• Journal of Korean Neurosurgical Society
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• v.49 no.1
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• pp.1-7
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• 2011

Objective: Glutamate is a key excitatory neurotransmitter in the brain, and its excessive release plays a key role in the development of neuronal injury. In order to define the effect of nimodipine on glutamate release, we monitored extracellular glutamate release in real-time in a global ischemia rat model with eleven vessel occlusion. Methods: Twelve rats were randomly divided into two groups: the ischemia group and the nimodipine treatment group. The changes of extracellular glutamate level were measured using microdialysis amperometric biosensor, in coincident with cerebral blood flow (CBF) and electroencephalogram. Nimodipine (0.025 ${\mu}g$/100 gm/min) was infused into lateral to the CBF probe, during the ischemic period. Also, we performed Nissl staining method to assess the neuroprotective effect of nimodipine. Results: During the ischemic period, the mean maximum change in glutamate concentration was $133.22{\pm}2.57\;{\mu}M$ in the ischemia group and $75.42{\pm}4.22\;{\mu}M$ (p<0.001) in the group treated with nimodipine. The total amount of glutamate released was significantly different (P<0.001) between groups during the ischemic period. The %cell viability in hippocampus was $47.50{\pm}5.64$ (p<0.005) in ischemia group, compared with sham group. But, the %cell viability in nimodipine treatment group was $95.46{\pm}6.60$ in hippocampus (p<0.005). Conclusion: From the real-time monitoring and Nissl staining results, we suggest that the nimodipine treatment is responsible for the protection of the neuronal cell death through the suppression of extracellular glutamate release in the 11-VO global ischemia model of rat.

• The Korean Journal of Physiology and Pharmacology
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• v.28 no.3
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• pp.239-252
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• 2024

Dexmedetomidine displays multiple mechanisms of neuroprotection in ameliorating ischemic brain injury. In this study, we explored the beneficial effects of dexmedetomidine on blood-brain barrier (BBB) integrity and neuroinflammation in cerebral ischemia/reperfusion injury. Sprague-Dawley rats were subjected to middle cerebral artery occlusion (MCAO) for 1.5 h and reperfusion for 24 h to establish a rat model of cerebral ischemia/reperfusion injury. Dexmedetomidine (9 ㎍/kg) was administered to rats 30 min after MCAO through intravenous injection, and SB203580 (a p38 MAPK inhibitor, 200 ㎍/kg) was injected intraperitoneally 30 min before MCAO. Brain damages were evaluated by 2,3,5-triphenyltetrazolium chloride staining, hematoxylin-eosin staining, Nissl staining, and brain water content assessment. BBB permeability was examined by Evans blue staining. Expression levels of claudin-5, zonula occludens-1, occludin, and matrix metalloproteinase-9 (MMP-9) as well as M1/M2 phenotypes-associated markers were assessed using immunofluorescence, RT-qPCR, Western blotting, and gelatin zymography. Enzyme-linked immunosorbent assay was used to examine inflammatory cytokine levels. We found that dexmedetomidine or SB203580 attenuated infarct volume, brain edema, BBB permeability, and neuroinflammation, and promoted M2 microglial polarization after cerebral ischemia/reperfusion injury. Increased MMP-9 activity by ischemia/reperfusion injury was inhibited by dexmedetomidine or SB203580. Dexmedetomidine inhibited the activation of the ERK, JNK, and p38 MAPK pathways. Moreover, activation of JNK or p38 MAPK reversed the protective effects of dexmedetomidine against ischemic brain injury. Overall, dexmedetomidine ameliorated brain injury by alleviating BBB permeability and promoting M2 polarization in experimental cerebral ischemia/reperfusion injury model by inhibiting the activation of JNK and p38 MAPK pathways.

