Spatial extent of oxygen metabolism and hemodynamic changes during functional activation of the rat somatosensory cortex
Spatial extent of oxygen metabolism and hemodynamic changes during functional activation of the rat somatosensory cortex
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DOI：
10.1016/j.neuroimage.2005.04.024
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发表时间：
2005-08-15
期刊：
影响因子：
5.7
通讯作者：
Boas, DA
中科院分区：
文献类型：
--
作者：
Dunn, AK;Devor, A;Boas, DA
采用多波长反射成像和激光散斑增强脑血流成像相结合的方法，比较了大鼠体感皮层氧合血红蛋白(HBO)、脱氧血红蛋白(HBr)、总血红蛋白浓度(HBT)、脑血流量(CBF)和脑氧代谢率(CMRO2)在前爪刺激和胡须刺激下的空间变化。各血流动力学参数与CMRO2的反应在峰值时的空间范围相似，在刺激开始后的早期，HBR的变化空间范围小于HBO、HBT、CBF和CMR02-此外，与CBF和HBT变化相关的幂定律系数存在轻微的空间依赖性。虽然CMRO2的反应是一种代谢指标，因此预计会比血流动力学参数具有更局部性的反应，但这里的结果表明，情况可能并非如此，这可能是因为光学成像技术对皮质浅层的敏感性增加，与IV层相比，皮质浅层代谢和神经元激活的横向范围更大。此外，我们发现测量的CMRO2变化的空间范围对计算CMRO2变化的假设不敏感，如基线血红蛋白浓度、血管加权常数和组织散射的波长依赖性。功能反应的多参数全场成像提供了对功能激活的血流动力学反应的更完整的图像，包括对CMRO2变化的空间和时间估计。(C)2005 Elsevier Inc.保留所有权利。
The spatial extent of the changes in oxy-hemoglobin (HbO), deoxyhemoglobin (HbR), total hemoglobin concentration (HbT), cerebral blood flow (CBF), and the cerebral metabolic rate of oxygen (CMRO2) in response to forepaw and whisker stimulation were compared in the rat somatosensory cortex using a combination of multi-wavelength reflectance imaging and laser speckle contrast imaging of cerebral blood flow. The spatial extents of the response of each hemodynamic parameter and CMRO2 were found to be comparable at the time of peak response, and at early times following stimulation onset, the spatial extent of the change in HbR was smaller than that of HbO, HbT, CBF, and CMR02- In addition, a slight spatial dependence was found in the power law coefficient relating changes in CBF and HbT. Although the CMRO2 response is a metabolic measure and thus expected to have a more localized response than the hemodynamic parameters, the results presented here suggest that this may not be the case in general, possibly due to the increased sensitivity of optical imaging techniques to superficial cortical layers where the lateral extent of the metabolic and neuronal activation is larger compared to that in layer IV. In addition, we found that the measured spatial extent of the CMRO2 changes was insensitive to assumptions made in the calculation of the CMRO2 changes such as baseline hemoglobin concentrations, vascular weighting constants, and wavelength dependence of tissue scattering. Multi-parameter full field imaging of the functional response provides a more complete picture of the hemodynamic response to functional activation including the spatial and temporal estimation of CMRO2 changes. (c) 2005 Elsevier Inc. All rights reserved.