• Title/Summary/Keyword: brain stimulation

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A Study of the Effect of Acoustic Noise Attenuator on Auditory Functional MRI (소음 감쇠기를 이용한 청각의 뇌기능 자기공명영상)

  • Kim, S.H.;Kim, I.S.;Lee, J.J.;Park, J.A.;Lee, Y.J.;Yeo, J.R.;Bae, S.J.;Lee, S.H.;Chang, Y.
    • Investigative Magnetic Resonance Imaging
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    • v.9 no.2
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    • pp.134-139
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    • 2005
  • Purpose : To evaluate the usefulness of acoustic noise attenuator on auditory fMRI examination. Materials and methods : The acoustic noise attenuator consists of mask, earmuff and silicon earplug. The soft polyurethane sheet and polyurethane form , which has a good soundproof characteristic were used for mask and earmuff. Auditory fMRI experiments of 500 Hz pure tone stimulation were performed in three different cases; first all of mask, earmuff and earplug, secondly earmuff and earplug only and finally without attenuator in 4 normal hearing volunteers. For data acquisition, BOLD MR imaging technique was employed at a 1.5T MR scanner equipped with high performance gradient system. The raw data were analyzed using a SPM-99 analysis software and the activation maps were obtained. Results : In case of all items of acoustic attenuator used, the results revealed that activation was focused on primary auditory area. When only earmuff and earplug were used, the results showed that the activation spread over primary auditory and secondary associative areas. Last, when no device used, only weak activation was observed on the right auditory cortex. Conclusion : It is expected that the acoustic noise attenuator, which consists of earplugs, earmuffs and mask, is a very useful device in auditory fMRI study.

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Evaluation of the anticonvulsant effect of tropinone derivatives (Tropinone 유도체의 항경련성 효과 평가)

  • 김익수;서덕준
    • Journal of Life Science
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    • v.12 no.5
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    • pp.505-514
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    • 2002
  • The aim of this study was to evaluate the anticonvulsant activity of four agents derived from tropinone (T-1: 2,4-dipyrrolylmethenylnortropinone, T-2: 2,4-diphenylmethenylnortropinone, T-3 : 2,4-difurfurylmethenylnortropinone, T-4 : 2,4-dimethoxyphenylmethenylnortropinone) in NIH Swiss mouse. Pentylenetetrazole (nZ) was injected via intraperi-toniurn in mouse and Maximal Electroshock (MES) stimulation was through both conjunctivas by electrodes. Tropinone derivatives were treated at 15 minutes before PTZ or MES procedure. PIZ of 25 mg/kg induced generalized seizure in mouse, effects of tropinone derivatives on PTZ-induced seizure were monitored. Compared with control group, T-4 decreased seizure grade most effectively. Also T-4 increased onset time of PTZ-induced seizure. This result showed that T-4 is most effective on PTZ-induced seizure. In MES-induced seizure, T-1 decreased seizure grade and recovery time. nNOS expression in hippocampus and cortex were increased in nZ- and MES-induced seizure animals compared with control. Pretreatment of tropinone derivatives in PTZ-induced seizure did not affected nNOS expression in brain tissues, but T-1 and T-4 decreased nNOS expression in cortex of MES-induced seizure animals. These findings suggest that tropinone derivatives have specific anticonvulsant activities according to PTZ- and MES-induced seizure. 2,4- dimethoxyphenylmethenylnoroopinone is most effective in PTZ-induced seizure and 2,4-di methoxyphenylmethenylnortropinone is most effective in MES-induced seizure.

Effects of Virtual Reality Images on Body Stability : Focused on Hand Stability (VR 영상이 신체 안정성에 미치는 영향 : 손 안정성을 중심으로)

  • Han, Seung Jo;Kim, Sun-Uk;Koo, Kyo-Chan;Lee, Kyun-Joo;Cho, Min-Su
    • Journal of Digital Convergence
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    • v.15 no.8
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    • pp.391-400
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    • 2017
  • The purpose of this paper is to present the effect of image stimulation on body stability as a conceptual model and to investigate the effect of image stimulus(2D, VR) on body stability(hand stability) through experiments Recently, stereoscopic images such as virtual and augmented reality are combined with smart phones and exercise equipments, and the diffusion is becoming active. The possibility of a safety accident or human error is also increasing as it temporarily affects the balance of the body and hand stability after the image stimulus is removed. The conceptual model is presented based on the results of previous studies. Based on the experimental results, the conceptual model has been explained in combination with the human information processing process and cognitive resource models that take place in the brain. Twenty subjects were exposed to 2D and VR stimuli, and display fatigue was measured by cybersickness questionnaire and hand stability by hand steadiness tester. Experimental results show that VR images induce higher display fatigue and lower hand stability than 2D. In this study, it is meaningful that hand stability according to image type and display fatigue level which have not been tried yet is revealed through conceptual model and experiment.

