| Project/Area Number |
09680821
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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 |
神経・脳内生理学
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| Research Institution | Tokyo Medical University |
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Principal Investigator |
SASAKI Mitsuyoshi Tokyo Medical Univ., Dep. of Physiol, Ph.D., 医学部, 助教授 (10170698)
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| Project Period (FY) |
1997 – 1998
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| Project Status |
Completed (Fiscal Year 1998)
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| Budget Amount *help |
¥2,100,000 (Direct Cost: ¥2,100,000)
Fiscal Year 1998: ¥1,000,000 (Direct Cost: ¥1,000,000)
Fiscal Year 1997: ¥1,100,000 (Direct Cost: ¥1,100,000)
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| Keywords | bladder / micturition / spinal cord / pelvic_nerve / parasympathetic / nerve / ganglion reflex / preganglionic neurone |
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| Research Abstract |
The pontine micturition centre is essential for the micturition contraction. Reflex discharges in the bladder branch of the pelvic nerve after stimulation of other bladder branch are also thought to be evoked via this centre. The present study focuses on whether there is a sacral reflex centre that has not recently been considered. The hypogastric nerves of both sides were cut in all experiments. (1) Contraction-relaxation fluctuations with small amplitudes and relatively fast intervals observed after transection of the spinal cord were dependent on the intravesical pressure, showing maximal amplitudes (80-100 mmH20) at around 100-150 mmH20 of the intravesical pressure. After removal of the spinal cord, these fluctuations dramatically reduced (10-30 mmH20), suggesting that the fluctuations were evoked by a spinal reflex as well as by a ganglion reflex. (2) In preparations where all collaterals between the two bladder nerve branches of the pelvic nerve were split, electrical stimulation of one bladder branch evoked early (20-40 ms) and late (around 100 ms) reflexes on the other bladder branch. When recording from the sacral parasympathetic preganglionic neurones with a glass microelectrode, stimulation of the bladder branch of the pelvic nerve also evoked early (14-26 ms) and late (62-106 ms) reflexes. The latency of the early reflex in both preparations indicated that this was evoked via the spinal cord. Firings between the early and late reflex were reduced, suggesting that, from the intracellular study, it was caused by IPSPs. The early reflex was larger during micturition contraction than when the bladder was relaxed, indicating that the early reflex was dependent on the bladder activity similar to the long reflex.
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