The infraslow fluctuation of sigma power during sleep and its links to markers of arousal and memory reactivation across development (opens in new tab)

Sleep is both a state of disconnection from the environment and a critical period for restoration. But how does sleep balance responsiveness with the protection of key functions? The infraslow fluctuation of sigma power (ISFS)—the clustering of sleep spindles over 10–100 s—is thought to regulate this trade-off in rodents by alternating between fragile periods of high arousability and protected periods of spindle-rich stability. However, the organization of arousal and memory reactivation mark...