• 대한의생명과학회지
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• 제16권4호
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• pp.259-264
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• 2010

This study was designed to investigate the effects of nitric oxide on the neuronal activity of rat cerebellar Purkinje cells. Sprague-Dawley rats aged 14 to 16 days were decapitated under ether anesthesia. After treatment with pronase and thermolysin, the dissociated Purkinje cells were transferred into a chamber on an inverted microscope. Spontaneous action potentials and potassium current were recorded by standard patch-clamp techniques under current and voltage-clamp modes respectively. 15 Purkinje cells revealed excitatory responses to $20\;{\mu}M$ of sodium nitroprusside (SNP) and 4 neurons (20%) did not respond to SNP. Whole potassium currents of Purkinje cells were decreased by SNP (n=10). Whole potassium currents of Purkinje cells were also decreased by L-arginine, substrate of nitric oxide (n=10). These experimental results suggest that nitric oxide increases the neuronal activity of Purkinje cells by altering the resting membrane potential and after hyperpolarization.

• Natural Product Sciences
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• 제9권4호
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• pp.260-263
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• 2003

Ethanol extract of the root of Clitoria ternatea Linn (CTEE) was evaluated for different neuropharmacological actions, such as general behaviour, exploratory behaviour, muscle relaxant activity and phenobarbitone induced sleeping time, in rats and mice. The extract was found to cause reduction in spontaneous activity, decrease in exploratory behavioural pattern by the head dip and Y- maze test, reduction in the muscle relaxant by rotarod, $30^{\circ}C$ inclined screen and traction tests. In addition CTEE significantly potentiated the phenobarbitone-induced sleeping time. Preliminary tests indicate that the ethanol extract of Clitoria ternatea Linn. At the doses of 100 and 150 mg/kg showed significant neuropharmacological activity.

• The Korean Journal of Physiology
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• 제18권1호
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• pp.37-50
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• 1984

The effects of $Ca^{++}$ and its antagonists (verapamil and $La^{+++}$) upon the spontaneous contraction and the contracture induced by 60 mM K-Tyrode solution were studied in the isolated uterine muscle. Longitudinal muscle strips were prepared from the rat uteri at estrous stage. All experiments were performed in tris-buffered Tyrode solution which was aerated with 100% $O_2$ and kept at 35^{\circ}$. The results obtained were as follows: 1) In the uterine strips contracting spontaneously, both the amplitude of peak tension and the area of contraction curve increased dose-dependently in the range of $0.5${\sim}8$ mM $Ca^{++}$. The frequency of contraction increased as the concentration of $Ca^{++}$ increased up to 2 mM, but above this concentration the frequency decreased. In $Ca^{++}-free$ media, however, contraction did not develop. In the contracture induced by 60 mM K-Tyrode solution, the developed tension increased dose-dependently as the concentration of external $Ca^{++}$ increased to 8 mM. In the absence of external $Ca^{++}$ K-contracture appeared, but it was not sustained. 2) The spontaneous contraction of rat uterus was suppressed by verapamil in proportion to an increase of its concentration and totally abolished at the concentration of $3{\times}10^{-4}\;g/l$, but the spontaneous contraction re-appeared by addition of $Ca^{++}$. The amplitude of peak tension recovered completely but the recovery of frequency was incomplete. K-contracture decreased in a dose-dependent manner after the treatment with verapamil and totally disappeared at its concentration of $3{\times}10^{-4}\;g/l$. Even in this case contracture developed again by extra $Ca^{++}$. 3) The spontaneous contractile activity was inhibited by $La^{+++}$. At the concentration of $10^{-4}$M $La^{+++}$, fibrillation appeared. In the strip inhibited by $10^{-5}M\;La^{+++}$, contractility recovered completely by extra $Ca^{++}$ while in the $10^{-4}M\;La^{+++}$ treated preparation, the rhythmic spontaneous contraction did not develop even at the concentration of 16 mM $Ca^{++}$. After the initial transient depression of contracture tension by $10^{-3}M$ of $La^{+++}$, the strip stowed considerably large size of contracture, hardly influenced by external $Ca^{++}$ or verapamil. The results obtained in this experiment suggest that in the rat uterine muscle there would be some competitive actions between $Ca^{++}$ and its antagonists. It is speculated that $Ca^{++}$ plays an important role in the conduction of excitation, and $La^{+++}$ influences upon cellular $Ca^{++}$ mobilization and re-uptake process as well as transmembrane $Ca^{++}$ transport in a K-depolarized state.

