Long-Term Potentiation of Excitatory Synaptic Strength in Spinothalamic Tract Neurons of the Rat Spinal Cord

허성원,박주민 대한약리학회 2013 The Korean Journal of Physiology & Pharmacology Vol.17 No.6

Spinal dorsal horn nociceptive neurons have been shown to undergo long-term synaptic plasticity,including long-term potentiation (LTP) and long-term depression (LTD). Here, we focused on the spinothalamic tract (STT) neurons that are the main nociceptive neurons projecting from the spinal cord to the thalamus. Optical technique using fluorescent dye has made it possible to identify the STT neurons in the spinal cord. Evoked fast mono-synaptic, excitatory postsynaptic currents (eEPSCs) were measured in the STT neurons. Time-based tetanic stimulation (TBS) was employed to induce long-term potentiation (LTP) in the STT neurons. Coincident stimulation of both pre- and postsynaptic neurons using TBS showed immediate and persistent increase in AMPA receptor-mediated EPSCs. LTP can also be induced by postsynaptic spiking together with pharmacological stimulation using chemical NMDA. TBS-induced LTP observed in STT neurons was blocked by internal BAPTA, or Ni2+, a T-type VOCC blocker. However, LTP was intact in the presence of L-type VOCC blocker. These results suggest that long-term plastic change of STT neurons requires NMDA receptor activation and postsynaptic calcium but is differentially sensitive to T-type VOCCs.

Long-Term Potentiation of Excitatory Synaptic Strength in Spinothalamic Tract Neurons of the Rat Spinal Cord

Sung Won Hur,Joo Min Park 대한생리학회-대한약리학회 2013 The Korean Journal of Physiology & Pharmacology Vol.17 No.6

Spinal dorsal horn nociceptive neurons have been shown to undergo long-term synaptic plasticity, including long-term potentiation (LTP) and long-term depression (LTD). Here, we focused on the spino-thalamic tract (STT) neurons that are the main nociceptive neurons projecting from the spinal cord to the thalamus. Optical technique using fluorescent dye has made it possible to identify the STT neurons in the spinal cord. Evoked fast mono-synaptic, excitatory postsynaptic currents (eEPSCs) were measured in the STT neurons. Time-based tetanic stimulation (TBS) was employed to induce long-term potentiation (LTP) in the STT neurons. Coincident stimulation of both pre- and postsynaptic neurons using TBS showed immediate and persistent increase in AMPA receptor-mediated EPSCs. LTP can also be induced by postsynaptic spiking together with pharmacological stimulation using chemical NMDA. TBS-induced LTP observed in STT neurons was blocked by internal BAPTA, or Ni²⁺, a T-type VOCC blocker. However, LTP was intact in the presence of L-type VOCC blocker. These results suggest that long-term plastic change of STT neurons requires NMDA receptor activation and postsynaptic calcium but is differentially sensitive to T-type VOCCs.

Long-Term Potentiation of Excitatory Synaptic Strength in Spinothalamic Tract Neurons of the Rat Spinal Cord

Hur, Sung Won,Park, Joo Min The Korean Society of Pharmacology 2013 The Korean Journal of Physiology & Pharmacology Vol.17 No.6

Spinal dorsal horn nociceptive neurons have been shown to undergo long-term synaptic plasticity, including long-term potentiation (LTP) and long-term depression (LTD). Here, we focused on the spinothalamic tract (STT) neurons that are the main nociceptive neurons projecting from the spinal cord to the thalamus. Optical technique using fluorescent dye has made it possible to identify the STT neurons in the spinal cord. Evoked fast mono-synaptic, excitatory postsynaptic currents (eEPSCs) were measured in the STT neurons. Time-based tetanic stimulation (TBS) was employed to induce long-term potentiation (LTP) in the STT neurons. Coincident stimulation of both pre- and postsynaptic neurons using TBS showed immediate and persistent increase in AMPA receptor-mediated EPSCs. LTP can also be induced by postsynaptic spiking together with pharmacological stimulation using chemical NMDA. TBS-induced LTP observed in STT neurons was blocked by internal BAPTA, or $Ni^{2+}$, a T-type VOCC blocker. However, LTP was intact in the presence of L-type VOCC blocker. These results suggest that long-term plastic change of STT neurons requires NMDA receptor activation and postsynaptic calcium but is differentially sensitive to T-type VOCCs.

공공요양병원의 효율성 분석

박성훈 ( Sung Hun Park ),백승권 ( Seung Kwon Baek ),김대철 ( Dae Cheol Kim ) 대한설비관리학회 2016 대한설비관리학회지 Vol.21 No.2

This study analyzes the efficiency of public long-term care hospitals that are mostly in operation under the government consignment. Using the Data Envelopment Analysis (DEA), the study finds the overall relative efficiencies of public long-term care hospitals and identifies the causes of inefficiency in terms of size and pure technical efficiency. For the nationwide expansion of public long-term care hospitals in the future, the study also provides the identification of the relationships between the potential demands on the public long-term care hospitals in the local communities and efficiencies of those hospitals. To do these, the efficiencies of 58 public long-term care hospitals are analyzed. The results of the CCR and BCC models show that the overall efficiency of public long-term care hospitals is relatively low with an average of 0.62. It is also verified that the potential demand on the public long-term care hospitals in the local community affects the efficiency of the hospitals.

Long-term Synaptic Plasticity: Circuit Perturbation and Stabilization

Park, Joo Min,Jung, Sung-Cherl,Eun, Su-Yong The Korean Society of Pharmacology 2014 The Korean Journal of Physiology & Pharmacology Vol.18 No.6

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.