Ghrelin Attenuates Dexamethasone-induced T-cell Apoptosis by Suppression of the Glucocorticoid Receptor (덱사메타손에 의해 유발된 흉선 T세포사멸에 대한 그렐린의 세포사멸억제효과)

  • Lee, Jun Ho
    • Journal of Life Science
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    • v.24 no.12
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    • pp.1356-1363
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    • 2014
  • Ghrelin is a 28 amino acid orexigenic peptide hormone that is secreted predominantly by tX/A cells in the stomach, and it plays a major role in energy homeostasis. Activated ghrelin has an n-octanoyl group covalently linked to the hydroxyl group of the Ser3 residue, which is critical for its binding to the G-protein coupled growth hormone secretagogue receptor-1a (GHS-R1a). According to recent reports, both ghrelin and its receptor, GHS-R1a, are expressed by a variety of immune cells, including T- and B-lymphocytes, monocytes, and dendritic cells, and ghrelin stimulation of leukocytes provides a potent immunomodulatory signal controlling systemic and age-associated inflammation and thymic involution. Here, we report that ghrelin protected murine thymocytes from dexamethasone (DEX)-induced cell death both in vivo and in vitro. Subsequently, we explored the molecular mechanisms of the antiapoptotic effect of ghrelin. According to our experiments, ghrelin inhibited the expression of proapoptotic proteins via the regulation of glucocorticoid receptor (GR) phosphorylation. As a result, ghrelin inhibited the proapoptotic activation of proteins, such as Caspase-3, PARP, and Bim. These data suggest that ghrelin, through GHS-R, inhibits the pathway to apoptosis by regulation of the proapoptotic protein activation signal pathway. They provide evidence that blocking apoptosis is an essential function of ghrelin during the development of thymocytes.

Classification of Negative Emotions based on Arousal Score and Physiological Signals using Neural Network (신경망을 이용한 다중 심리-생체 정보 기반의 부정 감성 분류)

  • Kim, Ahyoung;Jang, Eun-Hye;Sohn, Jin-Hun
    • Science of Emotion and Sensibility
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    • v.21 no.1
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    • pp.177-186
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    • 2018
  • The mechanism of emotion is complex and influenced by a variety of factors, so that it is crucial to analyze emotion in broad and diversified perspectives. In this study, we classified neutral and negative emotions(sadness, fear, surprise) using arousal evaluation, which is one of the psychological evaluation scales, as well as physiological signals. We have not only revealed the difference between physiological signals coupled to the emotions, but also assessed how accurate these emotions can be classified by our emotional recognizer based on neural network algorithm. A total of 146 participants(mean age $20.1{\pm}4.0$, male 41%) were emotionally stimulated while their physiological signals of the electrocardiogram, blood flow, and dermal activity were recorded. In addition, the participants evaluated their psychological states on the emotional rating scale in response to the emotional stimuli. Heart rate(HR), standard deviation(SDNN), blood flow(BVP), pulse wave transmission time(PTT), skin conduction level(SCL) and skin conduction response(SCR) were calculated before and after the emotional stimulation. As a result, the difference between physiological responses was verified corresponding to the emotions, and the highest emotion classification performance of 86.9% was obtained using the combined analysis of arousal and physiological features. This study suggests that negative emotion can be categorized by psychological and physiological evaluation along with the application of machine learning algorithm, which can contribute to the science and technology of detecting human emotion.

In vitro response of rat microglia and human polymorphonuclear cells (PMN) to immunoactive compounds