• The Korean Journal of Physiology and Pharmacology
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• 제4권1호
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• pp.15-24
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• 2000

Although nociceptive informations are thought to be processed via different neural mechanisms depending on the types of stimuli, sufficient data have not been accumulated yet. We performed a series of experiments to elucidate the possible neural mechanisms as to chemical stimuli such as formalin, capsaicin and ATP. Single unit activity of wide dynamic range (WDR) neurons and high threshold cells were recorded extracellularly from the lumbosacral enlargement of cat spinal cord before and after chemical stimulation to its receptive field (RF). Each chemical substance - formalin $(20{\mu}l,\;4%),$ capsaicin (33 mM) or Mg-ATP (5 mM)- was injected intradermally into the RFs and then the changes in the spontaneous activity, mechanical threshold and responses to the peripheral mechanical stimuli were observed. In many cases, intradermal injection of formalin (5/11) and capsaicin (8/11) resulted in increase of the spontaneous activity with a biphasic pattern, whereas ATP (8/8) only showed initial responses. Time courses of the biphasic pattern, especially the late response, differed between formalin and capsaicin experiments. One hour after injection of each chemical (formalin, capsaicin, or ATP), the responses of the dorsal horn neurons to mechanical stimuli increased at large and the RFs were expended, suggesting development of hypersensitization (formalin 6/10, capsaicin 8/11, and ATP 15/19, respectively). These results are suggested that formalin stimulates peripheral nociceptor, local inflammation and involvement of central sensitization, capsaicin induces central sensitization as well as affects the peripheral C-polymodal nociceptors and neurogenic inflammation, and ATP directly stimulates peripheral nociceptors.

• Research in Vestibular Science
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• 제17권4호
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• pp.142-151
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• 2018

Objectives: Excitability o medial vestibular nucleus (MVN) in the brainstem can be affected by changes in the arterial blood pressure. Several animal studies have demonstrated that acute hypotension results in the alteration of multiunit activities and expression of cFos protein in the MVN. In the field of extracellular electrophysiological recording, tetrode technology and spike sorting algorithms can easily identify single unit activity from multiunit activities in the brain. However, detailed properties of electrophysiological changes in single unit of the MVN during acute hypotension have been unknown. Methods: Therefore, we applied tetrode techniques and electrophysiological characterization methods to know the effect of acute hypotension on single unit activities of the MVN of rats. Results: Two or 3 types of unit could be classified according to the morphology of spikes and firing properties of neurons. Acute hypotension elicited 4 types of changes in spontaneous firing of single unit in the MVN. Most of these neurons showed excitatory responses for about within 1 minute after the induction of acute hypotension and then returned to the baseline activity 10 minutes after the injection of sodium nitroprusside. There was also gradual increase in spontaneous firing in some units. In contrast small proportion of units showed rapid reduction of firing rate just after acute hypotension. Conclusions: Therefore, application of tetrode technology and spike sorting algorithms is another method for the monitoring of electrical activity of vestibular nuclear during acute hypotension.

