• Annals of Clinical Neurophysiology
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• v.2 no.2
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• pp.107-113
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• 2000

Background & Objectives : Motor evoked potentials(MEPs) to magnetic trans cranial stimulation were performed to evaluate upper motor neuron involvement and relationship to lower motor neuron involvement in motor neuron disease patients. Method : MEPs were obtained in the 17 consecutive patients with motor neuron disease. These patients were divided into three group based on clinical evidence of upper and lower motor neuron involvement, bulbar symptom; amyotrophic lateral sclerosis(ALS), progressive muscular atrophy(PMA), progressive bulbar palsy(PBP). MEPs were recorded from abductor pollicis brevis and abductor hallucis muscles. Abnormal MEPs were defined by delayed central motor conduction time or absent MEP. Results : MEPs were abnormal in 64%(11/17) of patients; 100%(7/7) in ALS, 64%(4/7) in PMA, 0%(0/3) in PBP respectively. In 68 total recording muscles, 34 muscles had evidence of motor weakness and showed abnormal responses in 59%(20/34). Whereas 34 muscles with normal strength, only 3%(1/34) of muscles showed abnormal response. Conclusion : MEPs are well correlated with upper motor neuron signs in ALS and may detect masking upper motor neuron signs in PMA. The muscles with lower motor neuron sign(weakness) usually relate with abnormal MEPs reponses.

• BMB Reports
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• v.33 no.3
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• pp.202-207
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• 2000

The depletion of intracellular calcium stores by thapsigargin treatment evoked extracellular calcium-dependent membrane currents in Xenopus laevis oocytes. These currents have been compared to those evoked by microinjection of a calcium influx factor (CIF) purified from Jurkat T lymphocytes. The membrane currents elicited by thapsigargin treatment (peak current, $163{\pm}60$ nA) or CIF injection (peak current, $897{\pm}188$ nA) were both dependent on calcium entry, based on their eradication by the removal of extracellular calcium. The currents were, in both cases, attributed primarily to well-characterized $Ca^{2+}-dependent$ $Cl^-$ currents, based on their similar reversal potentials (-24 mV vs. -28 mV) and their inhibition by niflumic acid (a $Cl^-$ channel blocker). Currents induced by either thapsigargin treatment or CIF injection exhibited an identical pattern of inhibitory sensitivity to a panel of lanthanides, suggesting that thapsigargin treatment or CIF injection evoked $Cl^-$ currents by stimulating calcium influx through pharmacologically identical calcium channels. These results indicate that CIF acts on the same calcium entry pathway activated by the depletion of calcium stores and most lanthanides are novel pharmacological tools for the study of calcium entry in Xenopus oocytes.

• Annals of Clinical Neurophysiology
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• v.23 no.2
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• pp.69-81
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• 2021

Cortico-cortical evoked potential (CCEP) mapping is a rapidly developing method for visualizing the brain network and estimating cortical excitability. The CCEP comprises the early N1 component the occurs at 10-30 ms poststimulation, indicating anatomic connectivity, and the late N2 component that appears at < 200 ms poststimulation, suggesting long-lasting effective connectivity. A later component at 200-1,000 ms poststimulation can also appear as a delayed response in some studied areas. Such delayed responses occur in areas with changed excitability, such as an epileptogenic zone. CCEP mapping has been used to examine the brain connections causally in functional systems such as the language, auditory, and visual systems as well as in anatomic regions including the frontoparietal neocortices and hippocampal limbic areas. Task-based CCEPs can be used to measure behavior. In addition to evaluations of the brain connectome, single-pulse electrical stimulation (SPES) can reflect cortical excitability, and so it could be used to predict a seizure onset zone. CCEP brain mapping and SPES investigations could be applied both extraoperatively and intraoperatively. These underused electrophysiologic tools in basic and clinical neuroscience might be powerful methods for providing insight into measures of brain connectivity and dynamics. Analyses of CCEPs might enable us to identify causal relationships between brain areas during cortical processing, and to develop a new paradigm of effective therapeutic neuromodulation in the future.

• Proceedings of the Korean Society for Emotion and Sensibility Conference
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• 2011.11a
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• pp.3-4
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• 2011

• The Journal of Internal Korean Medicine
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• v.16 no.1
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• pp.104-129
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• 1995

Sabaeksan and Sabaeksangagaryureuk, a traditional prescription, has been used in Korea for many centuries as a treatment for chronic respiratory disease. The purpose of the present study was to determine the effect of Sabaeksan and Sabaeksangagaryureuk on acetylcholine-induced tracheal smooth muscle contraction in guinea pigs and norepinephrine-induced vascular smooth muscle contraction in pigs. Guinea pig (500g, female) were killed by CO2 exposure and a segment (8-10mm) of the thoracic trachea from each guinea pig and renal artery from each pig were cut into equal segments and mounted 'in pairs' in a tissue bath. Contractile force was measured with force displacement transducers under 0.5g loading tension. The dose of acetylcholine (Ach) and norepinephrine (NE) which evoked 50% of maximal response ($ED_{50}$) was obtained from cumulative dose response curves for acetylcholine (10-7-10-4M) and norepinephrine (10-7-10-4M). Contractions of tracheal smooth muscle evoked by Ach ($ED_{50}$) were inhibited significantly by Sabaeksan and Sabaeksangagaryureuk. Propranolol (10-7M) slightly but significantly attenuated the inhibitory effects of Sabaeksan and Sabaeksangagaryureuk. Indomethacin and methylene blue (10-7M) did not significantly alter the inhibitory effect of Sabaeksan and Sabaeksanga-garyureuk. Contractions of vascular smooth muscle evoked by NE (NE50) were inhibited significantly by Sabaeksan and Sabaeksangagaryureuk. Propranolol (10-7M) slightly but significantly attenuated the inhibitory effects of Sabaeksan and Sabaeksangagaryureuk. Indomethacin and methylene blue (10-7M) did not significantly alter the inhibitory effect of Sabaeksan and Sabaeksangagaryureuk. These results indicate that Sabaeksan and Sabaeksangagaryureuk can relax acetylcholine-induced contraction of guinea pig tracheal smooth muscle, and norepinephrine-induced contraction of pig vascular smooth muscle that this inhibition involves, in part, the relation of adrenergic receptor.