• The Journal of Korean Medicine
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• v.26 no.4
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• pp.87-97
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• 2005

Backgrounds: Intracerebral hemon-hage is one of the most devastating types of stroke. Ginseng radix, the root of Panax Ginseng, C. A. MEYER (Araliaceae), is one of the most famous medicinal herbs with various therapeutic applications. Objectives: In the present study, the effect of aqueous extract of Ginseng radix on intracerebral hemorrhage-induced neuronal cell death in rats was investigated. Materials and Methods: Step-down avoidance task, Nissl staining, immunohistochemistry for caspase-3 and terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) assay were used for this study. Results: The present results show that hemorrhage-induced lesion volume and apoptotic neuronal cell death in the striatum were significantly suppressed by treatment with Ginseng radix, resulting in enhancement of short-ten-n memory. Conclusions: We have shown that Ginseng radix has a neuroprotective effect on stroke, and aids the recovery from central nervous system sequelae following stroke.

• The Korea Journal of Herbology
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• v.27 no.2
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• pp.61-67
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• 2012

Objective : Angelica Gigas Nakai is a popular oriental medicine used for the treatment of vascular diseases. The aim of this study is to investigate neuroprotective effect of the water extract of Anelicae Gigantis Radix Palva (AG) in transient middle cerebral artery occlusion (tMCAO)-induced ischemic rats via the regulation of angiogenesis-related molecules. Methods : Sprague-Dawley rats were intraperitoneally administrated with AG water extract at doses of 10, 25, 50 mg/kg body weight after tMCAO (90 min occlusion). reperfusion for 24 hr infarction volumes were measured by 2,3,5-tetrazolium chloride (TTC) staining. Brain tissues were observed neuronal cell injuries by nissl staining, and also brain-blood barrier (BBB) permeability change by evans blue. Expression of vascular endothelial growth factor (VEGF), angiopoietin-1 (Ang-1) and Tie-2 receptor protein in brain tissues was determined by western blot. Results : AG water extract significantly reduced infarction volume in ischemic brains of rats, degradation of neuronal cell, BBB permeability and expression of VEGF protein dose-dependently. Ang-1 protein was increased dose-dependantly, not significantly. Conclusion : This study suggests that AG water extract shows neuroprotective effect by preventing BBB breakdown, with regulating angiogenesis factor VEGF and Ang-1.

• Proceedings of the KSAR Conference
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• 2002.06a
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• pp.19-19
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• 2002

This study was to examine whether the in vitro differentiated neural cells derived from human embryonic stem (hES, MB03) cells can be survived and expressed tyrosin hydroxylase(TH) in grafted normal or PD rat brain. To differentiate in vitro into neural cells, embryoid bodies (EB: for 5 days, without mitogen) were formed from hES cells, neural progenitor cells(neurosphere, for 7-10 days, 20 ng/㎖ of bFGF added N2 medium) were produced from EB, and then finally neurospheres were differentiated into mature neuron cells in N2 medium(without bFGF) for 2 weeks. In normal rat brain, neural progenitor cells or mature neuron cells (1×10/sup 7/ cells/㎖) were grafted to the striatum of normal rats. After 2 weeks, when the survival of grafted hES cells was examined by immunohistochemical analysis, the neural progenitor cell group indicated higher BrdU, NeuN＋, MAP2＋ and GFAP＋ than mature neuron cell group in grafted sites of normal rats. This result demonstrated that the in vivo differentiation of grafted hES cells be increased simultaneously in both of neuronal and glial cell type. Also, neural progenitor cell grafted normal rats expressed more TH pattern than mature neuron cells. Based on this data, as a preliminary test, when the neural progenitor cells were grafted into the striatum of 6-hydroxydopamine lesioned PD rats, we confirmed the cell survival (by double staining of Nissl and NeuN) and TH expression. This result suggested that in vitro differentiated neural progenitor cells derived from hES cells are more usable than mature neuron cells for the neural cell grafting in animal model and those grafted cells were survived and expressed TH in normal or PD rat brain.

