• The Korean Journal of Physiology and Pharmacology
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• v.15 no.3
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• pp.163-169
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• 2011

Corticosterone is known to modulate GABAergic synaptic transmission in the hypothalamic paraventricular nucleus. However, the underlying receptor mechanisms are largely unknown. In the anterior hypothalamic area (AHA), the sympathoinhibitory center that project GABAergic neurons onto the PVN, we examined the expression of glucocorticoid receptor (GR) and mineralocorticoid receptor (MR) of GABAergic neurons using intact GAD65-eGFP transgenic mice, and the effects of corticosterone on the burst firing using adrenalectomized transgenic mice. GR or MR immunoreactivity was detected from the subpopulations of GABAergic neurons in the AHA. The AHA GABAergic neurons expressed mRNA of GR (42%), MR (38%) or both (8%). In addition, in brain slices incubated with corticosterone together with RU486 (MR-dominant group), the proportion of neurons showing a burst firing pattern was significantly higher than those in the slices incubated with vehicle, corticosterone, or corticosterone with spironolactone (GR-dominant group; 64 vs. 11~14%, p<0.01 by $x^2$-test). Taken together, the results show that the corticosteroid receptors are expressed on the GABAergic neurons in the AHA, and can mediate the corticosteroid-induced plasticity in the firing pattern of these neurons. This study newly provides the experimental evidence for the direct glucocorticoid modulation of GABAergic neurons in the AHA in the vicinity of the PVN.

• BMB Reports
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• v.54 no.12
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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.

• Journal of Nutrition and Health
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• v.34 no.7
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• pp.727-733
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• 2001

The present study was conducted to identify the mechanism about the regulation of appetite by examining the expression patterns of neuropeptide Y in the hypothalamus of mice either fasting mouse for 24 hours or with anorexia mutant mouse. In order to investigate the patterns of expression of neurpeptide Y, immunohistochemistry was employed for measurements at the tissue level, along with the molecular biological techniques of reverse transcription polymerase chain reaction(RT-PCR) and dot blotting. The results of this study are as follows. The level of expression of neruopeptide Y, a neuropeptide known to enhance appetite, was shown to be lowered in the arcuate nucleus(ARC), paraventricular nucleus(PVN), lateral hypothalamic area(LHA), and dorsomedial hypothalamic nucleus(DMN) in both the fasting and anorexia mutant groups when measured via immunohistochemistry, a tissue-level method. RT-PCR and dot blotting, the molecular biological methods employed in this study, revealed that the level of neuropeptide Y mRNA in the entire hypothalamus was similar in the control and fasting groups and lower in the anorexia mutant group. The results of the present study showed that while the levels of expression of the neuropeptide Y in the various hypothalamic regions studied did not exhibit regular increases or decreases when measured immunohistochemically. But the entire hypothalamus via molecular biological methods showed that the changes in these levels were more definite in the anorexia mutant group than in the fasting group.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.37 no.3
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• pp.195-204
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• 2011

Introduction: This study examined the regulatory mechanism underlying the meal-induced changes in the hypothalamic-pituitary-adrenal gland (HPA) axis activity. Materials and Methods: Male Sprague-Dawley rats (250-300 g) were hired for two different experiments as follows; 1) rats received either 8% sucrose or 0.2% saccharin ad libitum after 48 h of food deprivation with the gastric fistula closed (real feeding) or opened (sham feeding). 2). rats received 5 ml of intra-oral infusion with 0.2% saccharin or distilled water after 48 h of food deprivation. One hour after food access, all rats were sacrificed by a transcardiac perfusion with 4% paraformaldehyde. The brains were processed for c-Fos immunohistochemistry and the cardiac blood was collected for the plasma corticosterone assay. Results: Real feedings with sucrose or saccharin and sham feeding saccharin but not sucrose, following food deprivation decreased the plasma corticosterone level. c-Fos expression in the nucleus tractus of solitarius (NTS) of the fasted rats was increased by the consumption of sucrose but not saccharin, regardless of the feeding method. On the other hand, the consumption of sucrose or saccharin with real feeding but not the sham, induced c-Fos expression in the paraventricular nucleus (PVN) of the fasted rats. The intra-oral infusion with saccharin or water decreased the plasma corticosterone level of the fasted rats. Intra-oral water infusion increased c-Fos expression in both the PVN and NTS, but saccharin only in the NTS in the fasted rats. Conclusion: Neither restoration of the fasting-induced elevation of plasma corticosterone nor the activation of neurons in the PVN and NTS after refeeding requires the palatability of food or the post-ingestive satiety and caloric load. In addition, neuronal activation in the hypothalamic PVN may not be an implication in the restoration of the fasting-induced elevation of the plasma corticosterone by oropharyngeal stimuli of palatable food.

