• Title/Summary/Keyword: Action Potentials

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AN ELECTROMYOGRAPHIC STUDY OF THE MASSETER MUSCLES IN CHILDREN WITH SPACE MAINTAINER (보극장치(保隙裝置) 장착아동(裝着兒童)의 교근활성도(咬筋活性度)에 관(關)한 근전도학적(筋電圖學的) 연구(硏究))

  • Ahn, Kyu-So
    • Journal of the korean academy of Pediatric Dentistry
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    • v.1 no.1
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    • pp.49-55
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    • 1974
  • Electromyographic studies were performed on the action of the masseter muscles. Among the children aged from 6 to 8 years, ten children with normal occlusion and another ten with space maintainer were selected. The children were divided into 3 groups. They were: 1) A group: Children who removed space maintainer 2) B group: Children who inserted space maintainer 3) C group: Children with normal occlusion. The electromyogram was recorded with 4 channel polygraph. (Grass model VII) Electrodes which were cup-typed gold disks, 9 millimeters in the diameter, were located on the superficial layer of masseter muscles. The electromyogram was recorded in the physiologic rest position, molar occlusion, chewing movement, protraction, left lateral movement, and right lateral movement. The conclusions were as follows. 1. In the physiologic rest position, lateral movement, the electrical potentials of the masseter muscles were not changed clearly in each groups. 2. In molar occlusion, chewing movement, The electrical potentials of the masseter muscles of the B group were almost 10% higher than those of A group, and were almost 60-70% in comparision with C group. 3. In protraction, the electrical potentials of the masseter muscles of the B group were almost 40% higher than those of A group, and were almost equal to C group. 4. The electrical activities of the masseter muscles in the mandibular movements were in the following order: (1) Molar occlusion (2) Chewing movement (3) Protraction (4) Lateral movement.

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Effect of Motor Imagery Training on Somatosensory Evoked Potentials and Upper Limb Function in Stroke Patients

  • Choi, Jongbae;Yang, Jongeun
    • Journal of International Academy of Physical Therapy Research
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    • v.11 no.1
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    • pp.2005-2011
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    • 2020
  • Background: Motor imagery is the mental representation of an action without overt movement or muscle activation. However, few previous studies have demonstrated motor imagery training effects as an objective assessment tool in patients with early stroke. Objective: To investigate the effect of motor imagery training on Somatosensory Evoked Potentials (SSEP) and upper limb function of stroke patients. Design: A quasi-experimental study. Methods: Twenty-four patients with stroke were enrolled in this study. All subjects were assigned to the experimental or control group. All participants received traditional occupational therapy for 30 minutes, 5 times a week. The experimental group performed an additional task of motor imagery training (MIT) 20 minutes per day, 5 days a week, for 4 weeks. Both groups were assessed using the SSEP amplitude, Fugl-Meyer assessment of upper extremity (FMA UE) and Wolf motor function test. Results: After the intervention, the experimental group showed significant improvement in SSEP amplitude and FMA UE than did the control group. Conclusion: These findings suggest that the MIT effectively improve the SSEP and upper limb function of stroke patients.

생체 신호처리

  • 박상희
    • Journal of Biomedical Engineering Research
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    • v.10 no.2
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    • pp.97-101
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    • 1989
  • N1 and N2 gross neural action potentials were measured from the round window of the guinea pig cochlea at the onset of the acoustic stimuli. N1-N2 audiograms were made by means of regulating stimulant intensities in order to produce constant N1-N2 potentials as criteria for different input tone pip frequencies. The lowest threshold was measured with an input tone pip I5 dB SPL in intensity and 12 KHz in frequency when the animal was in normal physiological condition. The procedure of experimental measurements is explained in detail. This experimental approach is very useful for the investigation of the Cochlear function. Both noN1inear and active functions of the Cochlea can be monitored by N1-N2 audiograms.