• Proceedings of the KSAR Conference
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• 2003.06a
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• pp.80-80
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• 2003

Huntington's disease (HD) is an autosomal dominant neurodegenerative disorder characterized by motor, cognitive, and psychiatric symptoms, accompanied by marked cell death in the striatum and cortex. Stereotaxic injection of quinolinic acid (QA) into striatum results in a degeneration of GABAergic neurons and exhibits abnormal motor behaviors typical of the illness. The objective of this study was carried out to obtain basic information about whether parthenogenetic mouse embryonic stem (PmES) cells are suitable for cell replacement therapy of HD. To establish PmES cell lines, hybrid F1 (C57BL/6xCBA/N) mouse oocytes were treated with 7% ethanol for 5 min and cytochalasin-B for 4 hr to initiate spontaneous cleavage. Thus established PmES cells were induced to differentiate using bFGF (20ng/ml) followed by selection of neuronal precursor cells for 8 days in N2 medium. After selection, cells were expanded at the presence of bFGF (20 ng/ml) for another 6 days, then a final differentiation step in N2 medium for 7 days. To establish recipient animal models of HD, young adult mice (7 weeks age ICR mice) were lesioned unilaterally with a stereotaxic injection of QA (60 nM) into the striatum and the rotational behavior of the animals was tested using apomorphine (0.1mg/kg, IP) 7 days after the induction of lesion. Animals rotating more than 120 turns per hour were selected and the differentiated PmES cells (1$\times$10$^4$cells/ul) were implanted into striatum. Four weeks after the graft, immunohistochemical studies revealed the presence of cells reactive to anti-NeuN antibody. However, only a slight improvement of motor behavior was observed. By Nissl staining, cell mass resembling tumor was found at the graft site and near cortex which may explain the slight behavioral improvement. Detailed experiment on cell viability, differentiation and migration explanted in vivo is currently being studied.

• Journal of Ginseng Research
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• v.43 no.4
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• pp.499-507
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• 2019

Background: Ginsenoside Rb1 (Rb1), a dominant component from the extract of Panax ginseng root, exhibits neuroprotective functions in many neurological diseases. This study was intended to investigate whether Rb1 can attenuate cisplatin-induced memory impairments and explore the potential mechanisms. Methods: Cisplatin was injected intraperitoneally with a dose of 5 mg/kg/wk, and Rb1 was administered in drinking water at the dose of 2 mg/kg/d to rats for 5 consecutive wk. The novel objects recognition task and Morris water maze were used to detect the memory of rats. Nissl staining was used to examine the neuron numbers in the hippocampus. The activities of superoxide dismutase, glutathione peroxidase, cholineacetyltransferase, acetylcholinesterase, and the levels of malondialdehyde, reactive oxygen species, acetylcholine, tumor necrosis factor-${\alpha}$, interleukin-$1{\beta}$, and interleukin-10 were measured by ELISA to assay the oxidative stress, cholinergic function, and neuroinflammation in the hippocampus. Results: Rb1 administration effectively ameliorates the memory impairments caused by cisplatin in both novel objects recognition task and Morris water maze task. Rb1 also attenuates the neuronal loss induced by cisplatin in the different regions (CA1, CA3, and dentate gyrus) of the hippocampus. Meanwhile, Rb1 is able to rescue the cholinergic neuron function, inhibit the oxidative stress and neuroinflammation in cisplatin-induced rat brain. Conclusion: Rb1 rescues the cisplatin-induced memory impairment via restoring the neuronal loss by reducing oxidative stress and neuroinflammation and recovering the cholinergic neuron functions.

• The Korea Journal of Herbology
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• v.27 no.6
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• pp.83-90
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• 2012

Objectives : Modified Bo-Yang-Hwan-O-Tang (mBHT) is a polyherbal medicine of twelve herbs traditionally used in the treatment of cerebral and cardiac stroke and vascular dementia. The purpose of this study was to evaluate the neuroprotective effect, pyramidal neuronal cell, inflammation and apoptosis of mBHT against global ischemia in rats. Methods : Global ischemia was produced by two-vessel occlusion(2-VO) in SD male rats. mBHT at dose of 500 mg/kg was orally administrated for 2 weeks or 6 weeks after global ischemia. The histopathological changes of ischemic brain were observed by staining of hematoxylin and eosin (H&E) and Nissl and immunohistochemisty with anti-GFAP (glial fibrillary acidic protein) antibody as a astrocyte marker. The expression of inducible nitric oxide synthase (iNOS) and apoptotic proteins such as Bax, Bcl-2 and caspase-3 was determined by western blot. Results : mBHT treatment significantly inhibited the pyramidal neuronal loss in CA1 of hippocampus of global ischemic rats by 2-VO. mBHT also suppressed the activation of astrocytes in the CA1 at 6 weeks after ischemia. In addition, mBHT significantly increased the expression of anti-apoptotic protein, Bcl-2 on iscemic brain, and significantly attenuated the expression of apoptotic proteins, Bax and caspase-3. Conclusions : These results indicate that mBHT inhibits neuronal cell damage induced in global ischemia by 2-VO, suggesting that mBHT may be a potential candidate for the treatment of vascular dementia.