• BMB Reports
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• 제54권12호
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• pp.620-625
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• 2021

Microglia are known to be activated in the hypothalamic paraventricular nucleus (PVN) of rats with cardiovascular diseases. However, the exact role of microglial activation in the plasticity of presympathetic PVN neurons associated with the modulation of sympathetic outflow remains poorly investigated. In this study, we analyzed the direct link between microglial activation and spontaneous firing rate along with the underlying synaptic mechanisms in PVN neurons projecting to the rostral ventrolateral medulla (RVLM). Systemic injection of LPS induced microglial activation in the PVN, increased the frequency of spontaneous firing activity of PVN-RVLM neurons, reduced GABAergic inputs into these neurons, and increased plasma NE levels and heart rate. Systemic minocycline injection blocked all the observed LPS-induced effects. Our results indicate that LPS increases the firing rate and decreases GABAergic transmission in PVN-RVLM neurons associated with sympathetic outflow and the alteration is largely attributed to the activation of microglia. Our findings provide some insights into the role of microglial activation in regulating the activity of PVN-RVLM neurons associated with modulation of sympathetic outflow in cardiovascular diseases.

• Advances in Traditional Medicine
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• 제6권3호
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• pp.221-231
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• 2006

The aim of the present study is to investigate central nervous system (CNS) activity of the methanol extracts of leaves of Caesalpinia bonducella (MECB) and stem bark of Bauhinia racemosa (MEBR) (Caesalpinaceae) in Swiss albino mice and Wistar albino rats. General behavior, exploratory behavior, muscle relaxant activity and phenobarbitone sodium-induced sleeping time were studied. The results revealed that the methanol extracts of leaves of Caesalpinia bonducella at 100 - 200 mg/kg and stem bark of Bauhinia racemosa 100 - 200 mg/kg caused a significant reduction in the spontaneous activity (general behavioral profile), remarkable decrease in exploratory behavioral pattern (Y-maze and head dip test), a reduction in muscle relaxant activity (rotarod and traction tests), and also significantly potentiated phenobarbitone sodium-induced sleeping time. The results suggest that MECB and MEBR exhibit CNS depressant activity in tested animal models.

• 대한한방내과학회지
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• 제19권1호
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• pp.57-72
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• 1998

This study has been carried out to investigate the effects of Ukgansan(UGS) extract on anti-convulsive, antipyretic, analgesic, sedative and GABAergic system of experimental animals. The results of this study were as follows : 1. UGS extract prolonged significantly the beginning time to convulsion and death induced by strychnine. 2. UGS extract prolonged significantly the time to death induced by electrical shock of ECT unit.(3 sec, 200 F, 25 mA) 3. On the experiment of hypothermic effects of UGS extract on the rectal temperature of mouse, UGS extract decreased significantly the rectal temperature of mouse 4. On the experiment of antipyretic effects of UGS extract on the febrile induced by the subcutaneous injection of $150\;{\mu}g/kg$ endotoxin in mouse, UGS extract decreased significantly the rectal temperature of mouse. 5. On the experiment of analgesic effects of UGS extract on the writhing syndrome induced by intraperitoneal injection 0.7% acetic acid 1 ml/100g in mouse, the writhing syndrome induced by acetic acid was reduced significantly by administration of UGS extract. 6. On the experiment of effects of UGS extract on spontaneous motor activity measured by wheel cage method in mice, the spontaneous motor activity was reduced significantly by administration of UGS extract. 7. On the experiment of effects of UGS extract on the activity of GABA-transaminase(GABA-T) in mouse brains after 21 days of oral administration of UGS extract. the activity of GABA-T was reduced significantly by administration of UGS extract. 8. On the experiment of effects of UGS extract on the activity concentration of GABA in mouse brain after 21 days of oral administration of UGS extract, the activity concentration of GABA was reduced significantly by administration of UGS extract. 9 On the experiment of effect of UGS water extract on the activity of GAD in mouse brain after 21 days of oral administration of UGS extract, the activity of GAD was reduced significantly by administration of UGS extract. According to the these results, Ukgansan extracts reveal the effects on the anti-convulsive, antipyretic, analgesic, sedative and GABAergic system.

