• Journal of Microbiology and Biotechnology
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• 제22권3호
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• pp.422-430
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• 2012

Previous studies have demonstrated that repeated restraint stress in rodents produces increases in depression and anxiety-like behaviors and alters the expression of corticotrophin-releasing factor (CRF) in the hypothalamus. The current study focused on the impact of Bupleurum falcatum (BF) extract administration on repeated restraint stress-induced behavioral responses using the forced swimming test (FST) and elevated plus maze (EPM) test. Immunohistochemical examinations of tyrosine hydroxylase (TH) expression in rat brain were also conducted. Male rats received daily doses of 20, 50, or 100 mg/kg (i.p.) BF extract for 15 days, 30 min prior to restraint stress (4 h/day). Hypothalamic-pituitary-adrenal axis activation in response to repeated restraint stress was confirmed base on serum corticosterone levels and CRF expression in the hypothalamus. Animals that were pre-treated with BF extract displayed significantly reduced immobility in the FST and increased open-arm exploration in the EPM test in comparison with controls. BF also blocked the increase in TH expression in the locus coeruleus of treated rats that experienced restraint stress. Together, these results demonstrate that BF extract administration prior to restraint stress significantly reduces depression and anxiety-like behaviors, possibly through central adrenergic mechanisms, and they suggest a role for BF extract in the treatment of depression and anxiety disorders.

• The Korean Journal of Physiology and Pharmacology
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• 제17권5호
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• pp.393-403
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• 2013

Baicalein (BA), a plant-derived active flavonoid present in the root of Scutellaria baicalensis, has been widely used for the treatment of stress-related neuropsychiatric disorders including depression. Previous studies have demonstrated that repeated restraint stress disrupts the activity of the hypothalamic-pituitary-adrenal (HPA) axis, resulting in depression. The behavioral and neurochemical basis of the BA effect on depression remain unclear. The present study used the forced swimming test (FST) and changes in brain neurotransmitter levels to confirm the impact of BA on repeated restraint stress-induced behavioral and neurochemical changes in rats. Male rats received 10, 20, or 40 mg/kg BA (i.p.) 30 min prior to daily exposure to repeated restraint stress (2 h/day) for 14 days. Activation of the HPA axis in response to repeated restraint stress was confirmed by measuring serum corticosterone levels and the expression of corticotrophin-releasing factor in the hypothalamus. Daily BA administration significantly decreased the duration of immobility in the FST, increased sucrose consumption, and restored the stress-related decreases in dopamine concentrations in the hippocampus to near normal levels. BA significantly inhibited the stress-induced decrease in neuronal tyrosine hydroxylase immunoreactivity in the ventral tegmental area and the expression of brain-derived neurotrophic factor (BDNF) mRNA in the hippocampus. Taken together, these findings indicate that administration of BA prior to the repeated restraint stress significantly improves helpless behaviors and depressive symptoms, possibly by preventing the decrease in dopamine and BDNF expression. Thus, BA may be a useful agent for the treatment or alleviation of the complex symptoms associated with depression.

• Laboraroty Animal Research
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• 제34권4호
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• pp.203-210
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• 2018

Stress severely disturbs physiological and mental homeostasis which includes adult neurogenesis in hippocampus. Neurogenesis in hippocampus is a key feature to adapt to environmental changes and highly regulated by multiple cellular signaling pathways. The primary cilium is a cellular organelle, which acts as a signaling center during development and neurogenesis in adult mice. However, it is not clear how the primary cilia are involved in the process of restraint (RST) stress response. Using a mouse model, we examined the role of primary cilia in repeated and acute RST stress response. Interestingly, RST stress increased the number of ciliated cells in the adult hippocampal dentate gyrus (DG). In our RST model, cell proliferation in the DG also increased in a time-dependent manner. Moreover, the analysis of ciliated cells in the hippocampal DG with cell type markers indicated that cells that were ciliated in response to acute RST stress are neurons. Taken together, these findings suggest that RST stress response is closely associated with an increase in the number of ciliated neurons and leads to an increase in cell proliferation.

