• 제목/요약/키워드: Motor neurons

검색결과 176건 처리시간 0.026초

Evidence for Excitatory Input to Ventral Spinocerebellar Tract Neurons Mediated by Motoneuron Collaterals

  • Kim, Jong-Hwan;Shim, Dae-Moo
    • The Korean Journal of Physiology
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    • 제30권1호
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    • pp.117-124
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    • 1996
  • This study evaluated the hypothesis that motoneuron collaterals modulate the excitability of ventral spinocerebellar tract neurons. In acute cats, 128 ventral cerebellar tract cells were studied extracellularly to determine the effects of ventral root stimuli. The majority of the cells responded to ventral root stimulation with either short or long latency increases in spike discharge. In many cells with sufficient spontaneous activity ventral root stimulation also evoked a long lasting reduction in activity. In preparations with the dorsal root ganglion removed VSCT neurons had similar response properties. In some cells contralateral ventral root stimulation also evoked excitatory responses. These findings indicate the VSCT can provide the cerebellum with information regarding activity in the final output neurons of the motor system, the alpha motoneurons.

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근위축성 측삭 경화증의 하 운동 신경원 과흥분성: 운동유발전위를 이용한 분석 (Lower Motor Neuron Hyperexcitability in Amyotrophic Lateral sclerosis: Analysis Using Motor Evoked Potentials)

  • 배종석;홍석찬;김민기;김병준
    • Annals of Clinical Neurophysiology
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    • 제5권1호
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    • pp.21-26
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    • 2003
  • Background & Objectives: Hyperexcitablity of motor system is a well-established characteristic pathophysiologic finding of amyotrophic lateral sclerosis (ALS). Whereas little is known about the source of excitability according to the progression of the disease. We evaluated the excitability and its source in advanced ALS patients using transcranial magnetic stimulation (TMS). Meterial & Methods: Motor evoked potentials (MEP) by TMS were recorded for abductor pollicis brevis muscles in 20 patients, 11 men and 9 women, with ALS. Mean age was $54.2{\pm}12.1years$, and mean disease duration was $13.9{\pm}13.4years$. Serial magnetic stimulations were applied to get the parameters; excitability threshold (ET), amplitude and latency of MEP. We also had a facilitated MEP (fMEP). Results: The parameters were analyzed according to the clinical settings. ET was higher in ALS(mean $63.5{\pm}18.1$) than normal control (mean $46.0{\pm}8.4$, p<0.01). Amplitudes of MEP were reduced in ALS ($2.6{\pm}3.6mV$; control $6.5{\pm}3.1mV$, p<0.01). Duration of the disease and ET showed significant inverse correlation (Spearson correlation coefficient = -0.57, p<0.01). Duration of the disease and fMEP/MEP ratio showed less but also significant inverse correlation (Spearson correlation coefficient, r = -0.52, p < 0.05). Conclusions: Lower ET in advanced ALS patients, in spite of decreased fMEP/MEP ratio, may indicate the hyperexcitability of lower motor neurons in these patients. This study suggests that lower motor neurons is hyperexcitable due to upper motor neuron dysfunction at advanced stage.

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합곡과 대장의 중추신경로와의 연계성에 관한 연구 (Studies of the Central Neural Pathways to the Hapgok(LI4) and Large Intestine)

  • 이창현;정한솔
    • 동의생리병리학회지
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    • 제25권2호
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    • pp.217-226
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    • 2011
  • The aim of this study is to identify central neural pathway of neurons following the projection to the large intestine and Hapgok(LI4) which is Won acupoint of the large intestine meridian of hand-yangmyeong. In this experiment, Bartha's strain of pseudorabies virus was used to trace central localization of neurons related with large intestine and acupoint(LI4) which has been known to be able to regulate intestinal function. The animals were divided into 3 groups: group 1, injected into the large intestine; group 2, injected into the acupoint(LI4); group 3, injected into the acupoint(LI4) after severing the radial, ulnar, median nerve. After four days survival of rats, PRV labeled neurons were identified in the spinal cord and brain by immunohistochemical method. First-order PRV labeled neurons following the projection to large intestine, acupoint(LI4) and acupoint(LI4) after cutting nerve were found in the cervical, thoracic, lumbar and sacral spinal cord. Commonly labeled neurons were labeled in the lumbosacral spinal cord and thoracic spinal cord. They were found in lamina V- X, intermediomedial nucleus and dorsal column area. The area of sensory neurons projecting was L5-S2 spinal ganglia and T12-L1 spinal ganglia, respectively. In the brainstem, the neurons were labeled most evidently and consistently in the nucleus tractus solitarius, area postrema, dorsal motor nucleus of vagus nerve, reticular nucleus, raphe nuclei(obscurus, magnus and pallidus), C3 adrenalin cells, parapyramidal area(lateral paragigantocellular nucleus), locus coeruleus, subcoeruleus nucleus, A5 cell group, periaqueductal gray matter. In the diencephalon, PRV labeled neurons were marked mostly in the arcuate nucleus and median eminence. These results suggest that overlapped CNS locations are related with autonomic nuclei which regulate the functions of large intestine-related organs and it was revealed by tracing PRV labeled neurons projecting large intestine and related acupoint(LI4).

