• Biomolecules & Therapeutics
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• v.4 no.2
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• pp.167-173
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• 1996

This study was undertaken to evaluate a behavior-electroencephalogram (EEG) pattern relationship in pilocarpine- and kainic acid-induced convulsions of rats. Also we intended to examine the effect of a noncompetitive N-methyl-D-aspartate (NMDA) receptor antagonist, MK-801, and diazepam on the pilocarpine-induced behavioral and electrical seizures in rats. The electrical activities at frontal and hippocampal areas and behavior activities were measured in freely moving rats. At the beginning of the experiments, the rats displayed an exploratory behavior. This awake and moving phase with a low amplitude, irregular, 4-10 Hz wave was followed by a still phase. Pilocarpine (400 mg/kg, i.p.) and kainic acid (0.5 mg/kg, i.c.v.) induced tonic and clonic seizures. The pilocarpine-induced change in electrical activities exhibited a weak correlation with behavioral convulsion at all stages. The amplitude and duration of the electrical response were not linear with the degree of behavioral score. An application of MK-801 (dizocilpine, 7.5 mg/kg) did not affect the amplitudes of the convulsant-induced electrical activities, though the same dose of this drug caused the deformation of the electrical pattern. There was no effect of MK-801 on the behavioral and electrical activities as expected. Diazepam (1 mg/kg) did not affect the amplitude of the electrical activities induced by pilocarpine but changed the pattern of these activities. Our study shows that there is no linear relationship between degree of behavior and amplitude of electrical activities of convulsants. This may indicate that the NMDA receptor stimulation can be processed by the neocortical or hippocampal network in a different way between behavioral and electrical activities.

• The Korean Journal of Physiology and Pharmacology
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• v.22 no.3
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• pp.301-309
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• 2018

Statins mediate vascular protection and reduce the prevalence of cardiovascular diseases. Recent work indicates that statins have anticonvulsive effects in the brain; however, little is known about the precise mechanism for its protective effect in kainic acid (KA)-induced seizures. Here, we investigated the protective effects of atorvastatin pretreatment on KA-induced neuroinflammation and hippocampal cell death. Mice were treated via intragastric administration of atorvastatin for 7 days, injected with KA, and then sacrificed after 24 h. We observed that atorvastatin pretreatment reduced KA-induced seizure activity, hippocampal cell death, and neuroinflammation. Atorvastatin pretreatment also inhibited KA-induced lipocalin-2 expression in the hippocampus and attenuated KA-induced hippocampal cyclooxygenase-2 expression and glial activation. Moreover, AKT phosphorylation in KA-treated hippocampus was inhibited by atorvastatin pretreatment. These findings suggest that atorvastatin pretreatment may protect hippocampal neurons during seizures by controlling lipocalin-2-associated neuroinflammation.

• Journal of Ginseng Research
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• v.47 no.3
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• pp.390-399
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• 2023

Background: Gintonin (GT), a Panax ginseng-derived lysophosphatidic acid receptor (LPAR) ligand, has positive effects in cultured or animal models for Parkinson's disease, Huntington's disease, and so on. However, the potential therapeutic value of GT in treating epilepsy has not yet been reported. Methods: Effects of GT on epileptic seizure (seizure) in kainic acid [KA, 55mg/kg, intraperitoneal (i.p.)]-induced model of mice, excitotoxic (hippocampal) cell death in KA [0.2 ㎍, intracerebroventricular (i.c.v.)]-induced model of mice, and levels of proinflammatory mediators in lipopolysaccharide (LPS)-induced BV2 cells were investigated. Results: An i.p. injection of KA into mice produced typical seizure. However, it was significantly alleviated by oral administration of GT in a dose-dependent manner. An i.c.v. injection of KA produced typical hippocampal cell death, whereas it was significantly ameliorated by administration of GT, which was related to reduced levels of neuroglial (microglia and astrocyte) activation and proinflammatory cytokines/enzymes expression as well as increased level of the Nrf2-antioxidant response via the upregulation of LPAR 1/3 in the hippocampus. However, these positive effects of GT were neutralized by an i.p. injection of Ki16425, an antagonist of LPA1-3. GT also reduced protein expression level of inducible nitric-oxide synthase, a representative proinflammatory enzyme, in LPS-induced BV2 cells. Treatment with conditioned medium clearly reduced cultured HT-22 cell death. Conclusion: Taken together, these results suggest that GT may suppress KA-induced seizures and excitotoxic events in the hippocampus through its anti-inflammatory and antioxidant activities by activating LPA signaling. Thus, GT has a therapeutic potential to treat epilepsy.

