PDF(Pubmed)
Abstract：
Neuromodulatory nuclei that are part of the ascending arousal system (AAS) play a crucial role in regulating cortical state and optimizing task performance. Pupil diameter, under constant luminance conditions, is increasingly used as an index of activity of these AAS nuclei. Indeed, task-based functional imaging studies in humans have begun to provide evidence of stimulus-driven pupil-AAS coupling. However, whether there is such a tight pupil-AAS coupling during rest is not clear. To address this question, we examined simultaneously acquired resting-state fMRI and pupil-size data from 74 participants, focusing on six AAS nuclei: the locus coeruleus, ventral tegmental area, substantia nigra, dorsal and median raphe nuclei, and cholinergic basal forebrain. Activation in all six AAS nuclei was optimally correlated with pupil size at 0-2 s lags, suggesting that spontaneous pupil changes were almost immediately followed by corresponding BOLD-signal changes in the AAS. These results suggest that spontaneous changes in pupil size that occur during states of rest can be used as a noninvasive general index of activity in AAS nuclei. Importantly, the nature of pupil-AAS coupling during rest appears to be vastly different from the relatively slow canonical hemodynamic response function that has been used to characterize task-related pupil-AAS coupling.
摘要：
作为提升性唤醒系统（AAS）的一部分的神经调节核在调节皮层状态和优化任务表现中起着至关重要的作用。瞳孔直径,在恒定亮度条件下，越来越多地用作这些AAS核的活性指标。的确,基于任务的人体功能成像研究已经开始提供刺激驱动的瞳孔-AAS耦合的证据。然而,在休息期间是否存在如此紧密的瞳孔-AAS耦合尚不清楚。为了解决这个问题，我们同时检查了74名参与者的静息状态fMRI和瞳孔大小数据，专注于六个AAS核：蓝斑，腹侧被盖区,黑质,背侧和正中中缝核,和胆碱能基底前脑。在0-2s滞后时，所有六个AAS核中的激活与瞳孔大小最佳相关，表明自发的瞳孔变化几乎立即伴随着AAS中相应的BOLD信号变化。这些结果表明，在休息状态下发生的瞳孔大小的自发变化可用作AAS细胞核活动的非侵入性一般指标。重要的是,静息时瞳孔-AAS耦合的性质似乎与用于表征任务相关瞳孔-AAS耦合的相对较慢的典型血液动力学响应函数有很大不同.
