• The Journal of Korean Physical Therapy
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• v.21 no.1
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• pp.73-80
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• 2009

Purpose: In order to examine difference in the activity of potential of spinal neurons and cortical neurons according to muscle contraction type in post stroke hemiplegic subjects and healthy subjects, the present study conducted an experiment as follows. Methods: The subjects in the experimental group were 17 left-side hemiplegic subjects (9 female, 8 male; mean age, 63.41$\pm$9.86 years) with the right hand as the dominant hand selected among post stroke hemiplegic subjects, and 17 age matched healthy control subjects (10 female, 7 male; mean age, 64.12$\pm$12.07 years). Movement-related cortical potentials (MRCPs) were measured using surface electromyography and electroencephalography while concentric and eccentric movements were made alternately. Results: As to the pattern of the activity of MRCP, which indicates the activity of motor cortical neurons, we found that the amplitude is high (p<0.01), the length of excitement is short (p<0.01) and the ascending gradient of amplitude to the peak increases (p<0.05) in post stroke hemiplegic subjects' lesion sites different from healthy subjects. Conclusion: The activity of cortical neurons was no difference in activity according to contraction type was observed in post stroke hemiplegic subjects' lesion sites. This suggests that there is no distinction in the activity of cortical neurons between concentric contraction and eccentric contraction. Accordingly, if post stroke hemiplegic subjects' activity of motor cortex is analyzed by measuring MRCPs, it is considered useful in research on neural plasticity or as a ground of clinical effects in the area of physical therapy for the central nervous system.

• YAKHAK HOEJI
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• v.40 no.6
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• pp.720-726
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• 1996

The neurotoxicity induced by L-glutamate in primary cultures of rat cortical cells could be attenuated by diterpene constituents of Ginkgo biloba leaves, ginkgolides A, B and C. At the concentration of 100 nM, ginkgolides up-regulated the activity of glutathione reductase in primary cultures of rat cortical cells exposed to 100 ${\mu}$M glutamate. Furthermore, ginkgolides increased the content of reduced glutathione in glutamate-treated cortical cells. However, ginkgolides showed little effect in reducing superoxide dismutase activity. Ginkgolides did, however, markedly block the production of malondialdehyde, a byproduct of lipid peroxidation in glutamate-treated rat cortical cells.

• The Journal of Korean Physical Therapy
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• v.23 no.6
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• pp.49-53
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• 2011

Purpose: The purpose of this study is to investigate whether dual-hemisphere transcranial direct current stimulation (tDCS) could induce more cortical activity, compared to single-hemisphere, using functional MRI (fMRI). Methods: One right-handed healthy subject was recruited. Three phases of dual-hemisphere tDCS (i.e. anodal tDCS over the left-dominant primary sensoriomotor cortex (SM1) and cathodal tDCS over the right-non dominant SM(1) were consecutively delivered on to a subject, during fMRI scanning. The voxel count and the intensity index in the averaged cortical map were analyzed among the three tDCS phases. Results: Our result showed that cortical activation was observed on all the three phases of the dual-hemisphere tDCS. Voxel count and intensity index were as following; 912 and 4.07 in the first phase, 1102 and 3.90 in the second phase, 1031 and 3.80 in the third phase. Conclusion: This study demonstrated that application of the dual-hemisphere tDCS could induce cortical activity and maintain to recruit cortical neurons. Our findings suggested that application of dual-hemisphere tDCS could produce efficiency of the ongoing tDCS effect to facilitate cortical excitability.

• Natural Product Sciences
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• v.14 no.3
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• pp.156-160
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• 2008

The methanolic extract of Rhus verniciflua Stokes (RVS-T) and its fractions (RVS-H, RVS-C, RVS-E and RVS-B) showed significant neuroprotective activity against glutamate-induced toxicity in primary cultures of rat cortical cells. RVS-B, which showed the most potent neuroprotective activity, was further fractionated to yield RVS-B5. Treatment of cortical cells with the RVS-T, RVS-B and RVS-B5 reduced the cellular ROS level and restored the reduced activities of glutathione reductase and SOD induced by glutamate. Although, the activity of glutathione peroxidase was not virtually changed by glutamate, RVS-B5 increased the glutathione peroxidase activity. In addition, these three tested fractions significantly restored the content of GSH which was decreased by glutamate insult in our cultures. Taken together, it could be postulated that RVS extract, in particular its fraction RVS-B5, protected neuronal cells against glutamate-induced neurotoxicity through acting on the antioxidative defense system.

