• The Journal of Internal Korean Medicine
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• v.32 no.1
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• pp.100-112
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• 2011

Objectives : This study investigated the effects of electroacupuncture on memory, depression, and plasma stress hormone levels in rats that were under immobilization stress. Materials and Methods : The immobilization-only group was given two hours of immobilization stress for 10 consecutive days. The immobilization and high frequency EA group was given two hours of immobilization stress simultaneously with high frequency (100Hz) electroacupuncture stimulation on the right ST-36 (Zusanli) for 10 consecutive days. We conducted the inhibitory avoidance and forced swimming tests to recognize whether immobilization stress and electroacupuncture have effects on memory and depression. We collected blood samples from the tail of each rat at 30, 60, 90, and 120-minute intervals during the immobilization stress and EA stimulation to measure plasma concentrations of ACTH, corticosterone, melatonin, and norepinephrine induced by immobilization stress and electroacupuncture. Results : There was a significant effect of high frequency on the increase in anamnesis based on the result of the inhibitory avoidance test, but there was no significant effect of decreasing depression based on the result of the forced swim test. Also, there was no significant effect on the response indicated by stress hormones. Conclusions : 1. High frequency electroacupuncture (100Hz) improved anamnesis in immobilization stress states under the inhibitory avoidance task. 2. High frequency electroacupuncture (100Hz) did not reduce depression induced by immobilization stress under the forced swimming test. 3. High frequency electroacupuncture (100Hz) did not decrease stress hormones through blood sampling.

• Progress in Medical Physics
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• v.19 no.2
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• pp.95-101
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• 2008

In this study, we observed the alteration of choline signal intensity in hippocampus region of the depressive rat model induced by forced swimming test (FST). The purpose of this study was to evaluate the antidepressant efficacy in the depressive animal model using MR spectroscopy. Fourteen experimentally naive male Sprague-Dawley rats weighting $160{\sim}180\;g$ were used as subjects. Drug injection group was exposed to the FST except for control group. The drugs were administered subcutaneously (SC) in a volume equivalent to 2ml/kg. And three injections were administered 23, 5, and 1h before beginning the given test. 1H MR spectra were obtained with use of a point resolved spectroscopy (PRESS) localization sequence performed according to the following parameters: repetition time, 2500 ms; echo time, 144 ms; 512 average; 2048 complex data points; voxel dimensions, $1.5{\times}2.5{\times}2.5\;mm^3$ ; acquisition time, 25min. There were no differences in NAA/Cr and Cho/Cr ratio between the right and the left hippocampus both normal control rats and antidepressant-injected rats. Also, no differences were observed in NAA/Cr and Cho/Cr ratio between the normal control rats and the antidepressant-injected rats both the right and the left hippocampus. In this study, we found the recovery of choline signals in the depressive animal model similar to normal control groups as injecting desipramine-HCl which was antidepressant causing anti-immobility effects. Thus, we demonstrated that MR spectroscopy was able to aid in evaluating the antidepressant effect of desipramine-HCl.

• Journal of Life Science
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• v.31 no.11
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• pp.995-1003
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• 2021

Chromatin remodeling regulates gene expression through epigenetic mechanisms. Aberrations in histone modification have been associated with depression-like behaviors in animal models. Additionally, growing evidence also indicates that epigenetic modification is associated with depression. p11 (S100A10) has been implicated in the pathophysiology of depression both in human and rodent models. In the present study, we investigated alterations in histone acetylation and methylation at the promoter of the p11 gene in the hippocampus of mice subjected to chronic unpredictable stress (CUS). C57BL/6 mice were exposed to CUS daily for 3 weeks. Depression-like behaviors were measured with the forced swimming test (FST). The levels of hippocampal p11 expression were analyzed by quantitative real-time polymerase chain reaction (PCR) and Western blotting. The levels of acetylated and methylated histone H3 at the promoter of p11 were measured by chromatin immunoprecipitation followed by real-time PCR. CUS-exposed mice displayed depression-like behaviors with prolonged immobility in FST. CUS led to significant decreases in the expression of p11 at both protein and mRNA levels. Meanwhile, there was a decrease in histone H3 acetylation (Ac-H3) and H3-K4 trimethylation (H3K4met3) and an increase in H3-K27 trimethylation (H3K27met3) at the p11 promoter. These results indicate that chronic stress causes the epigenetic suppression of p11 expression in the hippocampus.

