• Title/Summary/Keyword: Central neuron

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Upper Motor Neuron Involvement in Motor Neuron Disease: Motor Evoked Potentials Study (운동 신경원 질환에서의 상부 운동 신경원 침범: 운동 유발 전위 연구)

  • Kim, Sung Hun;Park, Kyung-Seok;Kim, Joo-Yong;Lee, Kwang-Woo
    • 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.

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Implementation of Excitatory CMOS Neuron Oscillator for Robot Motion Control Unit

  • Lu, Jing;Yang, Jing;Kim, Yong-Bin;Ayers, Joseph;Kim, Kyung Ki
    • JSTS:Journal of Semiconductor Technology and Science
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    • v.14 no.4
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    • pp.383-390
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    • 2014
  • This paper presents an excitatory CMOS neuron oscillator circuit design, which can synchronize two neuron-bursting patterns. The excitatory CMOS neuron oscillator is composed of CMOS neurons and CMOS excitatory synapses. And the neurons and synapses are connected into a close loop. The CMOS neuron is based on the Hindmarsh-Rose (HR) neuron model and excitatory synapse is based on the chemical synapse model. In order to fabricate using a 0.18 um CMOS standard process technology with 1.8V compatible transistors, both time and amplitude scaling of HR neuron model is adopted. This full-chip integration minimizes the power consumption and circuit size, which is ideal for motion control unit of the proposed bio-mimetic micro-robot. The experimental results demonstrate that the proposed excitatory CMOS neuron oscillator performs the expected waveforms with scaled time and amplitude. The active silicon area of the fabricated chip is $1.1mm^2$ including I/O pads.

Anodal Effects of Transcranial Direct Current Stimulation on the Excitability of Central Neuron (양극 경두개 직류 전기 자극이 중추신경원의 흥분성에 미치는 영향)

  • Lim, Young-Eun;Jung, Jin-Sun;Lee, Jeong-Woo
    • Journal of the Korean Academy of Clinical Electrophysiology
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    • v.9 no.2
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    • pp.19-24
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    • 2011
  • Purpose : This study is to examine the effects of transcranial direct current stimulation on the excitability of the central neuron. Methods : This study selected 24 suitable women in their twenties. A positive electrode of transcranial direct current stimulation was placed on the primary motor area (M1) C4 and a negative electrode was placed on the left supraobital. A stimulation of 0.04mA/$cm^2$ was applied for 20 minutes. H-reflex and V wave used diagnostic electromyography. An active electrode was placed at the muscle belly of the medial gastrocnemius muscle at a prone posture. An electrical stimulation was given to the posterior tibial nerve. Measurements were made before and after the stimulation. All data were analyzed with SPSS 12.0 and between each measuring before and after the change of the H-reflex and V wave amplitude. Results : There were no significant differences in all H wave, M wave, and V wave amplitude before and after transcranial direct current stimulation. There were no significant differences in the change of H/M ratio and V/M ratio before and after transcranial direct current stimulation. Conclusion : We know that transcranial direct current stimulation cannot have an influence on a normal grown-up person's central neuron.

Neurochemical Studies of Standardized Ginseng Extract G115 on the Central Dopaminergic Activity (II) (표준화된 인삼추출물 G115의 중추도파민신경계에 대한 신경화학적 연구(II))

  • 이순철;유관희;김용호
    • Journal of Ginseng Research
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    • v.16 no.3
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    • pp.183-189
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    • 1992
  • Effect of the standardized ginseng extract(G115) on the central monoaminergic systems were investigated in comparison with that of halcperidol in rats. Immediately after sacrificed by decapitation, the strlata and frontal cortex were removerl. Concentations of the monoamines dopamine and serctorLin and their metabolites were deterinintd by HPLC-EC. G115 increased the concentration of 5-HIAA and DOPAC/UA ratio in striatum. However, dopaminrrgic neuronal activities were not affected by G115 that decreased the concentratio,Is of 5-HT and 5-HIAA in frontal cortex. G115 in combination with apomorphine significantly irlcreased the concentration of DA and S-HT but decreased the DO PAC/DA ratio and 5-HIAA/5-HT ratio only in frontal cortex. These results suggest that G115 like HPD inhibits the activity of nigrostriatal dopamine neuron in striatum. However, unlike HPD it activates central monoaminergic neuron activity in frontal cortex.

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Changes of Action Potential of Central Neuron by Maximal Voluntary Isometric Contraction (최대 수의적 등척성 수축력에 의한 중추신경원의 활동전위 변화)

  • Moon, Dal-Ju;Kim, Kye-Yoep;Jeong, Jin-Gyu;Kim, Sue-Hyun;Kim, Tae-Youl
    • The Journal of Korean Physical Therapy
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    • v.18 no.3
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    • pp.37-45
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    • 2006
  • Purpose: This study analyzed changes in spinal neuron and action potential of motor unit depending on voluntary contraction on spinal neuron adaptation. Methods: It selected 80 university students in their twenties and divided into experimental groups of 25% MVIC (I), 50% MVIC (II), 75% MVIC (III) and 100% MVIC (IV) depending on maximum voluntary isometric contraction (MVIC) and performed isometric exercise of plantar flexor muscle to each experimental group with given contraction for 20 times. It measured Mmax, H/Mmax, Hmax latency, V/Mmax, V wave latency before and after exercise, compared method and volume of contraction. Results: H/Mmax ratio showed significant difference in comparison among groups (p<0.01) and there was difference in I and IV groups. V/Mmax ratio showed significant difference in comparison among experimental groups (p<0.05) and there was difference in I and IV groups. When voluntary contraction level was maximum, changes were greatest. However, no significantly difference was to Mmax, H latency and V wave latency. Conclusion: These results suggest that amplitude changes of voluntary contraction level, spinal neuron and supra-spinal neuron had a dose connection that the more contraction level, the better central activation seem to decrease highly for a short time.

