Stress hormone awakens our brain 100 times a night to shape our memory

Amazing stuff! Is that the reason, why we often have weird or odd dreams? (just kidding) 😄

"... The research centers on the levels of a stress hormone called noradrenaline, which fluctuates wildly and awakens our brain without us even realizing it and may have implications for the way we retain memories. ...
noradrenaline causes you to wake up more than 100 times a night. And that is during perfectly normal sleep ..."

From the abstract:

"Sleep has a complex micro-architecture, encompassing micro-arousals, sleep spindles and transitions between sleep stages. Fragmented sleep impairs memory consolidation, whereas spindle-rich and delta-rich non-rapid eye movement (NREM) sleep and rapid eye movement (REM) sleep promote it. However, the relationship between micro-arousals and memory-promoting aspects of sleep remains unclear. In this study, we used fiber photometry in mice to examine how release of the arousal mediator norepinephrine (NE) [a.k.a. noradrenaline] shapes sleep micro-architecture. Here we show that micro-arousals are generated in a periodic pattern during NREM sleep, riding on the peak of locus-coeruleus-generated infraslow oscillations of extracellular NE, whereas descending phases of NE oscillations drive spindles. The amplitude of NE oscillations is crucial for shaping sleep micro-architecture related to memory performance: prolonged descent of NE promotes spindle-enriched intermediate state and REM sleep but also associates with awakenings, whereas shorter NE descents uphold NREM sleep and micro-arousals. Thus, the NE oscillatory amplitude may be a target for improving sleep in sleep disorders."

Stress hormone awakens our brain 100 times a night to shape our memory

Memory-enhancing properties of sleep depend on the oscillatory amplitude of norepinephrine (no public access; but article above contains link to PDF file)