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The Effect of Heat on the Spiking Patterns of the Cells in Aplysia (군소 세포의 발화 형태에 미치는 열자극 효과)

  • Hyun, Nam-Gyu
    • Progress in Medical Physics
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    • v.18 no.2
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    • pp.73-80
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    • 2007
  • Fruitful findings have been produced from five out of sixty cells which were obtained from each 63 individual Aplisia caught at the Jeju coast. Spiking patterns of three out of five cells, such as relaxation oscillator, bursting within a short time of the inter-burst interval, chaotic bursting, period doubling sequences, bursting with long trains of action potentials separated by short silent periods, regular repeated beating or elliptic bursting, and silent states had been changed in order as the temperature was lowered to $10^{\circ}C\;from\;32^{\circ}C$. In the intervals of every about 40 minutes repeated ups and downs of temperature produced similar firing patterns at the allowable temperature ranges. The other two cells showed difference from these. The amplitudes of the action potentials of the two cells will not be highly decreased in 24 hours. Average spike frequencies, the inter-burst interval, peak to peak spike amplitude of action potentials, minimum potential values are compared and analyzed by using the computer programme. The spike frequencies according to temperature show the distribution of bell type, with maximal spike frequencies at intermediate temperatures and minimal ones at either end. The most common pattern consist of high spike frequency during failing and low one during rising temperatures.

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Effects of Histamine on Cultured Interstitial Cells of Cajal in Murine Small Intestine

  • Kim, Byung Joo;Kwon, Young Kyu;Kim, Euiyong;So, Insuk
    • The Korean Journal of Physiology and Pharmacology
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    • v.17 no.2
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    • pp.149-156
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    • 2013
  • Interstitial cells of Cajal (ICCs) are the pacemaker cells in the gastrointestinal tract, and histamine is known to regulate neuronal activity, control vascular tone, alter endothelial permeability, and modulate gastric acid secretion. However, the action mechanisms of histamine in mouse small intestinal ICCs have not been previously investigated, and thus, in the present study, we investigated the effects of histamine on mouse small intestinal ICCs, and sought to identify the receptors involved. Enzymatic digestions were used to dissociate ICCs from small intestines, and the whole-cell patch-clamp configuration was used to record potentials (in current clamp mode) from cultured ICCs. Histamine was found to depolarize resting membrane potentials concentration dependently, and whereas 2-PEA (a selective H1 receptor agonist) induced membrane depolarizations, Dimaprit (a selective H2-agonist), R-alpha-methylhistamine (R-alpha-MeHa; a selective H3-agonist), and 4-methylhistamine (4-MH; a selective H4-agonist) did not. Pretreatment with $Ca^{2+}$-free solution or thapsigargin (a $Ca^{2+}$-ATPase inhibitor in endoplasmic reticulum) abolished the generation of pacemaker potentials and suppressed histamine-induced membrane depolarization. Furthermore, treatments with U-73122 (a phospholipase C inhibitor) or 5-fluoro-2-indolyl des-chlorohalopemide (FIPI; a phospholipase D inhibitor) blocked histamine-induced membrane depolarizations in ICCs. On the other hand, KT5720 (a protein kinase A inhibitor) did not block histamine-induced membrane depolarization. These results suggest that histamine modulates pacemaker potentials through H1 receptor-mediated pathways via external $Ca^{2+}$ influx and $Ca^{2+}$ release from internal stores in a PLC and PLD dependent manner.