• Journal of Oral Medicine and Pain
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• 제37권2호
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• pp.81-91
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• 2012

타액이 대부분의 구강 내 질환에 영향을 주는 것으로 알려져 있다. 반대로, 여러 전신적 조건이 타액의 흐름에 영향을 줄 수 있으며 이는 구강 건조증을 야기할 수 있는데, 특히 사회심리적 스트레스는 타액의 부족과 구강 건조증의 병인으로 큰 역할을 할 수 있다. 많은 연구에서 자율신경계 반응에 의한 스트레스의 타액선에의 거시적 효과에 중점을 두어왔다. 본 연구에서는 구속 스트레스 조건 하에서 백서(Rat) 이하선에서 clusterin의 변화를 관찰하였다. 연구를 위해, 10마리의 백서를 이용, 3그룹으로 구분하였다. 1) 그룹 1: 대조군으로 rat 2마리 2) 그룹 2 : 실험대조군으로 2마리를 두어 2시간 동안 restraint cone을 사용하여 구속스트레스를 부여 3)그룹 3 : 실험군으로 6마리를 두어 매일 2시간씩 restraint cone을 사용하여 구속 스트레스를 부여 백서는 스트레스 부여 후 즉시(그룹 2) 희생하거나 24, 48, 72 시간 후 희생하여 이하선을 절취하였다. Western blotting과 면역조직화학검사를 시행하여 다음과 같은 결과를 얻었다. 1. 백서의 이하선에서 clusterin이 약간 증가하였고 구속 스트레스 부여 직후 타액선관에서 명확하게 관찰되었다. 2. 백서의 이하선에서 clusterin은 구속 24시간, 48시간 후에 매우 감소되었으며, 타액선관에서도 소량 관찰되었다. 3. 백서의 이하선에서 clusterin은 구속 72시간 후 현저하게 증가되었으며, 역시 타액선관에 밀집하여 증가되었다.

• The Korean Journal of Physiology and Pharmacology
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• 제13권4호
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• pp.315-319
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• 2009

Astragalus Membranaceus (AM) is a useful Korean herb that has been clinically prescribed for stress-related illness. The objective of the present study was to examine the anti-stress effects of AM on repeated stress-induced alterations of anxiety, learning and memory in rats. Restraint stress was administered for 14 days (2h/day) and AM (400mg/kg) given by oral administration, in the AM group, for the same period. Starting on the eighth day, the rats were tested for spatial memory on the Morris water maze test (MW) and for anxiety on the elevated plus maze (EPM). Changes of expression on immunohistochemistry were studied for cholineacetyl transferase (ChAT) and tyrosine hydroxylase (TH) in the brain. The results showed that the rats treated with AM had significantly reduced stress-induced deficits on learning and memory on the spatial memory tasks. In addition, the ChAT immunoreactivities were increased. In the EPM, treatment with AM increased the time spent in the open arms (p<0.001) compared to the control group. In addition, AM treatment also normalized increases of TH expression in the LC (p<0.001). In conclusion, administration of AM improved spatial learning and memory and reduced stress-induced anxiety. Thus, the present results suggest that AM is able to recover behavioral and neurochemical impairments induced by stress.

