• 제목/요약/키워드: Cortical activity

검색결과 240건 처리시간 0.033초

근위축성 측상경화증 환자에서 등세모근의 신경생리학적 검사 (The Electrophysiological Studies of the Trapezius Muscle in Patients with Amyotrophic Lateral Sclerosis)

  • 조중양;전종은;이광우
    • Annals of Clinical Neurophysiology
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    • 제6권2호
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    • pp.85-91
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    • 2004
  • Background: Needle electromyography (EMG) and motor evoked potential (MEP) of the genioglossus (tongue) are difficult to perform in evaluations of the craniobulbar region in amyotrophic lateral sclerosis (ALS). Therefore, we investigated the yields of needle EMG and MEP recorded from the upper trapezius, since it receives innervation from the lower medulla and upper cervical cord. Methods: Needle EMG and MEP of the upper trapezius were obtained in 17 consecutive ALS patients. The needle EMG parameters recorded included abnormal spontaneous activity and motor unit action potential (MUAP) morphology. An upper motor neuron (UMN) lesion was presumed when either response to cortical stimulation was absent, or the central conduction time was delayed (>mean+2SD). Results: Of the five patients with bulbar-onset ALS, four had abnormalities in the upper trapezius and four in the tongue by needle EMG. In contrast, of the 12 patients with limb-onset ALS, 11 had abnormalities in the upper trapezius, and only five in the tongue. When MEP was performed, it was found that three of the five patients with bulbar symptoms and three of the six patients with isolated limb involvement had abnormal MEP findings. Conclusions: Electrophysiological studies of the upper trapezius are more sensitive those of the tongue in patients without bulbar symptoms. Thus, needle EMG and MEP of the upper trapezius are alternative tools for assessing bulbar and rostral neuraxial involvement in the diagnosis of ALS.

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파킨슨씨병 모델 흰쥐에서 줄무늬체 도파민 수용체의 발현에 대한 연구 (Experimental Study on the Expression of Striatal Dopamine Receptors in the Rat Model of Parkinsonism)

  • 오창완;한대희;정천기;조사선;박경한;김용식;박찬웅
    • Journal of Korean Neurosurgical Society
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    • 제29권2호
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    • pp.155-166
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    • 2000
  • This study was designed to investigate the underlying mechanisms for the temporal changes of the striatal dopamine D2 receptors in the rat model of parkinsonism. After injection of the 6-hydroxydopamine into the substantia nigra of adult rats, we measured the receptor binding capacity(Bmax), mRNA and protein of the D2 receptor at 2, 4 and 8 weeks. Following the lesion, mRNA and protein were elevated simultaneously on both sides of the striata. They showed more increase on the normal side at 2 and 4 weeks, and then they were almost equally abundant on both sides at 8 weeks. We also observed their increased production in the diffuse cortical and subcortical regions. The Bmax value also increased bilaterally in both striata, and was higher on the normal side at 2 weeks and then on the lesioned side at 4 and 8 weeks. These findings suggest that production of the striatal D2 receptor is regulated at the transcriptional level in this animal model. They also imply that this control may be mediated through a pathway which can have influence on the whole brain, rather than the local control of the dopamine content alone. The measured functional activity(Bmax) of the D2 receptor was not proportional to the amount of the receptor mRNA and proteins produced. This difference may be explained by the post-translational modification of the receptor proteins, which may be controlled by such factor as the local concentration of dopamine.

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fMRI를 이용한 성인 편마비의 항조절점 운동이 대뇌피질의 활성화에 미치는 효과 (The Effect on Activity of Cerebral Cortex by Key-point Control of The Adult Hemiplegia with fMRI)

