| Project/Area Number |
12557003
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 展開研究 |
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| Research Field |
General physiology
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| Research Institution | Shimane University (School of Medicine) |
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Principal Investigator |
HIROTA Akihiko Shimane University (School of Medicine), Department of Physiology, Professor, 医学部, 教授 (50156717)
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| Co-Investigator(Kenkyū-buntansha) |
YAZAWA Itaru Shimane University (School of Medicine), Department of Physiology, Instructor, 医学部, 助手 (40360656)
ITO Shin-ichi Shimane University (School of Medicine), Department of Physiology, Assistant Professor, 医学部, 助教授 (10145295)
ENOMOTO Koh-ichi Shimane University (School of Medicine), Department of Physiology, Instructor, 医学部, 助手 (70112125)
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| Project Period (FY) |
2000 – 2003
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| Project Status |
Completed (Fiscal Year 2003)
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| Budget Amount *help |
¥12,300,000 (Direct Cost: ¥12,300,000)
Fiscal Year 2003: ¥2,000,000 (Direct Cost: ¥2,000,000)
Fiscal Year 2002: ¥2,700,000 (Direct Cost: ¥2,700,000)
Fiscal Year 2001: ¥3,200,000 (Direct Cost: ¥3,200,000)
Fiscal Year 2000: ¥4,400,000 (Direct Cost: ¥4,400,000)
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| Keywords | OPTICAL RECORDING / CCD VIDEO CAMERA / LIQUID CRYSTAL PANEL / TWO DIMENSIONAL MEMBRANE POTENTIAL RECORDING / VOLTAGE-SENSITIVE DYE |
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| Research Abstract |
We have developed optical system for monitoring the membrane potential using CCD video camera. Since the size of membrane potential change is proportional to the fractional change (change in fluorescent light divided by the resting fluorescent light level) of the optical signal, it must be an ideal condition for optical recording using CCD video camera that the resting fluorescent light level is uniform. If there are not so many differences among the DC level in each CCD camera pixel, it is possible to subtract constant DC value from the output of CCD camera and then amplified for improvement the signal to noise level in optical signals. For this purpose, we have tried to install a liquid crystal panel in the light path and controlled the level of incident light in each pixel independently.
In 2000 and 2001, we bought a high speed CCD camera and match its frame speed to 1000 frames per second, changed the camera controller and changed the do power supply to a stable one with very low ripple. In 2002, we bought a microtome with an oscillating blade, and tried to record the membrane potential optically from live slice preparation. Finally it was found that the saturation level of the CCD camera was too low to detect the membrane potential using absorption optical signals. In 2004, we tried in situ recording from the cerebrum of rat, but the moving artifact, which derived from the respiration and/or heartbeat, was very big. So, we cannot record the membrane potential dependent optical signal without summation of the optical signal. The saturation level of our CCD camera is sometimes not large enough for the brightest point even illuminated by a tungsten-halogen lamp. Installing a liquid crystal panel in the light path makes it possible to increase the intensity of the incident light and then the signal to noise level seems much improved, but the noise level is still not small enough for a single sweep optical recording.
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