• 제목/요약/키워드: LTP

검색결과 124건 처리시간 0.03초

Long-term Synaptic Plasticity: Circuit Perturbation and Stabilization

  • Park, Joo Min;Jung, Sung-Cherl;Eun, Su-Yong
    • The Korean Journal of Physiology and Pharmacology
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    • 제18권6호
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    • pp.457-460
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    • 2014
  • At central synapses, activity-dependent synaptic plasticity has a crucial role in information processing, storage, learning, and memory under both physiological and pathological conditions. One widely accepted model of learning mechanism and information processing in the brain is Hebbian Plasticity: long-term potentiation (LTP) and long-term depression (LTD). LTP and LTD are respectively activity-dependent enhancement and reduction in the efficacy of the synapses, which are rapid and synapse-specific processes. A number of recent studies have a strong focal point on the critical importance of another distinct form of synaptic plasticity, non-Hebbian plasticity. Non-Hebbian plasticity dynamically adjusts synaptic strength to maintain stability. This process may be very slow and occur cell-widely. By putting them all together, this mini review defines an important conceptual difference between Hebbian and non-Hebbian plasticity.

학습과 기억에서 NMDA 수용체의 역할 (The Role of NMDA Receptor in Learning and Memory)

  • 김승현;신경호
    • 수면정신생리
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    • 제7권1호
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    • pp.10-17
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    • 2000
  • To investigate the neurobiological bases of learning and memory is one of the ambitious goals of modern neuroscience. The progress in this field of recent years has not only brought us closer to understanding the molecular mechanism underlying long-lasting changes in synaptic strength, but it has also provided further evidence that these mechanisms are required for memory formation. Since twenty years ago, several studies for the tests of the hypothesis that NMDA-dependent hippocampal long-term potentiation(LTP) underlies learning have been reported. Also, in the recent year, data from mutant mice showed that a potential role for NMDA-dependent LTP in hippocampal CA1 and spatial learning. Although the current evidence for the role of NMDA receptor in learning and memory is not still obvious, NMDA receptor seems to act as a critical switch for activation of a cascade of events that underlie synaptic plasticity.

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장거리이동 예측 모델링을 위한 우리나라의 $SO_2$ 및 NOx 배출량 산정 (Estimation of $SO_2$ and NOx Emissions for the Long-range transport Modeling in Korea)

  • 김정수;김록호;유철
    • 한국대기환경학회:학술대회논문집
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    • 한국대기환경학회 2000년도 추계학술대회 논문집
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    • pp.167-169
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    • 2000
  • 최근의 대기확산 모델링은 도시규모 뿐만 아니라 동북아지역의 대기오염물질 장거리이동 현상을 다루는 빈도가 매우 높아졌다. 모델링을 위해서는 기상자료와 배출량자료를 준비하는 것이 매우 중요한 과정이다. 본 연구에서는 우리나라 주도로 수행중인 '동북아 장거리이동 대기오염물질 공동 조사사업(LTP project)'과 관련하여 모델링분야의 공동 수행과제인 SO$_2$ 및 NOx 배출량 산정에 관한 것을 소개하였다. UNDP가 제안한 배출원 목록 수립방법을 이용하여 1998년에 대한 1$^{\circ}$$\times$ 1$^{\circ}$ 간격의 격자형 자료가 산정되었으며, 향후 LTP project의 모델링분야에서 활용될 예정이다. (중략)

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LTP계 결정화유리의 Ag이온교환에 따른 항균특성 (The Anti-Bacterial Properties of LTP Crystallized Glass by Ag Ion Exchange)

