Project/Area Number |
11680810
|
Research Category |
Grant-in-Aid for Scientific Research (C)
|
Allocation Type | Single-year Grants |
Section | 一般 |
Research Field |
神経・脳内生理学
|
Research Institution | Tokyo Medical University |
Principal Investigator |
SASAKI Mitsuyashi Tokyo Medical Univ.Medicine, Associate, 医学部, 助教授 (10170698)
|
Project Period (FY) |
1999 – 2000
|
Project Status |
Completed (Fiscal Year 2001)
|
Budget Amount *help |
¥2,100,000 (Direct Cost: ¥2,100,000)
Fiscal Year 2000: ¥1,000,000 (Direct Cost: ¥1,000,000)
Fiscal Year 1999: ¥1,100,000 (Direct Cost: ¥1,100,000)
|
Keywords | urinary bladder / micturition / Barrington's nucleus / sacral cord / pons / brainstem / 橋排尿中枢 / ニューロン |
Research Abstract |
Barrington's nucleus projects directly to the sacral parasympathetic nucleus. The prupose of this study was to clarify whether neurons in Barrington's nucleus that increase their firing druing bladder contractions project to the spinal cord and, if so, to which level(s) the axon reaches. Single unitsl were recorded in Barrington's nucleus of cat with glass microelectrodes, and the termination level of descending axons was determined by antidromic stimulation of the spinal cord. Thirty-nine neurons projecting to the spinal cord were located in rostral parts of the dorsolateral pontine tegmentum, medial and ventral to the mesencephalic trigeminal tract. This is consistent with previous neuronal tracing studies. All neurons increased their firing rates during contraction associated with micturition. In 19 examined neurons, the most caudal level of the descending axon distributed between the L7 and the S3 level. Stimulation of the axon at this most caudal level resulted in antidromic spike latencies ranging between 19.5 ms and 45.0 ms. These antidromic latencies were much smaller than previously reported orthodromic conduction times between neurons in Barrington's nucleus and sacral preganglionic neurons innervating the bladder. The mean conduction velocity of the descending axon from the cell body to the border between Th13 and the L1 ranged between 7.2m/s and 27.7 m/s. The decrease of the mean conduction velocity was observed at the lumbar as well as at the sacral segments, suggesting that axons issue collaterals to the lumbur level as well as to the sacral level.
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