• Journal of Acupuncture Research
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• v.18 no.2
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• pp.51-66
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• 2001

The purpose of this morphological studies was to investigate the central neural pathway projecting to the acupoints $B_{62}$ and $K_6$ using the neuroanatomical method following injection of transsynaptic neurotropic virus, pseudorabies virus(PRV-Ba and PRV-Ga) into the $B_{62}$ and $K_6$. After survival times of 96 hours following injection into the twenty rats with PRV-Ba(Bartha strain) and PRV-Ga(Bartha strain, ${\beta}$-galacidodase insertion). They were perfused, and their spinal cord and brain were frozen sectioned($30{\mu}m$). These sections were stained by X-gal histochemical and PRV immunohistochemical staining method, and observed with light microscope. The results were as follows : 1. In spinal cord, overlaped PRV-Ba and PRV-Ga labeled neurons projecting to the $B_{62}$ and $K_6$ were founded in thoracic, lumbar and sacral spinal segments. In thoracic spinal segments, Densely labeled areas were founded in lamina IV, V, VII(intermediolateral nucleus) and X areas. In lumbar segemnts, labeled areas were founded in lamina II, IV, V and X areas. In sacral spinal segments, labeled areas were founded in lamina IV, V and VI areas. 2. In brain, overlaped PRV-Ba and PRV-Ga labeled neurons projecting to the $B_{62}$ and $K_6$ were founded in the $A_1$ noradrenalin cells/$C_1$ adrenalin cells/caudoventrolateral reticular nucleus, rostroventrolateral reticular nuclens, nucleus tractus solitarius, area postrema, raphe obscurus nucleus, raphe paltidus nucleus, raphe magnus nucleus, lateral paragigantoceltular nucleus, lateral rcticular nucleus, gigantocellular nucleus, locus coeruleus, subcoeruleus nucleus, motor trigeminal nucleus, Kolliker-Fuse nucleus, $A_5$ cell group, central gray matter, oculomotor nerve, paraventricular hypothalamic nucleus, median eminence, amygdaloid nucleus, frontal cortex, forelimb area, hindlimb area, 1, 2 areas of parietal cortex and granular and agranular cortex. This results were suggest that overlaped PRV-Ba and PRV-Ga labeled areas projecting to the $B_{62}$ and $K_6$ may be related to the emotional relay pathway in the central autonomic center.

• The Korean Journal of Physiology and Pharmacology
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• v.17 no.2
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• pp.121-125
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• 2013

The purpose of this study is to investigate the antinociceptive effects of ginsenosides on toothache. c-Fos immunoreactive (IR) neurons were examined after noxious intrapulpal stimulation (NS) by intrapulpal injection of 2 M KCl into upper and lower incisor pulps exposed by bone cutter in Sprague Dawley rats. The number of Fos-IR neurons was increased in the trigeminal subnucleus caudalis (Vc) and the transitional region between Vc and subnucleus interpolaris (Vi) by NS to tooth. The intradental NS raised arterial blood pressure (BP) and heart rate (HR). The number of Fos-IR neurons was also enhanced in thalamic ventral posteromedial nucleus (VPMN) and centrolateral nucleus (CLN) by NS to tooth. The intradental NS increased the number of Fos-IR neurons in the nucleus tractus solitarius (NTS) and rostral ventrolateral medulla (RVLM), hypothalamic supraoptic nucleus (SON) and paraventricular nucleus (PVN), central cardiovascular regulation centers. Ginsenosides reduced the number of c-Fos-IR increased by NS to tooth in the trigeminal Vc and thalamic VPMN and CLN. Naloxone, an opioid antagonist, did not block the effect of ginsenoside on the number of Fos-IR neurons enhanced by NS to tooth in the trigeminal Vc and thalamic VPMN and CLN. Ginsenosides ameliorated arterial BP and HR raised by NS to tooth and reduced the number of Fos-IR neurons increased by NS to tooth in the NTS, RVLM, hypothalamic SON, and PVN. These results suggest that ginsenosides have an antinociceptive effect on toothache through non-opioid system and attenuates BP and HR increased by NS to tooth.

• Journal of Acupuncture Research
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• v.17 no.2
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• pp.95-117
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• 2000

