• Proceedings of the Zoological Society Korea Conference
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• 2003.08a
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• pp.178.1-178
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• 2003

No Abstract, See Full Text

• Molecules and Cells
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• v.41 no.5
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• pp.373-380
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• 2018

Synapses and neural circuits form with exquisite specificity during brain development to allow the precise and appropriate flow of neural information. Although this property of synapses and neural circuits has been extensively investigated for more than a century, molecular mechanisms underlying this property are only recently being unveiled. Recent studies highlight several classes of cell-surface proteins as organizing hubs in building structural and functional architectures of specific synapses and neural circuits. In the present minireview, we discuss recent findings on various synapse organizers that confer the distinct properties of specific synapse types and neural circuit architectures in mammalian brains, with a particular focus on the hippocampus and cerebellum.

• Natural Product Sciences
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• v.13 no.2
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• pp.101-104
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• 2007

Four isoflavones including tectorigenin (1), irisflorentin (2), irigenin (3), and tectoridin (4) have been isolated from the 70% EtOH extract of Belamcanda chinensis rhizome. The evaluation for protective effect of compounds 1-4 against glutamate-induced cytotoxicity in hippocampal HT22 cell line was conducted. Compound 1 showed significant protective effect with an EC$_{50}$ value of 67.25 ${\pm}$ 1.2 ${\mu}$M, whereas compounds 2-4 were inactive. These results suggest that compound 1 may possess the neuroprotective activity against oxidative cellular injures.

• Journal of Microbiology and Biotechnology
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• v.29 no.9
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• pp.1369-1374
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• 2019

We isolated Lactobacillus mucosae NK41 and Bifidobacterium longum NK46 from human feces, which induced BDNF expression in corticosterone-stimulated SH-SY5Y cells, and examined their anti-depressive effects in mice. NK41, NK46, and their (1:1) mixture significantly mitigated immobilization stress (IS)-induced anxiety-like/depressive behaviors, hippocampal $NF-{\kappa}B$ activation, BDNF expression, $Iba1^+$ cell population, and blood corticosterone, $TNF-{\alpha}$, IL-6, and lipopolysaccharide levels. Furthermore, they inhibited colitis marker $NF-{\kappa}B$ activation, and $TNF-{\alpha}$ expression in mice with IS-induced anxiety/depression. They additionally suppressed gut Proteobacteria and Bacteroidetes populations and bacterial lipopolysaccharide production. These findings suggest that NK41 and NK46 may alleviate anxiety/depression and colitis by suppressing gut dysbiosis.

• Animal cells and systems
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• v.15 no.4
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• pp.279-286
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• 2011

Hypoxic ischemia injury is a common cause of functional brain damage, resulting from a decrease in cerebral blood flow and oxygen supply to the brain. The main problems associated with hypoxic ischemia to the brain are memory impairment and dopamine dysfunction. Hypothermia has been suggested to ameliorate the neurological impairment induced by various brain insults. In this study, we investigated the effects of hypothermia on memory function and dopamine synthesis following hypoxic ischemia to the brain in rats. For this purpose, a step-down avoidance task, a radial eight-arm maze task, and immunohistochemistry for tyrosine hydroxylase (TH) and 5-bromo-2'-deoxyuridine (BrdU) were performed. The present results indicated that the hypoxic ischemia-induced disturbance of the animal's performances and spatial working memory was associated with a decrement in TH expression in the substantia nigra and striatum, and an increase in cell proliferation in the hippocampal dentate gyrus. Hypothermia treatment improved the animals' performance and spatial working memory by suppressing the decrement in TH expression in the substantia nigra and striatum and the increase in cell proliferation in the dentate gyrus. We suggest that hypothermia can be an efficient therapeutic modality to facilitate recovery following hypoxic ischemia injury to the brain, presumably by modulating the dopaminergic cell loss.