• Korean Journal of Biological Psychiatry
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• v.27 no.1
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• pp.27-35
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• 2020

Objectives Ketamine has been reported to have antidepressant effects or psychotomimetic effects. The aim of this study was to investigate the behavioral effects of ketamine treatment at various sub-anesthetic doses in adolescent and adult naïve mice. Methods In each experiment for adolescent and adult mice, a total of 60 male Institute of Cancer Research mice were randomly divided into 6 groups, which were intraperitoneally treated with physiological saline, 10, 20, 30, 40, and 50 mg/kg ketamine for consecutive 3 days. At 1 day after last injection, the locomotor and depressive-like behaviors were evaluated in mice, using open field test (OFT) and forced swim test (FST), respectively. Results In case of adolescent mice, ketamine dose was negatively correlated with total distance traveled in the OFT (Spearman's rho = -0.27, p = 0.039). In case of adult mice, we found significant positive correlation between ketamine dose and duration of immobility in the FST (Spearman's rho = 0.45, p < 0.001). Immobility time in the 50 mg/kg ketamine-treated mice was significantly higher compared to the saline-treated mice (Dunnett's post-hoc test, p = 0.012). Conclusions We found that the repeated treatment with ketamine could decrease the locomotor or prolong the duration of immobility in mice as the dose of ketamine increased. Our findings suggest that sub-anesthetic doses of ketamine might induce schizophrenia-like negative symptoms but not antidepressant effects in naïve laboratory animals.

• Korean Journal of Food Science and Technology
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• v.41 no.4
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• pp.413-416
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• 2009

The sap of the white birch is one of the most widely used herbal medicines to treat gastrointestinal tract, jaundice, and various periodontal diseases. The purpose of this study was to measure the effect of white birch sap on in vivo immune agents in mice. The treatment of white birch sap on the forced swimming test has been used as a screening model for new immune enhancement agents. The hematological examination was significantly different in neutrophil, lymphocyte, and monocyte counts between treatment and control groups. Moreover the white birch sap changed the phagocytic index, immobility duration time, and leukocyte counts in mice.

• Journal of Life Science
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• v.29 no.9
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• pp.1002-1009
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• 2019

Early life stress (ELS) increases the risk of depression. ELS may be involved in the susceptibility to subsequent stress exposure during adulthood. We investigated whether epigenetic mechanisms of p11 promoter affect the vulnerability to chronic unpredictable stress (CUS) induced by the maternal separation (MS). Mice pups were separated from their dams (3 hr/day from P1-P21). When the pups reached adulthood, we applied CUS (daily for 3 weeks). The levels of hippocampal p11 expression were analyzed by quantitative real-time PCR. The levels of acetylated and methylated histone H3 at p11 promoter were measured by chromatin immunoprecipitation. Depression-like behavior was measured by the forced swimming test (FST). The MS and CUS group exhibited significant decreases in p11 mRNA level and the MS plus CUS group had a greater reduction in this level than the CUS group. The MS plus CUS group also resulted in greater reduction in H3 acetylation than the CUS group. This reduction was associated with an upregulation of histone deacetylase 5. Additionally, the MS plus CUS group showed a greater decrease in H3K4met3 level and a greater increase in H3K27 met3 level than the CUS group. Consistent with the reduction of p11 expression, the MS plus CUS group displayed longer immobility times in the FST compared to the control group. Mice exposed to MS followed by CUS had much greater epigenetic alterations in the hippocampus compared to adult mice that only experienced CUS. ELS can exacerbate the effect of stress exposure during adulthood through histone modification of p11 gene.

• Science of Emotion and Sensibility
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• v.10 no.2
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• pp.243-252
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• 2007

Anti-depressant and anti-anxiety effects of Saccharomyces cerevisiae extract and its hydrolyzed fraction. The purpose of the present study was to examine the effect of Saccharomyces cerevisiae extract (SCE) and its hydrolyzed fraction (SCE-40) on depression and anxiety-related behaviors in mice. Actions of SCE and SCE-40 on serotonin, norepinephrine and GABAergic systems in the rat cerebral cortex membranes were also examined. SCE and SCE-40 significantly reduced the immobility time in the forced swimming and tail suspension test in mice. Duration time of the open arms in the elevated plus maze test was significantly increased in the SCE and SCE-40-treated groups, compared with the saline-treated control group. SCE and its fraction SCE-40 significantly inhibited serotonin and norepinephrine transporter and GABA receptor binding, compared to the saline-treated group. In addition, serotonin and norepinephrine reuptake were significantly suppressed by SCE and SCE-40. These results demonstrate that SCE and SCE-40 produce anti-depressant and anti-anxiety effects through enhancing central serotonin, norepinephrine and GABAergic transmissions. These results suggest that SCE and SCE-40 as functional food might prove to be an effective antidepressant and anti-anxiety agent.