大鼠感觉运动系统静息态脑网络研究

Study on Resting-State Functional Connectivity of Rat Sensorimotor System

为了理解啮齿类动物的脑功能连接,本文利用9.4T fMRI获得轻度麻醉状态下大鼠静息状态及刺激激活的数据,通过互相关分析构建节点之间的相关系数矩阵并计算相应的网络参数.结果发现:给予前爪电刺激时,刺激对侧初级感觉皮层(S1)、丘脑(Tha)有较强的正激活,双侧尾状壳核(CPu)有较强的负激活.静息状态时大鼠感觉/运动皮层内部、丘脑内部的连接性较强,而感觉/运动皮层与丘脑之间的连接较弱,双侧感觉运动系统之间存在较强的同步低频振荡,感觉运动系统在静息态时的脑网络具有小世界属性.结果提示,啮齿类动物在大脑信息处理中的功能分离和整合可能与人类存在某些相似性,支持哺乳动物中枢神经系统的基本功能存在遗传保守性的观点.

In order to better understand functional connectivity of rodent brain, we analyzed the functional magnetic resonance imaging （fMRI） data of the resting-state and forepaw electrical stimulation from lightly anesthetized rat at 9.4 T using cross-correlation analysis. The results showed that the primary somatosensory cortex （S1） and thalamus （Tha） were significantly positively activated, the caudate putamen nucleus （CPu） was significantly negatively activated during forepaw stimulation. The higher connectivity bilateral intra-sensory/motor cortices and bilateral intra- thalamus, but lower connectivity between sensory/motor cortex and thalamus were found during the resting state. Synchronized low frequency fluctuation （LFF） was observed between functionally related brain regions. In addition, the brain network of sensorimotor system showed small-world feature during resting-state. These results suggested that rodents have some similar properties with human in functional separation and integration during brain information processing, and strongly support the view that the underlying physiology of CNS is conserved across mammalian species.