麻醉大鼠皮层及纹状体静息态脑功能网络连接

Functional connectivity analysis of cortex and striatum in anesthetized rat brain: A resting-state empirical study

目的以功能连接分析方法探讨大鼠麻醉状态和呼吸、心跳消失早期状态不同脑部位静息态自主性BOLD低频振荡(LFBF)信号的变化。方法对SD大鼠20只,于吸入麻醉后应用7.0T小动物磁共振仪行MRI,采集鼠脑解剖及功能成像数据;处死大鼠,呼吸、心跳停止5 min后以相同方法行鼠脑MRI;分别以大脑皮层和纹状体为ROI,以功能连接分析方法行脑功能相关性分析。结果麻醉状态下皮层相关性强于纹状体,信号差异范围以皮层为主;呼吸、心跳停止早期皮层与纹状体相关性差异变小,信号差异以皮层之外的区域为主;相应ROI内两种状态相关系数差异有统计学意义。结论麻醉状态下大鼠脑功能活动网络依然存在。LFBF信号蕴含着神经活动的生理性信息,可能为研究局限性脑缺血早期脑神经活动变化及预后评估提供一种新的技术。

Objective To investigate the changes of low-frequency blood oxygenation level-dependent fluctuation（LFBF） in resting-state between the isoflurane-anesthetized and heartbeat-respiratory-disappeared with functional connectivity analysis.Methods fMRI-BOLD measurements of 20 male Sprague-Dawley rats were performed with 7.0T animal MR scanner during anesthetized with isoflurane,the same measurements were executed 5 min after respiratory and cardiac arrest by over-anesthetized.Cerebral cortex and striatum were regarded as ROIs.Functional correlation analysis between ROIs was performed with functional connectivity analysis.Results The correlation of cortex was greater than that of striatum during the anesthetized state,and the main difference of signal zone was in the cortex.Meanwhile,in the early stage of respiratory and cardiac arrest,the difference of correlation between cortex and striatum decreased and the main difference of signal zone was out of the cortex.The difference of correlation coefficient of ROIs between two states was statistically significant.Conclusion Functional network of rats brain still exist in the anesthetized state.LFBF possesses neururgic physiological information.The changes of LFBF between two states could be applied as a new approach to observe the change of nervous activity and prognostic evaluation once acute ischemic stroke happened.