가변부하를 갖는 직류 서보 전동기의 속도제어를 위한 뉴로-퍼지 제어기 설계 (Design of Neuro-Fuzzy Controller for Velocity Control of DC Servo Motor with Variable Loads)

  • 김상훈;강영호;남문현;김낙교
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1999년도 하계학술대회 논문집 B
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    • pp.513-515
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    • 1999
  • In this paper, Neuro-Fuzzy controller which has the characteristic of Fuzzy control and artificial Neural Network is designed A fuzzy rule to be applied is selected automatically by the allocated neurons. The neurons correspond to Fuzzy rules which are created by the expert. In order to adaptivity, the more precise modeling is implemented by error back propagation learning of adjusting the link-weight of fuzzy membership function in Neuro-fuzzy controller. The more classified fuzzy rule is used to include the property of Dual mode Method. To test the effectiveness of the algorithm designed above the experiment for DC servo motor with variable load as variable load plant is implementation.

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뉴로-퍼지 제어기를 이용한 교류 서보 전동기의 속도제어 (Speed control of AC Servo Motor with Neuro-Fuzzy Controller)

  • 김종현;김상훈;고봉운;김낙교
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2001년도 하계학술대회 논문집 D
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    • pp.2018-2020
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    • 2001
  • In this study, a Neuro-Fuzzy Controller which has the characteristic of Fuzzy control and Artificial Neural Network is designed. A fuzzy rule to be applied is automatically selected by the allocated neurons. The neurons correspond to Fuzzy rules are created by an expert. To adapt the more precise modeling is implemented by error back propagation learning of adjusting the link-weight of fuzzy membership function in the Neuro-Fuzzy controller. The more classified fuzzy rule is used to include the property of dual mode method. In order to verify the effectiveness of an algorithm designed above, an operating characteristic of a AC servo motor is investigated.

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퍼지-뉴럴 제어 시스템을 이용한 직류 서보 전동기의 위치 및 속도 제어 (The position and Speed Control of a DC Servo-Motor Using Fuzzy-Neural Network Control System)

  • 강영호;정헌주;김만철;김낙교
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1993년도 하계학술대회 논문집 A
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    • pp.244-247
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    • 1993
  • In this paper, Fuzzy-Neural Network Control system that has the characteristic of fuzzy control to be controlled easily end the good characteristic of a artificial neural network to control the plant due to its learning is presented. A fuzzy rule to be applied is selected automatically by the allocated neurons. The neurons correspond to Fuzzy rules which ere created by a expert. To adaptivity, the more precise modeling is implemented by error beck-propagation learning of adjusting the link-weight of fuzzy membership function in Fuzzy-Neural Network. The more classified fuzzy rule is used to include the property of Dual Mode Method. To test the effectiveness of the algorithm presented above, the simulation for position end velocity of DC servo motor is implemented.

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MPTP로 유도된 신경 독성에 대한 NXP031의 개선 효과 (Ameliorative Effects of NXP031 on MPTP-Induced Neurotoxicity)

  • 이주희;송민경;김연정
    • Journal of Korean Biological Nursing Science
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    • 제23권3호
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    • pp.199-207
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    • 2021
  • Purpose: The purpose of this study was to investigate effects of NXP031, an inhibitor of oxidation by specifically binding to the complex of DNA aptamer/vitamin C, on dopaminergic neurons loss and the reaction of microglia in an animal model of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced subchronic Parkinson's disease (PD). Methods: A subchronic PD mouse model was induced via an intraperitoneal (IP) injection of MPTP 30 mg/kg per day for five days. NXP031 (vitamin C/aptamer at 200 mg/4 mg/kg) and vitamin C at 200 mg/kg were administered via IP injections at one hour after performing MPTP injection. This process was performed for five days. Motor function was then evaluated with pole and rotarod tests, after which an immunohistochemical analysis was performed. Results: NXP031 administration after MPTP injection significantly improved motor functions (via both pole and rotarod tests) compared to the control (MPTP injection only) (p<.001). NXP031 alleviated the loss of dopaminergic neurons in the substantia nigra (SN) and striatum caused by MPTP injection. It was found to have a neuroprotective effect by reducing microglia activity. Conclusion: NXP031 can improve impaired motor function, showing neuroprotective effects on dopaminergic neurons in the SN and striatum of MPTP-induced subchronic Parkinson's disease mouse model. Results of this study suggest that NXP031 has potential in future treatments for PD and interventions for nerve recovery.