The purpose of this morphological studies was to investigate the relation between the meridian, acupoints and viscera using neuroanatomical tracers. The common locations of the spinal ganglia, sympathetic chain ganglia, spinal cord and brain projecting to the large intestine meridian were observed following injection of transganglionic tracer, WGA-HRP and transsynaptic neurotropic virus, pseudorabies virus(PRV), Bartha strain(Ba) and PRV-Ba-Gal (Galactosidase)) into the the large intestine(cecum, colon and rectum), ST37 and LI4. After survival times of 96 hours following injection into the thirty rats with WGA-HRP, PRV-Ba and PRV-Ba-Gal. They were perfused, and their spinal ganglia, sympathetic chain ganglia, spinal cord and brain were frozen sectioned($30{\mu}m$). These sections were stained by HRP and X-gal histochemical and PRV immunohistochemical staining method, and observed with a light microscope. The results were as follows : 1. WGA-HRP labeled neurons innervating the large intestine were observed bilaterally within the T13-L4 sympathetic chain ganglia, and T9-11 spinal ganglia. WGA-HRP labeled neurons innervating ST37 were observed within the L3-5 sympathetic chain ganglia, and L2-4 spinal ganglia. WGA-HRP labeled neurons innervating LI4 were observed in the middle cervical ganglion and stellate ganglion, and C5-8 spinal ganglia. 2. In spinal cord, PRV-Ba labeled neurons projecting to the large intestine, ST37 and LI4 were found in thoracic, lumbar and sacral spinal segments. Densely labeled areas of each spinal cord segment were founded in lamina N, V, VII(intermediolateral nucleus), Ⅸ, X and dorsal nucleus. 3. In medulla oblongata, PRV-Ba and PRV-Ba-Gal labeled neurons projecting to the large intestine, ST37 and LI4 were commonly found in the A1 noradrenalin cells/C1 adrenalin cells/caudoventrolateral reticular nucleus, dorsal motor nucleus of vagus nerve, nucleus tractus solitarius, raphe obscurus nucleus, raphe pallidus nucleus, raphe magnus nucleus and gigantocellular nucleus. 4. In pons, PRV-Ba and PRV-Ba-Gal labeled neurons were commonly found in locus coeruleus, Kolliker-Fuse nucieus and A5 cell group. 5. In midbrain, PRV-Ba and PRV-Ba-Gal labeled neurons were commonly found in central gray matter. 6. In diencephalon, PRV-Ba and PRV-Ba-Gal labeled neurons were commonly found in paraventricular hypothalamic nucleus. These results suggest that PRV-Ba and PRV-Ba-Gal labeled common areas projecting to the large intestine may be correlated to that of the large intestine meridian, ST37 and LI4. Especially, These morphological results provide that interrelationship of meridian-acupoints -viscera may be related to the central autonomic pathways.

• Science of Emotion and Sensibility
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• v.10 no.2
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• pp.253-261
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• 2007

Light is a synchronizing stimulus to regulate the circadian rhythms and neuroendocrine activities in both humans and animals. The retinohypothalamic tract is involved in the day/night cycle and neuroendocrine activities. In particular, melatonin secretion has been known to be affected by light and correlated with many aspects of health problems. This review introduces the role of the light in the biological rhythm and neuroendocrine activities, its relationship with health problems, and the characteristics of retinohypothalamic tract.

• The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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• v.29 no.3
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• pp.150-158
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• 2016

Objectives : We want to know the effect of Gyejakjimo-tang in mice model of acute pain.Methods : We investigated writhing reflex in mice with acetic acid-induced abdominal pain using mice, we observed c-Fos protien expression by immunohistochemistry dyeing method in the paraventricular nucleus(PVN) and supraoptic nucleus(SON) of the hypothalamus.Results : All of Gyejakjimo-tang treated group suppressed acetic acid-induced writhing response as acetic acid injuction group, but in 100㎎/㎏ Gyejakjimo-tang treated group and 200㎎/㎏ Gyejakjimo-tang treated groups represernted significance. All of Gyejakjimo-tang treated groups(50, 100 and 200㎎/㎏ Gyejakjimo-tang-treated group), Fos-positive cells in PNV significantly decreased as acetic acid injuction group, and All of Gyejakjimo-tang-treated groups Fos-positive cells in SON significantly decreased as acetic acid injuction group.Conclusions : The present results showed that the mice pre-treated with the aqueous extract of Gyejakjimo-tang showed analgesic effect on acetic acid-induced abdominal pain.

• Journal of Korean Physical Therapy Science
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• v.9 no.4
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• pp.53-61
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• 2002

This study was carried out to investigate the effects of electrical stimulation on the change oxytocin(OT) immunoreactive cells in the hypothalamus of the male SD rats. Fifteen healthy and normal male rats were divided into three groups, 5 SD rat in each group. The one group has been stimulated by electro-acupuncture(EA, 2Hz) for 30 min and the other group by EA for 1hr 30 min and control group has not been stimulated. The results were summarized as follows. OT immunoreactive cells were found in the Paraventricular nucleus (PVN), Supraoptic nucleus(SON) and Lateral Magnocellular Area(LMA). The number of OT immunoreactive cells of PVN were significantly increased after 30 min as compared with control group (p<0.05) and were also significantly increased after 1hr 30min than 30 min(p<0.05). The number of OT immunoreactive cells of SON were significantly increased after 30 min and 1hr 30 min(p<0.05) as compared with control group, but decreased after 1hr 30 min than 30 min. The number of immunoreactive hells of LMA significantly increased after 30 min(p<0.05) as compared with control group, but significantly decreased after 1hr 30 min than 30 min(p<0.05). These results show that OT is released into the hypothalamus in response to electrical stimulation.