Effects on Functional Recovery of Eccentric Exercise-Induced Muscle Damage by Phonophoresis of Piroxicam Gel (피록시캄 겔의 음파영동이 원심성 운동-유발 근 손상의 기능회복에 미치는 효과)

  • Choi, Sug-Ju;Kim, Tae-Youl;Song, Myung-Soo;Kim, Young-Il;Moon, Sung-Ki
    • Journal of the Korean Academy of Clinical Electrophysiology
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    • v.1 no.1
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    • pp.17-29
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    • 2003
  • This study was investigated the effects on functional recovery of eccentric exercise-induced muscle damage by phonophoresis transdermal permeation of piroxicam gel and observed the change of amplitude at muscle action potential. Through eccentric exercise-induced muscle damage, performed healthy men and women take eccentric resistance exercise and measured action, potentials. The subjects were divided into three groups of four men each 24 hour, 48 hour, 72 hour. The results of this were as follows: 1. Change of maximal action potential at maximal voluntary contraction : The phonophoresis group was increase more than control group and gel group. 2. Change of average action potential at maximal voluntary contraction : The gel group was increase more than control group and phonophoresis group. 3. Change of maximal action potential at pain subthreshold voluntary contraction : The phonophoresis group was increase more significantly than control group and gel group. 4. Change of average action potential at pain subthreshold voluntary contraction : The phonophoresis group was increase more significantly than control group and gel group. In conclusion, the change of muscle action potential amplitude by eccentric exercise-induced muscle damage showed that the phonophoresis by pulsed ultrasound of piroxicam gel was improved the recovery of muscle function.

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Action mechanism of estrogen potentials of Ginko biloba extracts and its major components in human breast cancer cell

  • Kim, Yun-Hee;Oh, Seung-Min;Lee, Hee-Sung;Chung, Kyu-Hyuck
    • Proceedings of the PSK Conference
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    • 2003.04a
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    • pp.166.2-167
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    • 2003
  • The important biological activities of estrogen were reproduction and physiological processes in a number of tissues, including liver, bone, brain, blood vessels, adipose tissue and so on. The regulation of estrogen level is important a prevention of estrogen-related disease. Ginkgo biloba extracts (GSE) are extracted from leaves of the Ginkgo biloba tree. GSE contains 24% phytoestrogen, which are kaempferol, quercetin, and isorhamnetin. (omitted)

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Conduction Block of the Primary Afferent Fibers by Topically Applied Allyl Isotheocyanate

  • Shin, Hong-Kee;Kim, Kee-Soon
    • The Korean Journal of Physiology
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    • v.28 no.2
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    • pp.123-132
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    • 1994
  • The present study was undertaken to elucidate the desensitization of cutaneous receptors and the conduction block of the afferent nerves induced by direct application of allyl isotheocyanate (mustard oil) to the receptive field (RF) or onto the afferent nerve, respectively. Dorsal horn cell responses to mechanical stimulations of RF were completely suppressed when mustard oil was applied to either the afferent nerve or the whole area of RF. C-fiber responses of dorsal horn cells were more susceptive to mustard oil than A-fiber activities. This was confirmed by the experiment in which the compound action potentials recorded from rat tibial nerve before and after topical application of mustard oil were compared. The higher the concentration of mustard oil and the longer the application time, the more powerful desensitization or conduction block was induced. From the results of the present study, it is suggested that the desensitization of the afferent fiber and sensory receptors induced by mustard oil results mainly from the conduction block of C-fiber in the primary afferent nerve.

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A Selection Method of Optimal Digital Low-pass Differentiator for Spike Detection of Surface Motor Unit Action Potential (표면 운동단위 활동전위 스파이크 검출을 위한 최적의 디지털 저역통과 미분기 선정 방법)

  • Lee, Jin;Kim, Sung-Hwan
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.60 no.10
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    • pp.1951-1958
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    • 2011
  • The objective of this study is to analyze the performance of digital low-pass differentiators(LPD) and then to provide a method to select effective LPD filter, for detecting spikes of surface motor unit action potentials(MUAP). The successful spike detection of MUAPs is a first important step for EMG signal decomposition. The performances of simple and weighted LPD(SLPD and WLPD) filters are analyzed based on different filter lengths and varying MUAPs from simulated surface EMG signals. The SNR improving coefficient and effective MUAP duration range from the analysis results can be used to select proper LPD filters under the varying conditions of surface EMG.