| Project/Area Number |
12670916
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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 |
Radiation science
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| Research Institution | National Institute of Neuroscience, NCNP |
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Principal Investigator |
OGINO Takashi National Institute of Neuroscience, NCNP, Biochemistry & cell biology, Ph. D., 神経研究所・診断研究部, 室長 (50185526)
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| Co-Investigator(Kenkyū-buntansha) |
NAKAMURA Shun National Institute of Neuroscience, NCNP, Biochemistry & cell biology, Head, 神経研究所・診断研究部, 部長 (00134619)
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| Project Period (FY) |
2000 – 2001
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| Project Status |
Completed (Fiscal Year 2001)
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| Budget Amount *help |
¥3,200,000 (Direct Cost: ¥3,200,000)
Fiscal Year 2001: ¥1,100,000 (Direct Cost: ¥1,100,000)
Fiscal Year 2000: ¥2,100,000 (Direct Cost: ¥2,100,000)
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| Keywords | 1H MRI / CSF production / hypocaonia / hypercapnia / rat / brain / micro-imaging / Gd-DTPA / NMR / brain function / CSF flow / 脳機能画像法 / デオキシヘモグロビン / 初期応答 / initial dip / 負のBOLD効果 / 時間分解fMRI法 / EPI法 / fMRI法 |
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| Research Abstract |
The early response to rat forepaw stimulation in functional MRI (fMRI) was investigated. Furthermore, cerebrospinal fluid (CSF) secretion of rat was monitored by longitudinal relaxation time-weighted magnetic resonance imaging (T_<1>-weighted MRI) in combination with ventricular injection of a T_<1>-relaxation reagent : gadoliniunrdiethylene triamine-N, N, N', N". N"-pentaacetic acid (Gd-DTPA). A cannula was inserted in the left lateral ventricle, and 5 ul of 8.5 mM Gd-DTPA was injected as a CSF marker. Changes in the image intensity of the CSF were measured every 30 sec, and the turnover rate of CSF (k) in the left lateral ventricle was obtained from the dilution of Gd-DTPA, based on the assumption of a single compartment model. In the control conditions, k was 0.158±0.009 min^<-1> at an arterial blood CO_<2> tension (pCO_<2>) of 38.6±2.2mmHg (n=10), which corresponds to the CSF secretion rate of 3.6 ul min^<-1>. The k value was decreased (0.078±0.010 min^<-1>, n=4) by a carbonic anhydrase inhibitor (acetazolamide). The turnover rate was decreased by hypocapnia (0.094±0.019min^<-1>, pCO_<2> = 24.7±2.9mmHg, n=4), and it increased gradually and reached a plateau level due to hypercapnia (0.194±0.011min^<-1>, pCO_<2> = 104.5±7.1 mmHg, n=10). These results suggested that CO_<2> upregulates the secretion of CSF in the rat.
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