Treadmill exercise enhances motor coordination and ameliorates Purkinje cell loss through inhibition on astrocyte activation in the cerebellum of methimazole-induced hypothyroidism rat pups

  • Shin, Mal-Soon;Kim, Bo-Kyun;Lee, Shin-Ho;Kim, Tae-Soo;Heo, Yu-Mi;Choi, Jun-Ho;Kim, Chang-Ju;Lim, Baek-Vin
    • 운동영양학회지
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    • 제16권2호
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    • pp.73-84
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    • 2012
  • Thyroid hormones are important for the development of the brain including the cerebellum. In the present study, we investigated the effect of treadmill exercise on the survival of Purkinje neurons and the activation of astrocytes in the cerebellar vermis of hypothyroidism-induced rat pups. On the day of perinatal 14, pregnant rats were divided into two groups (n = 5 in each group): the pregnant control group and the pregnantmethimazole (MMI)-treated group. For the induction of hypothyroidism in the rat pups, MMI was added to the drinking water (0.02% wt/vol), from the day of perinatal 14 to postnatal 49. After delivery, male rat pups born from the pregnant control group were assigned to the control group. Male rat pups born from the MMI-treated group were divided into the hypothyroidism-induction group, the hypothyroidism-induction with treadmill exercise group, and the hypothyroidism-induction with thyroxine (T4) treatment group (n = 10 in each group). The rat pups in the exercise group were forced to run on a treadmill for 30 min once a day for 4 weeks, starting on postnatal day 22. In the hypothyroidism-induced rat pups, motor coordination was reduced and Purkinje cell death and reactive astrocytes in the cerebellar vermis were increased. Treadmill exercise enhanced motor coordination, increased the survival of Purkinje neurons, down-regulated reactive astrocytes, and enhanced brain-derived neurotrophic factor (BDNF) and receptor tyrosine kinase B (TrkB) expressions in the hypothyroidism-induced rat pups. These results suggest that treadmill exercise has beneficial effects in terms of protecting against thyroid dysfunction by increasing T3 and T4 and the related protein, BDNF, as well as TrkB, inhibition on astrocyte activation and the reduction of Purkinje cell loss regarding the cerebellum in hypothyroidism rat pups.

저빈도 전침자극이 류마토이드 관절염 유발 흰쥐 대뇌피질 Nicotidamide Adenine Dinucleotide Phosphate-diaphorase(NADPH-d) 양성세포 발현에 미치는 영향 (Effect of Low Frequency Electroacupuncture on Nicotidamide Adenine Dinucleotide Phosphate-diaphorase(NADPH-d) Positive Neurons in the Brain Cortex of Rat with Adjuvant Induced Rheumatoid Arthritis)

  • 정기훈;노정두;김이화;이은용
    • Journal of Acupuncture Research
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    • 제25권3호
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    • pp.179-187
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    • 2008
  • Objectives & Methods : This study was to investigate effect of low frequency electroacupuncture on NADPH-d positive neurons in the brain cortex of rat with adjuvant induced rheumatoid arthritis. Experimental groups were divided into 6 groups ; Normal, Control, $ST_{36}$, $SP_9$, $ST_{36}+SP_9$ and Non-Acupoint. Normal group, non-arthritic group, was injected normal saline, and the other groups were injected FCA. Each acupoint groups were treated by 2Hz electroacupuncture at each acupoints and NA group was treated by 2Hz electroacupuncture at non-acupoint. Each groups were evaluated by the number of NADPH-d positive neurons in primary somatosensory area(S1), secondary somatosensory area(S2), motor area and caudate putamen by using an image analyzer and a microscope. Results : 1. In S1, the number of NADPH-d positive neuron cells in the $ST_{36}$ group were significantly(p<0.05) increased compared with the control group. 2. In S2, the number of NADPH-d positive neuron cells in all electroacupuncture groups were not significantly changed compared with the control group. 3. In motor area, the number of NADPH-d positive neuron cells in $ST_{36}$ group, $SP_9$ group, NA group were significantly(p<0.05) increased compared with the control group. 4. In Caudate putamen, the number NADPH-d positive neuron cells in all electroacupuncture groups were significantly(p<0.05) decreased compared with the control group. Conclusions : Our result demonstrated that low frequency electroacupuncture on $ST_{36}$ & $SP_9$ normalized expression of NADPH-d positive neurons in the brain cortex of the rheumatoid arthritis model in rats.

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