Regional variation in interhemispheric coordination of intrinsic hemodynamic fluctuations.
Regional variation in interhemispheric coordination of intrinsic hemodynamic fluctuations.
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DOI：
10.1523/jneurosci.4544-08.2008
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发表时间：
2008-12-17
期刊：
影响因子：
--
通讯作者：
Milham MP
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文献类型：
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作者：
Stark DE;Margulies DS;Shehzad ZE;Reiss P;Kelly AM;Uddin LQ;Gee DG;Roy AK;Banich MT;Castellanos FX;Milham MP
长期以来，电生理学研究已经证明了左右半球之间的高度相关活动，但对这种半球间协调的区域变化知之甚少。虽然认知模型和神经解剖学证据表明初级感觉运动皮层与高阶关联区域之间的协调存在差异，但这些差异尚未得到表征。在这里，我们使用静息态功能磁共振成像数据采集62名健康志愿者检查自发低频血流动力学波动的区域间相关性。使用概率地图集，我们相关的概率加权的时间序列，从112个地区，包括整个大脑。然后，我们研究了区域变化之间的相关活动同伦区域，对比初级感觉运动皮层，单峰关联区，和异峰关联区。与以前的研究一致，强烈相关的自发活动之间注意到所有的同伦区域，这是显着高于非同伦（异位和半球内）地区。我们进一步证明了在同伦半球间相关性的实质性区域差异，这在不同受试者之间是高度一致的。具体来说，大脑半球间的相关性存在梯度，初级感觉-运动皮层之间的相关性最高（0.758，sd =0.152），单峰关联区之间的相关性显著较低（0.597，sd =0.230），异峰关联区之间的相关性更低（0.517，sd =0.226）。这些结果表明，大脑半球间的协调功能的差异有关的大脑的层次细分。初级皮质的同步性可能反映了参与双侧感觉整合和运动协调的网络，而异模态关联区的协调性较低与这些区域的功能偏侧化一致。这种检查大脑半球间协调的新方法可能会产生关于不同疾病过程以及健康发展的见解。
Electrophysiological studies have long demonstrated a high degree of correlated activity between the left and right hemispheres, however little is known about regional variation in this interhemispheric coordination. While cognitive models and neuroanatomical evidence suggest differences in coordination across primary sensory-motor cortices versus higher-order association areas, these have not been characterized. Here, we used resting-state functional magnetic resonance imaging data acquired from 62 healthy volunteers to examine interregional correlation in spontaneous low-frequency hemodynamic fluctuations. Using a probabilistic atlas, we correlated probability-weighted time series from 112 regions comprising the entire cerebrum. We then examined regional variation in correlated activity between homotopic regions, contrasting primary sensory-motor cortices, unimodal association areas, and heteromodal association areas. Consistent with previous studies, robustly correlated spontaneous activity was noted between all homotopic regions, which was significantly higher than that between nonhomotopic (heterotopic and intrahemispheric) regions. We further demonstrated substantial regional variation in homotopic interhemispheric correlations that was highly consistent across subjects. Specifically, there was a gradient of interhemispheric correlation, with highest correlations across primary sensory-motor cortices (0.758,sd=0.152), significantly lower correlations across unimodal association areas (0.597,sd=0.230) and still lower correlations across heteromodal association areas (0.517,sd=0.226). These results demonstrate functional differences in interhemispheric coordination related to the brain’s hierarchical subdivisions. Synchrony across primary cortices may reflect networks engaged in bilateral sensory integration and motor coordination while lower coordination across heteromodal association areas is consistent with functional lateralization of these regions. This novel method of examining interhemispheric coordination may yield insights regarding diverse disease processes as well as healthy development.