• Journal of Yeungnam Medical Science
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• v.35 no.2
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• pp.192-198
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• 2018

Background: Chronic inflammation can lower the seizure threshold and have influence on epileptogenesis. The components of red ginseng (RG) have anti-inflammatory effects. The abundance of peripherally derived immune cells in resected epileptic tissue suggests that the immune system is a potential target for anti-epileptogenic therapies. The present study used continuous electroencephalography (EEG) to evaluate the therapeutic efficacy of RG in intrahippocampal kainic acid (IHKA) animal model of temporal lobe epilepsy. Methods: Prolonged status epilepticus (SE) was induced in 7-week-old C57BL/6J mice via stereotaxic injection of kainic acid (KA, 150 nL; 1 mg/mL) into the right CA3/dorsal hippocampus. The animals were implanted electrodes and monitored for spontaneous seizures. Following the IHKA injections, one group received treatments of RG (250 mg/kg/day) for 4 weeks (RG group, n=7) while another group received valproic acid (VPA, 30 mg/kg/day) (VPA group, n=7). Laboratory findings and pathological results were assessed at D29 and continuous (24 h/week) EEG monitoring was used to evaluate high-voltage sharp waves on D7, D14, D21, and D28. Results: At D29, there were no differences between the groups in liver function test but RG group had higher blood urea nitrogen levels. Immunohistochemistry analyses revealed that RG reduced the infiltration of immune cells into the brain and EEG analyses showed that it had anticonvulsant effects. Conclusion: Repeated treatments with RG after IHKA-induced SE decreased immune cell infiltration into the brain and resulted in a marked decrease in electrographic seizures. RG had anticonvulsant effects that were similar to those of VPA without serious side effects.

• Journal of Physiology & Pathology in Korean Medicine
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• v.28 no.6
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• pp.614-620
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• 2014

Kainic acid (KA) is a excitatory agonist causing epileptic seizure and excitotoxicity in the hippocampus. Gastrodia Elata (GE) is known to have anti-convulsant and anti-oxidant effects. This study was investigated a possible role of GE in suppressing epileptic seizure using KA-induced epilepsy mouse model. Eight-week-old male C57BL/6 mice were administrated GE (50 or 500 mg/kg) once a day for 5 days, and then injected KA (30 mg/kg) intraperitoneally. Behavioral changes in mice by KA were evaluated for 90 minutes immediately after the KA administration. Six hours after the KA administration, their brains were harvested and the expressions of glutamate decarboxylase 67 (GAD-67) and K+-Cl- cotransporter 2 (KCC2) in the hippocampus of the mice were measured by immunohistochemistry.GE delayed the onset of epileptic seizure after KA administration, suppressed the severity of the seizure and decreased the number of severe seizures dose dependently. Moreover, GAD-67 and KCC2 expressions in the cornu ammonis (CA) 1 and CA3 of 500 mg/kg GE administrated mice were significantly increased compared to those in KA-treated mice.GAD-67 and KCC2 play an important role in regulating GABAergic system. Our results suggest that GE has anti-convulsant effect against KA-induced epileptic seizure through enhancing GABAergic system.

• Korean Journal of Acupuncture
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• v.24 no.4
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• pp.99-110
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• 2007

Objectives : Epilepsy is one of the most common serious brain disorders that affect people of all ages, and it is characterized by recurrent unprovoked seizures. We examined whether acupuncture can reduce both the incidence of seizures and hippocampal cell death in dentate gyrus (DG) using a mouse model of kainic acid (KA)-induced epilepsy. Methods : ICR mice ($20{\sim}25$ g) were given acupuncture once a day at acupoint HT8 (sobu) bilaterally during 2 days before KA injection. After an intracerebroventricular injection of 0.1${\mu}g$ of KA, acupuncture treatment was subsequently administered once more (total 3 times), and the degree of seizure was observed for 20 min. Three hours after injection, we confirmed the neural cell death using cresyl violet staining and silver impregnation staining, and determined the expressions of c-Fos and glutamate decarboxylase (GAD)-67 using immunohistochemistry techniques in the DG. Results : KA induced epileptic seizure, neural cell death, increased c-Fos expression and decreased GAD-67 expression in the DG. Acupuncture treatment at HT8 reduced the severity of the epileptic seizure and inhibited neural cell death from KA. In addition, acupuncture normalized the expressions of c-Fos and GAD-67 in the same areas. Conclusions : These results demonstrated that acupuncture treatment at HT8 may reduce the KA-induced epileptic seizure and neural cell death in the DG possibly by normalizing c-Fos expressions and the gamma-aminobutyric acid neurons.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2000.10a
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• pp.84-95
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• 2000

Panax ginseng and the herbal medicinal mixtures containing ginseng have been widely used as a traditional medicinal prescriptions. In order to develop more efficient and protective prescriptions on seizures and subsequent memory deterioration, we investigated the biochemical and ethopharmacological effects of ginsenosides and fractions from the natural medicinal plant products related to control convulsions. In this studies we show results improving spatial teaming and memory deficits induced by kainic acid, a potent neurotoxic and neuroexcitatory analogue of the amino acid neurotransmitter glutamate.