  • Lombardi, Valter RM;Eetcheverria, Ignacio;Fernandez-Novoa, Lucia;Diaz, Joaquin;Seoane, Silvia;Cacabelos, Ramon
    • Advances in Traditional Medicine
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    • v.5 no.3
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    • pp.216-230
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    • 2005
  • Although the field of study in immune enhancing compounds is relatively new, natural products from plants represent a rich and promising source of novel molecules with immunomodulating properties, Microglial cells, the main immune effector cells of the brain, usually display a ramified morphology and low expression levels of immunologically relevant antigens such as MHC class I and class II. Since any compound which participates in activation of phagocytic cells contributes to the production of potentially toxic factors, the search for convenient in vitro test-systems and study of mechanisms of action of these agents are of great interest. Human blood polymorphonuclear (PMN) cells and primary microglial cells isolated from Sprague-Dawley rats were used as cellular screening tests for study of phagocytosis-stimulating action of immunomodulating agents. Numbers of phagocytic activity were evaluated by the phagocyte ingestion of yeast cells and NO-synthase activity, nitrite production, and nitroblue tetrazolium test were determined after phagocyte stimulation. It was possible to demonstrate that indexes of phagocytic activity can be used as quantitative indicators for measurement immunomodulating activity. As a positive control, Zymosan A-induced phagocytosis in both PMN cells and primary microglial cells was used. $IFN-{\gamma}$ (0.1 -1 U/ml) stimulated phagocytosis in PMN cells 1.2 times after 2 - 3 h incubation, although at higher concentrations (10 - 100 U/ml) it strongly inhibited phagocytosis. In a similar way, at higher concentrations, $IFN-{\gamma}$ (100 - 500 U/ml) suppressed phagocytosis in zymosan-A stimulated microglial cells. When Polypodium leucotomus, cambricum and vulgare extracts were tested alone, increased levels of phagocytosis were observed in PMN. In addition, microglial cells showed both increased phagocytosis and MHC class-II antigen expressions. Surprisingly, when PMN and microglia were treated with a combination of Polypodium and $IFN-{\gamma}$, phagocytosis was not inhibited. We did not find changes in NO-synthase activity and nitrite production in both microglia and PMN cells activated by different immunomodulating agents. These results indicate that primary microglial cell cultures as well as human PMN cells can provide reproducible quantitative results in screening phagocytic activity of different immunoactive compounds. Furthermore, both inhibitory or activation mechanisms might be studied using these in vitro experimental approaches.

The Effect of Cognitive Rehabilitation Program Using Virtual Reality (VR) Contents on Cognitive function, Depression, Upper Extremity Function and Activities of Daily Living in the Elderly (가상현실(Virtual Reality) 콘텐츠를 활용한 인지재활프로그램이 노인의 인지기능, 우울감, 상지기능 및 일상생활능력에 미치는 영향)

  • Kim, Young-June;Park, Jin-Hong;Cho, Young-Suk;Kim, Keum-Sook
    • Journal of Convergence for Information Technology
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    • v.10 no.8
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    • pp.203-212
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    • 2020
  • The purpose of this study was to investigate the effects of cognitive rehabilitation programs using Virtual Reality(VR) content on the daily living abilities such as cognitive abilities, depression, and upper extremity functions of the elderly. The study group analyzed the effectiveness by separating the experimental group, which is the virtual reality cognitive rehabilitation application group, and the control group, the universal cognitive stimulation program application group. As a result of the study, the MMSE-K score improved by 13.0% in the experimental group and 2.3% in the control group. The improvement in each area of the experimental group was found to be 3.1% MBI, 7.1% MFT(Rt.), 3.5% MFT(Lt.), and 25.4% K-GDS. As a result of comparing the pre-post score change between each group, there was a significant difference between groups in daily living ability (p<.001) and MFT(Rt.)(p<.01). In addition, as a result of comparing the changes in absolute alpha waves to confirm the degree of depression through brain waves, there was no statistically significant difference. However, in the experimental group, it was confirmed that the average value increased to a positive value. This study is an experiment to verify the effectiveness of the cognitive rehabilitation program using virtual reality contents, and suggests a new intervention method to maintain and improve the daily life ability, cognitive function, depression and upper extremity function of the elderly.

Effects of Joint Mobilization Techniques on the Joint Receptors (관절 가동운동이 관절 감수기에 미치는 영향)