• 한국한의학연구원논문집
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• 제2권1호
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• pp.205-225
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• 1996

This study has been carried out to investigate the effects of Youngyanggaksan (YGS) extract on the anticonvulsive, antipyretic, anlgesic, sedative and GABAergic system of experimental animals. The results of this study were as follows : 1. YGS extract prolonged significantly the beginning time to convulsion and time to death induced by strychnine. 2. YGS extract prolonged significantly the time to death induced by electrical shock of ECT unit (3sec, 200F, 25mA). 3. On the experiment of hypothermic effects of YGS extract on the rectal temperature of rats, YGS extract decreased significantly the rectal temperature of rats. 4. On the experiment of antipyretic effects of YGS extract on the febrile induced by the subcutaneous injection of $150{\mu}g/kg$ endotoxin in rats, YGS extract decreased significantly the rectal temperature of rats. 5. On the experiment of analgesic effects of YGS extract on the writhing syndrome induced by intraperitoneal injection 0.7% acetic acid 1ml/100g in rats, the writhing syndrome was reduced significantly by administration of YGS extract. 6. On the experiment of sedative effects of YGS extract on spontaneous motor activity measured by wheel cage method in mice, the spontaneous motor activity was reduced significantly by administration of YGS extract. 7. On the experiment of effects of YGS extract on the activity of GABA-transaminase(GABA-T) in rat brains after 21 days of oral administration of YGS extract, the activity of GABA-T was reduced significantly by administration of YGS extract. 8. On the experiment of effects of YGS extract on the activity concentration of GABA in rat brains after 21 days of oral administration of YGS extract the activity concentration of GABA was reduced significantly by administration of YGS extract. 9. On the experiment of effects of YGS extract on the activity of GAD in rat brains after 21 days of oral adminstration of YGS extract, the activity of GAD was reduced significantly by administration of YGS extract. According to the those results, Youngyanggaksan extract reveals the effects on the anticonvulsive, antipyretic, anlgesic, sedative and GABAergic system.

• 대한한방내과학회지
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• 제18권2호
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• pp.65-82
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• 1997

This study has been carried out to investigate the effects of Cheonmagudeungyeum(CGY) extract on anti-convulsive, antipyretic, analgesic, sedative and GABAergic system of experimental animals. The results of this study were as follows : 1. CGY extract prolonged significantly the beginning time to convulsion and death induced by strychnine. 2. CGY extract prolonged significantly the time to death induced by electrical shock of ECT unit(3 sec, 200 F, 25 mA) 3. On the experiment of hypothermic effects of CGY extract on the rectal temperature of mice, CGY extract decreased the rectal temperature of mice. 4. On the experiment of antipyretic effects of CGY extract on the febrile induced by the subcutaneous injection of $150\;{\mu}g/kg$ endotoxin in mice, CGY extract decreased significantly the rectal temperature of mice. 5. On the experiment of analgesic effects of CGY extract on the writhing syndrome induced by intraperitoneal injection 0.7% acetic acid 1 ml/100g in mice, the writhing syndrome induced by acetic acid was reduced significantly by administration of CGY extract. 6. On the experiment of effects of CGY extract on spontaneous motor activity measured by wheel cage method in mice, the spontaneous motor activity was reduced significantly by administration of CGY extract 7. On the experiment of effects of CGY extract on the activity of GABA - transaminase (GABA-T) in mouse brains after 21 days of oral administration of CGY extract, the activity of GABA-T was reduced significantly by administration of CGY extract. 8. On the experiment of effects of CGY extract on the activity concentration of GABA in mouse brain after 21 days of oral administration of CGY extract, the activity concentration of GABA was reduced significantly by administration of CGY extract. 9. On the experiment of effect of CGY water extract on the activity of GAD in mouse brain after 21 days of oral administration of CGY extract, the activity of GAD was reduced significantly by administration of CGY extract. According to the these results, Cheonmagudeungyeum extracts reveal the effects on the anti-convulsive, antipyretic, analgesic, sedative and GABAergic system.