  • 권면주;윤영진;강원호
    • 한국산학기술학회논문지
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    • 제3권3호
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    • pp.183-188
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    • 2002
  • Antibacterial glass ceramics composed of $5Li_2O{\cdot}36CaO{\cdot}20TiO_2{\cdot}27P_2O_5$ were Prepared. After ion exchange in the $AgNO_3$solution, crystallization phases were $AgTi_2(PO_4)_3$, $LiTi_2(PO_4)_3$ and $Ca_3(PO_4)_2$. In case of ion exchange, the crystallization phases started to be transformed from $LiTi_2(PO_4)_3$ to $AgTi_2(PO_4)_3$in 0.5 mole $AgNO_3$ solution and the transformation was almost completed in 1.0 mole. ion exchange rate of glass-ceramics powder, considering ion exchange time, was more fast than that of bulk. The bacteriostatic effect of the glass-ceramics on Staphyloroccus aureus and Salmonella typhi bacteria was more excellent than that of glass when the crystallization phase was transformed from LTP to AgTP.

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DCCA 처리와 산소 저온플라즈마 처리가 양모직물의 형태안정성과 태에 미치는 영향 (Effect of Low Temperature Plasma and DCCA treatment on the Dimensional Stability and Hand of Wool Fabric)

  • 정영진
    • 한국염색가공학회지
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    • 제20권4호
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    • pp.43-52
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    • 2008
  • Wool fabric was treated with oxygen low-temperature plasma (LTP) and dichloroisocyanuric acid. The effect of dimensional stability (relaxation shrinkage, hygral expansion, felting shrinkage), tensile strength and elongation, crease recovery, and hand of wool fabric between LTP, DCCA treated wool fabrics and control wool fabric were investigated. SEM photograph showed that a little micro crack was formed on the fiber surface by plasma treatment with hard condition and epicuticle scale was damaged by DCCA treatment. Felting shrinkage, tensile strength and total hand value were much different in each samples.

$Na^+/Ca^{2+}$ exchanger (NCX)-2, a temporal factor in regulation of synaptic plasticity and cognition

  • Shin, Hee-Sup
    • 한국생물물리학회:학술대회논문집
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    • 한국생물물리학회 2003년도 정기총회 및 학술발표회
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    • pp.21-21
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    • 2003
  • The role of a postsynaptic rise of [C $a^{2+}$]$_{i}$ in the induction of LTP and LTD has been well established. Both the levels and the duration of elevated [C $a^{2+}$]$_{i}$ are important in synaptic plasticity. LTP and LTD could be selectively induced according to intracellular $Ca^{2+}$ concentration. Although the specificity of $Ca^{2+}$ signaling can be achieved not only by amplitude but also by the frequency and duration of the calcium transient, the effects of changing amplitudes of $Ca^{2+}$ transients on synaptic plasticity have been extensively documented, but not so the effects of temporal changes.changes..

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Microwave Ablation Treatment of Liver Cancer with a 2,450-MHz Cooled-shaft Antenna: Pilot Study on Safety and Efficacy

  • Jiao, De-Chao;Zhou, Qi;Han, Xin-Wei;Wang, Ya-Feng;Wu, Gang;Ren, Jian-Zhuang;Wang, Yan-Li;Ding, Peng-Xu;Ma, Ji;Fu, Ming-Ti
    • Asian Pacific Journal of Cancer Prevention
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    • 제13권2호
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    • pp.737-742
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    • 2012
  • To evaluate efficacy of microwave ablation in a primary clinical study, sixty patients (44 men, 16 women; mean age 53 years) with 96, 1-8 cm (mean $3.20{\pm}0.17$ cm) liver cancers were treated with 2,450-MHz internally cooled-shaft antenna. Complete ablation (CA) and local tumor progression (LTP) rates as well as complications were determined. CA rates in small (< 3.0 cm), intermediate (3.1-5.0 cm) and large (5.1-8.0 cm) liver cancers were 96.4% (54/56), 92.3% (24/26) and 78.6% (11/14), respectively. During a mean follow-up period of $17.17{\pm}6.52$ months, LTP occurred in five (5.21%) treated cases. There was no significant difference in the CA and LTP rates between the HCC and liver metastasis patient subgroups (P<0.05). Microwave ablation provides a reliable, efficient, and safe technique to perform hepatic tumor ablation.