Noninvasive measurement of neuronal activity with near-infrared optical imaging
Noninvasive measurement of neuronal activity with near-infrared optical imaging
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DOI：
10.1016/j.neuroimage.2003.09.040
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发表时间：
2004-01-01
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：
Franceschini, MA;Boas, DA
扩散光学成像（DOI）单独提供的可能性，同时和非侵入性测量神经元和血管信号在大脑中的时间分辨率高达1毫秒。然而，虽然血流动力学信号的光学测量是建立良好的，神经元激活（所谓的快速信号）的光学测量才刚刚出现，需要进一步优化和验证。在这项工作中，我们提出了初步的研究，我们在10名健康志愿者在手指敲击，触觉刺激，电正中神经刺激测量的快速信号。我们使用的仪器（CW 4）与8源（690和830 nm）和16个检测器的位置比以前报道的研究中的仪器更多的optodes。这使我们能够同时记录同侧和对侧感觉运动皮层，同时测量诱发的血流动力学反应。我们使用25 ms/图像的采集时间;在平均约1000个事件后，信噪比约为10（4）。由于由于快速信号引起的预期相对强度变化（约10（-3））小于生理效应引起的相对强度变化（约10（-1）），我们增强了对竞争信号（如心跳相关强度变化）的抑制，并建立了评估快速信号鲁棒性的五个标准。我们在手指敲击期间的43%的测量中检测到快速信号，在触觉刺激期间的60%的测量中检测到快速信号，在正中神经电刺激期间的23%的测量中检测到快速信号。与快速信号相关的强度的相对变化约为0.07%，信号的潜伏期约为100 ms。All rights reserved.
Diffuse optical imaging (DOI) alone offers the possibility of simultaneously and noninvasively measuring neuronal and vascular signals in the brain with temporal resolution of up to 1 ms. However, while optical measurement of hemodynamic signals is well established, optical measurement of neuronal activation (the so-called fast signal) is just emerging and requires further optimization and validation. In this work, we present preliminary studies in which we measured the fast signal in 10 healthy volunteers during finger-tapping, tactile stimulation, and electrical median nerve stimulation. We used an instrument (CW4) with 8 source (690 and 830 nm) and 16 detector positions-more optodes than the instruments in previously reported studies. This allowed us to record the ipsilateral and contralateral sensorimotor cortex simultaneously, while at the same time measuring the evoked hemodynamic response. We used an acquisition time of 25 ms per image; after averaging approximately 1000 events, the signal-to-noise ratio was approximately 10(4). Since the expected relative intensity changes due to the fast signal (approximately 10(-3)) are smaller than the relative intensity changes due to physiological effects (approximately 10(-1)), we enhanced the suppression of competing signals such as the heartbeat-associated intensity changes, and established five criteria with which to assess the robustness of the fast signal. We detected the fast signal in 43% of the measurements during finger-tapping, 60% of those during tactile stimulation, and 23% of those during electrical median nerve stimulation. The relative changes in intensity associated with the fast signal were approximately 0.07% and the latency of the signal was approximately 100 ms. (C) 2003 Elsevier Inc. All rights reserved.