• Journal of Oral Medicine and Pain
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• 제38권2호
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• pp.121-136
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• 2013

구강 내에 발생되는 질환의 대부분은 타액의 영향을 받는다. 타액분비에 영향을 주는 요소 중에서 스트레스에 광범위하게 노출되어 있는 현대인들에게 나타나는 타액분비장애는 매우 중요한 문제로 대두되고 있는데, 스트레스가 타액선에 미치는 영향에 관해서는 자율신경에 의한 반응에 대하여만 알려져 있고 세포수준의 미시적 변화에 대한 연구는 미흡한 실정이다. 이에 본 연구에서는 구속 스트레스 조건하에서 타액선 세포의 변화를 광학현미경과 전자현미경을 이용하여 구조적인 변화를 관찰하였고, 세포자사와 간접적으로 관련이 있다고 알려진 clusterin를 이용하여 백서 이하선의 변화를 관찰하고자 하였다. 실험재료로는 웅성백서 18마리를 사용하였으며, 정상대조군 2마리, 실험대조군 2마리, 실험군 14마리를 배정하였고, 실험 대조군과 실험군은 매일 2시간씩 restraint cone을 사용하여 구속스트레스를 부여하였다. 이들은 각 군별로 즉일(실험대조군), 1일, 2일, 3일, 4일, 5일, 6일, 7일에 각각 2마리씩 희생한 후 이하선 조직을 절취하여 전자현미경검사와 clusterin 단백질 검색을 위한 면역조직화학검사를 시행 한 바 다음과 같은 결과를 얻었다. 1. 광학현미경 하에서, 백서의 이하선은 구속스트레스에 의하여, 스트레스가 반복됨에 따라 선포세포, 선포엽간 조직, 선포간 결체조직이 변성되어, 선포 간 이개 현상이 나타났으며, 실험 4일 후에는 선포 내에 공포가 관찰되었고 많은 수의 선조관이 관찰되었다. 2. 전자현미경 하에서, 백서의 이하선은 구속스트레스에 의하여, 선포세포 내의 층판상 구조인 rER이 실험 3일 후에 부종이 시작되기 시작하였으며, 4일 후에 심화되었고, 5일 후에는 심하게 부종되어 변성된 상이 관찰되었다. 3. 백서의 이하선에서 clusterin은 구속스트레스에 의하여, 선조관의 세포질에서 소실되었고, 개재관에서는 3일 후까지는 미약하게, 4일 후에는 매우 증가되었다가, 실험 5일 후부터는 점차 감소되는 양상을 보였다.

• The Korean Journal of Physiology and Pharmacology
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• 제14권6호
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• pp.371-376
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• 2010

Glycyrrhizae radix (GR) is an herbal medicine that is commonly used in the East Asia for treating a variety of diseases, including stomach disorders. The objective of the present study was to examine the anti-stress effects of GR on repeated stress-induced alterations of anxiety, learning and memory in rats. Restraint stress was administered for 14 days (2 h/day) to the rats in the Control and GR groups (400 mg/kg/day, PO). Starting on the eighth day, the rats were tested for spatial memory on the Morris water maze test (MW) and for anxiety on the elevated plus maze (EPM). We studied the changes of the expressions of cholineacetyl transferase (ChAT) and tyrosine hydroxylase (TH) in the locus coerleus (LC) using immunohistochemistry. The results showed that the rats treated with GR had significantly reduced stress-induced deficits on their learning and memory on the spatial memory tasks. In addition, the ChAT immunoreactivities were increased. Gor the EPM, treatment with GR increased the time spent in the open arms (p<0.001) as compared to that of the control group. Moreover, GR treatment also normalized the increases of the TH expression in the LC (p<0.001). In conclusion, administration of GR improved spatial learning and memory and reduced stress-induced anxiety. Thus, the present results suggest that GR has the potential to attenuate the behavioral and neurochemical impairments caused by stress.

