• Toxicological Research
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• v.12 no.2
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• pp.195-201
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• 1996

Endotoxic shock causes death in humans and animals via extreme hypoperfusion of peripheral organs. A massive production of nitric oxide (NO) both from the endothelical cells and smooth muscle cells has been proposed as a possible mechanism in this process. Since NO attenuated the contractility to vasoconstricting agents such as norepinephrine (NE) by directly acting on the smooth muscle cells, this mechanism was considered mainly as a postsynaptic mechanism. In this research it was investigated whether NO, thus released, also participates in the presynaptic events for the regulation of vascular tone in endotoxic shock. The role of NO was studied by adding NO donors or NO synthase inhibitor $N^\omega $methyl-L-arginine (NMA) in stimulated sympathetic nerves of the mesenteric vascular bed and the Langendorff heart of rats. Sodium nitroprusside (SNP), an NO donor, reduced the pressor responses of isolated mesenteric artery either to electrical stimulation or exogenously administered phenylephrine (PE). In this mesentery, although neither agent influenced NE release, in the presence of the adrenergic $\alpha_2$-receptor antagonist yohimbine, elecrical stimulation-evoked NE release was augumented by SNP. In the heart SNP facilitated the NE release induced by electrical stimulation, while NMA had no effect. From these results it is proposed that there exists a local reflex phenomenon in the junction between the sympathetic nerve terminals and the smooth muscle of resistance blood vessels; by which sympathetic responses are reduced by NO at the postjunctional level while NO facilitates NE release contributing to augumentation of sympathetic tone. All these facts suggest that NO produced during endotoxic shock has dual effects: whereas NO blunts the vasoconstrictive activity of NE at the postsynaptic level, NO presynaptically facilitates the release of NE from sympathetic nerve terminals.

• Stress
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• v.25 no.4
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• pp.239-245
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• 2017

Background: A quasi-experimental study with non-equivalent control groups was performed to determine an effect of aromatherapy foot bath on stress and autonomic nervous activity. Methods: To confirm the effect of aromatherapy foot bath, aromatherapy foot bath group was asked to have a bathing by dropping 0.5 cc in 18 L water after blending with a ratio of 6:3:1 with essential oil lavender, lemon, and tea tree and a foot bath group was asked for bathing only by water. Results: Aromatherapy foot bath group showed significant decrease in subjective stress score (t=3.465, p=0.001) and stress index (t=3.021, p=0.004) in addition to simultaneous increase in sympathetic nervous activity (t=-2.913, p=0.005). However, no significant stimulation of parasympathetic nervous system was observed (t=-1.831, p=0.072). Conclusions: As aromatherapy foot bath is a possible effective intervention for stress relief, it can be applied as an effective method to relieve the stress for healthy adults and patients.

• Journal of the Korea Convergence Society
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• v.12 no.2
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• pp.61-66
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• 2021

This study aimed to investigate the effect of changes in pain on the autonomic nervous system and brain waves after inducing delayed-onset muscle soreness(DOMS). Based on voluntary participation, 28 participants with induced-DOMS were randomly divided into control(non-treatment, n=14) and experiment groups(transcutaneous electrical nerve stimulation (TENS) and kinesio taping, n=14). Intervention was performed from first day to fifth days after the onset of DOMS. Measurements were performed using the Visual Analogue Scale(VAS), Heart Rate Variability(HRV), and brain wave before DOMS induction, 24 hours after, fifth day after, and eighth day after. According to the study results, when DOMS occurred, the activity of the sympathetic nervous system was increased or the activity of the parasympathetic nervous system was suppressed, and reduction of pain due to interventions showed the opposite activity. A decreased in alpha was seen during pain, but was not significant. These results will help develop and study pain management and treatment strategies.