  • 이원길
    • The Journal of Korean Physical Therapy
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    • 제15권3호
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    • pp.295-345
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    • 2003
  • This study investigated activation of cerebral cortex in patients with hemiplegia that was caused by neural damage. Key-point control movement therapy of Bobath was performed for 9 weeks in 3 subjects with hemiplegia and fMRI was used to compare and analyze activated degree of cerebral cortex in these subjects. fMRI was conducted using the blood oxygen level-dependent(BOLD) technique at 3.0T MR scanner with a standard head coil. The motor activation task consisted of finger flexion-extension exercise in six cycles(one half-cycles = 8 scans = $3\;sec{\times}\;8\;=\;24\;sec$). Subjects performed this task according to visual stimulus that sign of right hand or left hand twinkled(500ms on, 500ms off). After mapping activation of cerebral motor cortex on hand motor function, below results were obtained. 1. Activation decreased in primary motor area, whereas it increased in supplementary motor area and visual association area(p<.001). 2. Activation was observed in bilateral medial frontal gyrus, middle frontal gyrus of left cerebrum, inferior frontal gyrus, inter-hemispheric, fusiform gyrus of right cerebrum, superior parietal lobule of parietal lobe and precuneus in subjedt 1, parahippocampal gyrus of limbic lobe and cingulate gyrus in subject 2, and inferior frontal gyrus of right frontal lobe, middle frontal gyrus, and inferior parietal lobule of left cerebrum in subject 3 (p<.001). 3. Activation cluster extended in declive of right cellebellum posterior lobe in subject 1, culmen of anterior lobe and declive of posterior lobe in subject 2, and dentate gyrus of anterior lobe, culmen and tuber of posterior lobe in subject 3 (p<.001). In conclusion, these data showed that Key-point control movement therapy of Bobath after stroke affect cerebral cortex activation by increasing efficiency of cortical networks. Therefore mapping of brain neural network activation is useful for plasticity and reorganization of cerebral cortex and cortico-spinal tract of motor recovery mechanisms after stroke.

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Methanol Extract of Longanae Arillus Regulates Sleep Architecture and EEG Power Spectra in Restraint-Stressed Rats

  • Ma, Yuan;Eun, Jae-Soon;Lee, Kwang-Seung;Lee, Eun-Sil;Kim, Chung-Soo;Hwang, Bang-Yeon;Oh, Ki-Wan
    • Natural Product Sciences
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    • 제15권4호
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    • pp.213-221
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    • 2009
  • Longanae Arillus (the rind of fruits of Dimocarpus longan) has been consumed for the treatment of insomnia and anxiety in Asia. To provide further scientific basis to traditional uses of this fruit on insomnia, we evaluated the effects of methanol extract of Longanae Arillus (MELA) on the alteration of sleep architecture and electroencephalogram (EEG) power spectra in acutely and chronically restraint-stressed rats. Following postsurgical recovery, Polygraphic signs of sleep-wake activities were recorded for 24 h after MELA administration in rats. Rats in the acute stress and chronic stress were administered with MELA for 10 days. On the $8^{th},\;9^{th}\;and\;10^{th}$ day of MELA administration, the rats were stressed for 3 h once per day. On the $10^{th}$ day and 1 h after MELA administration, the rats were stressed once for 22 h in the chronic stress group. Acute and chronic stress induced alternations in cortex EEG recordings during non-rapid eye movement (NREM), rapid eye movement (REM) sleep and wakefulness. MELA shortened the total and REM sleep and increased the wakefulness in night time recording without changing daytime recordings. Chronic stress increased wakefulness and REM sleep, decreased total and NREM sleep in the daytime recording, and increased REM and decreased NREM sleep without changing total sleep and wakefulness in night time recording. These findings suggest that MELA ameliorated the alterations in REM and NREM sleep of acutely and chronically stressed rats via modulation of cortical ${\alpha}-$, ${\theta}-$ and ${\delta}-$ wave activity.

Blood Pulsation의 효과가 뇌 활성화에 미치는 영향을 알아보는 방법 (Estimation Method for Brain Activities are Influenced by Blood Pulsation Effect)

  • 이원호;구정훈;이형래;한기완;박진식;김재진;윤강준;김인영;김선일
    • 대한의용생체공학회:의공학회지
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    • 제28권3호
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    • pp.338-343
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    • 2007
  • BOLD T2*-weighted MR images reflects cortical blood flow and oxygenation alterations. fMRI study relies on the detection of localized changes in BOLD signal intensity. Since fMRI measures the very small modulations in BOLD signal intensity that occur during changes in brain activity, it is also very sensitive to small signal intensity variations caused by physiologic noise during the scan. Due to the complexity of movement of various organs associated with heart beat, it is important to reduce cardiac related noise rather than other physiological noise which could be required with relatively simple method. Therefore, a number of methods have been developed for the estimation and reduction of cardiac noise in fMRI study. But, each method has limitation. In this study, we proposed a new estimation method for brain activities influenced by blood pulsation effect using regression analysis with blood pulsation signal and the correspond slice of fMRI. We could find out that the right anterior cingulate cortex and right olfactory cortex and left olfactory cortex were largely influenced by blood pulsation effect for new method. These observed areas are mostly on the structure of anterior cerebral artery in the brain. That is convinced with that our method would be valid and our new method is easier to apply in practice and reduce computational burden than the retrospective method.

