• Proceedings of the Zoological Society Korea Conference
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• 1998.10b
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• pp.230.2-230
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• 1998

No Abstract, See Full Text

• Journal of Life Science
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• v.26 no.4
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• pp.475-483
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• 2016

The current study was conducted to evaluate beneficial effects of a new formula (CWC-9) using four traditional Oriental medicinal herbs, Cynanchum wilfordii, Rehmannia glutinosa, Polygala tenuifolia, and Acorus gramineus, on hippocampal cells and memory function. To examine the neuroprotective effects of a new four-herb extract, cell viability, cytotoxicity, and reactive oxygen species (ROS) assays were performed in HT22 cells and behavioral tests (Morris water maze and passive avoidance retention), Western blot, and immunohistochemistry were performed in a mouse model of focal cerebral ischemia. In HT22 hippocampal cells, pretreatment with CWC-9 resulted in significantly reduced glutamate-induced cell death with suppression of ROS accumulation caused by glutamate. In a mouse model of focal cerebral ischemia, we observed significant improvement of spatial and short-term memory function by treatment with CWC-9. Phosphorylated p38 mitogen-activated protein kinases (MAPK) in hippocampus of ischemic mice were decreased by treatment with CWC-9, but phosphorylated phosphatidylinositol-3 kinase (PI3K) and cAMP response element binding protein (CREB) were significantly enhanced. By immunohistochemical analysis, we confirmed higher expression of phosphorylation of CREB in the hippocampal neurons of CWC-9 treated mice. These results suggest that new multi-herb formula CWC-9 mainly exerted beneficial effects on cognitive function through regulation of neuro-protective signaling pathways associated with CREB.

• Journal of Life Science
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• v.17 no.1 s.81
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• pp.12-17
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• 2007

Curcumin is a natural phenolic yellow curry spice, derived from the tumeric, which has been used for the treatment of diseases associated with oxidative stress and inflammation. Curcumin is known to have both anti-oxidative and anti-inflammatory properties. These properties can be beneficial to protect the brain from the neurodegenerative diseases. We now report the neuroprotective effects of curcumin pretreatment in primary hippocampal neurons to glutamate-induced excitotoxicity. Pretreatment of embryonic mouse hippocampal cell cultures with low does of curcumin protected neurons against glutamate-induced death, however, this neuroprotection was not correlated with the modulation of oxidative stress. Interestingly, high dose of curcumin showed the cytotoxicity in primary cultured hippocampal neurons. Immunoblot analyses showed that levels of stress response. protein HSP70 were significantly elevated in neurons exposed to low dose of curcumin, whereas levels of cleaved PARP were increased in neurons exposed to high dose of curcumin. These findings show that curcumin can modulate neuronal responses to glutamate, and suggest possible use of curcumin and related compounds in the prevention and/or treatment of neurodegenerative disorders.

• BMB Reports
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• v.31 no.2
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• pp.117-122
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• 1998

Changes of lipocortin 1 (LC1) in the brain induced by immobilization stress were investigated in rats. Rats were immobilized for 0,1,2,3,4, and 5 h, and the brain slices were immunostained with anti-human LC1 antibodl (anti-LC1). Immunoreactivity of LCI (iLC1) was most prominent in neuronal cell bodies and processes of hippocampal CA regions and dentate gyrus. At rest without stress, most of the LC1 in the neuron located in the cytoplasm with the nuclei exhibiting relatively scarce immunoreactivity. Immobilization stress changed this intracellular distribution of LC1 by increasing nuclear LC1. The change was apparent in 1 h and reached the peak by 3 h. However, by 5 h of immobilization, the distribution pattern returned to that of the resting state. This transient nuclear translocation of LC1 was most prominent in $CA_1$ pyramidal neurons, and was not observed in areas other than the hippocampus. Adrenalectomy abolished this transient translocation of LC1. The roles of hippocampal LC1 as a mediator of glucocorticoid feedback signal and/or as an intracellar stress signaling protein could be suggested.

