Bottom-up sensory processing can induce negative BOLD responses and reduce functional connectivity in nodes of the default mode-like network in rats
Bottom-up sensory processing can induce negative BOLD responses and reduce functional connectivity in nodes of the default mode-like network in rats
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DOI：
10.1016/j.neuroimage.2019.04.065
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发表时间：
2019-08-15
期刊：
影响因子：
5.7
通讯作者：
Keliris, Georgios A.
中科院分区：
文献类型：
--
作者：
Hinz, Rukun;Peeters, Lore M.;Keliris, Georgios A.
默认模式网络是一个大规模的大脑网络，在休息和内部集中状态下活跃，在外部导向（自上而下）需要注意力的认知任务中失活和去激活。然而，这是不充分的理解，如果显着的刺激，能够触发自下而上的注意过程，也可能导致类似的减少活动和功能连接的DMN。在这项研究中，我们调查是否自下而上的感觉加工可以影响默认模式样网络（DMLN）的大鼠。使用块设计视觉功能磁共振成像（fMRI）检查DMLN活动，同时通过比较静息状态与持续刺激大脑状态下不可预测的闪光灯的功能连接来研究其同步性。我们证明，在DMLN地区的BOLD反应减少视觉刺激块和空白期间增加。此外，在连续视觉刺激期间，观察到DMLN和视觉网络之间的网络间功能连接以及DMLN内的网络内功能连接减少。这些结果表明，触发自下而上的注意机制在镇静大鼠可能会导致级联类似于自上而下的方向在人类的注意力，并能够失活和去激活的DMLN。
The default mode network is a large-scale brain network that is active during rest and internally focused states and deactivates as well as desynchronizes during externally oriented (top-down) attention demanding cognitive tasks. However, it is not sufficiently understood if salient stimuli, able to trigger bottom-up attentional processes, could also result in similar reduction of activity and functional connectivity in the DMN. In this study, we investigated whether bottom-up sensory processing could influence the default mode-like network (DMLN) in rats. DMLN activity was examined using block-design visual functional magnetic resonance imaging (fMRI) while its synchronization was investigated by comparing functional connectivity during a resting versus a continuously stimulated brain state by unpredicted light flashes. We demonstrated that the BOLD response in DMLN regions was decreased during visual stimulus blocks and increased during blanks. Furthermore, decreased inter-network functional connectivity between the DMLN and visual networks as well as decreased intra-network functional connectivity within the DMLN was observed during the continuous visual stimulation. These results suggest that triggering of bottom-up attention mechanisms in sedated rats can lead to a cascade similar to top-down orienting of attention in humans and is able to deactivate and desynchronize the DMLN.