论文标题
快速发作的扩散功能MRI信号反映了神经形态耦合动力学
A rapid-onset diffusion functional MRI signal reflects neuromorphological coupling dynamics
论文作者
论文摘要
功能磁共振成像（fMRI）改变了我们对体内大脑功能的理解。然而，fMRI下面的神经血管耦合机制与神经活动有些“遥远”。有趣的是，来自内在光学信号（IOSS）的证据表明，神经活动也与（亚）细胞形态学调节结合在一起。以前已经提出了扩散加权功能性MRI（DFMRI）实验来探测此类神经形态耦合，但是潜在的机制仍然激烈争议。在这里，我们在大鼠前虫刺激和急性切片中的IOSS上提供了体内超快DFMRI信号之间的第一个直接联系，刺激了光遗传学。我们揭示了迄今未报告的快速发作（<100 ms）DFMRI信号（i）与快速升高的IOSS动力学一致； （ii）证明与刺激期的点状定量对应关系； （iii），对血管挑战不敏感。我们的发现表明，可以通过DFMRI信号检测神经形态耦合，从而使神经活动的未来映射良好。
Functional Magnetic Resonance Imaging (fMRI) has transformed our understanding of brain function in-vivo. However, the neurovascular coupling mechanisms underlying fMRI are somewhat "distant" from neural activity. Interestingly, evidence from Intrinsic Optical Signals (IOSs) indicates that neural activity is also coupled to (sub)cellular morphological modulations. Diffusion-weighted functional MRI (dfMRI) experiments have been previously proposed to probe such neuromorphological couplings, but the underlying mechanisms have remained highly contested. Here, we provide the first direct link between in vivo ultrafast dfMRI signals upon rat forepaw stimulation and IOSs in acute slices stimulated optogenetically. We reveal a hitherto unreported rapid onset (<100 ms) dfMRI signal which (i) agrees with fast-rising IOSs dynamics; (ii) evidences a punctate quantitative correspondence to the stimulation period; (iii) and is rather insensitive to a vascular challenge. Our findings suggest that neuromorphological coupling can be detected via dfMRI signals, auguring well for future mapping of neural activity more directly.
