The effect of hypercapnia on the neural and hemodynamic responses to somatosensory stimulation
The effect of hypercapnia on the neural and hemodynamic responses to somatosensory stimulation
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DOI：
10.1016/j.neuroimage.2005.04.036
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发表时间：
2005-09-01
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
现代非侵入性成像技术利用神经活动与血流、体积和氧合变化之间的耦合来绘制人脑的功能结构。了解血流动力学反应如何受到刺激前基线灌注的影响对于成像数据的解释是重要的。为了解决这个问题，本研究测量血流动力学与光学成像光谱和激光多普勒血流仪，而多通道电生理学被用来记录局部场电位（LFP）和多单位活动（MUA）。在基线（正常碳酸血症）和两个水平的高碳酸血症（5%和10%）产生的灌注率升高期间记录啮齿动物桶皮质对晶须刺激的反应。除脱氧血红蛋白的“洗脱”，这是衰减，所有方面的神经和血液动力学反应的晶须刺激是相似的，在5%的高碳酸血症期间，在正常碳酸血症诱发。相比之下，10%的高碳酸血症产生皮层唤醒和减少电流汇和MUA引起的刺激。血流量和容量反应减少了类似的幅度，在电流槽中观察到的。然而，脱氧血红蛋白的“洗脱”比从神经活动中预期的要减弱得多。这些数据表明，基于灌注或血容量变化的成像技术可能比基于脱氧血红蛋白稀释的成像技术（如传统的BOLD fMRI）对基线变化更稳健。(c)2005年爱思唯尔公司All rights reserved.
Modern non-invasive imaging techniques utilize the coupling between neural activity and changes in blood flow, volume and oxygenation to map the functional architecture of the human brain. An understanding of how the hemodynamic response is influenced by pre-stimulus baseline perfusion is important for the interpretation of imaging data. To address this issue, the present study measured hemodynamics with optical imaging spectroscopy and laser Doppler flowmetry, while multichannel electrophysiology was used to record local field potentials (LFP) and multi-unit activity (MUA). The response to whisker stimulation in rodent barrel cortex was recorded during baseline (normocapnia) and elevated perfusion rates produced by two levels of hypercapnia (5 and 10%). With the exception of the 'washout' of deoxyhemoglobin, which was attenuated, all aspects of the neural and hemodynamic response to whisker stimulation were similar during 5% hypercapnia to those evoked during normocapnia. In contrast, 10% hypercapnia produced cortical arousal and a reduction in both the current sink and MUA elicited by stimulation. Blood flow and volume responses were reduced by a similar magnitude to that observed in the current sink. The deoxyhemoglobin 'washout', however, was attenuated to a greater degree than could be expected from the neural activity. These data suggest that imaging techniques based on perfusion or blood volume changes may be more robust to shifts in baseline than those based on the dilution of deoxyhemoglobin, such as conventional BOLD fMRI. (c) 2005 Elsevier Inc. All rights reserved.