• Korean Journal of Exercise Nutrition
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• v.13 no.2
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• pp.115-122
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• 2009

Intracerebral hemorrhage (ICH) is a common cause of stroke, and it occurs mainly in the striatum, thalamus, cerebellum, and pons. Physical exercise is known to ameliorate neurologic impairment induced by various brain insults. In the present study, the influence of pre-and post-conditioning of treadmill exercise on spatial learning ability, the lesion volume, and apoptotic neuronal cell death in the striatum following ICH in rats was investigated. ICH in the striatum was induced by injection of collagenase using strereotaxic instrument. The rats in the pre-exercise group were scheduled to run on a treadmill before ICH induction for 2 consecutive weeks. The rats in the post-exercise group were scheduled to run on a treadmill after ICH induction for 2 weeks. The rats in the pre-exercise and post-exercise group were scheduled to run on a preconditioning treadmill exercise 2 weeks before ICH induction until postconditioning treadmill exercise 2 weeks after ICH induction, except the day of surgery. For this study, radial arm maze task, Nissl staining, terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) assay, and immunohistochemistry for caspase-3 were performed. Our date showed that treadmill exercise suppressed the ICH-induced apoptotic neuronal cell death and decreased lesion volume in the stratum. Treadmill exercise also alleviated the ICH-induced impairment of spatial learning ability. Preconditioning treadmill exercise before the ICH insult and postconditioning treadmill exercise after the ICH insult showed similar effectiveness on the recovery of ICH. In this study, however, preconditioning exercise before the ICH insult and postconditioning exercise after the ICH insult showed the most potent effectiveness on the recovery of ICH.

• Journal of Ginseng Research
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• v.44 no.3
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• pp.442-452
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• 2020

Backgroud: Sleep deprivation (SD) impairs learning and memory by inhibiting hippocampal functioning at molecular and cellular levels. Abnormal autophagy and apoptosis are closely associated with neurodegeneration in the central nervous system. This study is aimed to explore the alleviative effect and the underlying molecular mechanism of stem-leaf saponins of Panax notoginseng (SLSP) on the abnormal neuronal autophagy and apoptosis in hippocampus of mice with impaired learning and memory induced by SD. Methods: Mouse spatial learning and memory were assessed by Morris water maze test. Neuronal morphological changes were observed by Nissl staining. Autophagosome formation was examined by transmission electron microscopy, immunofluorescent staining, acridine orange staining, and transient transfection of the tf-LC3 plasmid. Apoptotic event was analyzed by flow cytometry after PI/annexin V staining. The expression or activation of autophagy and apoptosis-related proteins were detected by Western blotting assay. Results: SLSP was shown to improve the spatial learning and memory of mice after SD for 48 h, accomanied with restrained excessive autophage and apoptosis, whereas enhanced activation of phosphoinositide 3-kinase/protein kinase B/mammalian target of rapamycin signaling pathway in hippocampal neurons. Meanwhile, it improved the aberrant autophagy and apoptosis induced by rapamycin and re-activated phosphoinositide 3-kinase/Akt/mammalian target of rapamycin signaling transduction in HT-22 cells, a hippocampal neuronal cell line. Conclusion: SLSP could alleviate cognitive impairment induced by SD, which was achieved probably through suppressing the abnormal autophagy and apoptosis of hippocampal neurons. The findings may contribute to the clinical application of SLSP in the prevention or therapy of neurological disorders associated with SD.