A5002043304- Neuroscience and Neuropharmacology Research
- Ion channel regulation and function
- Neural dynamics and brain function
- Cardiac electrophysiology and arrhythmias
- Neuroscience and Neural Engineering
- Photoreceptor and optogenetics research
- Advanced Database Systems and Queries
- Mitochondrial Function and Pathology
- Data Management and Algorithms
- Memory and Neural Mechanisms
- Flood Risk Assessment and Management
- Image and Signal Denoising Methods
- Image Enhancement Techniques
- Neurogenesis and neuroplasticity mechanisms
- Advanced Image Processing Techniques
- Cannabis and Cannabinoid Research
- Pancreatic function and diabetes
- Neurotransmitter Receptor Influence on Behavior
- Receptor Mechanisms and Signaling
- Advanced Vision and Imaging
- Video Surveillance and Tracking Methods
- Diabetes Treatment and Management
- Multimedia Communication and Technology
- Peer-to-Peer Network Technologies
- Cardiac Ischemia and Reperfusion
Seoul National University
2013-2025
New Generation University College
2000-2025
Hyundai Pharm (South Korea)
2025
Dongseo University
2009-2024
Seoul National University Hospital
2012-2024
Asan Medical Center
2024
University of Ulsan
2024
Kyung Hee University
2023
National University College
2006-2023
Yonsei University
1998-2022
Parkinson disease (PD) involves the selective loss of midbrain dopamine (mDA) neurons and is a possible target for stem cell-based therapy. Human induced pluripotent cells (hiPSCs) are potentially unlimited source patient-specific transplantation. However, it critical to evaluate safety hiPSCs generated by different reprogramming methods. Here, we compared multiple hiPSC lines derived virus- protein-based human ES (hESCs). Neuronal precursor (NPCs) (DA) delivered from lentivirus-based...
We find the realization of large converse magnetoelectric (ME) effects at room temperature in a hexaferrite Ba0.52Sr2.48Co2Fe24O41 single crystal, which rapid change electric polarization low magnetic fields (about 5 mT) is coined to ME susceptibility 3200 ps/m. The modulation magnetization then reaches up 0.62μ(B)/f.u. an field 1.14 MV/m. further that four states induced by different poling exhibit unique, nonvolatile versus curves, can be approximately described effective free energy with...
Short-term facilitation of recurrent excitatory synapses within the cortical network has been proposed to support persistent activity during working memory tasks, yet underlying mechanisms remain poorly understood. We characterized short-term plasticity at local in layer 2/3 rat medial prefrontal cortex and studied its presynaptic mechanisms. Low-frequency stimulation induced slowly developing facilitation, whereas high-frequency initially strong depression followed by rapid facilitation....
kappaS1. The effect of parvalbumin (PV) on [Ca2+] transients was investigated by perfusing adrenal chromaffin cells with fura-2 and fluorescein isothiocyanate (FITC)-labelled PV. As PV diffused into cells, the decay transformed from monophasic biphasic. proportion initial fast phase increased in parallel fluorescence intensity FITC, indicating that is responsible for phase. relationship between level using depolarizing trains stimuli. Within a train relative amplitude inversely dependent...
The clearance of Ca 2+ from nerve terminals is critical for determining the build-up residual after repetitive presynaptic activity. We found previously that K + -dependent Na /Ca exchangers (NCKXs) show polarized distributions in axon supraoptic magnocellular neurons and play a major role clearance. NCKXs terminals, however, has not been studied. investigated contribution NCKX conjunction with other mechanisms at calyx Held by analyzing decay transients evoked depolarizing pulses....
Generation of induced pluripotent stem (iPS) cells has been intensively studied by a variety reprogramming methods, but the molecular and functional properties differentiated from iPS have not well characterized.To address this issue, we generated human aortic vascular smooth muscle (HASMCs) using lentiviral transduction defined transcription factors these back into (SMCs).Established were shown to possess equivalent embryonic cells, in terms cell surface markers, global mRNA microRNA...
Glutamatergic synaptic terminals harbor reluctant vesicles (SVs) that contribute little to synchronous release during action potentials but are competent when stimulated by sucrose or direct intracellular application of calcium. It has been noted the proximity a release-competent SV calcium source is one primary factors differentiate SVs from fast-releasing ones at calyx Held synapse. not known whether can be converted into ones. Here we show recruited rapidly in an actin-dependent manner...
Significance During sustained nerve activity, synapses must continuously recycle vesicles. We used the unique opportunities for quantitative analysis offered by calyx of Held synapse to study late stages in process that renders vesicles release-ready. dissect two sequential steps with distinct pharmacology and kinetics, characterization which is essential an understanding molecular mechanisms transmitter release short-term plasticity.
Alzheimer's disease (AD) in the early stages is characterized by memory impairment, which may be attributable to synaptic dysfunction. Oxidative stress, mitochondrial dysfunction, and Ca²⁺ dysregulation are key factors pathogenesis of AD, but causal relationship between these dysfunction not clearly understood. We found that hippocampus an AD mouse model (Tg2576), handling dentate granule cells was impaired as second postnatal month, this caused impairment post-tetanic potentiation mossy...
Leptin is a pivotal regulator of energy and glucose homeostasis, defects in leptin signaling result obesity diabetes. The ATP-sensitive potassium (K(ATP)) channels couple metabolism to insulin secretion pancreatic β-cells. In this study, we provide evidence that modulates β-cell functions by promoting K(ATP) channel translocation the plasma membrane via AMP-activated protein kinase (AMPK) signaling. were localized mostly intracellular compartments β-cells fed state translocated fasted state....