• The Journal of Korean Medicine
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• v.39 no.3
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• pp.1-16
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• 2018

Objectives: The purpose of this study was to investigate the effects of 56 herbal formulae covered by the National Health Insurance Corporation (NHIC) on dementia-related biomarkers and neuronal cell changes. Methods: The 56 herbal formulae were extracted with 70% ethanol at $100^{\circ}C$ for 2 h. The antioxidant properties was measured by radical scavenging assay using ABTS+ radical. The acetylcholinesterase (AChE) activity was tested by Ellman's assay and $amyloid-{\beta}$ ($A{\beta}$) aggregation was determined using fluorescence method. To estimate the inhibitory effects of herbal formulae on neuronal cell death and inflammation using HT22 hippocampal cells and BV-2 microglia, respectively. Results: Among the 56 herbal formulae, Dangguiyukhwangtang, Banhasasimtang, Samhwangsasimtang, Cheongwiesan, Hwangryunhaedoktang, Banhabaekchulchunmatang, Jaeumganghwatang, Cheongseoikgitang, and Hoechunyanggyuksan has a significant inhibitory effects on acetylcholinesterase (AChE) activity. Doinseunggitang and Samhwangsasimtang exerted the effect on the inhibition of $amyloid-{\beta}$ ($A{\beta}$) aggregation. Additionally, 10 herbal formulae affected AChE and $A{\beta}$ aggregation revealed antioxidant activity as well as neuroprotective and anti-neuroinflammation effects in neuronal cell lines. Conclusions: 10 herbal formulae that have been shown to be effective against the major dementia markers have been shown to have antioxidant activity, neuronal cell protection and inhibition of brain inflammation. Further investigation of these herbal formulae will need to be validated in dementia animal models.

• Journal of Acupuncture Research
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• v.18 no.6
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• pp.206-214
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• 2001

The purpose of this study was to determine the effects of Puerariae flos herb-acupuncture on hippocampal neural cell proliferation. Sprague-Dawley rats were randomly assigned into 4 groups; control group, control with herb-acupuncture group, alcohol group, alcohol with herb-acupuncture group group. Control groups were received with NaCl, while alcohol intoxication groups were injected intraperitoneally with alcohol (2 g/㎏) twice per day for 3 days. Herb-acupuncture groups were injected on Zhongwan (CV 12) for 5 consecutive days. Bromo-deoxyuridine (BrdU) was injected into all animal per day for 5 days. For the detection of BrdU-positive cells in dentate gyrus of hippocampus, immunohistochemistry was performed. In alcohol group, a significant decrease in BrdU-positive cells was observed compared to control group. In alcohol with herb-acupuncture group, BruU-positive cells increased significantly compared to alcohol group. In conclusion, the present results revealed that new cell proliferation is enhanced in the dentate gyros of young Sprague-Dawley rats through Puerariae flos herb-acpuncuture in an acute alcoholic intoxication condition.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.08a
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• pp.277.2-277.2
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• 2013

Petri dishes and glass slides have been widely used as general substrates for in vitro mammalian cell cultures due to their culture viability, optical transparency, experimental convenience, and relatively low cost. Despite the aforementioned benefit, however, the flat two-dimensional substrates exhibit limited capability in terms of realistically mimicking cellular polarization, intercellular interaction, and differentiation in the non-physiological culture environment. Here, we report a protocol of culturing embryonic rat hippocampal neurons on the electro-spun polymeric network and the results from examination of neuronal cell behavior and network formation on this culture platform. A combinatorial method of laser-scanning confocal fluorescence microscopy and live-cell imaging technique was employed to track axonal outgrowth and synaptic connectivity of the neuronal cells deposited on this model culture environment. The present microfiber-based scaffold supports the prolonged viability of three-dimensionally-formed neuronal networks and their microscopic geometric parameters (i.e., microfiber diameter) strongly influence the axonal outgrowth and synaptic connection pattern. These results implies that electro-spun fiber scaffolds with fine control over surface chemistry and nano/microscopic geometry may be used as an economic and general platform for three-dimensional mammalian culture systems, particularly, neuronal lineage and other network forming cell lines.

