1996 Fiscal Year Final Research Report Summary
STUDY OF EFFECT OF SENSORY INPUT TO VOLUNTARY MOVEMENT MEASURED BY MAGNETOENCEPHALOGRAPHY
| Project/Area Number |
07670711
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Neurology
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| Research Institution | KYOTO UNIVERSITY |
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Principal Investigator |
NAGAMINE Takashi Kyoto University School of Medicine, Department of Brain pathophysiology, Assistant Professor, 医学研究科, 助手 (10231490)
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| Co-Investigator(Kenkyū-buntansha) |
IKEDA Akio Kyoto University School of Medicine, Department of Brain pathophysiology, Assist, 医学研究科, 助手 (90212761)
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| Project Period (FY) |
1995 – 1996
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| Keywords | voluntary movement / sensory input / magnetoencephalography / movement-related magnetic cortical field / somatosensory evoked field |
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| Research Abstract |
Effect of sensory input to voluntary movement has been studied by magnetoencephalography (MEG).
(1) Stable recording of somatosensory evoked magnetic field (SEF)
In order to avoid stimulus artifact produced by the short duration electric shock, various kinds of grounding have been tried. Placement of wide grounding electrode around the forearm proximal to the stimulus electrode revealed the complete elimination of the artifact.
(2) Recovery function of SEF
Paired electric shock with various interstimulus interval (ISI) ranging from 10 to 200 ms was applied to the median nerve and SEF was recorded. Subtraction of SEF to single shock from that to the paired shock resulted in the net response to the second shock. ISI with 20-60 ms produced suppression on the component 40-60 ms after the stimulus. Other components seemed to be stable.
(3) Movement-related magnetic field (MRCF)
Since MEG equivalent (Readiness field, RF) to Bereitschaftspotential (BP) starts later than BP in selfpaced movement, interval for self-pace movement has been evaluated, which does not interfere the RF.Interval exceeding 1.5 s disclosed that response can be recognized as that corresponding to a single movement.
(4) Interference to SEF by movement
Random button press with approximately 3 s interval was requested to normal volunteers, during the session with random electric shock with intervals ranging from 0.9 to 1.3s. SEF was categorized with respect to the timing to the voluntary contraction. Although SEF became smaller when the button press preceded the electric shock within 900 ms, SEF was not affected by the following voluntary movement even if it occurred within 900 ms after the electric shock.
These results indicate the close relationship between the sensory and motor cortex.
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