• BMB Reports
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• v.32 no.4
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• pp.339-344
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• 1999

We studied the effects of ginsenosides in immature rats based upon the previous results that ginseng has a suppressive or anticonvulsive activity. To examine the suppressive effect of ginsenosides on kainic acid-induced seizures, the severities and frequencies were observed for 4 h after injection of kainic acid (KA; i.p., 2 mg/kg b.w.) using 10-day-old male Sprague-Dawley rats ($22{\pm}2\;g$). Protopanaxadiol saponins such as ginsenoside-Rb1 (Rb1), ginsenoside-Rb2 (Rb2), ginsenoside-Rc (Rc), and ginsenoside-Rd(Rd) generally reduced the seizure activities while protopanaxatriol saponins such as ginsenoside-Rg1 (Rg1) and ginsenoside-Re (Re) rather increased stereotypic "paddling-like" movements. When vinyl-GABA (v-G) was injected together with Rb1 or Rc, KA-induced seizure severities were additionally reduced only by the injection of Rc, but not by Rb1. The level of gamma isozyme of protein kinase C (PKC-${\gamma}$) in the hippocampus increased about three times as much as that of normal rats at 4 h after KA injection. The increased level of PCK-${\gamma}$ by KA was significantly reduced to about 35% by the coinjection with v-G alone, but it was not changed by v-G together with Rb1 or Rc. The increased level of PKC-${\gamma}$ at 4 h after injection of KA was not consistent with the reduction of seizure severities between Rb1 and Rc. These results suggest that Rc and Rb1 may reduce seizure severity independent of PKC-${\gamma}$ levels, and Rc may additionally act with v-G regarding the GABA metabolism during the stage of KA-induced seizures in the immature rats.

• Journal of Korean Neurosurgical Society
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• v.29 no.7
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• pp.861-867
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• 2000

Purpose : Neuronal migration disorder(NMD) is a major underlying pathology of patients with intractable epilepsy. The role of NMD on seizure susceptibility or epileptogenecity, however, has not been documented. Methods : External irradiation of total amount of 250 cGY was performed to the fetal rats on days 16(E16) and 17(E17) of gestation. After delivery, the rats of 230-260g were decapitated for the histopathologic study. Epileptog-enecity of the NMD was studied by observing electroclinical events after intraperitoneal kainic acid(KA) injection in the control rats and NMD rats. Results : Histopathologic findings revealed focal and/or diffuse cortical dysplasia consisting of dyslamination of the cerebral cortex and appearance of the cytomegalic neurons, neuronal heterotopia in the periventricular white matter, dispersion of the pyramidal layer and the dentate gyrus of the hippocampus, and agenesis of the corpus callosum. Abnormal expression of neurofilaments protein(NF-M/H) was characteristically observed in the dysplastic neurons of the neocortex and hippocampus. Early ictal onset and prolonged ictal activity on EEG and clinical seizures were observed from the NMD rats unlike with the control rats. Conclusions : Exteranl irradiation on the fetal rats produced NMD. And the rats with NMD were highly susceptible to kainic acid provoked seizures. This animal model would be useful to study the pathophysiology of clinically relevant NMDs.

• The Korean Journal of Physiology and Pharmacology
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• v.13 no.4
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• pp.265-271
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• 2009

Nitric oxide (NO) has both neuroprotective and neurotoxic effects depending on its concentration and the experimental model. We tested the effects of NG-nitro-L-arginine methyl ester (L-NAME), a nonselective nitric oxide synthase (NOS) inhibitor, and aminoguanidine, a selective inducible NOS (iNOS) inhibitor, on kainic acid (KA)-induced seizures and hippocampal CA3 neuronal death. L-NAME (50 mg/kg, i.p.) and/or aminoguanidine (200 mg/kg, i.p.) were administered 1 h prior to the intracerebroventricular (i.c.v.) injection of KA. Pretreatment with L-NAME significantly increased KA-induced CA3 neuronal death, iNOS expression, and activation of microglia. However, pretreatment with aminoguanidine significantly suppressed both the KA-induced and L-NAME-aggravated hippocampal CA3 neuronal death with concomitant decreases in iNOS expression and microglial activation. The protective effect of aminoguanidine was maintained for up to 2 weeks. Furthermore, iNOS knockout mice ($iNOS^{-1-}$) were resistant to KA-induced neuronal death. The present study demonstrates that aminoguanidine attenuates KA-induced neuronal death, whereas L-NAME aggravates neuronal death, in the CA3 region of the hippocampus, suggesting that NOS isoforms play different roles in KA-induced excitotoxicity.