1 Endogenous calcium binding ratios (κS) in dendrites of cultured hippocampal neurons were estimated according to the single compartment model for transients intracellular Ca2+ concentration ([Ca2+]). In addition, electrophysiological characteristics classified by their autaptic currents and intrinsic firing patterns. These data analysed order determine whether a correlation between buffers type exists. 2 endogenous eliciting [Ca2+] with short depolarizations, while cells loaded fura-2. Two...
1. Stretch-activated channels (SACs) were studied in isolated rat atrial myocytes using the whole-cell and single-channel patch clamp techniques. Longitudinal stretch was applied by two electrodes. 2. In current configuration, mechanical of 20 % resting cell length depolarised membrane potential (RMP) from -63.6 +/- 0.58 mV (n = 19) to -54.6 2.4 13) prolonged action duration (APD) 32.2 8.8 ms 7). Depolarisation, if strong enough, triggered spontaneous APs. voltage increased conductance a...
In this paper, we propose a new level set-based partial differential equation (PDE) for the purpose of bimodal segmentation. The PDE is derived from an energy functional which modified version fitting term Chan-Vese model. designed to obtain stationary global minimum, i.e., set function evolves by Euler-Lagrange has unique convergence state. existence minimum makes algorithm invariant initialization function, whereas state it possible termination criterion on algorithm. Furthermore, since...
Background— Dimethyl lithospermate B (dmLSB) is an extract of Danshen, a traditional Chinese herbal remedy, which slows inactivation I Na , leading to increased inward current during the early phases action potential (AP). We hypothesized that this would be antiarrhythmic in setting Brugada syndrome. Methods and Results— The syndrome phenotype was created canine arterially perfused right ventricular wedge preparations with use either terfenadine or verapamil inhibit Ca pinacidil activate...
In this paper, we propose the use of Gauss curvature in a curvature-driven diffusion equation for noise removal. The proposed scheme uses as conductance term and controls amount diffusion. main advantage is that it preserves important structures, such straight edges, curvy ramps, corners, small-scaled features, etc.
The prolonged effects of N-methyl-D-aspartate (NMDA) receptor activation on the proliferation and differentiation hippocampal neural progenitor cells (NPCs) were studied. Under conditions mitogen-mediated proliferation, a single NMDA pulse (5 microM) increased fraction 5-bromo-2-deoxyuridine (BrdU)-positive (BrdU(+)) after delay 72 hours. Similarly, systemic injection (100 mg/kg) number BrdU(+) in dentate gyrus (DG) 28 days, but not 3 days. induced an immediate influx Ca(2+) into NPCs...
Previous studies indicate that boutons from the same axon exhibit distinct Ca 2+ dynamics depending on postsynaptic targets. Mossy fibers of hippocampal granule cells innervate synaptic targets via morphologically boutons. We investigated mitochondrial involvement in generation post-tetanic residual (Ca res ) at large and small en passant mossy fiber (MFBs). Mitochondria limited [Ca ] i build-up during high-frequency stimulation (HFS) MFBs, but not MFBs. The amount , quantified as a time...
At the immature calyx of Held, fast decay phase a Ca 2+ transient induced by tetanic stimulation (TS) was followed period elevated [Ca ] i for tens seconds, referred to as posttetanic residual calcium (Ca res ). We investigated source and its contribution potentiation (PTP). After TS (100 Hz 4 s), at Held largely abolished tetraphenylphosphonium (TPP + ) or Ru360, which inhibit mitochondrial Na -dependent efflux uniporter, respectively. Whereas control PTP lasted longer than , inhibition TPP...
OBJECTIVE AMP-activated protein kinase (AMPK) and the ATP-sensitive K+ (KATP) channel are metabolic sensors that become activated during stress. AMPK is an important regulator of metabolism, whereas KATP a cellular excitability. Cross talk between these systems poorly understood. RESEARCH DESIGN AND METHODS Rat pancreatic β-cells or INS-1 cells were pretreated for 2 h at various concentrations glucose. Maximum conductance (Gmax) was monitored by whole-cell measurements after intracellular...
Somatostatin improves visual perception by reducing excitatory inputs to the parvalbumin-positive interneurons in cortex.
Phosphatidylionsitol 4,5-bisphosphate (PIP(2)), a substrate of phospholipase C, has recently been recognized to regulate membrane-associated proteins and act as signal molecule in C-linked Gq-coupled receptor (GqPCR) pathways. However, it is not known whether PIP(2) depletion induced by GqPCRs can receptor-specific signals native cells. We investigated this issue cardiomyocytes where PIP(2)-dependent ion channels, G protein-gated inwardly rectifying K(+) (GIRK) background (IRK) various are...
We have shown previously that cardiac G protein-gated inwardly rectifying K + (GIRK) channels are inhibited by Gq protein-coupled receptors (GqPCRs) via phosphatidylinositol 4,5-bisphosphate (PIP 2 ) depletion in a receptor-specific manner. To investigate the mechanism of receptor specificity, we examined whether activation GqPCRs induces localized PIP depletion. When applied endothelin-1 to bath, GIRK channel activities recorded cell-attached patches were not changed, implying signal is...
It was recently discovered that a transparent $n$-type (Ba,La)SnO${}_{3}$ system has electrical mobility as high 320 cm${}^{2}$ V${}^{\ensuremath{-}1}$ s${}^{\ensuremath{-}1}$ at room temperature and superior thermal stability up to \ensuremath{\sim}500 \ifmmode^\circ\else\textdegree\fi{}C. To understand comparatively the carrier-scattering mechanism in doped BaSnO${}_{3}$, we investigate physical properties of single crystals BaSn${}_{1\ensuremath{-}x}$Sb${}_{x}$O${}_{3}$ ($x$ $=$ 0.03,...