• Molecules and Cells
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• v.25 no.4
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• pp.538-544
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• 2008

Activity-dependent local translation in the dendrites of brain neurons plays an important role in the synapse-specific provision of proteins necessary for strengthening synaptic connections. In this study we carried out combined fluorescence in situ hybridization (FISH) and immunocytochemistry (IC) and showed that more than half of the eukaryotic elongation factor 1A (eEF1A) mRNA clusters overlapped with or were immediately adjacent to clusters of PSD-95, a postsynaptic marker, in the dendrites of cultured rat hippocampal neurons. Treatment of the neurons with KCl increased the density of the dendritic eEF1A mRNA clusters more than two-fold. FISH combined with IC revealed that the KCl treatment increased the density of eEF1A mRNA clusters that overlapped with or were immediately adjacent to PSD-95 clusters. These results indicate that KCl treatment increases both the density of eEF1A mRNA clusters and their synaptic association in dendrites of cultured neurons.

• The Korean Journal of Physiology and Pharmacology
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• v.22 no.3
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• pp.249-255
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• 2018

Echinacoside, an active compound in the herb Herba Cistanche, has been reported to inhibit glutamate release. In this study, we investigated the effects of echinacoside on spontaneous excitatory synaptic transmission changes induced by 4-aminopyridine (4-AP), by using the in vitro rat hippocampal slice technique and whole-cell patch clamp recordings from CA3 pyramidal neurons. Perfusion with echinacoside significantly suppressed the 4-AP-induced epileptiform activity in a concentration-dependent manner. Echinacoside reduced 4-AP-induced increase in frequency of spontaneous excitatory postsynaptic currents (sEPSCs) but it did not affect the amplitude of sEPSCs or glutamate-activated currents, implicating a presynaptic mechanism of action. Echinacoside also potently blocked sustained repetitive firing, which is a basic mechanism of antiepileptic drugs. These results suggest that echinacoside exerts an antiepileptic effect on hippocampal CA3 pyramidal neurons by simultaneously decreasing glutamate release and blocking abnormal firing synchronization. Accordingly, our study provides experimental evidence that echinacoside may represent an effective pharmacological agent for treating epilepsy.

• Journal of Physiology & Pathology in Korean Medicine
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• v.19 no.2
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• pp.416-425
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• 2005

This study demonstrated neuroprotective and anti-oxidative effects of Puerariae Radix for cerebral ischemia. Neuroprotective effects were studied by using oxygen/glucous deprivation of the organotypic hippocampal slice cultures to complement limitations of in vivo and in vitro models for cerebral ischemia study. Anti-oxidative effects were studied on BV-2 microglia cells damaged by $H_2O_2$ and nitric oxide. The results obtained are as follows; The groups treated with 0.5 and $5{\mu}g/m{\ell}$ of Puerariae Radix revealed significant decreases of neuronal cell death area and cell death area percentages in CA1 region of ischemic damaged hippocampus cultures during whole 48 hours of the experiment. The groups treated with 0.5 and $5{\mu}g/m{\ell}$ of Puerariae Radix revealed significant decreases of neuronal cell death area and cell death area percentages in DG region of ischemic damaged hippocampus cultures during whole 48 hours of the experiment. The groups treated with 0.5 and $5{\mu}g/m{\ell}$ of Puerariae Radix revealed significant decreases of TUNEL-positive cells in both CA1 region and DG region of ischemic damaged hippocampus cultures. The group treated with $50\;{\mu}g/m{\ell}$ of Puerariae Radix demonstrated significant decrease of TUNEL-positive cells in CA1 region. The groups treated with 0.5 and $5{\mu}g/m{\ell}$ of Puerariae Radix revealed significant decreases of LDH concentrations in culture media of ischemic damaged hippocampus cultures. The groups treated with 0.5 and $5{\mu}g/m{\ell}$ of Puerariae Radix revealed significant increases of cell viabilities of BV-2 microglia cells damaged by $H_2O_2$. The group treated with $5{\mu}g/m{\ell}$ of Puerariae Radix revealed significant increase of cell viability of BV-2 microglia cells damaged by nitric oxide. These results suggested that Puerariae Radix of cerebral ischemic revealed neuroprotective effects through the control effect of apoptosis and oxidative damages.

