Separating neuronal activity and systemic low-frequency oscillation related BOLD responses at nodes of the default mode network during resting-state fMRI with multiband excitation echo-planar imaging
Frontiers in Neuroscience September 21, 2022 Atsushi Tachibana, Yoko Ikoma, Yoshiyuki Hirano et al.
Resting-state functional MRI (rsfMRI) measures spontaneous brain activity via BOLD signal changes, particularly within the default mode network (DMN). However, the BOLD signal may also be influenced by systemic low-frequency oscillations (SysLFOs) of non-neuronal origin that propagate through the brain at different arrival times, making it difficult to distinguish neural from non-neural responses. This study compared conventional single-shot EPI (Conv) with faster multiband EPI (MB) acquisition to evaluate time-lags between DMN nodes. Conv data suggested SysLFOs substantially influence apparent neuronal time-lags, while MB data implied that SysLFO and neuronal effects on the BOLD response may be separable. Higher time-resolution rsfMRI may help distinguish neuronal from non-neuronal BOLD changes.