Altered Cerebral Vasomotion with Decreased CGRP Level in Pial Arteries of Spontaneously Hypertensive Rats

  • Lee, Kwang-Ho;Choi, Jae-Moon;Hong, Ki-Whan
    • The Korean Journal of Physiology and Pharmacology
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    • 제2권5호
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    • pp.573-580
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    • 1998
  • The study aims to identify the mechanism (s) underlying the altered vasodilatory responses of the pial artery of spontaneously hypertensive rats (SHR) under a hypothesis that calcitonin gene-related peptide (CGRP) exerts a modulator role in the autoregulation of cerebral blood flow (CBF). The animals were divided into four groups: 1) Sprague-Dawley rats (SDR), 2) Wistar rats (WR), 3) SHR with high blood pressure $(BP{\ge}150\;mmHg),$ and 4) SHR with normotensive BP $({\le}150\;mmHg).$ The lower limit of CBF autoregulation in SHR shifted to a higher BP $(82.8{\pm}9.3\'mmHg,\;P<0.05)$ than that in SDR $(58.9{\pm}5.7\;mmHg)$. In SHR, whether the BP levels were high or normotensive, the vasodilator responses to a stepwise hypotension were significantly attenuated unlike with SDR and WR. When artificial cerebrospinal fluid (CSF) containing capsaicin $(3{\times}10^{-7}\;M)$ was suffused over the cortical surface, a transient increase in pial arterial diameter was observed in the SHR with high or normotensive BP. In contrast, SDR and WR showed a large increase in diameter, and the increase was sustained for over 10 minutes. In line with these results, the basal releases of CGRP-like immunoreactivity (CGRP-LI) in the isolated pial arteries from SHR with high and normotensive BP were $12.5{\pm}1.4\;and\;9.8{\pm}2.8\;fmole/mm^2/60\;min\;(P<0.05)$, while those from SDR and WR were $25.5{\pm}3.1\;and\;24.6{\pm}3.1\;fmole/mm^2/60\;min,$ respectively. The isolated basilar arteries showed similar results to those of the pial arteries in SHR. Thus, it is summarized that, in the SHR, the reduced autoregulatory vasodilator responses to stepwise hypotension and capsaicin may be, in part, ascribed to the decreased release of CGRP from the perivascular sensory nerve fibers of the pial arteries, and that altered vasomotor activity in SHR may not be related with the hypertensive tone.

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Chronophin activation is necessary in Doxorubicin-induced actin cytoskeleton alteration

  • Lee, Su Jin;Park, Jeen Woo;Kang, Beom Sik;Lee, Dong-Seok;Lee, Hyun-Shik;Choi, Sooyoung;Kwon, Oh-Shin
    • BMB Reports
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    • 제50권6호
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    • pp.335-340
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    • 2017
  • Although doxorubicin (Dox)-induced oxidative stress is known to be associated with cytotoxicity, the precise mechanism remains unclear. Genotoxic stress not only generates free radicals, but also affects actin cytoskeleton stability. We showed that Dox-induced RhoA signaling stimulated actin cytoskeleton alterations, resulting in central stress fiber disruption at early time points and cell periphery cortical actin formation at a later stage, in HeLa cells. Interestingly, activation of a cofilin phosphatase, chronophin (CIN), was initially evoked by Dox-induced RhoA signaling, resulting in a rapid phosphorylated cofilin turnover leading to actin cytoskeleton remodeling. In addition, a novel interaction between CIN and $14-3-3{\zeta}$ was detected in the absence of Dox treatment. We demonstrated that CIN activity is quite contrary to $14-3-3{\zeta}$ binding, and the interaction leads to enhanced phosphorylated cofilin levels. Therefore, initial CIN activation regulation could be critical in Dox-induced actin cytoskeleton remodeling through RhoA/cofilin signaling.