• Journal of Magnetics
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• v.18 no.2
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• pp.192-196
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• 2013

We have investigated the changes of electroencephalography (EEG) and electrocardiography (ECG) under pulsed magnetic field (PMF) and acupuncture stimulus on acupoint PC9. In order to compare quantitatively the effect of PMF and acupuncture stimulus, the difference of alpha activities are calculated from EEG spectra, and the spectrum curves of ECG were analyzed in the frequency domain of heart rate variability (HRV). The increase of alpha activities after both stimuli could be explained that the impulse of stimulus on PC9 might pass through sensory nerve following meridian and approach the cerebral cortex, causing the central nervous system (CNS) to be activated for pacifying emotion and calming the mind. The decrease in sympathovagal activity of HRV after both stimuli indicates that parasympathetic nerves were activated and the sympathetic nerves were in constrained condition. These findings suggest that PMF could be patient-friendly alternative non-invasive medical treatment for influencing human physiology, in comparison with acupuncture inserting the needle and inducing nervous and anxious state to subject.

• Journal of Biomedical Engineering Research
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• v.44 no.1
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• pp.33-40
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• 2023

Transcutaneous auricular vagus nerve stimulation (taVNS) is known to be effective in improving symptoms of numerous diseases such as depression and epilepsy by increasing vagus nerve activity through electrical stimulation. The purpose of this study is to investigate the effect of vagus nerve stimulation on the activity of autonomic nervous system and the changes in postprandial blood glucose levels. Seven healthy adults participated in a non-invasive transcutaneous auricular vagus nerve stimulation experiment. taVNS (25 Hz, 200 ㎲, biphasic pulse) was applied to the cymba concha (taVNS group) or the earlobe (Sham-taVNS group) of the left ear. As autonomic nervous system signals, skin conductance level, skin temperature, and heart rate were recorded during the application of taVNS. Postprandial blood glucose changes due to food intake were recorded at 5 min intervals for 25 minutes after taVNS or sham-taVNS. The taVNS showed a significantly lower skin conductance level than the shamtaVNS (p < 0.05). The increase rate of postprandial blood glucose was significantly lower in the taVNS than in the sham-taVNS (p < 0.05). These results showed that taVNS reduced the activity of the sympathetic nerve system and alleviated early rise in postprandial blood glucose. Although further studies in diabetic patients are needed, this study suggest that taVNS has a potential for clinical use to improve postprandial blood glucose.

• Journal of Korean Society of Forest Science
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• v.108 no.3
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• pp.440-453
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• 2019

This study was carried out to investigate the effect of watching a two-dimensional (2D) forest video and a virtual reality (VR) forest video on stress reduction in adults. Experiments were conducted in an artificial climate room, and 40 subjects participated. After inducing stress in the subjects, subjects watched a 2D gray video, 2D forest video, or VR forest video for 5 mins. The autonomic nervous system activity was evaluated continuously in terms of measured heart rate variability during the experiment. After each experiment, the subject's psychological state was evaluated using a questionnaire. The 2D forest video decreased the viewer's stress index, increased HF, and reduced heart rate compared with the 2D gray video. The VR forest video had a greater stress index reduction effect, LF/HF increase effect, and heart rate reduction effect than the 2D gray video. Psychological measurements showed that subjects felt more comfortable, natural, and calm when watching the 2D gray video, 2D forest video or VR forest video. We also found that the 2D forest video and VR forest video increased positive emotions and reduced negative emotions compared to the 2D gray video. Based on these results, it can be concluded that watching the 2D forest and VR forest videos reduces the stress index and heart rate compared with watching the 2D gray video. Thus, it is considered that the 2D forest video increases the activity of the parasympathetic nervous system, and the VR forest video increases the activity of the sympathetic nervous system. The increased activity of the sympathetic nervous system upon watching the VR forest video is judged to be positive sympathetic nerve activity, such as novelty and curiosity, and not negative sympathetic activity, such as stress and tension. The results of this study are expected to be the basis for examining the visual effects of forest healing, with hope that the utilization of VR, the technology of the fourth industrial revolution in the forestry field, will broaden.

• Sleep Medicine and Psychophysiology
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• v.12 no.1
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• pp.17-22
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• 2005

Sleep-disordered breathing (SDB) is associated with increased cardiovascular and cerebrovascular morbidity. Epidemiological and clinic-based studies have shown that SDB is related to impaired glucose tolerance and increased insulin resistance, independent of obesity. Despite of a consistent association between SDB and impaired glucose-insulin metabolism, the mechanism underlying this relationship has not been fully elucidated. It is recognized that hypoxemia and hypercapnia that occur in SDB provoke sympathetic nervous activity and catecholamine, epinephrine and norepinephrine, and cortisol are released. Sympathetic hyperactivity and increased catecholamines can impair glucose homeostasis by increasing glycogenolysis and gluconeogenesis, which can result in increased circulating insulin levels and increased risk of insulin resistance. A prospective study is needed to investigate the causal relationship between SDB and impaired glucose-insulin metabolism in a healthy population without diabetes, hypertension and obesity as etiologic risk factors.

