DWI and complex brain network analysis predicts vascular cognitive impairment in spontaneous hypertensive rats undergoing executive function tests.
DWI and complex brain network analysis predicts vascular cognitive impairment in spontaneous hypertensive rats undergoing executive function tests.
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DOI：
10.3389/fnagi.2014.00167
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发表时间：
2014
影响因子：
4.8
通讯作者：
Soria G
中科院分区：
文献类型：
--
作者：
López-Gil X;Amat-Roldan I;Tudela R;Castañé A;Prats-Galino A;Planas AM;Farr TD;Soria G
寻找血管性认知功能障碍的生物标志物是其早期诊断的迫切需要。这项研究的目的是检测和监测大脑结构和连接的变化，并将其与执行功能的下降相关联。我们在慢性高血压动物模型：自发性高血压大鼠中检查了早期诊断磁共振成像（MRI）预测发病前认知障碍的可行性。认知性能进行了测试，在操作性条件反射范式，评估学习，记忆和行为灵活性技能。出生后10、14、18、22、26和40周，行为测试与126个扩散梯度方向和0.3 mm3等轴分辨率获得的纵向扩散加权成像相结合。扩散加权成像分析在两种不同的方式，通过区域表征的扩散张量成像（DTI）指数，并通过评估的变化，在结构性脑网络组织的基础上Q球纤维束成像。已经在第一次评估的时间，DTI标量地图显示显着差异，在许多地区，表明损失的完整性在白色和灰质的自发性高血压大鼠相比，血压正常的对照组大鼠。此外，结构脑网络的图论分析表明，层次模块性，全局和局部功效显着下降，具有预测价值的区域三重交叉验证研究。此外，这些降低与在随后的时间点观察到的行为表现缺陷显著相关，这表明弥散加权成像和连接性研究可以揭示神经成像改变，即使认知障碍的明显体征变得明显。
The identification of biomarkers of vascular cognitive impairment is urgent for its early diagnosis. The aim of this study was to detect and monitor changes in brain structure and connectivity, and to correlate them with the decline in executive function. We examined the feasibility of early diagnostic magnetic resonance imaging (MRI) to predict cognitive impairment before onset in an animal model of chronic hypertension: Spontaneously Hypertensive Rats. Cognitive performance was tested in an operant conditioning paradigm that evaluated learning, memory, and behavioral flexibility skills. Behavioral tests were coupled with longitudinal diffusion weighted imaging acquired with 126 diffusion gradient directions and 0.3 mm3 isometric resolution at 10, 14, 18, 22, 26, and 40 weeks after birth. Diffusion weighted imaging was analyzed in two different ways, by regional characterization of diffusion tensor imaging (DTI) indices, and by assessing changes in structural brain network organization based on Q-Ball tractography. Already at the first evaluated times, DTI scalar maps revealed significant differences in many regions, suggesting loss of integrity in white and gray matter of spontaneously hypertensive rats when compared to normotensive control rats. In addition, graph theory analysis of the structural brain network demonstrated a significant decrease of hierarchical modularity, global and local efficacy, with predictive value as shown by regional three-fold cross validation study. Moreover, these decreases were significantly correlated with the behavioral performance deficits observed at subsequent time points, suggesting that the diffusion weighted imaging and connectivity studies can unravel neuroimaging alterations even overt signs of cognitive impairment become apparent.