cheol;Cheong, Mi Sun;Choi, Wonkyun;Lee, Sang Yeol;Cho, Moo Je;Kim, Min Chul;Chung, Woo Sik;Yun, Dae-Jin
    • Molecules and Cells
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    • 제27권4호
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    • pp.475-480
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    • 2009
  • The transcription of soybean (Glycine max) calmodulin isoform-4 (GmCaM-4) is dramatically induced within 0.5 h of exposure to pathogen or NaCl. Core cis-acting elements that regulate the expression of the GmCaM-4 gene in response to pathogen and salt stress were previously identified, between -1,207 and -1,128 bp, and between -858 and -728 bp, in the GmCaM-4 promoter. Here, we characterized the properties of the DNA-binding complexes that form at the two core cis-acting elements of the GmCaM-4 promoter in pathogen-treated nuclear extracts. We generated GUS reporter constructs harboring various deletions of approximately 1.3-kb GmCaM-4 promoter, and analyzed GUS expression in tobacco plants transformed with these constructs. The GUS expression analysis suggested that the two previously identified core regions are involved in inducing GmCaM-4 expression in the heterologous system. Finally, a transient expression assay of Arabidopsis protoplasts showed that the GmCaM-4 promoter produced greater levels of GUS activity than did the CaMV35S promoter after pathogen or NaCl treatments, suggesting that the GmCaM-4 promoter may be useful in the production of conditional gene expression systems.

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.

EST-based Identification of Genes Expressed in the Brain of the Olive Flounder Paralichthys olivaceus

  • Lee, Jeong-Ho;Noh, Jae-Koo;Kim, Hyun-Chul;Park, Choul-Ji;Min, Byung-Hwa;Kim, Young-Ok;Kim, Jong-Hyun;Kim, Kyung-Kil;Kim, Woo-Jin;Myeong, Jeong-In
    • Fisheries and Aquatic Sciences
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    • 제12권4호
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    • pp.286-292
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    • 2009
  • We have constructed a cDNA library using brain samples of olive flounder Paralichthys olivaceus. Here, we described the study on gene identification by screening 356 clones from the brain cDNA library of olive flounder. Here, we screened 356 clones from the library to identify genes. Of these, 176 (49.5%) were identified as orthologs of known genes from olive flounder and other organisms. Among the 176 EST clones, 33 (18.7%) represented 11 unique genes that are identical to expressed sequence tags (ESTs) reported for olive flounder, and 120 (68.2%) represented 102 unique genes known from other organisms. The percentage of unknown genes (50.5%) is higher than in other olive flounder cDNA libraries (Lee et al., 2003, 2006, 2007), reflecting the high complexity of brain tissue. Further studies of expression characterization and developmental behavior related to these genes should provide useful insight into the physiological functions of the brain in olive flounder.

No Late Effect of Ionizing Radiation on the Aging-Related Oxidative Changes in the Mouse Brain

  • Jang, Beom-Su;Kim, Seolwha;Jung, Uhee;Jo, Sung-Kee
    • 방사선산업학회지
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    • 제4권3호
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    • pp.203-207
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    • 2010
  • Radiation-induced late injury to normal tissue is a primary area of radiation biology research. The present study was undertaken to investigate whether the late effect of the ionizing radiation appears as an age-related oxidative status in the brain. Three groups of 4-month old C57BL/6 mice that were exposed to $^{137}Cs$ ${\gamma}-rays$ at a single dose (5 Gy) or fractionated doses ($1Gy{\times}5times$, or $0.2Gy{\times}25times$) at 2 months old were investigated for the oxidative status of their brains with both young (2-month) and old (24-month) mice. A significant (p<0.05) decrease in superoxide dismutase (SOD) activity was observed in old mice brains compared with that of the young mice. malondialdehyde (MDA) content was significantly (p<0.05) increased in the old mice brain. However, any significant difference in SOD activity and MDA contents of the irradiated brain was not observed compared to age-matched control group mice. SOD activity and MDA content were observed within good parameters of brain aging and there were no late effects on the age-related oxidative level in the ${\gamma}-ray$ irradiated mice brains.

Developmental Disability Animal Model Based on Neonatal Lipopolysaccharide with Altered 5-HT Function

  • Kim, Jae-Goo;Kim, Min-Soo;Lee, Se-Oul;Kim, Gun-Tae;Lee, Jong-Doo;Kim, Dong-Goo
    • The Korean Journal of Physiology and Pharmacology
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    • 제11권3호
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    • pp.113-119
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    • 2007
  • Developmental disability shows life-long behavioral abnormality with no significant physical malformation. This study was undertaken to develop an animal model for developmental disability by using two-factor approach. Lipopolysaccharide (LPS), a bacterial toxin, and NAN-190, a $5-HT_{1A}$ receptor antagonist, were administered to Sprague-Dawley rats on postnatal day (PND) 5 to induce inflammation and an altered 5-HT system, respectively. Long-term alteration of behavior occurred in the drug-treated groups. The LPS-treated group showed impaired motor coordination in the Rota-rod test. The LPS- treated or both LPS and NAN-190-treated groups showed impaired fore-paw muscle power in the wire maneuver test. These groups also showed decreased white matter volume and increased serotonergic fibers. The LPS and NAN-190-treated group also exhibited neurologic deficit in the placing reaction test and impaired equilibrium function in the tilt table test. The results showed that a variety of altered behaviors can be generated by two factor model, and suggested that combination of important etiologic factors and possible underlying defects is a promising strategy of establishing an animal model for developmental disabilities.

뇌활용성향과 기업경영 : 이병철회장과 정주영회장을 통한 탐험적 추론 (Brain Preference and Management : An Exploratory Reasoning from the Founders of Samsung and Hyundai Group, Lee and Chung)

  • 이홍
    • 한국경영과학회지
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    • 제30권1호
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    • pp.105-128
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    • 2005
  • The Purpose of the current study is to identify the differences between Samsung and Hyundai Group and the causes why the differences occurred. The study focuses on the founders of the two group as a main source of the differences, especially brain preference of the two founders. Two steps were employed to perform the study. Firstly, the two founders' characteristics were analyzed by using archival research. It was implicitly hypothesized that Group founders' characteristics explained the differences of the two Groups. It was found that the founder of Samsung Group, the late president Lee emphasized rationality, analysis, and cause/effect relationship and low risk taking, suggesting that he had left-brain preference. In contrast. the late president Chung, the founder of Hyundai Group, emphasized intuition, wholeness, contextual meaning, and risk taking, showing that he had right-brain preference. Secondly, a comparison between the two groups was performed in terms of business and financial risk in corporate portfolio, and management system. It was found that Hyundai Group was pursuing higher risk than Samsung Group. And it was observed that Samsung Group put more emphasis on formality in decision making and systematic control, and less emphasis on risk taking than Hyundai Group. From the two step research relationship between brian preference and management was reasoned. Research implications and limitations were discussed at the end of the study.