• Journal of Physiology & Pathology in Korean Medicine
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• v.16 no.5
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• pp.989-1000
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• 2002

The purpose of this study is to examine the toxic effects caused by xanthine oxidase/hypoxanthine(XO/HX) and the effects of herbal extracts such as JHYJ and GJHYJ on the treatment of the toxic effects. For this purpose, experiments with the cultured hippocampal cells from new born mice were done. The results of these experiments were as follows. 1. XO/HX, a oxygen radical-generating system, decreased the survival rates of the cultured cells on XTT assay and INT assay, the amount of DNA syntheses, and the amount of neurofilaments, and increased the lipid peroxidation. 2. JHYJ and GJHYJ have the efficacy of increasing the survival rates of the cultured cells. 3. JHYJ and GJHYJ have the efficacy of increasing the amount of neurofilaments and of decreasing the lipid peroxidation. 4. JHYJ and GJHYJ have the efficacy of increasing the amount of DNA syntheses. From the above results, it is suggested that Jihwangyeumja and Gamijihwangyeumja have marked efficacy as a treatment for the damages caused by the XO/HX-mediated oxidative stress. And Jihwangyeumja and Gamijihwangyeumja are thought to have certain pharmacological effects. Further dinical study of this pharmacological effects of Jihwangyeumja and Gamijihwangyeumja should be complemented.

• The Korean Journal of Physiology and Pharmacology
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• v.22 no.2
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• pp.145-153
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• 2018

The subgranular zone (SGZ) of hippocampal dentate gyrus (HDG) is a primary site of adult neurogenesis. Toll-like receptors (TLRs), are involved in neural system development of Drosophila and innate immune response of mammals. TLR2 is expressed abundantly in neurogenic niches such as adult mammalian hippocampus. It regulates adult hippocampal neurogenesis. However, the role of TLR2 in adult neurogenesis is not well studied in global or focal cerebral ischemia. Therefore, this study aimed to investigate the role of TLR2 in adult neurogenesis after photochemically induced cerebral ischemia. At 7 days after photothrombotic ischemic injury, the number of bromodeoxyuridine (BrdU)-positive cells was increased in both TLR2 knock-out (KO) mice and wild-type (WT) mice. However, the increment rate of BrdU-positive cells was lower in TLR2 KO mice compared to that in WT mice. The number of doublecortin (DCX) and neuronal nuclei (NeuN)-positive cells in HDG was decreased after photothrombotic ischemia in TLR2 KO mice compared to that in WT mice. The survival rate of cells in HDG was decreased in TLR2 KO mice compared to that in WT mice. In contrast, the number of cleaved-caspase 3 (apoptotic marker) and the number of GFAP (glia marker)/BrdU double-positive cells in TLR2 KO mice were higher than that in WT mice. These results suggest that TLR2 can promote adult neurogenesis from neural stem cell of hippocampal dentate gyrus through increasing proliferation, differentiation, and survival from neural stem cells after ischemic injury of the brain.

• The Korean Journal of Physiology and Pharmacology
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• v.17 no.4
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• pp.331-338
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• 2013

AMP-activated protein kinase (AMPK), an important regulator of energy metabolism, is activated in response to cellular stress when intracellular levels of AMP increase. We investigated the neuroprotective effects of AMPK against scopolamine-induced memory impairment in vivo and glutamate-induced cytotoxicity in vitro. An adenovirus expressing AMPK wild type alpha subunit (WT) or a dominant negative form (DN) was injected into the hippocampus of rats using a stereotaxic apparatus. The AMPK WT-injected rats showed significant reversal of the scopolamine induced cognitive deficit as evaluated by escape latency in the Morris water maze. In addition, they showed enhanced acetylcholinesterase (AChE)-reactive neurons in the hippocampus, implying increased cholinergic activity in response to AMPK. We also studied the cellular mechanism by which AMPK protects against glutamate-induced cell death in primary cultured rat hippocampal neurons. We further demonstrated that AMPK WT-infected cells increased cell viability and reduced Annexin V positive hippocampal neurons. Western blot analysis indicated that AMPK WT-infected cells reduced the expression of Bax and had no effects on Bcl-2, which resulted in a decreased Bax/Bcl-2 ratio. These data suggest that AMPK is a useful cognitive impairment treatment target, and that its beneficial effects are mediated via the protective capacity of hippocampal neurons.