Concurrent optical imaging spectroscopy and laser-Doppler Flowmetry: The relationship between blood flow, oxygenation, and volume in rodent barrel cortex
Concurrent optical imaging spectroscopy and laser-Doppler Flowmetry: The relationship between blood flow, oxygenation, and volume in rodent barrel cortex
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DOI：
10.1006/nimg.2001.0808
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发表时间：
2001-06-01
期刊：
影响因子：
5.7
通讯作者：
Mayhew, J
中科院分区：
文献类型：
--
作者：
Jones, M;Berwick, J;Mayhew, J
功能磁共振成像(FMRI)是基于神经活动和内源性顺磁造影剂脱氧血红蛋白浓度变化之间的耦合。血氧水平依赖(BOLD)信号的变化是由血容量、流量和耗氧量的复杂相互作用引起的。光学成像光谱(OIS)被用来测量随着神经活动增加而引起的血容量和饱和度的变化，而激光多普勒血流计(LDF)可以用来测量血流的变化，目前在神经血管研究中已经很常见。在这里，我们同时使用OIS和LDF来检测不同强度电刺激胡须垫对啮齿动物桶状皮质的血流动力学反应。光谱分析显示，刺激引起脱氧血红蛋白(Hbr)出现双相早期升高，然后低于基线水平，在3.7 S时达到最低值。没有证据表明相应的早期氧合血红蛋白(HbO(2))下降，刺激后HbO(2)仅在刺激后升高，在类似于3.2 S时达到最大值。血容量和血流量变化的时间进程相似。两者都在刺激开始后1秒内增加，并在与2.7 S相似的时间达到峰值，之后脑血流量恢复到基线的速度慢于脑血流量，用Hbr、Hbt和脑血流量的变化来估计氧耗变化(CIMRO2)，这些变化在刺激开始后1秒内增加，并在刺激开始后达到与2.2 S相似的峰值。对CBV和CBF的相对大小的分析表明，CBV的分数变化可以简单地标度为与CBF的分数变化相匹配，我们发现CBV=CBF0.29可以很好地近似。使用对吸入二氧化碳分数(FICO2)升高的反应也发现了类似的关系。(C)2001年学术出版社。
Functional magnetic resonance imaging (fMRI) is based on the coupling between neural activity and changes in the concentration of the endogenous paramagnetic contrast agent deoxygenated hemoglobin. Changes in the blood oxygen level-dependent (BOLD) signal result from a complex interplay of blood volume, flow, and oxygen consumption Optical imaging spectroscopy (OIS) has been used to measure changes in blood volume and saturation in response to increased neural activity, while laser Doppler Flowmetry (LDF) can be used to measure flow changes and is now commonplace in neurovascular research. Here, we use concurrent OIS and LDF to examine the hemodynamic response in rodent barrel cortex using electrical stimulation of the whisker pad at varying intensities. Spectroscopic analysis showed that stimulation produced a biphasic early increase in deoxygenated hemoglobin (Hbr), followed by a decrease below baseline, reaching minima at similar to3.7 s. There was no evidence for a corresponding early decrease in oxygenated hemoglobin (HbO(2)), which simply increased after stimulation, reaching maximum at similar to3.2 s. The time courses of changes in blood volume (CBV) and blood flow (CBF) were similar. Both increased within a second of stimulation onset and peaked at similar to2.7 s, after which CBV returned to baseline at a slower rate than CBF, The changes in Hbr, Hbt, and CBF were used to estimate changes in oxygen consumption (CIMRO2), which increased within a second of stimulation and peaked similar to2.2 s after stimulus onset. Analysis of the relative magnitudes of CBV and CBF indicates that the fractional changes of CBV could be simply scaled to match those of CBF, We found the relationship to be well approximated by CBV = CBF0.29. A similar relationship was found using the response to elevated fraction of inspired carbon dioxide (FICO2). (C) 2001 Academic Press.