The Analysis of Gamma Oscillation and Phase-Synchronization for Memory Retrieval Tasks

  • 김성필;최승현;김현택;이승환
    • 한국인지과학회:학술대회논문집
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    • 한국인지과학회 2010년도 춘계학술대회
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    • pp.37-41
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    • 2010
  • The previous investigations of electroencephalogram (EEG) activity in the memory retrieval tasks demonstrated that event-related potentials (ERP) during recollection showed different durations and the peak levels from those without recollection. However, it has been unknown that recollection in memory retrieval also modulates high-frequency brain rhythms as well as establishes large-scale synchronization across different cortical areas. In this study, we examined the spectral components of the EEG signals, especially the gamma bands (20-80Hz), measured during the memory retrieval tasks. Specifically, we focused on two major spectral components: first, we evaluated the temporal patterns of the power spectral density before and after the onset of the memory retrieval task; second, we estimated phase synchrony between all possible pairs of EEG channels to evaluate large-scale synchronization. Fourteen healthy subjects performed the memory retrieval task in the virtual reality environment where they selected whether or not t he present item was seen in the previous training period. When the subjects viewed the unseen items, the middle gamma power (40-60Hz) appeared to increase 200-500ms after stimulus onset while the low gamma power (20Hz) was suppressed all the way through the post-stimulus period 150ms after onset. The degree of phase synchronization in this low gamma level, however, increased when the subjects fetched the item from memory. This suggests that phase synchrony analysis might reveal different aspects of the memory retrieval process than the gamma power, providing additional information to the inference on the brain dynamics during memory retrieval.

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동측 및 대측 전침자극 전후의 뇌기능 변화에 관한 연구 (The Study of Brain Function Changes After Contralateral and Ipsilateral Application Of Electroacupuncture)

  • 우영민;신병철;남영
    • Journal of Acupuncture Research
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    • 제20권1호
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    • pp.22-34
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    • 2003
  • Objective : To ascertain whether the concept of the treatment side is associated with changes in the blind spot mapping that represents the brain function. Methods : Among the outpatients who visited to Department of Acupuncture & Moxibustion, National Medical Center from March 2002 to October 2002, we selected 40 clinical trial volunteers that showed right side physiological blind spot more enlarged than left, and underwent the examinations of Department of Opthalmology, National Medical Center for ruling out the pathological conditions. Physiological blind spot maps were used as an integer of brain activity before and after electroacupuncture application on the unilateral ST36 meridian point by dividing 40 subjects into two comparative groups for double-blind controlled study. Results: The significant changes in the blind spots were observed. Electroacupuncture application on the ipsilateral or contralateral ST36 of an enlargement cortical map were associated with the concept of determining the treatment side. In the case of electroacupuncture application on the ipsilateral side of an enlarged blind spot, there were decrease of $4.11{\pm}8.56cm$(17.3%) in blind spot perimetry length(p < 0.05). In the case of contralateral side, there were increase of $3.19{\pm}5.40cm$(13.7%) in blind spot perimetry length(p<0.05). The Differences were statistically significant(p<0.05). Conclusions: We found that eletroacupuncture application was associated with an increase or decrease in the brain function in the view of blind spot changes depending on the treatment side. These results suggest that the traditional acupuncture therapeutic strategy with determining the treatment side has clinical significance in the view of the brain function.

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Kami-bang-pung-tong-sung-san is Involved in Protecting Neuronal Cells from Cytotoxic Insults

  • Na Young Cheul;Nam Gung Uk;Lee Yong Koo;Kim Dong Hee
    • 동의생리병리학회지
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    • 제18권1호
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    • pp.265-273
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    • 2004
  • KBPTS is the fortified prescription of Bang-pung-tong-sung-san (BPTS) by adding Spatholobi Clulis and Salviae Miltiorrzae Radix. BPTS prescription has been used in Qriental medicine for the treatments of vascular diseases including hypertension, stroke, and arteriosclerosis, and nervous system diseases. Yet, the overall mechanism underlying its activity at the cellular levels remains unknown. To investigate the protective role of KBPTS on brain functions, noxious stimulations were applied to neurons in vitro and in vivo. KBPTS pretreatment in cultured cortical neurons of albino ICR mice rescued death caused by AMPA, NMDA, and kainate as well as by buthionine sulfoximine (BSO) and ferrous chloride (Fe/sup 2+/) treatments. Furthermore, KBPTS promoted animal's recovery from coma induced by a sublethal dose of KCN and improved survival by a lethal dose of KCN. To examine its physiological effects on the nervous system, we induced ischemia in the Sprague-Dawley rat's brain by middle cerebral artery (MCA) occlusion. Neurological examination showed that KBPTS reduced the time which is required for the animal after MCA occlusion to respond in terms of forelimb and hindlimb movement$. Histological examination revealed that KBPTS reduced ischemic area and edema rate and also protected neurons in the cerebral cortex and hippocampus from ischemic damage. Thus, the present data suggest that KBPTS may play an important role in protecting neuronal cells from external noxious stimulations.