• The Korean Journal of Physiology and Pharmacology
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• 제17권5호
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• pp.441-446
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• 2013

In the present study, the anti-depressant like effect of methyl gallate (MG) isolated from the stem bark of Acer barbinerve was examined in ICR mice. Body weight (BDW) and blood glucose (BDG) levels significantly decreased in the repeated restraint stress (RRS) group (2 h/day for 14 days) compared to the no stress (NS) group. To examine the effect of MG on RS-induced BDW loss and hypoglycemia, MG (10 mg/kg) and the anti-depressant fluoxetine (10 mg/kg) were administered daily for 14 days. Orally administered MG and fluoxetine significantly attenuated the RS-induced BDW loss and hypoglycemia. Interestingly, MG administered mice showed increased BDG levels in the normal and glucose feeding condition. Chronic RS-subjected mice showed immobilized and depressed behaviors. The effect of MG on the depressed behaviors was evaluated using the tail-suspension test (TST) and the forced swimming test (FST). In both tests, RS-induced immobilized behaviors were significantly reversed in MG and fluoxetine administered groups. Taken together, MG significantly attenuated the RS-induced BDW loss, hypoglycemia, and depressed behaviors. Considering that decreased BDG levels (hypoglycemia) can cause depression, MG may exert its anti-depressant like effect by preventing hypoglycemia. Our results suggest that MG isolated from A. barbinerve can exert anti-depressant like effect, and could be used as a new and natural anti-depressant therapy.

• The Korean Journal of Physiology and Pharmacology
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• 제18권3호
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• pp.263-268
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• 2014

The etiology of most psychiatric disorders is still incompletely understood. However, growing evidence suggests that stress is a potent environmental risk factor for depression and anxiety. In rodents, various stress paradigms have been developed, but psychosocial stress paradigms have received more attention than non-social stress paradigms because psychosocial stress is more prevalent in humans. Interestingly, some recent studies suggest that chronic psychosocial stress and social isolation affects mainly anxiety-related behaviors in mice. However, it is unclear whether chronic non-social stress induces both depression- and anxiety-related phenotypes or induces one specific phenotype in mice. In the present study, we examined the behavioral consequences of three chronic non-social stress paradigms: chronic predictable (restraint) stress (CPS), chronic unpredictable stress (CUS), and repeated corticosterone-HBC complex injection (RCI). Each of the three paradigms induced mild to severe depression/despair-like behaviors in mice and resulted in increased immobility in a tail suspension test. However, anxiety-related phenotypes, thigmotaxis and explorative behaviors, were not changed by the three paradigms. These results suggest that depression- and anxiety-related phenotypes can be dissociated in mouse stress models and that social and non-social stressors might affect brain circuits and behaviors differently.

• 운동영양학회지
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• 제23권3호
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• pp.13-21
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• 2019

[Purpose] Chronic stress is a precipitating factor for depression, whereas exercise is beneficial for both the mood and cognitive process. The current study demonstrates the anti-depressive effects of regular exercise and the mechanisms linked to hippocampal neurogenesis. [Methods] Mice were subjected to 14 consecutive days of restraint, followed by 3 weeks of treadmill running, and were then subjected to behavioral tests that included the forced swimming and Y-maze tests. Protein levels were assessed using western blot analysis and newborn cells were detected using 5-bromo-2'-deoxyuridine (BrdU). [Results] Three weeks of treadmill running ameliorated the behavioral depression caused by 14 days of continuous restraint stress. The exercise regimen enhanced BrdU-labeled cells and class III β-tubulin levels in the hippocampal dentate gyrus, as well as those of thioredoxin-1 (TRX-1) and synaptosomal β2-adrenergic receptors (β2-AR) under stress. In vitro experiments involving treatment with recombinant human TRX-1 (rhTRX-1) augmented the levels of phospho-extracellular signal-regulated kinases 1 and 2 (ERK1/2), nuclear β-catenin, and proliferating cell nuclear antigens, which were previously inhibited by U0216 and FH535 (inhibitors of ERK1/2 and β-catenin/T cell factor-mediated transcription, respectively). The hippocampal neurogenesis elicited by a 7-day exercise regimen was abolished by a selective inhibitor of β2-AR, butoxamine. [Conclusion] These results suggest that TRX-1-mediated hippocampal neurogenesis by β2-AR function is a potential mechanism underlying the psychotropic effect of exercise.