• Archives of Obesity and Metabolism
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• v.2 no.2
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• pp.37-44
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• 2023

Weight gain is defined as the increase in body weight, increasing the prevalence of obesity, and results in metabolic diseases. Weight gain was reportedly caused by the interaction between the obesogenic environmental factors and individual metabolic factors. Sociodemographic and environmental factors (demographic factors, lifestyle/behavioral factors, food/nutritional factors, socioeconomic factors), drug-related secondary causes (some of the corticosteroids, antihyperglycemics, antihypertensives, antidepressants, etc.), and metabolic factors (aging and hormonal changes, menopause and decreased sex hormones, decreased adipocyte degradation, decreased fibroblast growth factor 21, central sympathetic nervous system hyperactivity, decreased sympathetic-adrenomedullary system activity) are significant factors related to weight gain. It is crucial to prevent weight gain and maintain an ideal weight, but studies on the risk factors of weight gain are insufficient. Therefore, this study evaluated the factors associated with weight gain to find strategies for preventing unnecessary weight gain.

• The Korean Journal of Physiology and Pharmacology
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• v.16 no.1
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• pp.25-30
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• 2012

Under some pathological conditions as bile flow obstruction or liver diseases with the enterohepatic circulation being disrupted, regurgitation of bile acids into the systemic circulation occurs and the plasma level of bile acids increases. Bile acids in circulation may affect the nervous system. We examined this possibility by studying the effects of bile acids on gating of neuronal (N)-type $Ca^{2+}$ channel that is essential for neurotransmitter release at synapses of the peripheral and central nervous system. N-type $Ca^{2+}$ channel currents were recorded from bullfrog sympathetic neuron under a cell-attached mode using 100 mM $Ba^{2+}$ as a charge carrier. Cholic acid (CA, $10^{-6}M$) that is relatively hydrophilic thus less cytotoxic was included in the pipette solution. CA suppressed the open probability of N-type $Ca^{2+}$ channel, which appeared to be due to an increase in (no activity) sweeps. For example, the proportion of sweep in the presence of CA was ~40% at +40 mV as compared with ~8% in the control recorded without CA. Other single channel properties including slope conductance, single channel current amplitude, open and shut times were not significantly affected by CA being present. The results suggest that CA could modulate N-type $Ca^{2+}$ channel gating at a concentration as low as $10^{-6}M$. Bile acids have been shown to activate nonselective cation conductance and depolarize the cell membrane. Under pathological conditions with increased circulating bile acids, CA suppression of N-type $Ca^{2+}$ channel function may be beneficial against overexcitation of the synapses.

• The Journal of the Korea Contents Association
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• v.17 no.4
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• pp.219-228
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• 2017

This study is designed as a non-equivalent controlled before-and-after quasi-experimental study by having a control group for the effect of the interpersonal caring music activity program in children of single-parent families. Data collection was carried out in 22 children of single-parent families as the study group and in 23 children as the control group recruited from 22 community centers for children located in N city from July to September, 2014. As the study tool, the Heart Rate Variability (HRV) was used to measure loneliness, self-esteem scale and the stress response. With the collected data and using SPSS 18.0 for Window program, the Homogeneity test between the study group and the control group was conducted by using t-test and ${\chi}^2$-test while the study hypotheses were verified by analyzing with the independent t-test. The results of the study are as follows. Loneliness and self-esteem of the subjects did not show significant difference in the study groups. The sympathetic nervous system activity (normalized LF) has been lowered and the parasympathetic nervous system activity (normalized HF) has been increased as the stress response, while the sympathetic and the parasympathetic nervous system activity ratio (LF/ HF) score was lowered with significant difference, which had supported the hypotheses. Based on these results of this study, the interpersonal caring music activity program can be utilized as a stress management program for the children of single-parent families during a short period of time.