An arteriolar compliance model of the cerebral blood flow response to neural stimulus
An arteriolar compliance model of the cerebral blood flow response to neural stimulus
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DOI：
10.1016/j.neuroimage.2004.12.057
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发表时间：
2005-05-01
期刊：
影响因子：
5.7
通讯作者：
Liu, TT
中科院分区：
文献类型：
--
作者：
Behzadi, Y;Liu, TT
虽然功能磁共振成像（fMRI）是一种广泛使用的和强大的工具，用于研究脑功能，定量解释的fMRI测量的基础神经科学和临床研究可以复杂的受试者和会话间的变异性所产生的调制的基线血管状态的疾病，衰老，饮食和药物。特别是，最近的研究表明，脑血流量（CBF）和血氧水平依赖性（BOLD）的刺激响应的时间动态调制的变化，在基线CBF诱导的各种血管活性剂和血管顺应性与衰老相关的降低。这些影响是不容易解释的CBF和BOLD响应使用当前的模型。我们在这里提出了一个二阶非线性反馈模型的诱发脑血流反应，神经活动调制的小动脉平滑肌的顺应性。在该模型框架内，基线血管状态通过改变主动平滑肌成分和被动结缔组织成分对总体血管顺应性的相对贡献来影响动态响应。BOLD信号的基线依赖性通过将小动脉顺应性模型与先前描述的静脉室的球囊模型耦合来研究。数值模拟表明，该模型描述了一阶CBF和BOLD响应基线血管状态的依赖关系。(c)2005年爱思唯尔公司All rights reserved.
Although functional magnetic resonance imaging (fMRI) is a widely used and powerful tool for studying brain function, the quantitative interpretation of fMRI measurements for basic neuroscience and clinical studies can be complicated by inter-subject and inter-session variability arising from modulation of the baseline vascular state by disease, aging, diet, and pharmacological agents. In particular, recent studies have shown that the temporal dynamics of the cerebral blood flow (CBF) and the blood oxygenation level dependent (BOLD) responses to stimulus are modulated by changes in baseline CBF induced by various vasoactive agents and by decreases in vascular compliance associated with aging. These effects are not readily explained using current models of the CBF and BOLD responses. We present here a second-order nonlinear feedback model of the evoked CBF response in which neural activity modulates the compliance of arteriolar smooth muscle. Within this model framework, the baseline vascular state affects the dynamic response by changing the relative contributions of an active smooth muscle component and a passive connective tissue component to the overall vessel compliance. Baseline dependencies of the BOLD signal are studied by coupling the arteriolar compliance model with a previously described balloon model of the venous compartment. Numerical simulations show that the proposed model describes to first order the observed dependence of CBF and BOLD responses on the baseline vascular state. (c) 2005 Elsevier Inc. All rights reserved.