Dynamic Configuration of Coactive Micropatterns in the Default Mode Network during Wakefulness and Sleep

Abstract

The activity in the default mode network (DMN) rapidly fluctuates in different conscious stages during wakefulness and sleep, indicating high complexity for the role of DMN in consciousness. Tracking the dynamics of these fluctuations is critical for deeply understanding the physiological mechanism of consciousness. Here, we propose a coactive micropattern (CAMP) method to extract the dynamic configuration of local field potentials (LFPs) in the rat DMN. Three spatially stable CAMPs were detected from DMN gamma activity (40-80 Hz) across wakefulness and sleep, consisting of a common low-activity level micropattern, an anterior high-activity level micropattern and a posterior high-activity level micropattern. Temporal structures of these CAMPs were specific to different conscious stages. A dynamic balance across CAMPs emerged during wakefulness and was disrupted in sleep stages, demonstrating that the balanced dynamic configuration of CAMPs played a vital role in supporting higher cognitive functions and primary consciousness. Furthermore, all these CAMPs displayed strong phasic relationships to the up-down states of the slow DMN activity during deep sleep. Our study reveals that the consciousness levels of different conscious stages are determined by the dynamic configurations of DMN activity, and provides a potential three-state model for the consciousness during wakefulness and sleep.

Altered Coactive Micropattern Connectivity in the Default-Mode Network during the Sleep-Wake Cycle

“…Accordingly, we recorded the local field potentials (LFPs) from the rat DMN during wakefulness and sleep. To derive the FC networks from rat DMN dynamics, we proposed a novel coactive micropattern network (CAMP network) method to construct the FCs among DMN regions based on the coactive micropatterns (CAMPs) from DMN dynamics described in our previous work [29]. Our results illustrated more robust functional structures of the CAMP networks than the original DMN structure, and different CAMP networks played distinct roles in specific levels of consciousness.…”

“…Electrophysiological gamma activity is believed to be strongly correlated with the blood oxygen level-dependent (BOLD) signals, and the deactivation of gamma activity in DMN regions has been observed during external tasks. The description of the CAMP algorithm as well as its functional roles in different conscious states during the sleep-wake sleep has been systematically presented in our prior work [29]. Briefly, the original DMN activity was bandpass filtered into gamma oscillation, and the Hilbert transform was then applied to obtain the envelope activity of gamma oscillation.…”