• Journal of Pharmacopuncture
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• v.4 no.2
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• pp.49-56
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• 2001

This study was undertaken to determine whether Scutellaria baicalensis Georgi (SbG) extract exerts the protective effect against $HgCl_2$-induced alterations in membrane transport function in rabbit renal cortical slices. The slices were treated with 0.1 mM $HgCl_2$ for 60 min at $37^{\circ}C$. $HgCl_2$ caused an inhibition in PAH uptake by renal cortical slices. Such an effect was accompanied by depressed $Na^+-K^+$-ATPase activity and ATP depletion. SbG prevented $HgCl_2$-induced inhibition of PAH uptake in a dose-dependent manner at the concentration ranges of 0.01-0.1%. $HgCl_2$-induced inhibition of $Na^+-K^+$-ATPase activity and ATP depletion were significantly prevented by 0.05% SbG. These results suggest that SbG prevents $HgCl_2$-induced alterations in membrane transport function in rabbit renal cortical slices. Such protective effects of SbG may be attributed to inhibition of peroxidation of membrane lipid.

• The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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• v.13 no.2
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• pp.200-210
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• 2000

objective to ascertain whether the concept of the therapeutic side is associated with changes in the blind sport mapping that represents the brain function. design Physiological blind spot maps were used as an integer of brain activity before and after acupuncture needling on the meridian point Hapkok(合谷) and Techung(太衝) in the unilateral side decided by double-blind controlled study(20 subjects). setting outpatient clinic participants: adult volunteers intervention twenty subjects were divided into two comparative groups and underwent specific acupuncture therapy on the unilateral side. Blinded examiners obtained reproducible pre and post-acupuncture cortical maps, which were subjected to statistical analysis. main outcome measures Brain activity was demonstrated by reproducible circumferential measurements of cortical hemispheric blind spot maps before and after acupuncture on the unilateral side. in case of acupuncture needling on the ipsilateral side of an enlarged side of bilnd spot, there were reduction of blind spot in 7 cases of 10 subjects, and enlargement in 3 cases. in case of acupuncture needling on the contralateral side of the enlarged side of blind spot, there were enlargement of blind spot in 6 cases of 10 subjects, and reduction in 4 cases. results the significant changes in the blind spots before and after acupuncture were observed Acupuncture needlings on the ipsilateral or contralateral side of an enlarged cortical map were associated with the concept of the therapeutic side traditionally accepted in the oriental medical society. Acupuncture needling on the ipsilateral side of an enlarged blind spot map is associated with the reduction of map, and increaed contralateral cortical activity. Acupuncture needling on the side opposite an enlarged blind spot map is associated with the enlargement of map, and decreased cortical activity. conclusion Reproducible maps of cortical responses can be used to measure the neurological consequences of acupuncture needling. Acupuncture can affect the somatic sensory informations that reach to the contralateral thalamus, and so affect thalamic integration. we found that acupuncture therapy may be associated with an increase or a decrease in brain function depending on the side of acupuncture needling. thus, the traditional concept of the contralateral therapeutic theory in acupuncture approach has the clinical significance in the view of brain function.