• The Korean Journal of Physiology and Pharmacology
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• v.21 no.2
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• pp.259-265
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• 2017

Excessive influx and the subsequent rapid cytosolic elevation of $Ca^{2+}$ in neurons is the major cause to induce hyperexcitability and irreversible cell damage although it is an essential ion for cellular signalings. Therefore, most neurons exhibit several cellular mechanisms to homeostatically regulate cytosolic $Ca^{2+}$ level in normal as well as pathological conditions. Delayed rectifier $K^+$ channels ($I_{DR}$ channels) play a role to suppress membrane excitability by inducing $K^+$ outflow in various conditions, indicating their potential role in preventing pathogenic conditions and cell damage under $Ca^{2+}$-mediated excitotoxic conditions. In the present study, we electrophysiologically evaluated the response of $I_{DR}$ channels to hyperexcitable conditions induced by high $Ca^{2+}$ pretreatment (3.6 mM, for 24 hours) in cultured hippocampal neurons. In results, high $Ca^{2+}$-treatment significantly increased the amplitude of $I_{DR}$ without changes of gating kinetics. Nimodipine but not APV blocked $Ca^{2+}$-induced $I_{DR}$ enhancement, confirming that the change of $I_{DR}$ might be targeted by $Ca^{2+}$ influx through voltage-dependent $Ca^{2+}$ channels (VDCCs) rather than NMDA receptors (NMDARs). The VDCC-mediated $I_{DR}$ enhancement was not affected by either $Ca^{2+}$-induced $Ca^{2+}$ release (CICR) or small conductance $Ca^{2+}$-activated $K^+$ channels (SK channels). Furthermore, PP2 but not H89 completely abolished $I_{DR}$ enhancement under high $Ca^{2+}$ condition, indicating that the activation of Src family tyrosine kinases (SFKs) is required for $Ca^{2+}$-mediated $I_{DR}$ enhancement. Thus, SFKs may be sensitive to excessive $Ca^{2+}$ influx through VDCCs and enhance $I_{DR}$ to activate a neuroprotective mechanism against $Ca^{2+}$-mediated hyperexcitability in neurons.

• Journal of Oriental Neuropsychiatry
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• v.22 no.2
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• pp.163-176
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• 2011

Objectives : BCS(Bambusae concretio silicae) is used as a traditional medicine in Korea for the incipient stroke. Recent reports indicated that BCS has a neuroprotective effect by anti-convulsion effect. However, it's mechanism is not well studied. The purpose of this study was to investigate into the molecular mechanism of BCS for neuroprotection in normoxia of cultured rat hippocampal neurons. Methods : BCS (1.0, 2.5, 5.0, and $10.0\;{\mu}g/m{\ell}$) was added to culture media (Neurobasal supplemented with B27) on DIV 0, given a normoxia, and the cell viability was measured by typical phase-contrast images of the cultures with 1.0, 2.5, 5.0, and $10.0\;{\mu}g/m{\ell}$ on DIV 21. Effects of BCS on the expression of various synaptic proteins ($GABA_B$ R1, $GABA_B$ R2, GlyR, PSD95) were observed by immunocytochemistry showing on DIV 3, 7 and 21. Results : Typical phase-contrast images of the cultures indicated that BCS has a protective effect of rat hippocampal cells in normoxia. The BCS upregulated $GABA_B$ R1 after normoxia on DIV 7, $GABA_A$ ${\beta}2/3$ on DIV 21 and $GABA_B$ R2 on DIV 21. And the BCS downregulated PSD95 after normoxia on DIV 7. Conclusions : The present study showed evidence for the efficacy of BCS in Typical phase-contrast images, upregulation of inhibitory neurotransmitter receptors($GABA_B$ R1) and downregulation of PSD95 which eventually protected neuronal cell death in normoxia.