• The Korean Journal of Pain
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• v.19 no.2
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• pp.146-151
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• 2006

Background: Spinal cord stimulation is a well-established method for the management of several types of chronic and intractable pain. This form of stimulation elicits a tingling sensation (paresthesia) in the corresponding dermatomes. The goal of this study was to establish a correlation between the spinal levels of the implanted epidural electrodes and the paresthesia elicited due to stimulation of the neural structures. Methods: Thirty five patients, who received trial spinal cord stimulation, were evaluated. After the insertion of the lead to the selected position, the areas of paresthesia evoked by stimulation were evaluated. Results: Seventy-one percent of cases showed paresthesia in the shoulder area when the tip of the electrode was located between the C2⁣-C4 levels. At the upper extremities, paresthesia was evoked in 86⁣-93% of cases, regardless of the location of the electrode tip within the cervical spinal segments. The most common tip placement of the leads eliciting hand stimulation was at the C5 level. The most common level of electrode tip placement eliciting paresthesia of the anterior and posterior thigh and the foot were at the T7-⁣T12, T10⁣-L1 and T11-⁣L1 vertebral segments, respectively. Conclusions: Detailed knowledge of the patterns of stimulation induced paresthesia in relation to the spine level of the implanted electrodes has allowed the more consistent and successful placement of epidural electrodes at the desired spine level.

• Journal of Korean Ophthalmic Optics Society
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• v.5 no.2
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• pp.5-9
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• 2000

The visual evoked potential was electrophysiological method for the identify of the EEG response on visual cortex. This test was objective test method on the eye function. This study was used the visual evoked potential for the objective color test. The subjects was a normal color function in Korean adults. The test condition was performed on the differens distance and illumination. According to convergence condition of color vision target. On the appearance of EEG wave of visual stimulation on visual cortex. The most EEG wave style was delta wave, and the next amount wave form was beta wave and theta wave, and the least EEG wave form was alpha wave. The histogram of amplitude of EEG wave form was almost non-Gaussian shape, and the phase diagram of amplitude was almost all linear shape. On the kinds of color vision target, the frequency of EEG wave style appeared a similar results.

• Korean Journal of Acupuncture
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• v.17 no.1
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• pp.75-80
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• 2000

Fructus Aristolochiae has been used in Korea for many centuries as a treatment for various disease.The purpose of the present study is to determine the effect of Fructus Aristolochiae on norepinephrine(NE) induced blood vessel contraction in rabbits. Rabbit(2 kg, male) were killed by $CO_2$ exposure and a segment (8-10mm) of each rabbit was cut into equal segments and mounted in a tissue bath. Contractile force was measured with force displacement transducers under 2-3 g loading tension. The dose of norepinephrine(NE) which evoked 50% of maximal response ($ED_{50}$) was obtained from cumulative dose response curves for NE ($10^{-6}{\sim}10^{-3}M$). Contractions evoked by NE ($ED_{50}$) were inhibited significantly by Fructus Aristolochiae in abdominal aorta and femoral artery. Fructus Aristolochiae inhibited the relaxation pretreated propranolol and L-NNA in femoral artery. But Fructus Aristolochiae did not effect the relaxation pretreated ODQ in femoral artery and abdominal aorta. These results indicate that Fructus Aristolochiae can relax NE induced contraction of rabbit blood vessel selectively, and that this relaxation relates to nitric oxide synthesis and sympathetic action.

• Korean Journal of Biological Psychiatry
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• v.19 no.1
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• pp.29-37
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• 2012

The loudness dependence of the auditory evoked potential (LDAEP) has been proposed as a valid biomarker of central serotoninergic activity in humans. The specificity and sensitivity of the LDAEP to changes in serotonergic neurotransmission have recently been explored in many studies about pharmacology and genetics. The majority of evidence for an association between the LDAEP and serotonin activity has come from animal studies. Genetic association studies with the LDAEP have provided conflicting reports with additional evidence outlining sensitivity to other neurotransmitter systems including the dopamine and glutamatergic systems. The LDAEP has been revealed to reflect the pathophysiology of various psychiatric illnesses. There is supporting evidence that major psychiatric disorders have differential LDAEP activities. Overall, the LDAEP shows strong evidence as a potential predictor of antidepressant treatment response. It need to be explored whether the LDAEP could be a biological marker of various psychiatric diseases and treatment prediction of antidepressants and serotonin related drugs.

• Journal of the Institute of Electronics and Information Engineers
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• v.50 no.12
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• pp.261-269
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• 2013

In this paper, the evoked potential(EP) was represented by additive delay model to comply with the variational noisy response of stimulus-event synchronization. The hybrid method of delay compensated-Wiener filtered-ensemble averaging(DWEA) was proposed to enhance the EP signal distortion occurred during averaging procedure due to synchronization timing mismatch. The performance of DWEA has been tested by surrogated simulation, which is composed of synthesized arbitrary delay and arbitrary level of added noise. The performance of DWEA is better than those of Wiener filtered-ensemble averaging and of conventional ensemble averaging. DWEA is endurable up to added noise gain of 7 for 10 % mean square error limit. Throughout the experimentation observation, it has been demonstrated that DWEA can be applied to enhance the evoked potential having the synchronization mismatch with added noise.