利用多模态光学脑成像研究前额叶静息态功能连接

Using Multimodal Optical Brain Imaging to Investigate Resting-State Functional Connectivity in Frontal Cortex

利用多模态光学脑成像测量了人脑前额叶的静息态功能连接.分别用近红外光谱(NIRS)和漫射相关谱(DCS)在人体大脑前额叶的相同位置记录了大脑8 min的自发波动信号,测量覆盖区域包括左侧额下皮层(IFC)及左背外侧前额叶(DLPFC).低频段血氧代谢信号(包括含氧血红蛋白、脱氧血红蛋白及总血红蛋白浓度)用来揭示基于血氧信号的静息态功能连接,而相同频段的脑血流信号用来确定基于脑血流的静息态功能连接.2类血液动力学参量的静息态功能连接均表明:背外侧前额叶区域内的连接大于背外侧前额叶与额下皮层之间的区域间连接,显示相邻的背外侧前额叶和额下皮层属于不同的功能区域.此外基于2类血液动力学参量的功能连接的定量比较发现,基于血氧代谢的连接强度更大,表明在同一个功能区内,静息时血氧代谢信号的时间同步性更高.

Multimodal optical imaging is used to investigate resting-state functional connectivity （RSFC） in the frontal cortex.8 minutes of spontaneous activity of brain is separately recorded by near infrared spectroscopy （NIRS） and diffuse correlation spectroscopy （DCS）.The measured area includes left inferior frontal cortex （IFC） and left dorsolateral prefrontal cortex （DLPFC）.Low frequency component of blood oxygenation signal （i.e., oxygenated hemoglobin, deoxygenated hemoglobin and total hemoglobin） is used to reveal oxygenation-based RSFC, while the cerebral blood flow signal in the same frequency range is used to identify cerebral blood flow-based RSFC.Both blood oxygenation-based and cerebral blood flow-based RSFC show that the intra-regional connectivity within DLPFC is stronger than the inter-regional connectivity between DLPFC and IFC, implying that DLPFC and IFC, each belongs to a distinct functional area, though they are anatomically adjacent.Quantitative comparison between RSFC revealed by the two classes of hemodynamic variables shows the oxygenation-based RSFC is stronger than the cerebral blood flow-based RSFC, indicating the blood oxygenation in a functional area is more synchronized in time than the cerebral blood in resting-state.