The effects of respiratory CO2 fluctuations in the resting-state BOLD signal differ between eyes open and eyes closed.

摘要: Resting fluctuations in arterial CO2 (a cerebral vasodilator) are believed to be an important source of low-frequency blood oxygenation level dependent (BOLD) signal fluctuations. In this study we focus on the two commonly used resting-states functional magnetic resonance imaging experiments, eyes open and closed, quantify degree which measured spontaneous partial pressure end-tidal (Petco2) relate BOLD time series. A significantly longer latency changes following Petco2 was found closed condition compared with open, may reveal different intrinsic vascular response delays reactivity or alteration net arising from altered neural activity closed. By allowing a spatially varying delay for compensation temporal difference, more consistent correlation map can obtained. Finally, Granger-causality analysis demonstrated “causal” relationship between BOLD. The identified dominant Petco2→BOLD directional coupling supports notion that indeed cause resting variance majority subjects.