• Journal of Biomedical Engineering Research
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• v.28 no.2
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• pp.258-264
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• 2007

Spatiotemporal changes of brain rhythmic activity at a certain frequency have been usually monitored in real time using scalp potential maps of multi-channel electroencephalography(EEG) or magnetic field maps of magnetoencephalography(MEG). In the present study, we investigate if it is possible to implement a real-time brain activity monitoring system which can monitor spatiotemporal changes of cortical rhythmic activity on a subject's cortical surface, neither on a sensor plane nor on a standard brain model, with a high temporal resolution. In the suggested system, a frequency domain inverse operator is preliminarily constructed, considering the individual subject's anatomical information, noise level, and sensor configurations. Spectral current power at each cortical vertex is then calculated for the Fourier transforms of successive sections of continuous data, when a single frequency or particular frequency band is given. An offline study which perfectly simulated the suggested system demonstrates that cortical rhythmic source changes can be monitored at the cortical level with a maximal delay time of about 200 ms, when 18 channel EEG data are analyzed under Pentium4 3.4GHz environment. Two sets of artifact-free, eye closed, resting EEG data acquired from a dementia patient and a normal male subject were used to show the feasibility of the suggested system. Factors influencing the computational delay are investigated and possible applications of the system are discussed as well.

• The Journal of Korean Physical Therapy
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• v.21 no.4
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• pp.65-71
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• 2009

Purpose: Transcranial direct current stimulation (tDCS) is a useful method for modulating the brain activity. This study compared the effect of continuous and interrupted tDCS using the change in the movement related cortical potential. Methods: Thirty healthy participants (male: 18 and female: 12) were assigned randomly to three groups; sham tDCS, continuous tDCS, which the current continuously flowed for 10 minutes, and interrupted tDCS, which the interrupted current flowed for 10 minutes (repetition: 4sec stimulation and 5sec rest) at an intensity of 1mA with anodal polarity. The effect of tDCS on the right primary motor area was measured from the movement related cortical potential (MRCP) before and after the experiment. MRCP consisted of the bereitshaftspotential (BP) and negative slope potential (NS) at Cz and C4. Results: Continuous and interrupted tDCS showed a significant difference in the changes in the BP, NS at Cz and C4 compared to the sham tDCS. However, there was no significant difference between the continuous tDCS and interrupted tDCS. Conclusion: The change in cortical activity by continuous and interrupted tDCS results from an improvement in the MRCP. An interrupted tDCS may be a safe and useful modality for stimulating the cortical region.

• The Journal of Korean Physical Therapy
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• v.24 no.4
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• pp.262-267
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• 2012

Purpose: This study was designed to analyze the differences in cerebral cortex activity of the elderly after extracting the movement related cortical potentials (MRCPs) from electroencephalogram (EEG) during a concentric and eccentric contraction of the elbow joint flexors, and entering them into the brain-mapping program to make the images. Methods: Right-dominant normal elderly people were divided into an eccentric contraction group and a concentric contraction group. Then, their MRCPs were measured using EEG and sEMG, during an eccentric and concentric contraction. Then, they were converted into images using the brain-mapping program. Results: Eccentric contraction group's $C_3$ and Cz showed statistically higher mean values of MRCP positive potential than the concentric contraction group. Conclusion: Researching a cerebral cortex activity, using MRCP, would provide basic data for clinical neuro-physiological researches on aging or neural plasticity of patients with a central nervous system injury.

• YAKHAK HOEJI
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• v.45 no.4
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• pp.419-425
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• 2001

The neuronal cell death induced by excess glutamate (Glu) has been implicated in many acute and chronic neurodegenerative diseases including cerebral ischemia. Glu-induced elevation of intra-cellular $Ca^{2+}$ plays a critical role in the excitotoxicity, partly through the activation of a variety of $Ca^{2+}$ dependent enzymes. In the present study, we investigated the Glu-induced modulation of $Ca^{2+}$/calmodulin-dependent protein kinase IV (CaMK IV), a multifunctional enzyme abundantly present in the nuclei of neurons. The exposure of cultured rat cortical neurons to $100{\mu}$M Glu for 3 min dramatically increased CaMK IV activity up to 4.5-fold of the control-treated enzyme activity. The activation was very rapid, reaching peak at 3 min and then declined gradually. Under the same experimental conditions, time-dependent acute and delayed neuronal cell death was observed. Immunoblot analyses using specific antibodies showed that the expressions of CaMK IV and $CaMKK_{\alpha}$ were time-dependently modulated by Glu. Taken together, these results imply that the modulation of CaMK IV activity by Glu may be involved in the cascade of events resulting in neuronal cell death in cortical cultures.