Glucocorticoid- and long-term stress-induced aberrant synaptic plasticity are mediated by activation of the glucocorticoid receptor

박혜진,이승헌,정지욱,김병채,류종훈,김동현 대한약학회 2015 Archives of Pharmacal Research Vol.38 No.6

Long-term stress is known to cause aberrantsynaptic plasticity and to impair learning and memory. Recent studies show that acute high concentration of glucocorticoidsexerts similar effects to those of long-termstress. In the present study, we conducted an electrophysiologicalstudy, western blot analysis, and behavioral study toexamine whether long-term stress and acute high concentrationof corticosterone share common mechanisms. Acutecorticosterone (1 lM) impaired LTP in the acute hippocampalslices, and this impairment was blocked by RU486, aglucocorticoid receptor (GR) antagonist. In the two-weekrestraint stress-treated rats, object recognition memory andhippocampal LTP were impaired and these impairmentswere restored by RU486 co-treatment. Moreover, thehippocampal BDNF level was also significantly reduced inthe corticosterone- or long-term stress-treated hippocampusand restored by RU486 co-treatment. These results suggestthat corticosterone and long-term stress induce aberrantsynaptic plasticity, memory impairment, and reduction inthe hippocampal BDNF level through GR activation. Takentogether, we suggest that acute high concentration of glucocorticoid-induced LTP impairment study may be a goodtool for screening the treatments for stress-induced psychiatricdisorders including memory impairment.

Induction of long-term potentiation and long-term depression is cell-type specific in the spinal cord

Kim, Hee Young,Jun, Jaebeom,Wang, Jigong,Bittar, Alice,Chung, Kyungsoon,Chung, Jin Mo Wolters Kluwer 2015 Pain Vol.156 No.4

<▼1><P>This study shows that the direction of synaptic plastic changes in the spinal cord is cell-type specific in response to nociceptive input.</P></▼1><▼2><P><B>Abstract</B></P><P>The underlying mechanism of chronic pain is believed to be changes in excitability in spinal dorsal horn (DH) neurons that respond abnormally to peripheral input. Increased excitability in pain transmission neurons, and depression of inhibitory neurons, are widely recognized in the spinal cord of animal models of chronic pain. The possible occurrence of 2 parallel but opposing forms of synaptic plasticity, long-term potentiation (LTP) and long-term depression (LTD) was tested in 2 types of identified DH neurons using whole-cell patch-clamp recordings in mouse spinal cord slices. The test stimulus was applied to the sensory fibers to evoke excitatory postsynaptic currents in identified spinothalamic tract neurons (STTn) and GABAergic neurons (GABAn). Afferent conditioning stimulation (ACS) applied to primary afferent fibers with various stimulation parameters induced LTP in STTn but LTD in GABAn, regardless of stimulation parameters. These opposite responses were further confirmed by simultaneous dual patch-clamp recordings of STTn and GABAn from a single spinal cord slice. Both the LTP in STTn and the LTD in GABAn were blocked by an NMDA receptor antagonist, AP5, or an intracellular Ca<SUP>2+</SUP> chelator, BAPTA. Both the pattern and magnitude of intracellular Ca<SUP>2+</SUP> after ACS were almost identical between STTn and GABAn based on live-cell calcium imaging. The results suggest that the intense sensory input induces an NMDA receptor-dependent intracellular Ca<SUP>2+</SUP> increase in both STTn and GABAn, but produces opposing synaptic plasticity. This study shows that there is cell type–specific synaptic plasticity in the spinal DH.</P></▼2>

Implementation of Memristive Bioelectronics Device for Synapse and Plasticity

주바에르 이브네 만난,김형석 제어로봇시스템학회 2020 제어로봇시스템학회 국내학술대회 논문집 Vol.2020 No.7

This paper represents a memristive bioelectronics device that imitates the bio-realistic behavior and plasticity of biological synapse. Especially, the proposed architecture exhibits synaptic plasticity of synapse (one of the important neurochemical foundations for learning and memory) which is demonstrated via effective and efficient imitation of shortterm plasticity (short-term facilitation (STF), short-term depression (STD)) and long-term plasticity (long-term potentiation (LTP), long-term depression (LTD)). Moreover, the memristive artificial circuit mimics the distinct biorealistic attributes (such as strong stimulation, exponentially decaying conductance trace of synapse, and voltage dependent synaptic responses) of a neuron. The proposed bioelectronics model is designed in SPICE and the bio-realistic functionalities are demonstrated via various simulations.

Long-term Synaptic Plasticity: Circuit Perturbation and Stabilization

박주민,정성철,은수용 대한약리학회 2014 The Korean Journal of Physiology & Pharmacology Vol.18 No.6

At central synapses, activity-dependent synaptic plasticity has a crucial role in information processing,storage, learning, and memory under both physiological and pathological conditions. Onewidely accepted model of learning mechanism and information processing in the brain is HebbianPlasticity: long-term potentiation (LTP) and long-term depression (LTD). LTP and LTD are respectivelyactivity-dependent enhancement and reduction in the efficacy of the synapses, which are rapid andsynapse-specific processes. A number of recent studies have a strong focal point on the criticalimportance of another distinct form of synaptic plasticity, non-Hebbian plasticity. Non-Hebbianplasticity dynamically adjusts synaptic strength to maintain stability. This process may be very slowand occur cell-widely. By putting them all together, this mini review defines an important conceptualdifference between Hebbian and non-Hebbian plasticity.

Long-term Synaptic Plasticity: Circuit Perturbation and Stabilization

Joo Min Park,Sung-Cherl Jung,Su-Yong Eun 대한생리학회-대한약리학회 2014 The Korean Journal of Physiology & Pharmacology Vol.18 No.6

At central synapses, activity-dependent synaptic plasticity has a crucial role in information pro-cessing, 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.