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The Effects of Global Synkinesis Level on Gait Ability in Post-Stroke Hemiplegic Patients (뇌졸중 후 편마비 환자의 Global Synkinesis 수준이 보행능력에 미치는 영향)

  • Lim, Jae-Heon;Lim, Young-Eun;Kim, Su-Hyon;Park, Kyeong-Soon;Kim, Tae-Youl
    • The Journal of Korean Physical Therapy
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    • v.20 no.3
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    • pp.9-18
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    • 2008
  • Purpose: We determined the effect of global synkinesis(GS) on gait ability, muscle contraction, and central neuron action potentials in post-stroke hemiplegic subjects. Methods: Thirty hemiplegia patients were evaluated for walking ability, muscle contraction, central neuron action potential, and comparing differences between the H-GS(high-global synkinesis) group and L-GS(low-global synkinesis) group. To obtain the GS level, surface electromyography(EMG) data were digitized and processed to root mean square(RMS). Walking ability was tested with a modified motor assessment scale(MMAS), a 10 m walking test, timed up and go(TUG) test, and a Fugl-Meyer assessment(FMA). Muscle contraction ability was measured as maximal isometric contraction(MIC) peak, MIC slope, and MIC ramp up using mechanomyography(MMG). Central neuron action potential was measured as the H/Mmax ratio or V/Mmax ratio using EMG. The data were analyzed with t-tests to determine the statistical significance. Results: MMAS(p<0.01), 10 m walking velocity(p<0.01), TUG(p<0.01), FMA-HKA(Hip, Knee, Ankle)(p<0.05), FMA-coordination(p<0.05), MIC peak (p<0.05), MIC slope(p<0.01), and MIC ramp up(p<0.05) were significantly different between H-GS and L-GS, as was the V/Mmax ratio(p<0.05), but H/Mmax was not. Conclusion: Lower GS levels indicated better walking ability and motor function. Therefore, intervention programs should consider GS levels in gait training of chronic hemiplegia.

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Network of hypothalamic neurons that control appetite

  • Sohn, Jong-Woo
    • BMB Reports
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    • v.48 no.4
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    • pp.229-233
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    • 2015
  • The central nervous system (CNS) controls food intake and energy expenditure via tight coordinations between multiple neuronal populations. Specifically, two distinct neuronal populations exist in the arcuate nucleus of hypothalamus (ARH): the anorexigenic (appetite-suppressing) pro-opiomelanocortin (POMC) neurons and the orexigenic (appetite-increasing) neuropeptide Y (NPY)/agouti-related peptide (AgRP) neurons. The coordinated regulation of neuronal circuit involving these neurons is essential in properly maintaining energy balance, and any disturbance therein may result in hyperphagia/obesity or hypophagia/starvation. Thus, adequate knowledge of the POMC and NPY/AgRP neuron physiology is mandatory to understand the pathophysiology of obesity and related metabolic diseases. This review will discuss the history and recent updates on the POMC and NPY/AgRP neuronal circuits, as well as the general anorexigenic and orexigenic circuits in the CNS. [BMB Reports 2015; 48(4): 229-233]

Running Control of Quadruped Robot Based on the Global State and Central Pattern

  • Kim, Chan-Ki;Youm, Young-Il;Chung, Wan-Kyun
    • 제어로봇시스템학회:학술대회논문집
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    • 2005.06a
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    • pp.308-313
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    • 2005
  • For a real-time quadruped robot running control, there are many important objectives to consider. In this paper, the running control architecture based on global states, which describe the cyclic target motion, and central pattern is proposed. The main goal of the controller is how the robot can have robustness to an unpredictable environment with reducing calculation burden to generate control inputs. Additional goal is construction of a single framework controller to avoid discontinuities during transition between multi-framework controllers and of a training-free controller. The global state dependent neuron network induces adaptation ability to an environment and makes the training-free controller. The central pattern based approach makes the controller have a single framework, and calculation burden is resolved by extracting dynamic equations from the control loop. In our approach, the model of the quadruped robot is designed using anatomical information of a cat, and simulated in 3D dynamic environment. The simulation results show the proposed single framework controller is robustly performed in an unpredictable sloped terrain without training.

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The Effect of Acrylamide on the Ultrastructures of Nervous System of the Mouse (생쥐 신경계의 미세구조에 미치는 Acrylamide의 영향)

  • 김동수;하재청
    • The Korean Journal of Zoology
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    • v.33 no.4
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    • pp.454-460
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    • 1990
  • The effed of acrylamide on the nervous system has heen morphologically studied using light and electron microscopes. The light micrographs on central and pedpheral nervous tissues of mouse treated with acrylamide monomer showed total vacuolation of spinal cord, cell degradation containing neuron and neuroglia, and distal nerve fiber degeneration. The electron micrographs showed ultrastrudural changes. Abnormal mitochondria in neuron, splitting of myelin sheath in lumbar ventral root nerve, partial disintergration of myelin sheath and axoplasmic degeneration in sciatic nerve, and overafl polyneuropathies in nervous system were observed. These results suggest that acrylarnide intoxicated mouse shows distal behavioral neuropathy as an earlist clinical sign, but the initial effect of acrylamide on the nervous system seems to appear at nearly the same time in both central and peripheral nervous systems.

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