  • Kim, Suhn-Yeop
    • The Journal of Korean Academy of Orthopedic Manual Physical Therapy
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    • v.2 no.1
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    • pp.9-19
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    • 1996
  • Type I, II, III are regarded as "true" joint receptors, type IV is considered a class of pain receptor. Type I, II and III mechanoreceptors, via static and dynamic input, signal joint position, intraarticular pressure changes, and the direction, amplitude, and velocity of joint movements. Type I mechanoreceptor subserve both static and dynamic physiologic functions. Type I are found primarily in the stratum fibrosum of the joint capsule and ligaments. Type I receptors have a low threshold for activation and are allow to adapt to changes altering their firing frequency. Type II receptors have a low threshold for activation. These dynamic receptors respond to joint movement. Type II receptors are thus termed rapidly adapting. Type II joint receptors are located at the junction of the synovial membrane and fibrosum of the joint capsule and intraarticular and extraarticular fat pads. Type III receptors have been found in collateral ligaments of the joints of the extremities. Morphologically similar to Golgi tendon organ. These dynamic receptors have a high threshold to stimulation and are slowly adating. Type IV receptors possess free nerve ending that have been found in joint capsule and fat pads. They are not normally active, but respond to extreme mechanical deformation of the joint as well as to direct chemical or mechanical irritation. Small amplitude oscillatory and distraction movements(joint mobilization) techniques are used to stimulate the mechanoreceptors that may inhibit the transmission of nociceptors stimuli at the spinal cord or brain stem levels.

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Betulinic Acid Inhibits LPS-Induced MMP-9 Expression by Suppressing NF-kB Activation in BV2 Microglial Cells

  • Lee, Jae-Won;Choi, Yong-Joon;Kim, Song-In;Lee, Sue-Young;Kang, Sang-Soo;Kim, Nam-Ho;Kwon, Yong-Soo;Lee, Hee-Jae;Chun, Wan-Joo;Kim, Sung-Soo
    • Biomolecules & Therapeutics
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    • v.19 no.4
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    • pp.431-437
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    • 2011
  • Aberrant activation of microglia has been reported to cause neuronal damages by releasing a variety of pro-inflammatory cytokines. Besides where microglia become active, damages have been also observed in remote places, which is considered due to the migration of activated microglia. Therefore, an agent that could suppress abnormal activation of microglia and their subsequent migration might be valuable in activated microglia-related brain pathologies. The objective of the present study was to evaluate anti-inflammatory effects of betulinic acid on lipopolysaccharide (LPS)-stimulated BV2 microglial cells. Pretreatment of betulinic acid significantly attenuated LPS-induced NO production and protein expression of iNOS. Betulinic acid also significantly suppressed LPS-induced release and expression of cytokines such as TNF-${\alpha}$ and IL-$1{\beta}$. Furthermore, betulinic acid significantly uppressed LPS-induced MMP-9 expression, which has been suggested to play an important role in the migration of activated microglia. In order to understand the possible mechanism by which betulinic acid suppresses LPS-induced cytokine production and migration of microglia, the role of NF-kB, a major pro-inflammatory transcription factor, was examined. Betulinic acid significantly suppressed LPS-induced degradation of IKB, which retains NF-kB in the cytoplasm. Therefore, nuclear translocation of NF-kB upon LPS stimulation was significantly suppressed with betulinic acid. Taken together, the present study for the first time demonstrates that betulinic acid possesses anti-inflammatory activity through the suppression of nuclear translocation of NF-kB in BV2 microglial cells.

A Systematic Review on Non-Medication Intervention for Self- Injurious Behavior of Individuals With Autism Spectrum Disorders (자폐스펙트럼장애의 자해행동 중재에 관한 체계적 고찰 : 비약물치료 중심으로)

  • Kim, Seul-kee;Choi, Jeong-sil
    • The Journal of Korean Academy of Sensory Integration
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    • v.17 no.1
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    • pp.30-42
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    • 2019
  • Objective : The purpose of this study is to analyze non-medication interventions for self-injurious behavior of individuals with autism spectrum disorders, using a systematic review, and to provide evidence of appropriate services for individuals with autism spectrum disorders with self-injury behaviors in the clinical practice of occupational therapy. Methods : Using the electronic databases PubMed, Medline (ProQuest), DBpia, RISS, KISS, and NDSL, we searched for articles published in Korean and international journals from December 2004 to November 2018. The main search term were "Autism OR Autism Spectrum Disorder AND Therapy OR Treatment Or Intervention AND Self Injurious Behavior." Qualitative analysis was performed, and the results are presented in the PICO format. Results : A total of 12 articles were selected. The quality of the evidence was highest in level IV and level V. Single studies with an experimental design were the most common. Behavior therapy was the most common type of intervention. The next most common interventions were behavioral therapy, brain stimulation and control, and sensory integration therapy with behavioral therapy. The self-injury behaviors of individuals autism spectrum disorders were decreased, and was statistically significant. Conclusion : This study investigated the use of non-medication interventions for children with autism spectrum disorders who showed self-injury behavior. Future research should use higher-level designs, and investigate differences between various non-medication interventions.