Reducing vascular variability of fMRI data across aging populations using a breathholding task
Reducing vascular variability of fMRI data across aging populations using a breathholding task
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DOI：
10.1002/hbm.20307
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发表时间：
2007-09-01
影响因子：
4.8
通讯作者：
D'Esposito, Mark
中科院分区：
文献类型：
--
作者：
Handwerker, Daniel A.;Gazzaley, Adam;D'Esposito, Mark
在功能性MRI（fMRI）研究中，血氧水平依赖性（BOLD）反应的幅度和形状因脑区、受试者和人群而异。这种变异性可能是次要的神经活动或脉管系统的差异，从而复杂的解释BOLD信号的变化，在功能磁共振成像实验。我们比较了BOLD对神经活动和血管挑战的反应，并在26名年轻受试者（年龄18-36岁）和24名老年受试者（年龄51-78岁）中测试了分离这些影响的方法。每名受试者在同一扫描会话中的单独运行期间执行visuornotor扫视任务（对神经活动的血管反应）和屏气任务（由高碳酸血症引起的血管扩张）。对于扫视任务，信号幅度显示出显着的下降与老化的FEF，SEF，和V1，和延迟的时间达到峰值与老化的V1。眼跳和高碳酸血症任务的信号幅度在受试者内以及个体和群体之间显示出显着的线性回归。这两项任务的峰值时间和相干相位测量值的线性回归较弱，但有时很显著。在将扫视任务幅度除以高碳酸血症任务幅度后，V1中随年龄增长的显著幅度降低，这意味着信号降低是神经起源的。这些发现可能会导致一种方法来确定血管反应性诱导的差异，在人群中的BOLD反应和方法的发展，以一种简单的，非侵入性的方式来解释这些脉管系统的差异的影响。(c)2006 Wiley-Liss，Inc.
The magnitude and shape of blood oxygen level-dependent (BOLD) responses in functional MRI (fMRI) studies vary across brain regions, subjects, and populations. This variability may be secondary to neural activity or vasculature differences, thus complicating interpretations of BOLD signal changes in fMRI experiments. We compare the BOLD responses to neural activity and a vascular challenge and test a method to dissociate these influences in 26 younger subjects (ages 18-36) and 24 older subjects (ages 51-78). Each subject performed a visuornotor saccade task (a vascular response to neural activity) and a breathholding task (vascular dilation induced by hypercapnia) during separate runs in the same scanning session. For the saccade task, signal magnitude showed a significant decrease with aging in FEF, SEF, and V1, and a delayed time-to-peak with aging in V1. The signal magnitudes from the saccade and hypercapnia tasks showed significant linear regressions within subjects and across individuals and populations. These two tasks had weaker, but sometimes significant linear regressions for time-to-peak and coherence phase measures. The significant magnitude decrease with aging in V1 remained after dividing the saccade task magnitude by the hypercapnia task magnitude, implying that the signal decrease is neural in origin. These findings may lead to a method to identify vascular reactivity-induced differences in the BOLD response across populations and the development of methods to account for the influence of these vasculature differences in a simple, noninvasive manner. (c) 2006 Wiley-Liss, Inc.