中文摘要：

目的利用静息态fMRI观察运动皮质的功能连接网络及其小世界性。方法对90名健康成年志愿者行静息态fMRI数据采集,分别以双侧M1区为种子点获得全脑正性及负性功能连接脑图。以这些区域作为节点,计算其平均聚类系数Cp和平均最短路径长度Lp、全脑随机网络属性Crand和Lrand;按照公式γ=Cp/Crand〉1和λ=Lp/Lrand≈1分别计算γ及λ值,以验证其小世界网络属性。结果静息态以M1区为种子点的正激活区域主要包括双侧初级运动皮质、运动前区及辅助运动区;负激活区域包括双侧额上回、楔前叶、缘上回、角回、双侧颞上回及小脑后叶。在矩阵稀疏度0.1≤Sparsity〈0.5范围内,这些区域的小世界属性符合γ=Cp/Crand〉1及λ=Lp/Lrand≈1。结论运动皮质的正性连接主要集中在运动系统内,负性连接与脑的默认网络类似,运动皮质功能网络具有小世界性。

英文摘要：

Objective： To observe the functional connectivity and small-world network of motor cortex in healthy subjects using resting-state fMRI. Methods： Ninety healthy adults underwent resting-state fMRI. The positive and negative correlation functional mappings within the whole brain were acquired using bilateral M1 as ROI respectively. The average clustering coefficients （Cp） and shortest path （Lp） of this network were calculated using these functional connectivity brain regions as node points. The parameter Crand and Lrand of random networks were also generated. At last, equality of the formulas γ=Cp/Crand〉1, and λ=Lp/Lrand≈1 were calculated to verify the small-word network of motor cortex property. Results： The positive correlated areas included bilateral primary motor cortex, premotor area and supplementary motor cortex. Negative correlation areas were observed in the bilateral superior frontal cortex, supramarginal gyrus, angular gyrus, superior temporal gyrus, the precuneus and the bilateral posterior lobe of cerebellum. The functional network of motor cortex had the property of small-worldness within the range of 0.1≤Sparsity〈0.5. Conclusion： The positive correlation areas are mainly limited in the motor cortex, and the negative connectivity maps are similar with the default mode networks. The functional network of motor cortex has small-word property.