1987 Fiscal Year Final Research Report Summary
Construction of apparatus measuring micro-potential field around excitable tissue
| Project/Area Number |
61870007
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| Research Category |
Grant-in-Aid for Developmental Scientific Research
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| Allocation Type | Single-year Grants |
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| Research Field |
General physiology
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| Research Institution | Nagoya University, Medical School |
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Principal Investigator |
TOMITA Tadao Nagoya University, Medical School, 医学部, 教授 (50078763)
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| Co-Investigator(Kenkyū-buntansha) |
TOKUNO Hiroyuki Nagoya University, Medical School, 医学部, 助手 (60155520)
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| Project Period (FY) |
1986 – 1987
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| Keywords | field potential of biological tissue / measutement of micro-potential field / vibrating electrode / 生体電気発生 |
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| Research Abstract |
Gastrointestinal smooth muscles produce a spontaneous electrical activity (slow wave) which is responsible for automaticity. In order to investigate the initiation and propagation of the slow wave, a device was constructed to detect a very weak potential field caused by slow waves around the smooth muscle, using a vebrating electrode. When the electrode vibrates, the potential difference within vibration distance is modulated at a frequency of vibration. This modulated signal can be amplified by a lock-in amplifier with a high signalnoise ration. A piezoelectric vibrator provided by the Tohoku Kinzoku Kogyo and a lock-in amplifier (type 5600) made by NF Electronic Instrument gave satisfactory results. Glass microelectrodes were used both as a vibrating probe and an indifferent electrode. The electrodes had tip diameter of 2-5 <micrn>m and resistance of 1-5 m<omega> when filled with physiological solution. Vibration frequency was usually set at around 20 Hz and its amplitude at 10-20 <micrn>m. With this recording system, slow potential changes of about 5 <micrn>V could be recorded above the circular muscle layer of guinea-pig stomach. This potential was considered to be due to the slow ware, because it disappeared when vibration was stopped and when the electrode was moved away from the preparation. This method will be useful for a continuous recording of electrical activity. Since the fibre arrangement is very complicated, however, it is necessary to use a very fine preparation for quantitative analysis of the recorded potential field in relation to the site of generation or propagation of slow wave within the tissue.
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